Notice that any
theorem-proving process that works forward — that is, that finds
only true theorems — can be described as an information-accumulating
rather than a solution-searching process.
Obsolete links are updated when possible, or,
unfortunately, removed
28 august 2005. Hantavirus (Bunyaviridae
family, puumala type) infections in France, Belgium, Germany and
Luxembourg in 2005 are more common than usual (more than 500 cases in
all, ten times more than in 2004). This may be connected to an
increase of the population of bank voles. Their population size is
known to vary according to the availability of food, and hantavirus is
carried by these animals. These viruses cause hemorrhagic fevers with
renal syndrome. The types present in Europe are usually less dangerous
than those in Asia or in the Americas.
26
august 2005. For some time, backyard poultry has been dying
off in Bulgaria. The cause of the disease is not flu but Newcastle
disease, an endemic disease caused by another virus (a paramyxovirus)
which has most probably been transmitted by wild pigeons. It
is likely that, because of the bird's flu scare, this type of fairly
frequent event will be the cause of overreactions by the public. In
Vietnam, bird flu has killed three civet-cats at a national park,
marking the first time the virus has been reported in the species. The
disease has already infected and killed predators
in the past. Eaten as delicacies in South-East Asia, civet-cats are
infamous as they were supposed for some time to have been the vectors
of the SARS virus. The true problem about avian flu is not that a
vaccine will be difficult to invent (we know already that this will be
possible), but simply a question of infrastructures: we do not have
enough factories to make the vaccine into the required number of
doses. We could already witness the situation last winter, when it was
necessary to remove from the market a defective batch of the vaccine:
it was not possible de vaccinate all the persons in need. We can
therefore expect that, if the disease appears within three years, a
situation of crisis where we will have to chose between the victims of
the "ordinary" flu (mostly aging people) and the general population,
to decide which vaccine should be prepared in the factories we
possess. Sleeping sickness (trypanosomiasis) is gaining ground in the
region of Isangi, located in the Tshopo district, Congo-Kinshasa. This
letal disease, which stays invisible for a long time in the patients,
can be cured but the treatment has often very dangerous side effects.
23 august 2005. Animal
infectious diseases play a major role in the (re)emerging diseases
that affect humans. Unfortunately, many animals are subject to endemic
diseases, such as foot-and-mouth disease (there is an ongoing outbreak
in Mongolia), or, in birds Newcastle disease (active in UK at the
present time). Avian flu is developing both in Mongolia and extending
westwards in Russia, menacing Europe, where a cacophony of reactions
can be heard (the poultry industry represents a considerable amount of
agro-food industry resources). Interestingly one appears suddenly to
understand the role of migratry birds, as well as the well known
origin of the virus. For those interested to follow our vision of the
present episode, see what we wrote about Milvus
migrans (curiously, scavengers are rarely considered as
sentries, while they live from the flesh of dead animals), and
subsequently on cranes, of
the spread of the virus in
Japan, and on the usual development of the disease in China,
where pigs play the role of
intermediate hosts.
17 august 2005. The outbreak
of the deadly Streptococcus suis infection
in the Sichuan province in China has triggered systematic reporting of
related infections in China, ending up with reports from many cities.
Hong Kong found today its ninth infection in a few weeks.
16 august 2005. The H5N1 flu
virus is expanding westwards in Russia (it also reached Kazakhstan and
Mongolia in the past weeks). The virus, probably carried there by migrating
birds, was discovered mid-July in Novosibirsk and has spread
through Tyumen, Omsk, Kurgan, Altai and now Chelyabinsk in the Ural
mountains, which is approximately 1,000 km west of Novosibirsk.
9 august 2005. A rare strain
of cholera has infected more than 2000 people in Uganda in the past
weeks. More than 50 died of the disease. In Guinea Bissau the toll is
even heavier: 84 deaths and more than 5000 cases. Another media-driven
controversy agitates scientists interested in China as the
outbreak of Streptococcus suis continues to kill people
and pigs in the Sichuan province. The bird's flu epidemic is not yet
contained in Siberia.
4 august 2005. For
some time the way the Severe Acute Respiratory Syndrome coronavirus
(SARS-CoV) entered cells was somewhat controversial. Two different
cell receptors had been proposed to be the entry port, based on cell
cultures. A new study using mice knock-out mutants, by a collaboration
between scientists in Beijing, Austria, USA and Canada, proves
unambiguously that the receptor is angiotensin-converting enzyme 2
(ACE2). Because this enzyme acts in a very important hormone
regulatory cascade (the renin-angiotensin cascade) this explains why
the symptoms of the disease are often dramatic and letal. The
media-driven controversy about bird's flu between the Chinese Ministry
of Agriculture, the Department of Microbiology at the University of
Hong Kong and the private university of Shantou in the Guangdong
province is still active (see July, 8th), while in Siberia flocks of
contaminated fowls are slaughtered.
1 august 2005. Poliomyelitis
is far from eradicated. While it remains endemic in Madagascar, it
surfaced again in Angola, with two cases of paralysy. The last
outbreak was back in 2001.
31 july 2005. A 20-year-old
poultry farm workman showing bird flu symptoms has been hospitalized
in Kazakhstan's Pavlodar region, where 600 domestic geese died between
July 20 and July 30 as a result of an outbreak of the disease in the
area. The patient, from the village of Golubovka, was later diagnosed
with double pneumonia.
30 july 2005. Health
authorities in Siberia challenge their initial identification of the
virus responsible for bird flu there, stating that it most probably is
H5N1. As the oubreak has most probably been transmitted by migrating
birds, this raises concern about its propagation in Northern
countries, then back to new Southern countries when the summer will
end.
26 july 2005. The bird flu
outbreak in Siberia is fortunately caused by a H5N2 virus, not the
H5N1 dangerous type. Pigs have been found to be H5N1 positive in
Indonesia, which proceeded to slaughter infected animals. The
Indonesian government has officially appointed Persahabatan Hospital
in Rawamangun, East Jakarta, and Sulianti Saroso Hospital in Sunter,
North Jakarta, as referral hospitals in response to the recent deaths
of three Tangerang residents from bird flu. The mysterious death of
300 egrets in a forest park in Guangzhou (Canton) triggers fear in the
population of a new bird flu outbreak in the region. The rumor spreads
that people have eaten some of the birds or sold them on the markets.
25
july 2005. A mysterious epidemic is affecting the Sichuan
province in China. Some 80 persons appear to have been affected and 20
died of the disease. No person-to-person contagion was monitored but
the outbreak seems to be on the rise. Media in Hong Kong and Taiwan
hint at a contamination by a Streptococcus associated to pigs.
21 july 2005. For the first
time, Russia reports H5 bird flu on its territory (Anatidae, in
Central Siberia). This could correspond to the Qinghai episode in
China. Dengue fever is spreading in Singapore.
16 july 2005. In a first for
Mainland China, scientists from Beijing unravel the details of the
recent outbreak of flu affecting Anatidae (the family of birds
comprising ducks, geese and the like) in the Qinghai region, a
controversial matter (see other details on the july 8th
entry): "Highly pathogenic H5N1 influenza virus infection in migratory
birds" by Jinhua Liu,1* Haixia Xiao,2,6* Fumin
Lei,3* Qingyu Zhu,4 Kun Qin,1 Xiaowei
Zhang,5 Xinglin Zhang,1 Deming Zhao,1
Guihua Wang,2,6 Youjun Feng,2,6 Juncai Ma,2
Wenjun Liu,2 Jian Wang,5 George F. Gao21College of Veterinary Medicine, China Agricultural
University, Beijing 100094. 2Institute of Microbiology,
Chinese Academy of Sciences, Beijing 100080. 3Institute of
Zoology, Chinese Academy of Sciences, Beijing 100080. 4Institute
of Microbiology and Epidemiology, Academy of Military Medical
Sciences, Beijing 100071. 5Beijing Genomics Institute,
Chinese Academy of Sciences, Beijing 101300. 6Graduate
School, Chinese Academy of Sciences, Beijing. This
works shows that the virus isolated from a peregrine falcon in Hong
Kong carried markers of virulence similar to those of the geese found
at the Qinghaihu Lake. The Indonesian health ministry says bird flu is
suspected in the recent deaths of a man and his two daughters near
Jakarta.
14 july 2005. More than ten
new cases of patients infected by bird flu are hospitalized in Hanoi.
One died of the disease.
11 july 2005. Bird flu is
affecting agains Japan fowls, with a first outbreak in the
Philippines, while Thailand's poultry is infected again... China
develops a new "anti-fusion" drug to prevent entry of the HIV in human
cells. Cholera is spreading at the border between Mali and Senegal.
8 july 2005. An interesting
controversy has begun between Guan Yi, at the Universities of Hong
Kong and Shantou (the latter being supported by the famous tycoon LI
Kashing) and authorities in Mainland China, led by Jia Youling,
director general of the Veterinary Bureau of the Chinese Ministry of
Agriculture. According to Guan, the authorities try to prevent him to
have direct access to the samples of avian flu when outbreaks occur,
while, according to Jia, the conclusions drawn by Guan are in error
and indicate a lack of understanding of bird's migrations...
6 july 2005. A new liver cell
line discovered by Takaji Wakita at the Department of Microbiology,
Tokyo Metropolitan Institute for Neuroscience has been improved to
allow robust
cultivation of the hepatitis C virus in cell culture. This is a
considerable improvement which will allow to better analyse the letal
hepatitis C and possibly lead to efficient treatment or vaccine.
3 july 2005. The US National
Science Advisory Board for Biosecurity (NSABB) met for the first time
to discuss research on "dual use" biotechnology derived weapons, with
Craig Venter discussing the potential use of "synthetic" bacteria.
26 june 2005. Chicken are
infected in Japan by the H5N2 influenza virus. This family of viruses,
less dangerous than the H5N1 strains have repeatedly
infected birds last year (in august in South Africa, and earlier
in the USA and in Taiwan. As usual, reaction to diseases follows
epidemics, rather than precede and prevent them: SARS is the pretext
for development of a variety of vaccines, using the rather trivial
"spike" protein of the virus as the target. Tobacco transgenic plants
are now producing an efficient SARS oral vaccine candidate using this
antigen.
22 june 2005. The cholera is
back in Touba, Senegal, where it may have infected as many as 250
people. As in many other places where cholera is endemic, authorities
tend to hide the fact under the general term of "diarrhoeal disease".
Flu is infecting chickens again in Vietnam. In China authorities deny
having instructed farmers to use amantadine in fowl breeding. The
situation is complicated as rules about drug trading are not clearly
enforced in many places while many companies are selling drugs that
should be under restricted access all over the country (the situation
is often the same in Europe with drugs used in veterinary medicine).
As early as 1996, the first patient infected with a vancomycin
resistant straing of staphylococci was already identified in a
hospital in Beijing for that very same reason.
19 june 2005. The rumor is
spreading that Chinese authorities have recommended the use of
amantadine, a drug potentially useful against bird's flu as a
prophylactic measure against the disease in poultry farms all over the
country. This is likely to trigger a controversy, as in the case of
large scale vaccination of animals, as this might drive selection of
new virus variants, and they will in this case be resistant to
amantadine. The present circulating virus genotype Z appears to be
resistant to amantadine. One may wonder whether this policy might have
already selected those variants. Obtained after random screening of
many thousands of compounds by pharmaceutical companies, two
compounds, amantadine and rimantidine, target the M2 ion channel on
the virus. They are however very difficult to use with dangerous side
effects. This means that large-scale use of the molecule would
probably have been impossible. However this practice, if confirmed,
shows that concerted action world-wide is absolutely needed to prevent
dangerous practice to jeopardize our attemps to prevent or control the
likely pandemic. More human cases are identified in Vietnam, while it
seems possible that one person in Indonesia had been infected earlier
this year by the virus, without much adverse effects. The outcome of
the SARS meeting in Hangzhou produced a
remarkable result: cinanserin, a drug in therapeutic usage against
schizophrenia since the 1970s, was identified as a cure for the SARS
epidemic and is the only ready-to-use medicine among the total 15
possible anti-SARS remedies studied by the participants in the
meeting. Two viruses related to SARS-CoV were also identified.
15 june 2005. Six new avian
flu human cases in Vietnam...
14 june 2005. Anthrax is
endemic in many countries in the world as the spores of its agent Bacillus
anthracis are extremely resistant and can remain dormant in the
soil for decades. Cattle or sheep herds are often infected, and humans
get contaminated when manipulating the slaughtered animals or their
skin, used as leather. Two outbreaks are active at the moment, one in
Zimbabwe (where a large outbreak occurred in 1978-1980) in Gutu
district in Masvingo with five cases reported, and one in India in the
state of Tamil Nadu (two cases). The
second annual meeting of the Sino-European Project on SARS Diagnostics
and Antivirals (SEPSDA) is opening in Hangzhou (China).
9 june 2005. A new avian flu
outbreak affecting geese is developing in the Northwest province of
Xinjiang. The authorities have ordered the culling of 13,000 birds in
farms located near the region of the outbreak. Three persons have
contracted the disease in Vietnam during the past three weeks (from
poultry). On the front of the other recorded epidemics (not including
the most prevalent diseases, aids, malaria, cholera and diarrhoeal
diseases, dengue fever etc), Marburg fever is probably under control
in Angola, where some 423 people have probably been infected so far,
357 fatal), no new cases of Ebola fever were recorded in Congo, 52
persons have been hit by legionellosis in Norway (where the cause has
been identified). The same disease outbreak near Lyon in France is no
over, but the cause has not been clearly established. A vaccine
against Marburg or Ebola fever would be easy to obtain, as trials on
monkeys have been successful, but these diseases being only contagious
by direct contact their spread should be easy to contain, at least in
conditions where basic hygiene is culturally well understood and
accepted. A remarkable study, where the gene of the protein which can
become a dangerous prion is manipulated to control synthesis of a
truncated protein, yielding a prion without anchor in the cell
membranes, shows in mice that this creates deposits which look very
much like the Alzheimer plaques. This suggest some kind of link — this
could be convergence — between these two brain degenerative diseases.
And this makes the more important to study the spread of prions and
related spongiform encephalopathies, which, although sporadic, seem on
the rise in some places.
5 june 2005. Back
in february this year an annoucement was made that a new,
extremely dangerous HIV strain emerged in a patient in New York City.
Fortunately this seems to have been an overreaction of scientists and
authorities eager to enhance their reputation. We should not, however,
lower our guard against the disease, as Japan is witnessing now an
increase in new cases at a rate similar to that found in the
developing world.
4 june 2005. Background flu
is a disease of Anatidae (ducks, geese and the like); the reason why
it used to spread to humans is a route centred on the standard living
custom of Chinese farmers who keep together ducks and pigs for their
living (the character for "family" is a pig under a roof). It goes from
ducks, to pigs, to humans. Usually the disease is fairly
innocuous to ducks. From time to time the virus spreads to other
birds, with more severe symptoms (as it is less adapted there). This
is the case of the recent H5N1 chicken flu, which probably started
from a complex
reassortment from several bird strains in 1997. New viruses
always tend to explore new hosts. Either they are killed rapidly by
the various levels of the immune system - and nothing is visible - or
they cause havoc, often being extremely dangerous. In such cases,
because they are less adapted, they do not propagate easily in the
community of the new hosts. This appears to be the situation of the
present avian flu outbreak. The danger will come (this seems to become
the situation in Vietnam) when virus mutants will begin to adapt to
their new human hosts. While they will be less (but still) letal, they
will begin to propagate from humans to humans. This is the situation
monitored by all health authorities in the world. A consequence of
these observations is that the viruses which might become the most
dangerous are either those which will take a route from Anatidae to a
mammal and then to humans, or viruses infecting another type of birds
and attenuated directly in humans (this seems to be the route followed
at the moment by the virus). It is important to be aware that the
virus which will create the epidemic will be present in the
environment well before the epidemic starts. It is therefore of the
utmost importance to monitor the molecular changes (analyse the virus
genome) in a systematic way. The two foci which are of most concern
are therefore South-East Asia (where attenuated forms already appear
to exist), and Indonesia (where it appears that pigs have already been
infected, most of them, fortunately, with not much symptoms). The
situation in China is intermediate, and under investigation. The most
recent outbreak, affecting geese, and being in the remote province of
Qinghai, is possibly less dangerous. However it is likely that the
virus comes from migrating birds which might have been infected in
South-East Asia. Also, in contrast to what is often perceived in the
West, the Central Chinese government does not have the considerable
power usually thought it has. Information, often, does not go from the
place where events happen to the authorities, and lack of information
is often the nightmare of health authorities. Furthermore local
potentates decide what is important and what is not as a function of
their (supposed) interest, not of the superior interest of the
country. Finally, rumors spread extremely fast, in particular with the
use of mobile phones (less so, fortunately, in the remote parts of
China). This situation is most dangerous as China may become the first
victim of the disease (although South-East Asia seems perhaps more
likely). The most important way to control the epidemic would be to
restrict population movements (regions placed under quarantine).
Rumors and panick are unfortunately most likely to make people flee
from affected regions (as witnessed with the Marburg disease in Angola
for example) creating new foci. The consequence is that, rather than
pointing fingers at the deficiencies of the Chinese authorities, we
should, by all means, try to help them. In this respect it is
interesting to compare the way SARS was controlled in the world: China
was not the worse, by far. Also, there have been three laboratory
accidents with that virus: in Singapore first, then in Taiwan, and
finally in Beijing. One should also stress the recent distribution of
the dangerous H2N2 virus which circulated at the beginning of the 1957
epidemic, was sent by accident to hundreds of laboratories in the USA
and 17 countries, demonstrating that we are certainly not without
deficiencies. We should only follow positive and constructive voices,
and organise for what appears to be more or less inevitable. A strike
resulting in the arrest of the activity of a cleaning water station
near Goma in Congo, led the population to drink water from the
neighboring contaminated lake, causing a serious outbreak of cholera.
1 june 2005. An Italian team
of scientists recently reported that resveratrol, a polyphenol present
in grapes inhibits in vitro, and apparently in vivo in mice, the
replication of viruses, in particular the influenza virus. This looks
like good news but needs substantial confirmation. This molecule
apparently modifies the redox state of the cell. Another study at the
Karolinska Institute in Stockholm, with a core molecule of the widely
used curcuma spice (curcumin) also targets the redox state, with interesting
results against cancer. All this points to a particularly
important role of the sulfur
atom metabolism. While the outbreak of Legionnaire's disease is
under control near Lyon in France, an outbreak has been identified in
Norway in the two cities Sarpsborg and Fredrikstad. It is being
monitored.
31 may 2005. A tenth patient
died of Ebola fever in Congo (Brazzaville) showing that the disease is
still rampant. The WHO has declared Indonesia as still endemic for
bird flu: 16.2 million birds died last year of the virus, while the
toll seems to be much lower this year (300,000 in the first quarter).
The virus was also found in some pig farms a few weeks ago: the
authorities have asked to relocate all pig farms away from poultry
farms. Marburg fever still slowly progresses in Angola.
29 may 2005. The fact that the
Chinese authorities took some time to declare the presence of active
foci of foot-and-mouth disease on their territory triggers questions
about the extent of bird's flu. Some activists take this as a pretext
to assume that there has been human cases. There is no hint however
that this is the case. In fact, at the present time, it appears that
the form affecting poultry is more prone to infect humans directly
than the form infecting Anatidae. Vietnam accepts to discontinue its
controversial program of H5N1 flu vaccine that the WHO feared might
accelerate the evolution of the virus towards a more contagious form.
A group of scientists of the Massachusetts Institute of Technology
proposes a new printing technique to create large number of identical
DNA chips. In this new printing method, called Supramolecular
Nano-Stamping (SuNS), single strands of DNA self-assemble upon a
surface to duplicate a nano-scale pattern made of their complementary
DNA strands. The duplicates are identical to the master. This method,
if successful, will lower considerably the cost of DNA chips and
trigger wide use for diagnostic purposes.
28 may 2005. Several cases of
unidentified infectious diseases have been diagnosed in Northern
Vietnam. They are neither flu, nor dengue, nor usual encephalitis.
Epidemiological analysis suggests that they may be caused by vectors.
Several foci of likely H5N1 bird's flu have been killing Anatidae
(birds of the family of ducks and geese) in the remote Qinghai
province. As far as we know no human cases have been identified. It
will be important to monitor the persons who have been in contact with
the birds. Molecular epidemiological studies are planned. They should
help to know whether the virus comes from South East Asia, while birds
were migrating, and to monitor the types of mutations involved. Highly
letal strains of the virus might be less dangerous than milder forms,
as they die with the animals they infect. The major concern of the WHO
at the moment is precisely that the viral form in South East Asia is
becoming somewhat attenuated (and therefore can spread more easily).
Several foci of foot an mouth disease have been discovered in Mainland
China, creating havoc on the meat market.
22 may 2005. Beginning early
may hundreds of migratory birds have died in the western China Qinghai
province. It has now been established that these deaths are due to a
variant flu H5N1 virus. We noted several years ago that migratory
birds should be used as sentries to monitor the spread of bird
flu. This is therefore a matter of concern. Thailand has already
witnessed more than 8000 cases of dengue fever since the beginning of
the year, and has begun a new monitoring system.
16 may 2005. The legionellosis
outbreak north of Lyon is similar to that which affected the region of
Lens november 30, 2003 to
february 17, 2004. The present number of cases (34) matches that
reached then after one month, at the peak of the epidemic. While
Marburg fever recedes in Angola, a suspected oubreak of Ebola fever
seems to affect the Democratic Republic of Congo (nine deaths). This
may simply be a rumor triggered by the latter epidemic which is not
yet over (292 deaths among 336 known cases).
13 may 2005. The Indonesian
Ministry of Agriculture published that pigs have been infected by the
brid flu virus in the country. As the
most common route from birds to humans is through pigs, this
information is a matter of concern. France may be witnessing a new
outbreak of legionellosis as 20 cases have been found North of the
city of Lyon.
12 may 2005. A news article
published in the latest issue of Nature raises concern about
lack of cooperation between scientists involved in bird flu
research. Fortunately, authorities in countries affected by the bird
flu outbreak have resumed sharing viral specimens with World Health
Organization scientists after an eight-month lack of cooperation,
public health experts said yesterday.
11 may 2005. Cholera, which
remained endemic in the islands of São Tomé for some time has now
reached epidemic proportion (130 cases) in these small islands of West
Africa. Dengue fever is gaining momentum in the Philippines, while the
Institut Pasteur de Ho Chi Minh City reports 6,290 cases since the
beginning of the year. A meningitis outbreak in the capital of India
(214 cases and 16 deaths) seems to be slowly spreading to adjacent
states.
8 may 2005. The rumor is
spreading in the Guangdong province that thousands of children are
suffering flu-like symptoms at the end of the "long week" of vacation
in China. Because of the flu alert in South East Asia, people react
strongly and spread rumors through SMSs.
7 may 2005. The Scientist
summarizes the lessons from SARS, and shows how world-wide
collaboration was efficient in the rapid control of the epidemic. As
emphasized in the article, one of the lessons is that the reservoir
of the virus remains unknown. Canada has sent a third team of
scientists to Angola to help contain the Marburg fever outbreak and is
readying a fourth team to go later in the month if needed. New cases
continue to be reported, indicating that the message about the way the
disease is spread is not understood by some of the population. Vietnam
will test a locally made bird flu vaccine on humans and poultry this
summer after successful tests on mice and monkeys.
3 may 2005. The vaccine for
H3N2 next year flu is being prepared, but the mind of health
authorities everywhere have on their mind the H5N1 epidemic in
SouthEast Asia. The circulating viruses are today different from that
which caused the 1997 outbreak in Hong Kong. A synthetic vaccine
against the hemagglutinin antigen (the "H" in the H5N1 shorthand) is
being prepared, while the virus is slowly evolving to a less letal but
more contagious form (mortality decreased from 75% to 20%) that now
affects all age groups. Vietnam is planning to have a mass vaccination
of its poultry, but this may accelerate the mutation of the virus, and
drive it to a form that may start interhuman contamination. The death
toll of Marburg fever in Angola reached 280 persons. It seems still
difficult to prevent people to touch infected persons, while this is
the only route of contamination. Cholera is still endemic in many
places, it just killed 117 persons in Senegal (but seems on the
decline) and probably more than 100 persons in Nigeria. In Bangladesh
the authorities usually refuse to name the disease that causes letal
diarrhoeas, but it is likely to be, as usual, cholera.
29 april 2005. While SARS
memory fades, scientists at the Department of Biochemistry of the
University of Hong Kong have identified a class of chemicals (in
collaboration with German colleagues) which may be useful against
viruses, SARS-CoV included. These adamantane-derived
"bananins" are potent inhibitors of the helicase activities and
replication of SARS Coronavirus. More than 250 persons died from
Marburg fever in Angola, but the disease seems under control.
19
april 2005. The death toll from the Marburg fever epidemic in
Angola - the world's worst to date - stood yesterday at 235 of a total
of 257 identified cases, mostly young children. At least five hundred
persons might still be carrying the virus, as the common practice for
most Angolan families, is to prepare the body, and kiss and embrace
the deceased. Unfortunately filoviruses rapidly cover the skin of
patients, and touching infected people is a major route for contagion.
15 april 2005. The chemistry
of nucleic acids is undergoing an exceptional revolution, at least as
important as the revolution that happened when the Polymerase
Chain Reaction (PCR) was invented. The nucleotides, the building
blocks that make nucleic acids, are fairly unstable, and they are
costly to synthesize. Ribose in particular is a quite reactive sugar
(present in RNA, it is likely to have predated the more stable
deoxyribose). A few years ago scientists have therefore invented new
types of nucleic acids, that were easier to make and less prone to
decay. Eschenmoser and his colleagues first replaced the correct
sugars by other, while showing that the new molecules (TNA, for
tetrose nucleic acids) retained their properties to pair in an
antiparallel way as in the double helix, as well as pair with DNA or
RNA. This was followed by simpler peptide nucleic acids (PNA) where a
peptide replace the sugar phosphate backbone. Now Meggers and his
colleagues have created glycol nucleic acids (GNA) that are
extraordinarily simple, and still retain all the properties of nucleic
acids in duplex formation and hybridization with authentic
nucleic acids. The new
"glycol nucleotides" are extremely simple and economical and it
seems likely that one will have soon automatic and cheep processes to
make all kinds of GNA, including some where the nature of the bases
will be changed. One could expect creation of evolution in the test
tube with these new molecules. Meggers suggests that these nucleotides
might have predated the ones we find now. This is unlikely, in fact,
and his construction is typical of man-made inventions, rather than
the tinkering behaviour of life, which does not follow an intelligent
design, making use of the very
fact that it cannot make things too perfect.
14 april 2005. More than 6 000
persons have been infected by the cholera vibrios in Senegal, despite
intense effort by the government to contain the epidemic. Concern
rises that the outbreak might extend in the region of Diourbel on the
occasion of the Gamou (or Maouloud, religious ceremonies for the
anniversary of the death of the Prophet) on april 21 in several
religious places. In Uganda cholera is spreading in the Gulu district.
Marburg fever has now killed 215 in Angola.
13 april 2005. Adding to the
concern raised by a possible pandemic caused by the H5N1 bird flu
virus, the World Health Organisation reports that samples of the flu
H2N2 virus that caused the flu pandemic in 1957-1958 were
inadvertently sent to 3,747 laboratories in 18 countries, 61 of those
outside the United States and Canada (14 in Canada). The death toll
due to Marburg fever in Angola reached 210.
12 april 2005. Marburg
haemorrhagic fever, caused by a filovirus of the same family as the
Ebola virus, has killed more than 200 persons, mostly children under
5, in Angola. The reservoir of the virus is still unknown, but
scientists think this might be a small animal, perhaps a rodent.
Curiously, perhaps as in the case of the SARS outbreak in 2003, the
hospital ward where victims are treated seems to be the major source
of contagion. The Government of Angola is planning to close it to curb
the spread of the disease.
9 april 2005. The situation
has become dangerous in Angola after a team of the WHO has been
attacked by people fearing that its personnel was spreading the deadly
Marburg fever. 183 persons have died of the disease and it is
difficult to know the present situation as the WHO personnel who
attempted to trace the contacts of patients to prevent contagion
cannot work under correct conditions.
8 april 2005. The World Health
Organisation has advised the neighbouring countries around Angola to
go on a Marburg fever alert after confirmation the deadly Ebola-like
virus has now claimed 173 lives. Cockroaches are not only a plague
because they transmit diseases by their ubiquitous presence in dirty
places, but they are also the source of dangerous allergies.
Entomologists have recently >succeeded in identifying the chemical
structure of the strong attractant (pheromone) of Blattella
germanica, one of the commonest cockroach species. The sex
pheromone–producing gland in adult females was identified in 1993, but
thermal instability of the pheromone made characterization difficult.
The new identification will enable the design of chemical traps that
should be most useful in controlling the populations of these bugs.
6 april 2005. Despite an
impressive response to control the Marburg fever outbreak in Angola
the number of casualties reached 155 (out of 175 identified cases).
Cholera appears to surface in Dakar, the capital of Senegal.
5 april 2005. The bird flu
outbreak that is invading North Korea seems to be of the H7,
not H1 type. This would be a first for Asia. While that type is
usually less dangerous than the H1 type, the fact that flu virus can
reassort increases the danger of creating new mutations. Furthermore,
if this identification is confirmed, the route for the spread of the
virus, especially in such a closed country, becomes an important
enigma. After aving infected 163 persons and killed 150, Marburg fever
seems to be contained in Angola.
3 april 2005. Dogs may carry
the dangerous Ebola virus without showing signs of the disease. This
recent observation may help to find the elusive reservoir of the
virus, which spreads through direct contact with dead animals (often
primates) or infected humans. This is also important at the time of an
epidemic of the Marburg hemorrhagic fever that continues to spread in
Angola (up to 150 persons have be killed by the virus since last
fall). Cholera continues to spread in Senegal from the holy city of
Touba where pilgrims from the Mouride brotherhood come to celebrate
the departure into exile of their founder Sheikh Ahmadou Bamba in
1895.
29 march 2005. Bird flu has
now spread to North Korea, where it killed a large number of chicken.
News from that country are scarce however, and it is difficult to know
whether there are human cases. Still another family has been infected
in Vietnam, but there is no clear evidence of interhuman contagion.
Marburg hemorrhagic fever has killed 126 persons in Angola, including
an Italian doctor. It now appears that the epidemic, endemic in green
monkeys, lingered in the country since october.
23 march 2005. With the dry
season getting hot and dusty, the annual outbreak of meningitis is
developing in Sahelian West Africa. Many cases have appeared in the
region of Bouna (North East of Ivory Coast) a region controlled by the
rebels, and not easily accessible for vaccination or treatment.
22 march 2005. Prof. Chen
Zhu, already vice-president of the Chinese Academy of Sciences,
has been elected as a member of the CPPCC. As
at the onset of the SARS episode, wild rumors are spreading
about a large outbreak of avian flu in the Chau Hoa commune in central
Quang Binh province, 400 kilometers south of Hanoi, where it is said
that some 200 people are affected. While this is probably very
exaggerated, the situation needs to be monitored seriously.
13 march 2005.In
line with our expectations, the Special Administrative Region
(SAR) of Hong Kong received on the afternoon of march 12 a decree of
the State Affairs Council approving the resignation of Tung Chee Hwa
as the Chief Executive of the Hong Kong SAR. The interim Chief
Exectutive, Donald Tsang, immediately took the helm of the Hong Kong
SAR. Tung Chee Hwa, as expected, was nominated as a member of the
CPPCC with the title of vice-president.
12 march 2005. HIV in its
various forms uses to enter human cells (primarily, macrophages)
through a receptor, CCR5. Cells that carry the CCR5-delta32 deletion
(i.e. that have an altered receptor) are fairly impermeable to the
virus. The average frequency of this modified gene is particularly
high in European populations (10%, and 15% in Scandinavia). Scientists
from the United Kingdom propose that this results from the selection
pressure exerted on European populations in the past, where many
diseases spread as plagues, and killed a large proportion of
inhabitants of the continent. This may explain the relatively less
contagious nature of HIV in Europe. This hypothesis is likely to
trigger an interesting controversy.
11 march 2005. AIDS patient see
more and more often their disease escape treatment by antivirals (at
least 5% of them according to the most recent figures in UK. The same
situation is already a matter of concern in Africa (at least 5% of the
AIDS patients in Kenya), and it will shortly become extremely serious,
if the traffic of fake drugs, already very active, amplifies. In the
case of bird flu it seems that the parents of patients could be
infected without showing any apparent symptom. This unexpected
observation is ambiguous: if the people that are seropositive for the
virus have been infected by their kins, this would be the mark of an
interhuman contamination; in contrast, the fact that persons could be
infected without serious consequences indicates that the disease could
be less dangerous than what has been feared until now (however, this
could correspond only to a part of the population, older people in
particular).
6 march 2005. Initial reports
about an outbreak of pulmonary plague in a mine
of the Democratic Republic of Congo suggested that there might have
been some 400 cases. Fortunately, a retrospective study indicates that
the outbreak was limited to 57 suspect cases, including 16 deaths.
However the mine is likely to remain a serious source of contagion
while work there resumes.Type four dengue fever has caused outbreaks
recently in Indonesia. This is of major concern in the Northern region
of Australia where last year dengue fever outbreak was of type two.
Dengue fever, upon first infection is rarely fatal, but anyone who
acquires two different types of dengue fever is at risk of developing
dengue haemorrhagic fever, which can be fatal in a significant number
of patients.
3 march 2005. While concern
about the H5N1 bird flu likely pandemic is still on everybody's mind
(with at least two more human cases in Vietnam, and the death of more
than 12,000 chicken in West Java), China's
11th five-year plan is discussed in Beijing between March 2 and March
12 at the National Committee of Chinese People's Political
Consultative Conference (CPPCC) and National People's Congress
meetings. Many important decision will be reached, including
considerable changes in the direction of several ministries and other
structures such as the government of the Hong Kong Special
Administrative region (including changes at the head of the government
of the SAR). The present Chief Executive of the Hong Kong SAR will
most probably be elected to be one of the 25 vice-chairmen of the
CPPCC. The outbreak of pneumonic plague in a mining district of the
Democratic Republic of Congo appears to be smaller and more
geographically limited than was originally feared.
27 february 2005. After a
period of relative calm on the front of avian flu, and the end of the
international bird flu conference in Ho Chi Minh City on Friday, a
local newspaper reports that 36-year-old man and probably his younger
sister has been infected with bird flu in northern Vietnam, while an
older man apparently died of the disease. Infection apparently
appeared after the man drank chicken blood, a common practice in the
region.
26 february 2005. At the 12th
Annual Retrovirus Conference, which ended in Boston yesterday,
investigators reported discovery of two new human retroviruses (named
HTLV3 and HTLV4, for human T-lymphotropic virus) in rural Cameroon
among people who hunt monkeys and other primates. The new viruses have
not yet been linked to any disease, but they are being monitored out
of concern that they or similar retroviruses might trigger another
epidemic. In this context it is particularly worrying that experiments
in xenotransplantation (i.e. transplantation into humans of
animal organs) is not banned, but receive much public interest. It is
most important to recognize that danger comes from what is next to us,
rather than far to us (briefly, what is from animal origin is more
dangerous than from plant origin).
25 february 2005. The Li Ka
Shing Foundation of Hong Kong announced to donate 3 million Euro to
support the fight against bird flu. The donation will associate the
Institute Pasteur in Paris, the Joint Influenza Research Center of
Shantou University Medical College and the Faculty of Medicine of the
University of Hong Kong.
24 february 2005. An
outbreak of pneumonic plague has hit the mining area of Zobia, in the
region of Bas-Uele in Oriental Province, eastern Democratic Republic
of Congo (DRC). Forty three people died and 13 survived. A team from
the WHO and from the Institut Pasteur de Madagascar is investigating.
22 february 2005. As reported
at Promed, there is much controversy about the recent multiresistant
HIV AIDS case uncovered in New York City. The matter is being
discussed in Boston where almost 4,000 investigators meet in a
conference on AIDS. For the first time it has been possible to
replicate the HCV hepatitis virus in laboratory conditions after
making an astute DNA copy of the RNA virus genome. When transformed
into liver cells this artificial genome generated infectious viral
particles. This will permit in-depth studies of this still very
dangerous, but elusive virus, that causes liver cirrhosis at a very
high rate.
18 february 2005. Cholera,
which is endemic and under-reported in all regions with bad control of
the quality of water and hygiene has killed at least 15 persons in the
district of Anambra in Nigeria. On the front of avian flu, evidence is
accumulating that the virus can sometimes change its tropism from the
respiratory tract to the brain, causing encephalitis. After having
tested it on mice and monkeys, Vietnam authorities plan to use the
vaccine used against the disease in fowl in a trial on humans.
12
february 2005. A new, highly pathogenic strain of the HIV
virus has been discovered in a patient in New York city. This strain
causes rapid establishment of AIDS symptoms and is resistant to all
publicly available antivirals. Depending on the contact promiscuity of
the patient it will either die off (the most probable) or begin to
spread.
8 february 2005. The spread
of dengue fever is triggering red alert in Indonesia. Serious
outbreaks are affecting Malaysia and Singapore, where the number of
cases rises sharply as compared to the situation last year. Bird flu
is now present in Cambodia. A thorough study of last year's SARS
outbreak allows investigators to
better understand the virus evolution, and suggests that there
exists a reservoir different from civet cat (probably an animal eaten
up by this predator).
1 february 2005. Dengue fever
reappears in force in South East Asia, but it is too early to know
whether the impact will be as bad as in 2003. 4 cases have been
diagnosed in Saudi Arabia. In Netherlands an alert on tuberculosis led
to screen one fourth of the population of the small town of Zeist
(60 000 inhabitants).
29
january 2005. A 13-year-old girl became the latest victim to
die from avian flu in Ho Chi Minh City, bringing the human toll to 11
in the last month. This case is particularly worrying as it may
represent the second recent interhuman transmission
case. Cholera is spreading in western Kenya where major Busia
markets were yesterday closed to stem a cholera outbreak which has
claimed 10 lives.
21 january 2005. Cases of
contamination by HIV through blood transfusion are reappearing in
Taiwan. Vietnam announces its seventh bird flu death in three weeks,
while the disease reappears in poultry in Thailand.
19 january 2005. Kawasaki
disease, the most common cause of acquired heart disease in children
in developed countries, may be caused by a coronavirus (the family of
viruses that caused SARS). Another patient died in Vietnam from bird
flu, while a new human case (a 45-years old man) is detected.
18 january 2005. A
17-year-old boy suspected of having bird flu has died in Vietnam
bringing the death toll to 36. A small team from ICDDR,B leaves Dhaka
today to join colleagues from Nagasaki University Institute of
Tropical Medicine to assist with post-tsunami health needs assessment
in Sri Lanka. As reported by The Scientist, for the first time in
humans, investigators have discovered a large chromosomal
rearrangement in chromosome 17q21.31 that bears the mark of natural
selection, as reported on line in Nature Genetics. The
rearrangement, a 900-kilobase inversion polymorphism, appears in two
distinct lineages, H1 and H2, that have diverged for as long as 3
million years with no evidence of having recombined. The H2
lineage—which is rare in Africans, almost nonexistent in East Asians,
but found in 20% of Europeans—appears to undergo positive selection in
Iceland, with carrier females having 3.2% more children per generation
and higher recombination rates. The consequences of this discoveries
are considerable and already trigger an intense debate.
15 january
2005. The European Union summarizes the recent progress of
human influenza cases of bird flu. The situation expresses a sporadic
nature, concentrated in South East Asia, but clearly on the increase.
Bird flu has now reached Hanoi in Vietnam.
14 january 2005. The most
serious health problem in Northern Sumatra was not expected: many
cases of tetanos are showing up, usually too late to be treated,
resulting already in more than 20 deaths.
13 january 2005. A
35-year-old woman from Vietnam's southern Tra Vinh province died of
bird flu, becoming the fifth fatality due to the disease in the
country in the past two weeks.
12 january 2005.
Tuberculosis, hepatitis B, dysentery, gonorrhea and syphilis were the
top five most common infectious diseases, during the last fall in
China. In particular the incidence rate of tuberculosis remained the
first infectious disease in terms of incidence. It seems worth noting
that three of those top five diseases are sexually transmissible.
Twenty seven infectious diseases have to be reported, and more than 3
million people were affected last year. Jonathan Stoye and his team of
the Division of Virology at the National Institute for Medical
Research in London report that in some monkeys a gene product can
interfere with the replication of HIV. Most interestingly a single
amino acid difference in the human counterpart accounts for the fact
that the virus is able to replicate in human cells. A third case of
Bovine Spongiform Encephalopathy (BSE), is identified in Canada. This
case is important as the animal was born after a ban on food additives
was implemented, suggesting that food additives cannot be the cause of
the disease.
11 january 2005. Fourteen new
likely avian flu human cases (several said to have been fatal) are
reported in Vietnam while the 18-year-old girl affected dies from the
disease. This high level of human cases is not linked to
person-to-person contamination yet, but this corresponds to a
dangerous level of alert. A 30-kilometre-wide
"immune protection zone" has been set up along the border between
Vietnam and Yunnan Province in Southwest China, in an effort to stop
the spread of the bird flu outbreak from Vietnam to China.
10 january 2005. Vietnam
reports one more human bird flu case in a 18-year-old girl. The
concentration of new human cases there becomes a matter of concern.
Promed summarizes data from GeoSentinel sites increasingly reporting a
significant number of serious wound infections in those injured in the
tsunami. As expected, Aeromonas hydrophila and Pseudomonas
sp are found in many instances. Fortunately they are usually sensitive
to standard antibiotics treatment (when available).
9 january 2005. Showing a
fast reaction response, the Beijing Genomics Institute (BGI) sent to
Thailand on december 30th a Victim Identification Program team to help
identifying corpses from the victims of the tsunamis.
8 january 2005. An outbreak
of yellow fever is affecting the region of Faranah in Guinea. West
Africa has reservoirs of the moquito-borne disease in rodents. Bird
flu is spreading in Vietnam, with several human cases, and two deaths
in the past few days. Far from being eradicated poliomyelitis is on
the rise in Sudan since its reappearance last year. A small girl was
showing symptoms while arriving in Saudi Arabia from Sudan with her
family. The WHO reports endemic presence of the disease in Nigeria,
India, Pakistan, Niger, Afghanistan and Egypt. Since mid-2003, 13
countries have importated wild poliovirus of the same type as the
virus circulating in northern Nigeria. In four of these countries
(Burkina Faso, Chad, Cote d'Ivoire and the Sudan) wild poliovirus
transmission has been re-established (i.e. continued circulation for
more than 6 months).
7 january 2005. Information
about cholera outbreaks in the world is grossly underestimated because
goverments must notify the World Health Organisation and fail to do so
for they are afraid of consequences on trade and tourism. Bangladesh
and India are particularly affected, and this is very important at a
time when we need to consider the consequences of the december
tsunamis in the Indian Ocean. It is possible, however, to read between
the lines at the International Centre for Diarrhoeal Disease Research
(popularly known as Cholera Hospital in Bangladesh), Bangladesh
(ICDDR,B). For example a summary of Diarrhoea outbreaks in 2004 points
indirectly to cholera as the major cause, with two outbreaks that
usually occur during two times in a year- in the hot summer months of
April-June, and post-monsoon months of September and October. The
bibliography of the Centre is highly revealing in this respect: how
could publications refer to cholera cases in a country where there had
been no notification to the WHO? It is extremely important, at this
point, that information is spread before a catastrophic situation
builds up in Sri Lanka, India, Indonesia and Bangladesh in the next
few weeks.
6 january 2005. While we are
witnessing how weak we can be when facing geophysical events, we keep
on developing new techniques with an hybris that has no limit:
xenotransplantation is being performed between pigs and baboons (heart
transplantation) using genetically modified pigs (this week in Nature
Medicine). When we know how HIV spread to humans from butchery,
we should know that mammals are full of retroviruses that, once in a
foreign host will eventually recombine with host counterparts and
generate new forms, some of which will have a high probability of
becoming new infectious agents. Yes, new emerging diseases will be our
future, and, unfortunately, we will have caused them. A remarkable
convergence of microbiology and neurobiology is reported in the last
issue of Nature: beta-lactam antibiotics (the paradigm of
which being penicillin) have a strong effect on the expression of the
neuromediator glutamate transporter. These antibiotics apparently are
effective in delaying the symptoms of diseases such as the fatal
disease amyotrophic lateral sclerosis. Once again this emphasizes the
importance of serendipity in research, and shows that very distant
fields may have a considerable impact on each other.
5 january 2005. A
nine-year-old boy has died of bird flu in Vietnam (southern Mekong
province). As yet, there are no epidemics in the hard hit regions by
the recent tsunamis. The Swedish government has however collected
200,000 doses of drinkable cholera vaccine to send them to India and
Sri Lanka, where there exists known foci of cholera.
2 january 2005. The lack of
coordination of aid in the regions of South East Asia dramatically
affected by the tsunamis might result in the propagation of epidemics
(cholera and shigellosis in particular). This is particularly true in
the Northern region of Sumatra, where a separatist conflict has been
lingering for years, since authorities might tend to use the events as
a means to control the situation.
30 december 2004. A
16-year-old girl from southern Vietnam has become infected with the
bird flu strain that killed 32 people earlier this year and is in
critical condition.
29 december 2004. The root
and rhizome (underground stem) of Curcuma longa are used in
the make of of curries in India (curcumin). The are also used
medicinally, and many studies over the years have suggested a strong
anticancer, and gastric ulcer healing activities. Part of its action
is due to its scavenging of Reactive Oxygen Species (ROS) created by
the presence of the oxygen we live on (it is often forgotten that
oxygen was the first pollutant on the Earth, and that it is a very
toxic gas because of its high oxidizing potential). A second action
seems to be in modulating the activity of enzymes that degrade
proteins (proteases) outside the cells. Several studies have also
involved curcumin in preventing Alzheimer's disease. We need however
well designed clinical tests to investigate whether this is really
significant, which would be a major breakthrough for aging
populations. After the huge tsunamis that affected most of the Indian
Ocean and caused probably 100,000 deaths, outbreaks of cholera and
other gut diseases are expected. However, as yet, there is no sign of
unusual outbreaks (cholera is endemic in the region, as repeatedly
stressed in these updates). Avian flu does not recede (two new
outbreaks in Vietnam). The SARS virus has, as all RNA viruses, a high
mutation rate, making its genome highly variable. In HIV, for example,
this high rate of mutation contributes to the rapid appearance of
drug-resistant strains of the virus. In SARS and related viruses,
however, one segment of the RNA genome (the so-called s2m RNA) remains
virtually unchanged, suggesting that it is essential for the virus.
This triggers research on the corresponding structure to see how drugs
could interfere with that region, a typical "upstream" research bet to
suggest new pathways to intrefere with viruses virulence and
propagation.
28 december 2004. The Desert
Locust situation remains extremely serious in South Morocco, and to a
lesser extent in West Africa. Swarms are keeping arriving in Morocco
and Algeria from the Sahel. Intensive spread of insecticides is trying
to contain further extension of the swarms. There is a risk of
building up of swarms in Niger.
17 december 2004. Although
eating every day is more important than being healthy, we tend to
forget epidemics that affect our agro-food supplies. Plants are often
attacked by viruses, viroids, fungi and bacteria, and this sometimes
creates havoc. For example the pear "passe-crassane" almost
disappeared from our tables because it has been destroyed by Erwinia
amylovora, the agent of fireblight disease. Today, plantations
of citrus trees have to be completely wiped out in some regions of
Australia to try and control an outbreak of citrus canker disease,
caused by Xanthomonas citri, a particularly dangerous form of
Xanthomonas campestris (which is both a dangerous plant
pathogen, and the producer of a ubiquitous additive, xanthan gum).
9 december 2004. A fever
outbreak in Mombasa is investigated by health authorities as it could
be a resurgence of the O'nyong nyong fever, caused by a rare virus,
transmitted, as is malaria, by Anopheles mosquitoes. It gets
its name from a phrase in northern Uganda meaning "very painful and
weak". The first recorded epidemic occurred in 1959-1962 in Northern
Uganda affecting an estimated two million people in Kenya, Tanzania
and Uganda. After an apparent absence of 35 years it reappeared in
1996-1997, and, although not fatal it is a matter of concern as its
spread and reservoir are not understood. In China, the HIV case report
indicates that the HIV/AIDS epidemic is spreading into the general
population. by the end of 2003, the number of HIV cases was estimated
to reach 840,000. If the general trend is sustained, in six years, 10
million people in China will be HIV positive. The magazine Science,
dated december 10th, will published remarkable results on a new
treatment against tuberculosis, that interferes with the energy
management of the bacteria that cause the disease.
8 december 2004.
investigators at the University of New South Wales in Australia have
found that furanones isolated from the seaweed Delisea pulchra
can prevent Vibrio cholerae, the bacteria that cause cholera
from switching on their disease-causing mechanisms.
Bromylated-furanones have been known for some time to prevent bacteria
from measuring their number (the so-called "quorum-sensing" process)
interfering with the formation of biofilms. These compounds have
triggered intensive research in the domain of antibacterial agents
that would not kill bacteria, but interfere with their pathogenicity.
Polymers have been synthesized, containing the furanones, where
bacteria cannot colonize the surface.
5 december 2004. The patient
isolated in Nancy with respiratory disease is not infected by avian
flu. In Hong Kong a new rapid test for diagnosing H5N1 flu will be
announced this week.
2 december 2004. A
69-year-old man has been hospitalised in Nancy (France) with suspected
bird flu. The patient has recently returned from a trip to Vietnam.
1 december 2004. Amyotrophic
Lateral Sclerosis (ALS) is an incurable, paralyzing neurodegenerative
disorder that strikes 5 persons in every 100,000. Scientists from the
Flanders Interuniversity Institute for Biotechnology, under the
direction of Peter Carmeliet (Catholic University of Leuven), have
shown that administration of the vascular endothelial growth factor
(VEGF) protein protects rats with a severe form of ALS, allowing them
to live longer. While this is not a cure of the disease, this paves
the way for a treatment of this infamous disease. This discovery is
another indication that there is a link between the nervous system and
the blood system.
29 november 2004. The Journal
of Virology reports that a candidate SARS vaccine by Canadian
scientists (one attempt among many others) triggered severe liver
inflammation when tested in ferrets. This vaccine was producing the
"spike" protein of the virus, known to be the major target for
preventing adsorption of the virus on its host target cells. However
no adverse effect, until now, has been seen in patients tested in
China with another type of vaccine.
25 november 2004. The effect
of global warming on disease spreading might already be there. Dengue
fever is on the verge of becoming endemic in the south of Taiwan.
Several hundred cases have been found there, locally doubling last
year's number. If the virus rides out the winter the disease will
become perennial.
24 november 2004. Let us
forget for a while the spread of bird flu (new outbreaks in Malaysia),
to shift to a series of discoveries that may have enormous
consequences on the future of cancer research. Japanese scientists
working at the University of Tokyo have uncovered a protein coded by a
genome region involved in Down's syndrome, that apparently interferes
with the development of blood vessels (essential for tumor growth, but
also for brain development). Another type of work, derived from the
studies of Marc Tessier-Lavigne at the Howard Hughes Medical Institute
at Stanford University (Tessier-Lavigne is now at Genentech) showed
that guidance of blood vessels through the tissues is mediated by the
exact same system as the one mediating guidance of nerve cells axons
by a "repulsive" mechanism.
22 november 2004. As winter
approaches in the Northern hemisphere pneumopathies reappear. In Hong
Kong a sudden outbreak at a small hospital triggered fears that SARS
would be there again: this was fortunately not the case, but simply a
local outbreak of parainfluenza caused by a paramyxovirus.
China began to produce in Henan province large quantities of a new
gene-based reagent capable of quickly diagnosing SARS. A case of
Japanese encephalitis (transmitted by mosquitoes of the Culex
genus) in the town triggered a response of the local government, where
the question was asked to see whether one had to vaccinate pigs, which
can be intermediary hosts. Cholera is spreading at many places in
sub-Saharian Africa.
14 november 2004. Several
cholera outbreaks are recurrent in Africa, from East to West. At least
50 persons died of the disease in Nigeria, where several hundreds are
in a critical state. Several cases of dengue are confirmed in Macao. A
State Key Laboratory of Emerging Infectious Diseases has been approved
for establishment at Hong Kong University. Professor Kwok-yung Yuen
and Dr Guan Yi, will take charge of the laboratory. The laboratory
will be the only State Key Laboratory outside the Mainland, and the
only one on Emerging Infectious Diseases. As key components of China's
science and technology innovation structure, State Key Laboratories
emphasize top level basic research, that will be followed by
applications of basic research development, assembling and nurturing
outstanding investigators, as well as scholarly exchanges for the
country. The new laboratory will embody the newly completed P3
Laboratory and the Virus, Cell and Molecular Biology Laboratory.
10
november 2004. While nothing really new happened on the front
of avian flu (some 150 tigers died or were culled because of the
disease in Thailand), discussions at the WHO try to prepare the world
for a pandemic associated to the H5N1 virus. Scientists from the
Queensland Institute of Medical Research, Australia, tested
the effects of protease inhibitors normally used against HIV on a
drug-resistant line of Plasmodium falciparum, the agent
of malaria. While some did not have an effect, several of the
inhibitors blocked parasite growth in vitro at levels routinely
achieved in human patients. It will be necessary to get in vivo
results before drawing conclusions, but this might be good news for
Africa where both AIDS and malaria are endemic at a very high level.
2 november 2004. More that
400 persons have caught cholera in Senegal. A heron was found dead,
probably infected by the H5N1 bird flu virus (not yet confirmed) at
the border between Hong Kong and Shenzhen.
31 october 2004. The World
Health Organisation stresses the role of domestic ducks in the
propagation of the recent bird flu outbreaks. This fits with the
observation we emphasized about the origin of flu
as a duck disease.
26 october 2004. Senegal
suffers its first outbreak of cholera since eight years. This may be
correlated to the endemic situation in the region (Guinea and Sierra
Leone in particular).
25 october 2004. The usual
H3N2 flu is changing its type and will differ from that of last year
(A/Fujian) starting from an outbreak in New Zeland (A/Wellington), but
already spread through travel to Norway. This would make the present
vaccine less efficient than expected. Over-reactions in the domain of
epidemics are so widely spread that we need to pick out only some
relevant information in the domain of the bird flu scare. At this
point it is essential to remember that the red line will be trespassed
when person-to-person contamination will have been witnessed. However
it is perhaps significant to emphasize again two facts. Firstly,
animal to human contamination of any disease should always be taken
seriously, because of likely lack of immediate attenuation of the
virulent form of the pathogenic agent when it crosses a species
barrier. Unfortunately this aspect is not
well understood generally. Second, it is important as we noticed
repeatedly, in the case of avian flu, to
monitor scavenging sentinels, such as raptors because they
are the obvious end of the food chain eating sick or even dead birds.
In this context the fact that two eagles carried last week to
Belgium by a Thai man had been proven avian flu-infected has triggered
a strong reaction. Unfortunately this kind of smuggling is part of a
huge traffic that would need to be considered seriously as belonging
to the general system of illegal activities, all ending up in
the lack of control of funds transfer over the world, with all sorts
of negative consequences, in particular in the domain of terrorism.
21 october 2004. Since our
last update the count of dengue fever cases in Vietnam has kept
rising, reaching almost 60,000 persons this year (87 fatalities). A
variety of means are used to try to contain mosquito spread (including
using small crusatcea in water supply reservoirs) but this is only
with mitigated success.
20 october 2004. Seven more
tigers died from the H5N1 virus at the Sri Racha Tiger Zoo, 50 miles
east of Bangkok. The authorities decided to cull by potassium cyanide
injection 40 tigers showing symptoms of the disease, among the 400 or
so living in the zoo. While this confirms that the avian virus can
infect mammals the distance between tigers and humans does not
indicate that the virus is mutating towards a dangerous form for Man.
19 october 2004. The CERN is
fifty years old today. This institution that comprises some 6500 staff
is at the origin of the Hypertext Markup Language that allowed
construction of the Internet. This shows that repercussions of
academic research have world wide implications, in a way that is
utterly imprevisible. In the domain of health care, some odd ideas
might eventually lead to important discoveries: ethologists thought to
investigate how sick monkeys behave. They discovered that they tend to
eat
plants that they usually avoid. Apparently these plants may cure
some diseases, including malaria. Animal
self-medication may be an interesting trend to explore. The bird
flu epidemic, that has killed 31 people in southeast Asia this year,
has killed 23 tigers at a zoo in eastern Thailand. An elderly man
passed away from cholera in the ninth case reported in Singapore in
less than a week.
18 october 2004. Thirty cases
of dengue fever and 18 suspected cases have been found since September
in East China's Fujian Province. In 1999, the fever spread in several
cities of the province, and a few outside cases were found in 2000.
This shows that the disease is probably there to stay, in particular
if global warming tends to warm up China's provinces located north of
tropical areas, where the disease is endemic. An attempt to create a
birds flu vaccine in Australia has failed to protect fowls.
16 october 2004. The Third
Joint Meeting of Senior Health Officials of the Mainland, Hong Kong
and Macao has reached consensus on the measures for preventing avian
influenza and SARS (including quarantine), as colder season increases
the risk of revival of these diseases. Thailand, and probably Vietnam,
are still witnessing recurring episodes of bird flu. In
northern Uganda cholera is re-emerging in the displaced persons' camp
of Pabbo.
15 october 2004. Results from
the second phase of a trial, coordinated by Professor Pedro Alonso of
the University of Barcelona and involving more than 2,000 children in
Mozambique, showed that a candidate vaccine against malaria protected
30 per cent of them against the disease for at least six months.
Despite this evident message of hope published in The Lancet,
there is still a long way towards a vaccine, because parasites have
evolved many ways to evade immune defenses of their host, so that one
would need positive results staying on during a much longer period of
time to be confident that we are on the right track.
7 october 2004. A team of
scientists from the USA and Japan report in today's issue of Nature
that they succeeded in reconstructing letal components of the
1918-1919 flu pandemic in an attempt to understand the reason for the
extraordinary virulence of the corresponding virus (HspNsp). While
interesting and important these experiments raise some concern about
the possible
unethical use of the corresponding approach.
6 october 2004. Scientists
have imagination. One has, for some time, used giant rats (pouched
rats, Cricetomys gambianus) to smell landmines. And because
this approach appeared to be successful (these rats are easily tamed)
the idea came that they might be used to smell... tuberculosis. This
would allow doctors to identify foci of the disease and help control
it more rapidly. The World Bank is financing the study in Tanzania.
4 october 2004. Bird flu is
re-emerging in Indonesia, while it makes its 11th victim in Thailand.
A dog has also been infected there, further indicating that the virus
is increasing its adaptability to mammal hosts. After having reached
northern America in 1999, the West Nile virus is now present in Hawai.
Nobody knows how it got there but it is most likely that this was
through a contaminated mosquito that flied from the USA to Hawai
across the Pacific. Almost 1,800 persons (46 deaths) have already been
infected in the USA this year.
28 september 2004. Thai
health authorities are concerned by the death of a patient, a mother
who died from bird flu after caring for her daughther, who died a
short while ago from a disease that has not been identified
accurately. The sister of that woman was also infected, but is
fortunately recovering. If this were the case this would represent the
first known case of human-to-human contamination of the deadly
disease, indicating that we are on the verge of a dangerous epidemic.
However the situation is very similar to that witnessed in Hong Kong
in 1997, where limited human-to-human transmission occurred, with no
further contamination.
WHO:
Phases of pandemic response
Phase 0
Interpandemic period
Phase 0
Level 1
New influenza virus in human case
Phase 0
Level 2
Human infection confirmed in two or more
cases
Phase 0
Level 3
Human-to-human transmission confirmed
Phase 1
Confirmation of onset of pandemic
Phase 2
Regional and multiregional epidemics
Phase 3
End of first pandemic wave
Phase 4
Second or later wave of pandemic
Phase 5
End of pandemic
25 september 2004. Armed
conflicts lead to resurgence of contained epidemics. One observes a
severe epidemics of hepatitis in the Darfour region of Sudan, and
hepatitis E kills pregnant women and their babies in Iraq. The World
Health Organisation says it suspects bird flu has passed from
human-to-human in northern Thailand, marking what could be the first
such transmission of the dangerous H5N1 virus.
9 september 2004. Avian flu
is now clearly endemic in East Asia. An infant, who did not come
from a region known to be infected, died from the disease in Hanoi,
while several countries in the region are witnessing new outbreaks.
A Thai man who raised fighting cocks has died of the disease that
just had contaminated his stock.
3 september 2004. Bird flu again: the saga
continues (should we still stress events happening almost on a daily
basis?). Early this year we reported that it
had been found in a zoo that a leopard got infected by having
eaten infected chicken. Now scientists have shown the same with cats,
and, worse, they found that cats could transmit the disease to cats.
This shows that we are certainly not far from an outbreak within human
communities. Reseach in the domain should be developed in order
perhaps not to cure the disease, but to make it less letal. The
outbreak of cholera that affects Chad since the beginning of the rain
season has infected 3,000 people and 120 passed away. The epidemic in
Sierra Leone is still lingering there.