31
august 2004.
At the International Primatological Society, scientists from the
Republic of Congo indicated that an outbreak of Ebola
haemorrhagic fever might be killing gorillas. Two more patients
(one passed away) in Vietnam might have been infected by bird
flu recently.
29
august 2004.
Cholera remains endemic at many places in the world, and it
tends to spread as soon as the situation deteriorates. Sierra
Leone, which had been free from the disease since 1999 is now
facing an epidemic: since august 6th Health authorities have
identified 374 cases of the disease, that caused 40 fatalities.
23
august 2004.
China's ministry of agriculture denies that the H5N1 virus has
been found in pigs recently. However the virus was indeed
infecting pigs in 2003 and earlier this year, and it is expected
that the disease will be most likely to spread through this
indirect contamination route in the future. Vietnam is still
combatting the outbreak.
21
august 2004.
It seems now established that bird flu has contaminated pigs in
Chinese farms (other mammals have been
contaminated several times earlier, in particular predators and,
of course man). It is not yet clear whether there has been pig
to pig contamination. If so, then a human epidemic becomes
extremely likely.
19
august 2004.
In an effort to ensure a quick end to its first outbreak of bird
flu, Malaysia has gassed hundreds of birds in Kampung Baru Pekan
Pasir, a village near the Thai border and enforced a quarantine
for 10 kilometres around the property where two chickens have
been found to have avian influenza.
17
august 2004.
Bird flu is still rampant in Vietnam. More ostrich farms are hit
(by a less dangerous virus) in South Africa. A case of dengue
fever has been diagnosed in a Japanese patient staying in Nepal.
This might suggest extension of the mosquito-borne disease.
12
august 2004.
The bird flu strain (H5N2)
affecting South Africa is more virulent than in the past.
Vietnam faces a dengue fever outbreak more severe than last
year, with 45 fatalities 38,605 cases. Since
1969 dengue fever keeps on spreading in South East Asia. Three
imported cases have been discovered in Hong Kong. As reported by
the popular magazine Nature today blood transfusion
might be a source of Creuzfeld Jacob disease (vCJD) in a way
that went unsuspected. Most of the 142 vCJD deaths in UK are
believed to have been caused by beef products infected with the
agent of bovine spongiform encephalopathy. But two people are
now known to have been infected through blood transfusions
containing the disease-causing proteins known as prions. And
there is concern that in the latest case, revealed last week,
the recipient of the transfusion carried the prions for years
without developing the disease.
11
august 2004.
authorities in Vietnam are testing whether four patients
displaying acute respiratory symptoms were killed by avian flu.
10
august 2004.
The continuation of the human test of a SARS
vaccine started in may appears to be successful. A first
group of 18 volunteers were injected with a low dosage vaccine
and the second group of 18 with a high dose at the China-Japan
Friendship Hospital in Beijing. The first group have completed
the test while the second group have received the first of two
inoculations. No adverse effects have been recorded. The avian
flu virus that is killing ostriches in South African is of the
H5N2 type, usually considered a less dangerous type than the
feared H5N1 type. In the meantime Thailand banned the use of
vaccine against flu in birds, being concerned that this might
accelerate the evolution of the virus.
7
august 2004.
It is winter time in the Southern hemisphere and bird flu is
beginning to affect South Africa. Two ostrich farms have been
contaminated, spreading fear that the disease might extend to
other places. This makes it likely that there will be more or
less continuous outbreaks of avian flu, from now on. Vaccination
measures have been implemented in Chinese farms, but it is not
yet known whether this will be a successful approach.
6
august 2004.
Infection by the West Nile virus is now a well-established
scourge in Northern America. The holiday time in Europe makes
that media try to find all kinds of information to fill in their
programmes: legionellosis is thus a common theme of summer news
in France, for example (see last
year at the same period of the year).
1
august 2004.
Passive serotherapy (using serum from recovered patients) can
confer immediate protection against microbial infection.
Unfortunately, methods to rapidly generate human neutralizing
monoclonal antibodies from such sera are not yet available.
Lanzavecchia, Rappuoli and their colleagues have found an
original way to prove both that a vaccine against SARS is
possible and that the memory of the immune repertoire of
recovering patients can be used to generate a serum that can be
used against the disease. Using the serum from a patient they
isolated monoclonal antibodies specific for different viral
proteins, including 35 antibodies with strong in vitro
neutralizing activity. One such antibody confered protection in
vivo in a mouse model of SARS-CoV infection. We can therefore
safely assume that SARS will not be a significant menace in the
future. The student that died in Taiwan was affected by a still
unknown virus (now confirmed not to be SARS-CoV) with
superinfection by a dangerous bacterium that infects the lung of
immunocompromized patients, Pseudomonas aeruginosa (for
information on its genome see our database AeruList). While bird
flu is still lingering in South East Asia, the obvious but often
underestimated possible role of pigs in its transmission to man
is fortunately resurrected by some. This involvement had been
postulated many years ago (and we summarized ten years ago the
scenario of evolution of the virus from poultry, to pig, then to
man, by recalling that, in China ducks and pigs are used to live
together, as one can see in the Chinese character for the happy
"family", which represents a pig under a roof: the
Chinese pig also sneezes!).
29
july 2004.
Trypanosoma parasites are infamous for their role in the
sleeping sickness. They are also involved in a very dangerous
diseases that plagues South America, Chagas disease. Its agent
is Trypanosoma cruzi, but until recently it was not at
all understood how the disease could stay dormant in patients
and nevertheless induce strong autoimmune pathologic responses.
As remarked by The Scientist, a intriguing study by
Nadjar Nitz, Antonio Teixeira, and their colleagues, from the
University of Brasilia, published in the journal Cell
reports the integration of T. cruzi DNA into the genomes
of infected patients, as well as chicken and rabbit animal
models, suggesting that horizontal gene transfer may play a role
in T. cruzi host–parasite interactions. This would
indicate that aside from retroviruses such as HIV, some
pathogens could leave traces of their presence in the genome of
their host, a new path to understand diseases that escaped our
understanding. Horizontal
gene transfer is widespread and has been described many years
ago as contributing to bacterial speciation. It has been
known to explain how some tumors are created in plants (and this
natural mechanism was used to create Genetically modified
Organisms) but until now we did not suspect that such mechanisms
of parasitic DNA transfer could be associated to well-known
parasites. One student at a Taiwan army college has died and 23
have fallen ill from an unknown pathogen, but health officials
said it was unlikely to be SARS. Dengue fever and Japanese
encephalitis, both mosquito-borne diseases have been ruled out.
28
july 2004.
Vietnamese state media say bird flu has spread to the north
despite earlier assurances outbreaks in the south had been
contained. Scientists at Yale found remarkable properties of the
RNA helicase NS3 that unwinds the virus of hepatitis C for
replication inside the cell. NS3 is a major drug target against
HCV and understanding the helicase function will aid in the
development of HCV inhibitors. NS3 moves with a discontinuous
stepping motion that alternates rapid translocation with
pausing.
27
july 2004.
At this time of the year it is interesting to have a little
reflection on important health problems in the world. As an
example, in France, media start campaigning again about
Legionellosis (this time in the region of Nancy, in the east of
France). However the number of persons involved is as yet quite
small, while the likely number of persons affected yearly in the
country must probably be in hundreds, and be significantly
underreported. This disease may be a quite old one, that has
only been recognized recently (it is frequent that aged people
die of diseases with pneumonia-like symptoms). However this
disease is important because it is associated to our way of
using water, as hot water, or in cooling systems. If unchecked
it could slowly have very adverse consequences. Another
political remark comes from the near absence of US scientists at
the Bangkok meeting. Does this mean that AIDS is no longer a
priority in the US, or that the US is not interested in diseases
affecting the developing world? History will tell, but this is
an important fact to notice. On the front of avian flu, the
European Union has prolonged its ban on poultry import from
Asia. Flooding in Bangladesh, India and China will result in
water associated diseases outbreaks, but the large amount of
water involved for the moment is rather likely to wash out some
of the worse microbes (and vectors). The outbreaks will probably
start when water recedes. Two cases of West Nile Virus infection
have been confirmed in Ireland. In both instances, the patients
had recently visited the Algarve in Portugal.
23
july 2004.
Thailand authorities in Bangkok are testing two children as
possible cases of bird's flu. The government of Jakarta
implemented measures to vaccinate poultry.
22
july 2004.
A report published in the magazine Nature, combining
pathological, cytological and molecular investigations
identified Bacillus anthracis as the cause of death for
at least six wild chimpanzees (Pan troglodytes verus) in
the Taï National Park, Ivory Coast. Anthrax is an acute disease
that mostly infects ruminants, but other mammals, including man,
can be infected through contacting or inhaling high doses of
spores or by consuming meat from infected animals. Respiratory
and gastrointestinal anthrax are characterized by rapid onset,
fever, septicaemia and a high fatality rate without early
antibiotic treatment. These results suggest that epidemic
diseases represent substantial threats to wild ape populations,
and through bushmeat consumption also pose a hazard to human
health.
Thailand
confirmed three more outbreaks of bird flu in the capital
Bangkok after a spate of deaths among ducks and chicken over the
weekend. The outbreak re-emerges in Indonesia. Fear of cholera
or other water-borne diseases spreads in India after
catastrophic flooding.
21
july 2004.
Scientists from the World Health Organization National Influenza
Center at Erasmus Medical Center, (Rotterdam, Netherlands) and
the USA Department of Energy at Los Alamos National Laboratory
with collaborators from the University of Cambridge (UK) have
developed a computer modeling method for mapping the evolution
of the influenza virus. The model (published in the magazine Science)
aims at helping medical investigators worldwide develop a better
understanding of certain mutations in influenza and other
viruses that allow diseases to escape the human immune system.
16
july 2004.
The bird's flu outbreaks in Vietnam and Thailand is spreading.
The AIDS conference in Bangkok ends on mixed feelings, with much
concern about the spread of the disease in Asia.
11
july 2004.
At a time when 17,000 participants from 170 countries are
meeting in Bangkok to discuss the situation of AIDS in the
world, where Asia (including Indonesia) is now one of the
greatest concerns, dengue fever spreads in Bangladesh. South
Korea issues warnings about cholera after a traveller from
Manila entered the country with the disease. It also steps up
its surveillance of avian flu, to try to keep out contagion from
other Asian countries.
9
july 2004.
The government of Thailand will order the killing of open-billed
storks in a move to contain the spread of avian flu.
While it is clear that migrating birds are certainly spreading
the disease, this move might be quite inappropriate, and similar
in its disastrous effect with the killing of sparrows ordered by
Chairman Mao a long time ago. A similar unhappy situation might
be faced by beavers in the USA since they are now supposed to
create appropriate conditions for mosquitoes to breed, and bring
about the West Nile fever.
8
july 2004.
A group headed by Pr Peiris at the University of Hong Kong has
substantiated the conclusions drawn during the last bird's flu
episode, that the virus is becoming more and more dangerous, and
is now well implanted, at least in Southern China: their
"findings indicate that domestic ducks in southern China had a
central role in the generation and maintenance of this virus,
and that wild
birds may have contributed to the increasingly wide spread of
the virus in Asia." This last inference was already made
as early as 2001. The new virus strains are now established
firmly as endemic (see the conclusions already reached by other
scientists on March 19th).
7
july 2004.
Two crows found in West Elgin in Ontario have tested positive
for the West Nile virus. The outbreaks of H5N1 avian flu are
confirmed both in China and in Thailand, where two provinces are
affected. More than 300,000 Nigerians were infected with
tuberculosis last year out of which only 46,569 were detected
and placed on treatment. In Cambodia the campaign against dengue
fever has been a success this year with more that half the
number of infections and deaths in children as compared with the
situation last year.
6
july 2004.
Two cases of Japanese encephalitis (a mosquito vector-borne
disease) have been diagnosed in Hong Kong. A new bird flu
outbreak might be underway in Thailand. Northern China begins to
be affected by an outbreak of full-blown AIDS. This is due to
the blood contamination episode of 1995, when poor hygiene
corresponded to systematic collection of blood in the province.
China reports new cases of bird flu from Anhui province.
3
july 2004.
Active tuberculosis has been found in two patients from
Singapore, that were infected by SARS last year. This number of
cases is far too small to permit one to draw conclusions, but it
may be that the immune system of patients has been compromised,
at least for some time, by SARS.
2
july 2004.
The "official" position of the Chinese government on the last
SARS episode is now available as published by the China Daily.
It fits with the conclusions that could be obtained yesterday.
Interestingly, according to the World Health Organization two
laboratory workers in Beijing suffered from a SARS-like illness
in February and went back to work but were not detected until
they tested positive for SARS antibodies when hundreds of lab
workers were screened following the April outbreak. Two cases of
legionellosis have been identified in Normandy (France). The
origin of the disease is unknown.
1
july 2004.
Li Liming, director of the Chinese Center for Disease Control
and Prevention, has resigned for "mismanagement of the Severe
Acute Respiratory Syndrome (SARS) virus." While the exact cause
of the contamination is not yet public it is likely that the
outbreak occurred because the institute itself became
contaminated, which explained why two victims, both laboratory
workers, became infected even though their work did not involve
any handling of the virus.The Diarrhoea Virus Laboratory under
the Institute of Virus Diseases of the center was found to have
conducted SARS virus research adopting untested methods to kill
the virus in an ordinary lab. Also, the lab failed to report to
higher authorities the fact when unusual health conditions were
detected among some of their staff members. The bird flu
outbreak in Vietnam is extending infecting around 20,000 poultry
in recent days, now present in six southern provinces of the
country.
30
june 2004.
Avian flu is re-emerging in South-East Asia: more than 5,000
fowls in Vietnam's southern Bac Lieu Province have been culled
to prevent spreading of bird flu type A, sub-type H5. It is not
yet known whether this is the H5N1 letal type, but this seems
likely because of the apparent virulence of the outbreak. China,
with officially reported about 840,000 HIV carriers (likely to
be more than one million) and 80,000 AIDS patients, plans to
increase the number of national AIDS/HIV surveillance outlets
from the current 194 to 300 next year to perfect the existing
surveillance network. Fifthy million euros will be allocated to
strengthen AIDS/HIV control this year, a sharp increase over the
effort supported in the past years. Presence of West Nile virus
in dead birds in the USA is beginning to be recorded this year.
Figures for 2003 show that almost every state in the USA has
been affected last year. On the front of dengue fever more than
17,700 people have contracted the disease in Vietnam this year,
and 33 have died. 114 cases have been reported in Bangladesh
this season so far.
29
june 2004.
According to a report published by the Proceedings of the
National Academy of Sciences in the USA, the newer forms
of the H5N1 flu virus kill more rapidly than their predecessors.
This shows that the virus is still mutating to better adapt to
its host, and raises concern about possible adaptation to human
hosts.
26
june 2004.
Scientists at the National Institute of Allergy and Infectious
Diseases in Bethesda, USA, reported that four African green
monkeys given a single dose of a vaccine made of a protein of
the SARS coronavirus and then infected four weeks later with the
virus developed neutralizing antibodies and showed no sign of
the disease in their respiratory tracts. Several other attempts
by other scientists in the world also suggested that it was
likely that a synthetic vaccine would be efficient to protect
against the disease. It is therefore likely that SARS will no
longer be a major problem, especially with the type of measures
that have already been implemented in Asian countries to
restrict and control travel when any hint of an outbreak
happens. This is in sharp contrast with flu, for which we know
that we will be able to create a vaccine once a letal strain is
idenfied, but for which we unfortunately we already know that
several months will be necessary to produce enough doses of the
vaccine.
23
june 2004.
"It has been a year since Hong Kong emerged slowly but surely
from the shadow of one of the greatest threats to public
health in living memory." Thus begins an article in the
China Daily by the Hong Kong's secretary for health, welfare and
food to celebrate the end of the SARS outbreak last year. Data
have accumulated since then and the hypothesis that the virus is
lingering in the environment has been substantiated during the
last episode in december in Guangzhou, China. This accounts for
the likely protection of some people who could have been in
contact with an innocuous form of the virus and be protected by
it (the double
epidemic hypothesis). This would also be good news since
this would indicate that vaccination will be possible. A recent
study substantiates this straightforward hypothesis, and
suggests that vaccines using proteins of the virus will probably
be easy to construct. Another study from Singapore shows that
the virus can be present in body fluids, in particular in
tears, early in the course of the development of the
disease. More than 900 cholera cases have been reported from New
Delhi so far this year.
21
june 2004.
An oubreak of legionellosis (first case identified on june 10)
in Zaragoza (Spain), has triggered investigation of the possible
cause of contamination: bacteria have already been detected in 2
refrigeration towers of the Hospital Clinico de Zaragoza. This,
once again, demonstrates that the cooling systems now employed
everywhere can propagate dangerous diseases.
17
june 2004. As
reported in The Scientist at least seven people in an
Oakland research laboratory have been inadvertently exposed to
live anthrax bacteria that had twice been tested to be dead,
when it was found that mice inoculated with the "dead" spores
died from the disease. While the scientists involved could be
treated in time this demonstrates, once again, that laboratories
may be dangerous sources of letal diseases, if appropriate
precautions are not taken. Several regions in Hong Kong have
been found to be plagued by the Aedes albopictus
mosquito, which may carry the disease of dengue fever. According
to the Hong Kong Special Administrative Government, four areas
in Hong Kong were particularly affected. The Vietnamese
government has asked localities nationwide to keep on preventing
the reoccurrence of bird flu, following the deaths of fowls in
several areas, including some testing positive to avian
influenza viruses.
14
june 2004. Because
of global warming, in Central America dengue fever is spreading
above its former limit of 1,000 m. Some of its mosquito vector Aedes
aegypti have been found up to 2,200 m. The number of cases
in the world is estimated to be already of the order of 50
million cases a year. It is endemic in more than 100 countries
in South-East Asia, the western Pacific, Africa, the Americas
and the eastern Mediterranean.
13
june 2004. The
number of dengue fever cases in Vietnam is soaring. Up to 15,000
people have been detected to suffer from the disease there so
far this year, a year-on-year rise of 80 percent. While 45 cases
have been detected in Jeddah (Saudi Arabia), one patient died of
the disease. The Center for Disease Control in Taipeh (Taiwan)
reported that a second person had contracted dengue fever in a
laboratory, after the first case of dengue fever in Taiwan this
year had been declared the result of laboratory mismanagement.
This is a further indication of problems caused by diseases
manipulated in laboratories as examplified by the SARS last
outbreak in Mainland China (still not understood). The World
Health Organisation has reported that the death toll from the
Ebola outbreak in southern Sudan has held at seven this week,
with a number of infected people besides the dead of 23.
7
june 2004. Thirty
cases of dengue fever have been confirmed in Jeddah and the holy
city of Mecca in Saudi Arabia.
6
june 2004. Afghanistan
recorded its first AIDS casualties. The country is the world’s
top producer of opium. The United Nations says drug abuse is
becoming a serious problem in many parts of the country.
Officials estimate that about 200 to 300 Afghans are infected
with HIV. The real number could be higher, however, because the
social stigma associated with the disease keeps many sufferers
from seeking help. Intravenous drug use, shared needles, and
contaminated blood transfusions are believed to be the primary
modes of transmission in Afghanistan.
5
june 2004. While
there had been seven confirmed cases of the mosquito-borne
yellow fever and one death from yellow fever since the outbreak
in Bobo Dioulasso was first reported in early May, the WHO urges
the government of Burkina Faso to vaccinate one million persons
since there is a high risk of a major outbreak developping as
the rainy season gets under way this month. However, WHO
officials are concerned by the fact that the government has been
playing down the seriousness of the outbreak. This is hampering
efforts to raise 500 million CFA francs (US$1 million) from
donors for an immediate vaccination campaign against the
disease. In a move to better understand the spread of AIDS in
China, a nationwide data bank on all known HIV carriers and AIDS
patients is expected to be established by the end of this year,
with each HIV/AIDS patient having an individual file. This is
similar to what was done in Europe when it was understood that
tuberculosis has to be controlled. It has been a curiosity that
this type of information is not collected in Western countries
in the case of a disease that may spread fast for purely
socio-economical reasons, and that is mostly a matter of serious
concern for the poorest people. A reflection on this issue is
the more important as the likeliness of finding a vaccine
against AIDS is less probable than ever.
4
june 2004. The
natural host(s) of Ebola virus are unknown. Until recently it
was assumed that Ebola spread from a single outbreak across the
Congo basin. A recent study demonstrates that Ebola outbreaks in
the Gabon and the Republic of Congo are preceeded by virus
infection of large apes and deer, and that multiple strains of
virus cause simultaneous epidemics in the human population.
Scientists at the Genome Institute of Singapore developed a
faster method for detecting strains of the SARS virus. A DNA
chip containing a "fingerprint" of the virus genome reduces the
length of molecular testing of the disease to three days from
about one week. Speed is a critical step in bringing outbreaks
under control.
1
june 2004. The
Dutch biotechnology firm Crucell reported that a single dose of
its Ebola vaccine has successfully protected monkeys from the
deadly disease in trial tests. While Ebola has only a marginal
role among human diseases, its spectacular symptoms and deadly
outcome has made the virus a popular model for new plague types
(which is however fortunately quite unlikely because the mode of
contagion requires direct contact).
30
may 2004.
A second bird flu outbreak affects fowl in Texas. This is a
further warning that we shall probably witness in the next years
a dangerous flu outbreak. The H1N1 epidemic, that killed
millions in 1919 is still not completely understood. It is
however likely that it was caused by an avian virus that passed
through an intermediate animal, probably pig, where it adapted
to mammals. It is therefore extremely important to monitor, in
addition to bird to human contamination, any other type of
contamination of mammals by avian flu viruses. On the front of
dengue fever, Vietnam is dramatically affected this year, with
more than 35,000 patients affected, and increase of some 50% as
compared to last year. Transmitted by mosquitoes, dengue fever
is not very dangerous the first time a person is infected, but
the disease is often letal on a second infection.
25
may 2004.
The first preliminary results about the response and possible
unwanted side effects of a first SARS
vaccine are published today. Lin Jiangtao, head of the
Respiratory Medical Department at the China-Japan Friendship
Hospital, where the experiment is conducted, stated that all
four volunteers are in excellent condition with no adverse
effects of the vaccine. The number of cholera cases in the
capital of India, New Delhi is already 635, higher than last
year at the same period. Every year witnesses around 1,500 cases
in New Delhi. Five people have died of Ebola haemorrhagic fever
in southern Sudan. A Russian investigator has died after
sticking herself with a needle containing the Ebola virus. This
event stresses again the danger inherent to research on deadly
viruses in laboratories.
23
may 2004.
Four students volunteered in the clinical testing of a vaccine
against severe acute respiratory syndrome (SARS). The
volunteers, students from Beijing-based universities, were
injected a SARS vaccine or a SARS-virus free placebo Saturday
afternoon. No adverse reaction was found and the volunteers will
be followed for a period of 210 days, with monitoring of their
immune response. Further volunteers will be inoculated later on,
if no sign of adverse reaction is seen in this first team.
14
may 2004.
The strain of bird flu found in British Columbia is likely to be
of still another type, the H6 subtype (causing a mild form of
the disease). This demonstrates in a vivid manner how variable
is flu. The government of Burkina Faso announced that 25
suspected cases of yellow fever had been reported in the city of
Bobo-Dioulasso and the nearby town of Gaoua (close to the border
with Cote d'Ivoire and Ghana). Four cases have been confirmed.
12
may 2004. A
new strain of avian flu is just spreading in British Columbia
(Canada). Interestingly this strain does not appear to be of the
H7 subtype, but may be of the H5 subtype. Exploration of last
year's SARS outbreak gives new clues about its propagation, but
its origin is still not clear, despite indications that it is
derived from an animal virus.
9
may 2004.
Scientists in Guangzhou found that the SARS coronavirus could be
transmitted through sweat, urine and feces in addition to the
postulated route of infected droplets from the patients'
respiratory tracts. This was
suspected early on, but not confirmed. The oro-faecal
route had already been suspected as a cause in the Amoy Gardens
estate outbreak in Hong Kong in 2003.
7
may 2004.
Malaria kills more than 1 million people a year, 90% in Africa,
at a time when resistance of the parasite to the most common
drugs is exploding.
6
may 2004. While
the SARS outbreak seems over in China (159 persons have been
released from quarantine in Beijing), a new local outbreak
of H5 (H5N1 not yet confirmed, but likely) bird flu has been
detected in Vietnam.
5
may 2004.The
avian flu virus strain that infected poultry in West Canada
recently is of the H7N3 type (The H and N symbols represent
different proteins of the virus). There are fifteen varieties of
the H protein and nine of the N protein. Variants of the
proteins combine in different ways to make up specific viruses,
some of them more dangerous than others. In contrast to the H5N1
type, the H7N3 type is usually innocuous for man, and not very
dangerous to birds, but a recent mutation has made it extremely
virulent, explaining the outbreak in Canada. Reassortment of
genes from various strains, when co-infection occurs in a host,
can produce deadly variants. On the front of SARS, while no new
case is emerging, internet forums in China discuss the apparent
efficiency of some treatments involving Traditional Chinese
Medicine to make the disease milder and improve patients'
recovery.
4
may 2004. The
number of SARS cases in China has now been confirmed to nine,
with no further identified case. The origin of the outbreak is
not yet fully understood. In Taiwan, a recently developed SARS
vaccine will undergo animal testing as soon as high-security
laboratories re-open for SARS research. We remember that the
P3/P4 facility laboratory where these experiments have to be
performed (for security reasons) was the source of an
accident.
1
may 2004. An
outbreak of cholera has triggered some panic reactions in the
North West province of South Africa. Cholera remains endemic in
the world, particularly in Africa and India because of poor
hygiene. No new SARS case in the world. The second
student who was showing symptoms of atypical pneumonia has
been confirmed with the disease.
30
april 2004.
In a recent study from scientists in Toronto and at
the Prince of Wales hospital in Hong Kong it has been
demonstarted that last year SARS patients had a very high level
of the Th1 chemokine IFN-gamma-inducible protein-10 (IP-10) as
soon as they showed symptoms of the disease. Healthy people
never have a high level of the molecule. This finding is
important because this protein in the blood may be detected by
diagnostic kit, and it may help discriminate between SARS and
other fever causing pulmonary diseases such as flu. Further
study is however needed to know the actual significance of the
observation.
29
april 2004. Monitoring
possible outbreaks of dangerous diseases is a difficult task. In
addition to yearly epidemics of cholera or meningitis, as well
as the ubiquitous AIDS, with its associated diseases such as
tuberculosis, old diseases such as plague are still lingering in
the environment. Interestingly Russia recently reviewed possible
local foci in the southern Asia regions of the country. This may
suggest that there are already indication that suspect cases
have been observed. Fortunately, bubonic plague mostly
propagates through flea bites so that it is relatively easy to
stop an outbreak when it has been identified. On the SARS front,
the Chinese government is trying to curb down the number of its
laboratories working on SARS-CoV to diminish the number of
possible contamination sources. Governments of the many
countries which had sent scientists to the Virology Laboratory
that was at the origin of the outbreak have been warned by China
to test for suspect cases. Until now nothing of the kind has,
fortunately, been reported.
28
april 2004. China
reported one new suspected SARS case for the past 24 hours. This
patient, who worked at the same hospital as the nurse who
attended the index patient is in critical condition. None of the
quarantined people with close contact with the index case have
shown abnormal symptoms so far and 38 among them have been
removed from observation. All suspected SARS cases are connected
together: Chinese authorities say a 26-year-old lab worker named
Song, in Beijing, passed SARS to a 31-year-old nurse named Li,
whose father, mother, aunt and roommate also are ill and are
suspected SARS cases. Song returned to Anhui and her mother died
shortly thereafter, and experts suspect SARS. The newest
suspected case is a 49-year-old woman surnamed Zhang who was
being treated in the same hospital room as Li. More than 700
persons have now been quarantined. Teams of the WHO have arrived
in Beijing and are investigating the origin of the first cases,
as well as implementing tight measures to prevent possible
spread of the disease during the May festival. To
replace this event in perspective it is interesting to note that
during the last couple of weeks more than 1,500 patients have
been admitted with cholera at the Infectious Diseases Hospital
in Calcutta, India.
27
april 2004. The
authorities of China Anhui province reported that 143 persons
have been identified after having contacts with the SARS index
patient. Several are already discharged from quarantine. The
present absence of new putative SARS cases suggests that the
fear of an outbreak may hopefully soon be over.
26
april 2004. China
has quarantined more than 500 people in an attempt to control
the SARS outbreak triggered by a laboratory contamination. In a
fast reaction move triggered by the proximity of the 1st of May
holiday, the government has publicised details of trains and
buses used by the student at the origin of the outbreak and by
her mother, who died after caring for her. Both travelled to
Anhui province. The student contracted SARS while working in a
national laboratory specialized on dangerous diseases. It is
important to remember that in all high technology processes the
human factor is important. While the laboratory itself might be
of the best standard, human errors are always possible.
Fortunately the incubation time of SARS is short (normally less
than 10 days) so that absence of new cases within a few days
would suggest that the outbreak will soon be over. It
now appears that another student, working at the same lab as the
index patient also fell ill on April 17th. The fact that the
original patient caught the disease a month ago and that no case
of atypical pneumonia has yet been observed on her travel path
is in favor of the idea that she did only contaminate people
with close contact with her. This is why the World Heath
Organisation, which sent experts to analyse the situation in the
original laboratory, indicated that it could hope that the
consequences of this unfortunate event will soon be over,
provided no other person working at the incriminated laboratory
shows signs of the disease.
24
april 2004.
The cause of the recent outbreak of SARS in China is not yet
completely identified. The WHO is investigating whether it is a
laboratory accident, and if so, what is the source of the virus.
Indeed, SARS is caused by a virus that is continuously evolving:
probably starting as a rather innocuous virus
(as demonstrated by a recent study from Guangdong and Shanghai),
it evolves after a region of its genome is deleted into a rather
mild SARS form. Subsequently, the region of the genome that
codes for the "spike" protein, which allows to enter the host
cells, mutates and creates a highly infectious and pathogenic
"super spreader" form. If this were the form at the origin of
the outbreak, many persons might have been contaminated during
the travel of the student who caused the contamination... Avian
flu is still spreading in West Canada.
23
april 2004.
A possible second case of SARS has been diagnosed in China's
eastern Anhui Province. This patient, the mother of whom passed
away from unknown causes (possibly SARS), worked at the Center
for Disease Control in Beijing, probably on SARS-CoV. Both cases
appear in fact to have been connected, as the first case is a
nurse at the hospital where this patient was briefly
hospitalized before going back to Anhui province. All persons
who have been in contact with these patients have been placed in
observation and quarantined. Among those, six persons showing
fever may also be infected, rising the number of cases to nine.
Unfortunately, during her travel back to the Anhui Province this
patient might have contaminated others. Hospitals along the
train line have been placed on high alert for patients with
pneumonia symptoms. This would be the third instance of laboratory
contamination, showing that confinement of viruses under
strict laboratory rules must absolutely be enforced.
22
april 2004.
A new suspected SARS case has been identified in Beijing in a
nurse working at the Beijing Jiangong Hospital. Two relatives
also showed symptoms of the disease. These cases are under
investigation.
20
april 2004. The
New York Times reports that a patient was infected during last
fall by the H7N2 bird flu virus (much less letal than H5N1), and
that this had escaped attention. This further demonstrates
(after H7N7 last year in Europe and H5N1 in Asia) that avian flu
is able to be transmitted from birds to man. The signal of
danger will appear when this will have triggered a
person-to-person contamination. Cambodia is hit by two new avian
flu outbreaks, while others are spreading in Canada's British
Columbia (different viruses).
17
april 2004. According
to Xinhua news agency, Chinese scientists tested thousands of
people carrying SARS antibodies in 16 cities in Guangdong and
found that among 994 people working in animal markets, 10.6
percent carried positive antibodies. In
contrast, among 123 civet cat husbandry staff, only 3.25 percent
tested positive. Moreover many other animals, including foxes
and cats also carried the virus. The origin of SARS-CoV is
therefore not yet understood. A man from Ohio tested positive
for the West Nile virus, making this cases the earliest case
since the arrival of the disease in America.
15
april 2004. The
government of China takes the question of AIDS seriously, now
that some 1 million persons in China are probably infected by
HIV. Because the disease may become out of control and threat
the growth of the economy, the health ministry promised to fully
cover the treatment costs of poor patients, while offering free
testing to the whole population of the country.
13
april 2004.
Japan declares the H5N1 bird flu outbreak over, while the number
of British Columbia (Canada) farms infected by a H7 strain
reaches 25. Tuberculosis is not only affecting poor countries:
the number of tuberculosis patients in Japan is the highest
among rich, industrialized countries, with 32,828 people
contracting the disease in 2002.
7
april 2004.
Several rooks that migrated recently to Russia's Far East from
southeast Asia were found dead of suspected avian flu creating a
risk of spreading the disease in Northern parts of Asia and
Europe.
6
april 2004. Scientists
at the NIAID demonstrated in mice that a DNA vaccine could
induce neutralizing antibodies against SARS-CoV. This is the
demonstration that vaccination will be possible in case of
resurgence of the disease. However it is certainly unlikely that
DNA vaccines will be used, because they are still unwieldy.
Canada is plagued again by outbreaks of bird flu, probably
originated with wild ducks. This is the 18th oubreak of the H7N3
virus since february. Fortunately this brand of virus is less
dangerous for man than the Asian H5N1 type. China orders
quarantine for persons coming from Burkina Faso (West Africa)
for fear of contamination by bacteria causing meningitis.
2
april 2004. Human
diseases are not the only causes of concern triggered by viruses
and microbes: China is about to announce publicly that
foot-and-mouth disease is an endemic virus that is presently
causing havock in livestock.
27
march 2004. While
avian flu is abating, dengue fever is on the rise in Vietnam,
having killed twice as many people in Vietnam compared to the
same time last year, with 5,371 persons having contracted the
disease so far. In Indonesia the death toll due to the disease
climbs to 534, with 44,027 cases recorded so far this year.
25
march 2004. AIDS
remains the major source of concern for health in the world. As
an illustration Mozambican Prime Minister Luisa Diogo said in
Maputo that thee country reached the figure of 13.6 per cent
prevalence of HIV/AIDS among Mozambican adults. In South Africa
nearly half of state hospital patients in the country are
HIV-positive, and 15% of the health workers who look after them
also have the virus.
24
march 2004. Several
cases of a highly pathogenic strain of H7N3 avian flu have been
discovered in Western Canada. The UN Food and Agriculture
Organization warned that the deadly H5N1 virus has extended its
range in Indonesia. The first test at the University of
Rochester and Baylor College of Medicine of a vaccine designed
to protect people against one form of bird flu is under way,
tested in about 200 people. While that precise brand of vaccine
(acting against a form of the virus, H9,
which infected several people in Hong Kong in 1999) is not
designed to protect against the precise bird-flu virus causing
the current outbreak in poultry and in people, scientists will
learn whether it protects against another strain of the virus
that infects birds and people. Other investigators are now
developing vaccines that could protect against the H5 form,
which is responsible for most of the recent deaths in Asia. The
main difficulty with producing vaccine too early is that it is
known to lead to selection of new virus strains.
22
march 2004. A
team from the University of Amsterdam uncovered a new
coronavirus that could be highly related to SARS-CoV, the agent
that caused SARS last year. This virus, HCoV-NL63, causes
respiratory diseases such as bronchiolitis in children. While a
related common cold virus has been known for a very long time,
it is surprising that this new isolate took so long to be
identified. All this points to the idea that a virus related to
SARS-CoV is widely spread in the environment. This could explain
the
unusual pattern of the epidemic, that appeared to cause
the disease in some regions, while neighbour regions were
apparently immune.
21
march 2004. A
new outbreak of avian flu is affecting South Korea. Chicken, as
well as a magpie have died of the H5N1 disease. This indicates,
once again, that the virus has spread in wild, casting doubt on
the possibility to control the disease in the future.
20
march 2004. The
number of cases of dengue fever is on the rise in nine
Indonesian provinces. A twelve years old child dies of H5N1 bird
flu in Vietnam, bringing the present identified toll of the
disease to 24 (16 in Vietnam). An epidemic of meningitis had
killed dozens of people and infected hundreds more in northern
Nigeria.
19
march 2004. The
genome sequence of the H5 avian flu virus found in Japan was not
the same as that of the virus found in Vietnam, which has been
blamed for the deaths of at least 15 persons there since the
disease struck in January. The gene sequence does not match that
of the bird flu virus that caused human deaths in Hong Kong in
1997. In contrast the sequence of the genome virus found in
Japan is almost identical to that found in South Korea. This
suggests that the disease has been endemic in Eastern Asia for
many years, and that the virus is still evolving as several more
or less independent isolates. Because of possible reassortment
of pieces of this fragmented genome it may suddenly appear as a
highly virulent strain that might extend its host recipients.
18
march 2004. The
annual outbreak of meningitis is developing in Sahelian West
Africa. More than 400 people died in Burkina Faso where a
vaccination programme has been implemented. The dengue fever
epidemic has claimed more lives in several parts of Indonesia,
despite reports that the number of cases was declining. A
vaccine against bird flu would be available in one week
according to the UK's National Institute for Biological
Standards and Control (NIBSC). Preparation of a large number of
doses would however require much longer, since the vaccine is
developed on fertilized eggs.
17
march 2004. Two
new cases of brid flu have been reported from Cambodia, while
the disease appears to ebb down elsewhere. Preliminary data with
mice indicate that these animals can be vaccinated
against SARS-CoV.
14
march 2004. Dengue
fever is now affecting Australia's Northern Territories. 3,300
persons have been infected in Vietnam, where 5 passed away.
12
march 2004. Several
South Asian countries are hoping to been soon free of the recent
bird flu outbreak. Japan is still investigating the source of
its outbreak, monitoring scavenging birds as well as pigeons,
which tend to have frequent contacts with poultry. New
reflections will be needed about the spread of West Nile virus
in the USA after it has been discovered that a hybrid Culex
mosquitoe species might have been the main source of
contamination in the USA. Dengue fever, another mosquito spread
disease is still spreading in Indonesia, where the death toll
passed 427. This should be an incentive to develop more research
on insects and on insect pathogens, such as Photorhabdus
luminescens. An
outbreak of still another mosquito vector borne deadly disease,
yellow fever, is affecting the coast of West Africa.
8
march 2004. Thailand
has probably stopped the spread of avian flu and will resume
production of poultry early net month. The chairman of a poultry
company in Japan that failed to report bird flu on one of its
farms has hanged himself with his wife near the city of Kyoto.
The farm sold about 15,000 live chickens and also shipped some
900,000 eggs even after chickens started dying en masse. The
dead crows found in Kyoto had been infected by a H5 flu virus,
spreading concern that contamination might extend out of
contaminated farms.
7
march 2004. Two
crows found dead in Kyoto Prefecture, which has been hit by
outbreaks of a highly pathogenic strain of avian influenza, have
tested positive for bird flu. It is not yet known whether they
died from H5N1 avian flu. In China, thirty volunteers will be
selected for phase 1 clinical tests for a SARS vaccine, in a WHO
accepted test. The volunteers will be vaccinated only after
signing a consent form. A second phase will have more
participants from a wider age bracket. The final phase will only
be carried out if there is a new outbreak of SARS.
5
march 2004. More
than 200,000 people have been recently infected by dengue fever
in Indonesia and the death toll reaches 389.
4
march 2004. Japanese
authorities have called the army in to help disinfect an area of
the Kyoto prefecture hit by a new outbreak of bird's flu.
2
march 2004. 53
out of the 57 infected provinces and cities in Vietnam have
recorded no new outbreaks of the H5N1 virus in the past six to
26 days, raising hope that the outbreak will be out by the end
of this month. As reported by the official Xinhua Agency, the
China-ASEAN Special Meeting on Highly Pathogenic Avian Influenza
(HPAI) Control was held today in Beijing. The Deputy Prime
Minister of Thailand, the Minister of Animal Husbandry and
Fisheries of Myanmar, Vice-Ministers and senior officials for
agriculture and health, and experts from China and 10 ASEAN
countries, as well as officials from ASEAN Secretariat, UN Food
and Agriculture Organization, World Health Organization and
World Organization forAnimal Health participated in the Meeting.
Representatives from Hong Kong and Macao Special Administrative
Regions of China attended the meeting as members of the Chinese
delegation. The participants recognized the trans-boundary
nature of the disease, its threat to public health, and the need
for China and ASEAN to cooperate on HPAI prevention and control
so as to minimize economic losses, while preventing the
occurrence of birds to man, followed by person-to-person
contagion. In a common declaration they stated that they will:
"provide access to and exchange of information and experience on
HPAI status, prevention and control between China and ASEAN
through the ASEAN disease surveillance network, the ASEAN plus
three SARS focal point network and the proposed regional
veterinary network to work towards creating an early warning
system for epidemic recognition and control; enhance cooperation
among inspection and quarantine agencies for border management
in China and ASEAN countries to prevent the spread of the
disease and minimize its impact on health and trade; propose the
establishment of a China-ASEAN cooperation mechanism for public
health, through regular meetings of agriculture or health
ministers and their senior officials, and the convening of joint
meetings of the health and agriculture ministers as appropriate;
operationalize the "China-ASEAN Fund for Public Health" to
finance relevant cooperation between China and ASEAN in
addressing regional public health crisis; strengthen extensive
cooperation and exchanges with other countries, regional and
international organizations, such as WHO, FAO, OIE on HPAI
prevention and control; exchange HPAI expert teams and organize
joint technical training courses on HPAI-related technologies
and methodologies to include among others laboratory management,
diagnosis and testing, emergency response measures and quality
of vaccines in compliance with OIE international standards;
finally, China and ASEAN will mutually provide, within their
respective capacity, bilateral financial, material and technical
assistance to countries in the region hit and at risk to be
infected by HPAI. In this regard, the National Reference
Laboratory of China will share experience and offer technical
cooperation with diagnostic laboratories of ASEAN countries in
terms of diagnostic technology."
29
february 2004. Avian
flu remains a major concern for the World Health Organization.
However this should not make us forget that several other viral
diseases are of great concern: AIDS is on the rise in Asia, with
its terrible consequences in terms of propagation of other
diseases, such as tuberculosis. While hepatitis B vaccination
has been successful in China in restricting the propagation of
the virus, some 100 million people still live with the virus.
Hepatitis C is on the rise. Furthermore, with global
warming pending, diseases propagated by mosquito vectors
are now infecting people in more northern areas, and regions
such as Indonesia have underwent this year an epidemic of dengue
fever twice as severe as one year ago.
24
february 2004. For
the first time since 1983-84 a highly pathogenic and contagious
avian flu has been found in the United States. This triggered a
ban by the South Korea and the European Union governments of
poultry import from the USA, despite the fact that the strain
(H5N2) is not the feared H5N1 strain. The Chinese government
officially declares that there are at present no known SARS case
in the country. Dr. Albert Osterhaus and coworkers show that
early treatment with a long-acting form of interferon (pegylated
interferon-alpha), reduces lung damage caused by the SARS-CoV in
macaque monkeys. This may lower fatalities if it works in Man in
the case of a new outbreak.
23
february 2004. While
bird's flu no longer makes the headlines of media, the outbreak
of H5N1 bird flu in Asia is not under control yet. Fortunately
no person-to-person cases have been reported. The actual number
of persons infected by direct contact with birds is not know,
while the number of fatalities, which is registered as 22 is
certainly an underestimate (many diseases have flu symptoms).
About 50 outbreaks have been identified in China and 2 in Japan.
Another family of bird flu (of the H7 type) is developping in
North East USA and Canada. More than 80 million birds had to be
put to death world-wide and this causes an economic problem in
poultry industry. In the case of legionellosis several water
cooling towers have been found infected at a level higher than
acceptable in France. It will be interesting to increase
monitoring in all types of cooling and air-conditioning systems
world-wide.
17
february 2004. Some
500 open-billed storks were found dead in Ladkrabang district
and 300 birds had died at the Bueng Borapet wetland since Jan.
27, Prapat Panyachatraksa, the Thai minister of natural
resources and environment, told reporters. Laboratory tests
found 30 percent to 40 percent of the dead storks, which are
migratory birds, were infected with bird flu virus. After Tibet,
the outbreak hits Shandong in China, while the disease spread to
the island of Kyushu in Japan. The
legionellosis outbreak in the North of France is considered
over.
14
february 2004. After
a leopard died from bird flu in a thailandese zoo, probably
infected by a chicken it ate, authorities begin to isolate rare
animals, such as pandas in zoos. Several regions in Guangdong
have been recently affected by bird flu, raising concern in
Macao and Hong Kong. Fortunately, until now, no person-to-person
transmission has been reported anywhere. Legionellosis begins to
be recognized as an important disease for elderly persons in
France, since, in 2002 it is likely that more than 2000 persons
were affected by the disease in France, with a death rate of
13%. It is interesting to compare these observations with the
2003 SARS scare.
13
february 2004. India
called an emergency meeting of seven South Asian countries to
discuss urgent measures to combat Asia's bird flu epidemic. New
Delhi says heightened vigilance at its borders has so far
prevented the H5N1 virus, which has emerged in Cambodia, China,
Indonesia, Japan, Laos, South Korea, Thailand and Vietnam, from
erupting within Indian territory. Until now, agricultural
authorities have favoured culling over vaccination, in part
because vaccinated animals can still harbour and shed infectious
virus. Until recently it had not been possible to differentiate
between infected and uninfected vaccinated animals, so
vaccinated animals were still subject to trade bans. It is not
known how much vaccination selects for virus mutants, and this
is sometimes considered as a matter of concern.
- 11
february 2004. The
Standing Committee for Food Chain and Animal Health has
extended the ban on imports into the EU from Thailand of
poultry meat and meat products, wild and farmed feathered
game and eggs, for six months until 15 August 2004.
Compulsory inoculation is being carried out on poultry
raised in areas within five kilometers of regions in four
cities of central China's Hubei Province, where confirmed or
suspected bird flu cases are reported. Economic
considerations prevent many farmers to cull their poultry
(to understand the cost, it should be noted that 30 million
have been culled in Vietnam alone), in particular in the
poorest regions of the world. Vaccination of poultry could
be efficient, but there is a significant danger created by
the selective role of the vaccine, that might trigger a
faster evolution of the virus (those viral mutants escaping
control by the vaccine). More than 1 million homing pigeons
have been confined to their pens in Beijing as bird flu
spreads across China, but their keepers seem to be going
stir crazy, doubting whether the confinement will save them
from the disease. Migrating birds could spread the virus and
China has reacted to this possibility. However this may
result in a difficult time for endangered species and
precautions should be taken not to over-react. March is
usually the busiest season for homing pigeons in China, and
this practice may also propagate the virus. A second farm
has been hit with bird flu in Delaware (USA) (a H7 type
virus).
-
8 february 2004. Thirteen
regions of China are affected by the H5N1 bird flu outbreak.
An outbreak of an H7 strain of bird flu affected the east of
the USA (during last summer a dangerous outbreak of a
similar virus affected the Netherlands, where millions of
poultry had to be killed and a veterinarian died of the
disease, that is usually milder than that caused by the H5N1
virus).
- 7
february 2004. A
large number of poultry died in India, in the region near
Bangladesh, triggering panic. However the disease is not yet
identified. The situation of bird flu is complicated by the
political implications of the fight against the disease,
that make appropriate assessment (and decisions) awkward, if
not plainly wrong. It must be understood first that the
prime victim of the disease, by far, will be China if an
outbreak starts (with person-to-person contamination).
Unfortunately this does not seem to be well understood by an
underlying "antichinese" feeling that appears to be
lingering in the world. It must also be understood that
panic is one of the most efficient causes of epidemics. It
is also well reported, during the past epidemics of Black
Death, that the common reaction of panicked people is to
find a scapegoat, rather than promptly and efficiently fight
the disease. This means that conflicting interests or
strategies have to be dealt with. On the one hand it is
necessary that proper information is provided to the
institutions that can help best (the WHO in particular),
but, on the other hand it is necessary to have a proper
control over rumors that trigger panic, and it is essential
not to point finger at the wrong places. In addition it is
essential to understand that it is obviously extremely
difficult, if not plainly impossible, in a 1.3 billion
persons country such as China, to have a control on all
local authorities, at each and every steps in the
hierarchies (this is the price to pay for the development of
democracy: if that control existed this would, of course,
mean a terrifying dictatorship). Finally, the structure of
the Chinese economy is remarkably diverse, with extremely
poor regions with farming atomized into very small entities,
and quite wealthy regions with large poultry breeding farms.
While it is relatively easy to control the latter, and
slaughter animals when a bird flu outbreak happens, this is
almost impossible in the small scattered farms, with people
certainly not willing to kill their only resources; and,
naturally, proper reporting from these regions is almost
impossible to achieve. Education is another obvious problem.
Hence, rather than attack China, it would be much more
efficient and morally appropriate to help her try to solve
the problem. As a matter of fact, in the present outbreak,
smaller countries such as Indonesia might be much more of a
concern, because of almost total lack of information about
what is happening there. Finally, the present emphasis by
journalists of "eradicating" the disease is simply a fancy.
We shall indeed have to face a
H5N1 epidemics, if not this year, in one of the next coming
years. It is relatively easy to control (and eradicate) a
highly pathogenic disease, if its reservoir is known, and if
an efficient vaccine exists. This is not the case if the
disease can spread unnoticed, and if the reservoir cannot be
controlled. Slaughtering all poultry would not solve the
problem. Indeed flu is a disease of Anatidae (the family of
ducks and similar animals) where it is usuallly innocuous or
causes a mild disease. It can spread to all kinds of birds (mixed
H5N1 viruses have been indeed repeatedly identified),
and one of the problems of this widespread species affinity,
is that the virus mutates and adapts easily to its new
hosts, while being reassorted between hosts when there is
co-infection with several viruses of the same family. It can
then spread to mammals, and lead to the disease we know as
human flu. During the initial passage from a species to
another species, there is usually no intraspecies
contamination. This is probably the situation we have now
with H5N1 in man. Unfortunately, because of virus mutations
and reassortments, it is more than likely that a new form of
the virus will eventually spread from person to person. Two
strategies have to be combined to make this event less
likely, and to control it when it happens. First, one has to
diminish as much as possible the sources of contamination
(slaughtering animals is efficient, provided precautions are
taken so as to avoid aerosol contamination during the
process itself; vaccination of animals is a second helpful
action). Second, one has to prepare for the eventuality of
person-to-person contamination when it will be needed to act
fast: this will require isolation of the specific new virus,
and preparation of a vaccine from it (while, as indicated by
the WHO, reverse genetics will allow scientists to prepare
the vaccine strain in a week, this will require several
months, but the time will be shortened if infrastructures
providing facilities to prepare a large number of fertilized
eggs for preparation of the vaccine can be made readily
available), and this will require control of movements of
persons from the affected areas. The measures that have been
implemented during the SARS episode will certainly help in
this domain. However, lessons have to be taken from what
happened then, in particular about the negative role of
panic (people unobtrusively moving away from affected areas,
and underreporting, to escape quarantine measures). In the
North of France, and 11th person died from legionellosis,
while the disease has been identified in several regions of
the country. It is most likely that pneumonia caused by Legionella
pneumophila were not diagnosed in the past, and that
the diagnostic tools now identified give an unusual pattern
of this disease as compared to what was known in the past.
- 3
february 2004. An
85th case of legionellosis discovered in the region of Lens:
this suggests that the cause of contamination is not yet
identified with certainty. No further information
substantiated person-to-person contamination by the bird flu
virus. Thailand has slaughtered 27 million chickens in an
attempt to slacken the pace of bird flu, while another
suspected patient dies. China has placed 3,200 farmers under
observation. Indonesia confirmed that it had infection with
the H5N1 virus, but the measures to counteract the spread of
the disease are still unclear.
- 2
february 2004. In
addition to possible person-to-person contamination of bird
flu, there is concern that this year's human flu has reached
Vietnam. This would increase enormously the likeliness of
reassort between the bird flu virus and the human virus,
triggering the possibility for a pandemic similar to that
which infected persons in 1919. In Shanghai, officials at
the markets are urged to enforce a strict quarantine system
to ensure only those poultry products with a quarantine
certificate are sold in the city. 300,000 birds have been
slaughtered in a three kilometer radius of a suspected case
and the area has been disinfected. The district government
has also blocked all major intersections in the involved
area to ensure that no poultry is transported out. The fourth
SARS patient in Guangzhou was a medical doctor,
apparently without contact with SARS patients, according to
the local authorities. On january 30th a 84th case of
Legionellosis has been identified in the region of Lens. The
outbreak seems however to subside.
- 1
february 2004. Five
more provinces are affected in China by the H5N1 virus. The
WHO warns that one of the infected Vietnam sisters might
have got the virus from her brother. Flu is an old disease
of ducks (usually mild) and the usual transmission route is
from duck to pig to man. It is often coming from China,
because of the structure of Chinese farms (remember that the
Chinese character for family is the pig under a roof)... The
disease becomes dangerous when the transmission shifts
directly from man to man. A strong outbreak appears every
couple of decades or so ("Asian flu", "Hong Kong flu"
etc...), that progressively invades the whole world and
mutates to adapt to the reaction of the human immune system
on a more or less yearly basis. After somebody has got the
disease he or she usually recovers, with a strong immune
response. But this selects mutant viruses with the following
trick: the antibodies of the host adapt closely to the shape
of a protein covering the virus; but one way for the virus
to avoid being recognized is to change one motif of that
protein by a bigger motif. In this situation the antibodies
are more or less inefficient. During this adaptation time
people are however somewhat protected by the past infections
and the disease is not so dangerous. After some time, the
pool of variation is completely covered, and the only way
out for the virus is to undergo more drastic changes, such
as recombination with similar viruses. Thus, in general, one
finds a moderately severe disease every quarter of a
century, followed by "ordinary" outbreaks every year as the
rule. Now, there are sometimes new trends, corresponding to
the spreading of a form that is severe in birds (bird flu)
rather than mild. This severe disease can directly infect
man: this is the case of H5N1, and recently of H7N7. Now, if
that disease can adapt to transmit from man to man, then
this will create an extremely dangerous outbreak, because no
preexisting immunity is present in the human population.
This is why the WHO is concerned at present, because this
event will most probably happen in a not remote future. The
reason is the following: the flu virus is made of a
collection of independent fragments. Each one can mutate,
producing a form that may escape the immune system of the
host. But the most dangerous thing is when two different
flu viruses infect a given animal (man included).
Indeed, in this situation the fragment may reassort and
produce all kinds of viruses, some adapted to multiplication
in the human host, with a disguise allowing it to escape its
immune system. It is most likely that this will happen
sooner or later. The only way out is to try to guess what
will happen, and prepare a vaccine (ie preset the immune
system by vaccination) against the new virus... This is
today's challenge.
- 31
january 2004. China's
Health Ministry announced a new confirmed case of SARS in
Guangzhou, but said the patient - the country's fourth case
this season - had already been discharged from hospital.
This patient did not have contact with wild animals.
- 30
january 2004. Progresses
in the preparation of a bird flu vaccine are being made. As
for most such vaccines they require infection of fertilized
eggs, which is not without causing practical problems. The
SARS consortium has published its work on the origin of the
virus [PDF].
The double epidemic model, that accounts for this scenario
might also give ideas about the spread of the H5N1 flu.
- 29
january 2004. H5N1
flu is probably much more widespread than previously
thought. Since it last
record in february 2003 (where it sent a confusing
message at the onset of the SARS epidemic) it has
certainly lingered in China, and it was present last august
in Indonesia. Millions of chickens have been killed by the
virus or slaughtered, but it is unlikely that this will stop
the disease, which is now most certainly endemic throughout
Asia. In the ten countries affected by bird flu, it is not
certain that all are due to the H5N1 virus: in Pakistan it
may be the N7 virus, a similar strain that killed millions
of chicken (and one veterinarian) in Netherlands last
summer. Mass culling is however underway. In Hong Kong a
woman returning from Vietnam is showing signs of the
disease. Two further cases of legionellosis have
been diagnosed in northern France, putting the sickness toll
to 83.
- 28
january 2004. Bird
flu has crossed into China (in three provinces at
least: ducks that contaminated one man in Guangxi and
chicken in Hunan and Hubei), raising to 10 the number of
Asian countries affected by the dangerous virus as regional
officials prepare for crisis talks today in Bangkok. We
advocated to monitor the health status of migrating
scavengers such as Milvus
migrans as early as 2001 as possible sentries
indicating the existence of bird's flu in remote areas. This
black kite ("milan noir" in French, and "old eagle" in
Chinese) is travelling for very long distances while eating
mostly dead animals. It is therefore expected to be highly
sensitive to contamination (and this is why it is among the
species that are on the way to extinction), and the
monitoring of their populations might be a good indicator of
existing epidemics that are otherwise difficult to monitor.
A SARS epidemiological study about to be published
in Science demonstrates that several
viruses derive from a common ancestor. This indicates
that the reservoir may still be present, in agreement with
the scenario of the
double epidemic. A memorandum of understanding is
signed between the Chinese Academy of Sciences and the
Institut Pasteur, under the sponsorship of the President of
China, Hu Jintao, and the President of France, Jacques
Chirac, for the creation of an Institut Pasteur in China.
- 27
january 2004. Another
ExxonMobil factory is stopped because one of its
refrigerating towers is shedding high concentrations of Legionella
pneumophila, near Le Havre in France. Malaysia is
implementing anti-SARS measures to combat the
possible spreading of the bird's flu H5N1 virus.
- 26
january 2004. Eighty
one persons have been infected by legionellosis
near Lens, among which 10 passed away and 5 remain in
intensive care. The source of the contamination is still
obscure, because the pattern of infection does not match
with what is known about the disease.
- 24
january 2004. Thailand
informed the WHO of several laboratory confirmed cases of H5N1
avian influenza in man. Earlier an outbreak of an
epidemic that was interpreted as chicken cholera
(caused by the bacteria Pasteurella multocida and
can be cured by antibiotics) had surprizing features that
led to fears that, as other countries in South East Asia,
Thailand was contaminated by bird's flu. This information
prompted the European Union authorities to ban poultry
import from Thailand to Europe. The now widespread bird's
flu is almost certain not only to contaminate more persons,
but to lead to person-to-person contamination. This would
trigger a flu outbreak that might have disastrous
consequences. The flu virus is made of different segments
that can exchange in an individual contaminated by another
strain of the virus. The usual route is from birds to pigs,
then to persons. Simultaneity of infection by a virus
adapted to man (such as H3N2 a family of viruses that spread
in Europe this autumn) and by the bird's flu virus would
yield a recombinant both well adapted to multiplication in
Man and escape from its immune response. Several cases of dengue
were diagnosed in Hong Kong, indicating that the disease is
endemic, and may trigger an outbreak in the future.
- 22
january 2004. Legionellosis
is still there in the North of France, four more patients
have been identified, raising their number to 80. A dead
peregrine falcon was found near 2 chicken farms in Hong
Kong, and it was shown to be infected by bird's flu. This is
in line with the
suggestion we made in may 2001 that wild birds, in
particular migrating birds, might be involved in the
spread of the virus.
- 21
january 2004. On
the front of SARS fighting, the investigation of the WHO
continues. The reservoir of the virus is still unknown.
Thirty healthy volunteers in China accepted to be enrolled
in a SARS vaccine test. The H5N1 flu virus appears to be
present in 17 localities in Vietnam, but, as yet, no
person-to-person contamination has been discovered. However,
as a precautionary measure, the WHO is stepping up the
procedures needed to rapidly produce a new influenza vaccine
capable of protecting man against the H5N1 strain of avian
influenza recently detected. A new case of legionellosis was
diagnosed in the North of France, making the total number of
persons infected to 76.
- 19
january 2004. Bird's
flu has been found in 17 localities in the north and the
south of Vietnam, infecting some 2 million poultry. So far,
the WHO has not seen any sign of transmission of the virus
between persons. Unfortunately, as the number of infected
patients increase, the likeliness of person-to-person
transmission becomes more and more possible.
- 18
january 2004. At
the turning year from the Goat to the Monkey year, China has
upgraded its control on patients travelling, monitoring
cases of fever. Hundreds of millions of Chinese are
travelling during this period of the year. SARS does not
seem to have expanded. However there is much concern about
bird's flu, since the province of Guangdong, for example,
breeds some 1.36 billion poultry birds, while 5 more cases
have been reported in Vietnam, making it a true outbreak...
As in the epidemic of 1919 young adults seemed to be
particularly at risk.
- 17
january 2004. Again
two more cases of legionellosis in the region of Lens,
France: 75 persons infected, 10 deaths. All the outbreaks of
avian flu in Vietnam, South Korea and Japan are now
confirmed to have been caused by a H5N1 type of flu virus.
This virus caused the beginning of an outbreak in Hong Kong
in 1997, stopped by radical measures of killing all live
poultry in the region. The virus then subsequently came back
at several times in the region, in particular masking
the beginning of the outbreak of SARS in february 2003.
It is of extreme concern that the area now affected is so
large, because there can be recombination in and
transmission by most types of birds, leading to a potential
letal disease in man. In addition the virus is prone to
mutation that allows it to adapt fast to a new host. A flu
disease would be much more dangerous than SARS.
- 16
january 2004. Two
more cases of legionellosis in the North of France: 73
persons infected, 10 deaths. However the curve describing
the time of onset of symptoms for the first 69 cases may be
consistent with a decline in the outbreak. A case of H5N2
bird's flu, less dangerous than H5N1 has been diagnosed in
Taiwan. The recent SARS-CoV virus might be caused by
infection coming from civet cats, because the virus appears
to have been found in the restaurant where the last case (a
waitress there) was diagnosed. However this is just
indicative of a possible animal source.
- 15
january 2004. H5N1
bird's flu, the very dangerous virus of the family that
infected patients in Hong Kong in 1997 is now out of China.
Several cases have been diagnosed in Viet Nam and diagnosis
of avian influenza virus subtype H5N1 was made at the
National Institute of Animal Health, Ibaraki Prefecture, in
Japan. This is very disturbing because Japan apparently has
been immune from bird's flu since 1925, while Vietnam has
never reported the disease previously. If the disease
spreads to man, and then from person to person this will be
a major emergency. Vietnam said yesterday it had detected 18
suspected cases of bird flu in man, and that 13 victims had
died. And the World Health Organisation has warned it could
be much worse than SARS. Vietnam News Agency reported that
eighteen people have been found to have contracted influenza
A, of whom 13 died, including 11 children and two adults.
The WHO has confirmed three deaths from the H5N1 virus in
Vietnam, but it says it is carrying out tests to determine
if the bird flu virus killed the others. The cause of
contamination is not known, it could be directly from
poultry, or, a more dangerous source, through pigs that
would have caught it from poultry, paving the way for
person-to-person contamination (pigs are very similar to
man). On the SARS front, scientists in Hong Kong have
discovered antibodies against SARS-CoV in the sera of
patients collected in 2001 for a study of hepatitis B
infection. This
is consistent with the double epidemic
hypothesis that assumes the existence of a
pre-existing innocuous virus that can mutate, presumably
because of a region of mutational hot spot (deletion hot
spot in particular), to the virus causing SARS.
- 14
january 2004. More
rumors about SARS: New Zeland authorities investigate about
the death of a man who died in Russia from SARS-like
pneumonia. It is important indeed to investigate cases at
places out of China, if, indeed the double epidemic
hypothesis accounts for the emergence of SARS-CoV. Two crew
members of a flight from Guangzhou are isolated with
temperature in a negative pressure room in Sydney, for fear
of SARS (15th january, Australia time). As usual in this
time of the year (Northern hemisphere) the number of
pneumonia is important. This makes extremely difficult to
have an accurate and fast diagnostic of SARS. As a case in
point, the Hong Kong Department of Health has already
received 125 notifications of pneumonia of people who had
travelled in the Guangdong region recently. Legionellosis in
the North of France: 71 persons infected, 9 deaths. Reports
indicate the bird's flu (H5N1) might have infected some
people in Vietnam.
- 13
january 2004. Some
confusion arises about possible SARS cases in China. A
fourth possible case has been discarded, while the second
case, that of a waitress in Guangzhou has been confirmed. In
France, legionellosis makes a 9th victim while two more
patients are diagnosed with the disease. They are late
diagnosed patients, suggesting that the disease may have
stopped spreading.
- 12
january 2004. A
third patient likely to be infected by SARS-CoV, has been
isolated for observation in Guangzhou, where two other SARS
cases, one of them confirmed, have been treated.
Legionellosis makes an 8th victim in France (68 cases in the
region of Lens).
- 8
january 2004. A
second patient may have caught SARS-CoV in Guangdong and is
hospitalized in Guangzhou. Three reporters coming from a
possible contaminating area (wild animals market) have been
quarantined in hospital in Hong Kong. If, as expected, a
mild or innocuous form of the virus is endemic in Guangdong
it is likely that the disease will reappear after a first
round of mutations of the virus in some patients, causing
SARS. However it is somewhat unlikely that the
"super-spreader" form will appear shortly. This might
happen, however. This form would be the most dangerous one
(as demonstrated last year) and this justifies stringent
quarantine measures (as already applied) as well as measures
such as temperature control as they are already implemented
in Chinese airports. 62 patients have been infected by Legionella
pneumophila in the region of Lens (France).
- 7
january 2004. The
first SARS case found in Guangzhou since last year triggers
a frenzy of slaughtering of civet cats in Guangdong. This
may be an inadapted reaction because nothing proves really
that civet cats were the cause of the disease: correlation
is not cause! The animals found to carry SARS-CoV were
diverse, and this argues against the idea that they were the
source of the virus. They could have been infected by Man,
and/or they could have eaten up animals carrying the virus.
Indeed SARS-CoV
seems to be related to rodent viruses or viruses present
in the domestic cat. Furthermore, the patient recently
infected never ate civet cat...
- 6
january 2004. While
the SARS case in Guangzhou is confirmed by virus
neutralization antibody tests carried out by two
laboratories in Hong Kong that are part of the WHO
international laboratory reference network, as well as by a
laboratory under the Chinese Centre for Disease Control and
Prevention in Beijing, rumors spread that a traveller going
from Hong Kong to Philippines might have had the disease.
The Chinese patient is now cured and will be discharged on
thursday. It will be important to monitor further
developments as we are entering the winter time in the
Northern hemisphere. In the region of Lens two more cases of
legionellosis have been diagnosed, while the present source
of contamination is still unknown. The difficulty comes from
the fact that Legionella pneumophila is a normal
host of water, and that cofactors for infection (high
concentration of the bacteria aside) are not well known.
- 5
january 2004. Despite
identification of a cooling tower from the company Exxon as
a source, legionellosis is still spreading near Lens: 57
patients and 7 deaths. The way Legionella pneumophila
infects people is not well understood. It appears likely
that a significant number of bacteria is needed to cause
infection. A possible way might be that some bacteria can
enter amoebae where they are not killed, and even multiply.
In turn aerosols containing amoebae might create a focus
where bacteria still multiply, to a level where the immune
system becomes unable to cope with further multiplication.
The SARS case in Guangzhou is confirmed.
- 31
december 2003. The
legionellosis outbreak in Northern France is still
spreading, with 50 cases and 6 deaths. In the mean time
questions arise about the validity of the possible SARS case
diagnozed in Guangzhou.
- 29
december 2003. Legionellosis
keeps spreading in the North of France: 42 cases have now
been identified.
- 27
december 2003. A case of SARS seems to have
appeared in the Guangdong province, suggesting that the
virus, or its parent, is still present in the region. Data
from the province suggest that the virus derives from an
ancestor after a series of mutations. This fits with the
"double epidemic" hypothesis, that suggests the
presence of an innocuous virus mutating to the dangerous
SARS causing form. In France, legionellosis reaches 38
cases, since the end of november in the region of Lens. The
cause of infection is still not identified without
ambiguity.
- 18
december 2003. The
scientist working at a military hospital in Taiwan who was
probably infected by the SARS coronavirus travelled to
Singapore before showing signs of fever. As a precautionary
measure the government of Singapore decided to quarantine 70
persons in the unlikely case they had been infected. Because
the laboratory is supposed to be submitted to the highly
secure rules of P4 containment, this accident is a matter of
extreme concern.
- 17
december 2003. An
accidental case of SARS appears in Taipeh (Taiwan) showing
that conservation of pathogenic viruses is a matter of
concern.
- 16
december 2003. Legionellosis reaches 24
cases, with three deaths, in the region of Lens (France).
The source of infection is not yet identified.
- 12
december 2003. Legionellosis
is spreading in the region of Lens (19 cases, 2 deaths). Flu
(H3N2) reaches its peak in France. It will soon have
infected 3 million persons.
- 30
november 2003. A
case of Legionella infection is found in the region of Lens
(north of France).
- 10
november 2003. A
control test has confirmed the 7th Czech case of a domestic
cow with mad cow disease (BSE), in a 4-year-old cow from
Lomnice nad Popelkou, a town about 90 km northeast of
Prague. Flu
is slowly spreading in Europe (H3N2, a standard type of
flu).
- 30
october 2003. A
case of diphteria, probably caused by an unusual form of
Corynebacteria has been identified in a Paris hospital.
- 11
october 2003. While
the epidemic of infection by West Nile virus (a deadly
mosquito-borne disease) remains a matter of concern in
Northern America, and at a time when a case has been found
in France, scientists at Purdue University have determined
the structure of the West Nile virus, using cryoelectron
microscopy and advanced imaging techniques. The Purdue team
has determined the overall structure of the major surface
proteins in the virus. Because these proteins are
instrumental in allowing the virus to permeate its host
cells, this could be a step forward in combating the disease
by designing molecules that would mimick the binding
properties of the virus surface and thus interfere with host
cell invasion.
- 9
october 2003. After
its Hong Kong counterpart published its conclusions on SARS,
the Canadian Agency for Public Health reviews its
recommandations in the situation of communicable diseases
outbreaks.
- 2
october 2003. The
Hong Kong’s SARS Expert Committee, composed of local and
international experts from the fields of public health,
health service administrators, and communicable disease
control and set up by Hong Kong’s Chief Executive at the end
of May to review the management and control of the SARS
outbreak in Hong Kong, publishes its final report. The
reports summrizes major events in the SARS epidemic, and
addresses some key issues arising from the epidemic.
- 23
september 2003. An
11 member review panel appointed by the Singapore's Ministry
of Health has concluded that the recent SARS patient most
likely acquired the infection in the Environmental Health
Institute laboratory where he had worked. The virus has
indeed a sequence similar to that of coronaviruses
manipulated in that laboratory. Inappropriate laboratory
procedures and a cross-contamination of West Nile virus
samples with SARS coronavirus in the laboratory led to the
infection. No evidence could be found of any other source of
infection. This is fortunately an isolated case of SARS,
with no associated secondary infections.
- 12
september 2003. There
is a possibility that the recent SARS case in Singapore may
have resulted from a laboratory accident. The WHO will be
addressing the issue of laboratory safety at its meeting of
SARS scientific advisors in October 2003 in Geneva.
- 9
september 2003. The
government of Singapore warns that a student that had not
left the city for several months has been diagnosed with
SARS and hospitalized.
- 5
september 2003. The
"double epidemic" model of SARS,
where a rather innocuous coronavirus would spread,
segregating from time to time, at independent points,
variants that are causing SARS is an important
hypothesis that should not be dismissed. If this
scenario is exact, then it is likely that SARS will appear
again unless the original source has become extinct, a quite
unlikely scenario if this corresponds to a mild or even
invisible disease. This should be made known somehow so that
people are prepared.
- 4
september 2003. Eighteen
persons are infected by Legionella in the region of Poitiers
(France). The source of the bacteria is not yet identified.
The
SARS 2003 outbreak
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A
short description of relevant microbes
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