AlaskaDenise
In Memoriam
This is an especially good article as it makes important points, based on most current research, in easily understood language. Not the same ole diatribe. Thank you Jason.
http://www.bloomberg.com/apps/news?pid=10000087&sid=aj8QqyqWQokM&refer=top_world_news
May 9 (Bloomberg) -- Bird flu may be capable of invading people through the gut, not just the respiratory system, and diarrhea is sometimes the first symptom, said virologist Menno de Jong, whose team observed 18 cases in Vietnam.
Particles of the lethal H5N1 virus contained in the meat and blood of infected poultry may have been ingested by some patients, possibly causing their infection, said De Jong, who is head of the virology department at the Oxford University Clinical Research Unit in Ho Chi Minh City.
``In a number of patients the only exposure risk has been drinking raw duck blood,'' De Jong said in a phone interview yesterday. ``That could imply that the gastrointestinal tract is also a route of transmission or a route of first infection, and there are experiments in animals'' that suggest this.
Scientists are studying H5N1 patients to improve their understanding and treatment of the virus, which has the potential to mutate into a pandemic form that may kill millions of people.
If live virus particles are carried outside the lungs and surrounding tissues to other parts of the body, some antiviral treatments such as inhaled zanamivir, marketed by GlaxoSmithKline Plc as Relenza, may not be effective treatments, De Jong said.
The infection rate in humans is increasing after more than 30 countries across three continents reported initial outbreaks in birds this year. H5N1 has killed at least 115 of the 207 people known to have been infected since late 2003, according to the World Health Organization.
This year, 39 fatalities have been reported, almost as many as the 41 deaths recorded in the whole of 2005. Vietnam accounts for 93 cases and 42 deaths. The Southeast Asian nation hasn't reported any new infections in about six months.
Infected Birds
In almost all human H5N1 cases, infection was caused by close contact with sick or dead birds, such as children playing with them, or adults butchering them or taking off the feathers, according to the Geneva-based WHO. Cooking meat and eggs properly kills the virus.
In uncomplicated cases of seasonal influenza, disease is limited to infection in the nose, throat and lungs. In contrast, H5N1 was observed to have caused encephalitis, or swelling of the brain, in one patient in Vietnam, De Jong said. Virus particles collected from numerous sites could be cultured, including from the throat, rectum, blood and cerebral spinal fluid, he said.
In Blood
Live H5N1 virus particles were isolated from the blood of an infected 5-year-old Thai boy who was hospitalized and died in December, researchers led by Salin Chutinimitkul of the Chulalongkorn University in Bangkok, said in a letter to a U.S. government journal last week.
``Observing live influenza virus in human serum or plasma is unusual,'' said the letter, which will be printed in the May issue of the Emerging Infectious Diseases.
Some scientists believe the virus probably enters the bloodstream in the lowest branches of the tree-like respiratory system, where pulmonary capillaries surround the tiny air sacks, called alveoli, responsible for oxygen and carbon dioxide exchange.
De Jong said it is possible H5N1 may be replicating in the gastrointestinal tract after the virus was cultured from a rectal swab in a patient who had diarrhea.
``Diarrhea in some patients is the first symptom'' of infection, he said. That could mean that the ``initial site of infection in those particular patients may have been in the gastrointestinal tract, perhaps after the consumption of raw chicken or raw duck products.''
Treatment Challenges
The systemic nature of illness caused by H5N1 poses challenges for treating infected patients because, if the virus is spreading through the blood, so too must drugs that aim to combat the infection.
Roche Holding AG's Tamiflu and GlaxoSmithKline's Relenza have shown signs of fighting H5N1.
Some studies have shown the virus binds preferentially to human cells in the lower respiratory tract, whereas the highest concentration of orally inhaled Relenza is found in the upper respiratory tract.
``With the current data and with the current case reports, we should assume that you should seek systemic coverage with drugs,'' De Jong said. ``I think, for instance, that the current formulation of zanamivir isn't going to be of any use in the current avian flu. If a pandemic strain evolves, we have to reconsider it because we won't know if the change in the virus will also have changed the illness.''
GlaxoSmithKline, Europe's biggest drugmaker, is developing an intravenous form of Relenza, Nancy Pekarek, a U.S. spokeswoman for the London-based company, said yesterday. Scientists are still formulating the compound, and testing in people hasn't started, she said.
To contact the reporter on this story:Jason Gale in Singapore at j.gale@bloomberg.net
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http://www.bloomberg.com/apps/news?pid=10000087&sid=aj8QqyqWQokM&refer=top_world_news
May 9 (Bloomberg) -- Bird flu may be capable of invading people through the gut, not just the respiratory system, and diarrhea is sometimes the first symptom, said virologist Menno de Jong, whose team observed 18 cases in Vietnam.
Particles of the lethal H5N1 virus contained in the meat and blood of infected poultry may have been ingested by some patients, possibly causing their infection, said De Jong, who is head of the virology department at the Oxford University Clinical Research Unit in Ho Chi Minh City.
``In a number of patients the only exposure risk has been drinking raw duck blood,'' De Jong said in a phone interview yesterday. ``That could imply that the gastrointestinal tract is also a route of transmission or a route of first infection, and there are experiments in animals'' that suggest this.
Scientists are studying H5N1 patients to improve their understanding and treatment of the virus, which has the potential to mutate into a pandemic form that may kill millions of people.
If live virus particles are carried outside the lungs and surrounding tissues to other parts of the body, some antiviral treatments such as inhaled zanamivir, marketed by GlaxoSmithKline Plc as Relenza, may not be effective treatments, De Jong said.
The infection rate in humans is increasing after more than 30 countries across three continents reported initial outbreaks in birds this year. H5N1 has killed at least 115 of the 207 people known to have been infected since late 2003, according to the World Health Organization.
This year, 39 fatalities have been reported, almost as many as the 41 deaths recorded in the whole of 2005. Vietnam accounts for 93 cases and 42 deaths. The Southeast Asian nation hasn't reported any new infections in about six months.
Infected Birds
In almost all human H5N1 cases, infection was caused by close contact with sick or dead birds, such as children playing with them, or adults butchering them or taking off the feathers, according to the Geneva-based WHO. Cooking meat and eggs properly kills the virus.
In uncomplicated cases of seasonal influenza, disease is limited to infection in the nose, throat and lungs. In contrast, H5N1 was observed to have caused encephalitis, or swelling of the brain, in one patient in Vietnam, De Jong said. Virus particles collected from numerous sites could be cultured, including from the throat, rectum, blood and cerebral spinal fluid, he said.
In Blood
Live H5N1 virus particles were isolated from the blood of an infected 5-year-old Thai boy who was hospitalized and died in December, researchers led by Salin Chutinimitkul of the Chulalongkorn University in Bangkok, said in a letter to a U.S. government journal last week.
``Observing live influenza virus in human serum or plasma is unusual,'' said the letter, which will be printed in the May issue of the Emerging Infectious Diseases.
Some scientists believe the virus probably enters the bloodstream in the lowest branches of the tree-like respiratory system, where pulmonary capillaries surround the tiny air sacks, called alveoli, responsible for oxygen and carbon dioxide exchange.
De Jong said it is possible H5N1 may be replicating in the gastrointestinal tract after the virus was cultured from a rectal swab in a patient who had diarrhea.
``Diarrhea in some patients is the first symptom'' of infection, he said. That could mean that the ``initial site of infection in those particular patients may have been in the gastrointestinal tract, perhaps after the consumption of raw chicken or raw duck products.''
Treatment Challenges
The systemic nature of illness caused by H5N1 poses challenges for treating infected patients because, if the virus is spreading through the blood, so too must drugs that aim to combat the infection.
Roche Holding AG's Tamiflu and GlaxoSmithKline's Relenza have shown signs of fighting H5N1.
Some studies have shown the virus binds preferentially to human cells in the lower respiratory tract, whereas the highest concentration of orally inhaled Relenza is found in the upper respiratory tract.
``With the current data and with the current case reports, we should assume that you should seek systemic coverage with drugs,'' De Jong said. ``I think, for instance, that the current formulation of zanamivir isn't going to be of any use in the current avian flu. If a pandemic strain evolves, we have to reconsider it because we won't know if the change in the virus will also have changed the illness.''
GlaxoSmithKline, Europe's biggest drugmaker, is developing an intravenous form of Relenza, Nancy Pekarek, a U.S. spokeswoman for the London-based company, said yesterday. Scientists are still formulating the compound, and testing in people hasn't started, she said.
To contact the reporter on this story:Jason Gale in Singapore at j.gale@bloomberg.net
</PRE>
