Birdflu Mailing List: Immediate Treatment Needed

[William Weir (weirwilliam]

An important study show immediate treatment is needed for bird flu cases.
Here is the NY Times' report today:

http://www.nytimes.com/2006/09/11/world/11flu.html<http://www.nytimes.com/2006/09/11/world/11flu.html>

Bill Weir
weirwilliam [at] msn.com<mailto:weirwilliam [at] msn.com>

Immediate Treatment Needed for Bird Flu Cases, Study Says 
By DONALD G. McNEIL Jr.                    September 11, 2006

Avian flu kills in much the same way the global flu pandemic of 1918 did, by 
drowning victims in fluid produced in their own lungs, a new study has found. 
The study also suggests that immediate treatment with antiviral drugs is 
crucial, because the virus reproduces so quickly that, if not suppressed within 
the first 48 hours, it tends to push victims into a rapid decline to death.

"The paradigm 'hit hard and hit early' probably is very true for H5N1 
influenza," said Dr. Menno D. de Jong, an Oxford 
University<http://topics.nytimes.com/top/reference/timestopics/organizations/o/oxford_university/index.html?inline=nyt-org>
 virologist and the study's lead author. However, he added, because the body's 
own immune response does part of the damage, doctors should consider giving 
anti-inflammatory drugs along with antivirals like Tamiflu.

Although the results of the relatively small study are precisely what flu 
experts had predicted from laboratory work, Dr. Anne Moscona, a professor of 
pediatrics and immunology at the Weill 
Cornell<http://topics.nytimes.com/top/reference/timestopics/organizations/c/cornell_university/index.html?inline=nyt-org>
 Medical College, called it a "major advance," because so little clinical 
information had previously been gleaned from the 241 known cases of the 
disease.  Many of those cases have been in rural villages in Asia, where 
victims pick it up from backyard chickens and are buried before the virus that 
killed them is even identified. Provincial hospitals have done few autopsies 
and little genetic analysis.

This study, which appears in the October issue of Nature Medicine, was led by 
an Oxford research team in Ho Chi Minh City, Vietnam, and compared 18 people 
with the A(H5N1) avian flu in 2004 and 2005 to 8 people infected with seasonal 
human flus.   It found that the avian flu patients, and particularly the 13 who 
died from it, had unusually high levels of the virus in their bodies. 
Consequently, they also had high levels of the chemicals, known as cytokines 
and chemokines, that set off the immune system's inflammatory response. 

Those chemicals, some of which are produced in cells lining the narrowest 
passages in the lungs, draw in white blood cells to attack invaders. But doing 
so too vigorously can flood the lungs, causing deadly pneumonia.  The effect, 
known as the "cytokine storm" is the leading theory as to why so many young, 
previously healthy people died in the 1918-19 pandemic, known as the Spanish 
flu, which killed tens of millions of people. Seasonal flus tend to kill the 
very old and very young, who usually die from bacterial infections that develop 
days after the milder flu virus has irritated their lung tissue. 

The avian flu virus was easier to detect in throat swabs than in nasal swabs, 
Dr. de Jong said, which is the opposite of how seasonal flu is detected, and 
useful for doctors doing flu tests. And the virus was found in rectal swabs, 
which is important for hospitals to know because it means diarrhea, common 
among flu patients, can also spread the disease. Flu experts were surprised 
that such high concentrations of the virus were found in nose and throat swabs. 
Earlier studies had suggested that the avian flu is not easily transmitted 
between humans because, unlike seasonal flu, it attaches primarily to receptors 
found deep in the lungs.

Dr. de Jong said there could be several explanations: the throat swabs could 
have picked up virus coughed up from the lungs. Different receptors are spread 
up and down the breathing tract. And it is possible - though unproved - that 
some people may simply be born with receptors more amenable to the virus. That 
theory has been offered by epidemiologists who note that, even in villages 
where all the chickens are sick, human outbreaks tend to cluster in families.

The study also showed that some of the flu strains isolated in Vietnam had 
particular genetic changes that virologists have been watching for, fearing 
that these changes would make them more lethal.  But those changes appeared in 
only some patients, and in those who died as well as those who lived, "so I 
wouldn't make too much of it," Dr. Moscona said.  Henry L. Niman, a Pittsburgh 
biochemist who has been tracking viral changes and raised earlier alarms about 
E627K, agreed.

"Lethality in the virus may rely on several changes," he said. "But it's got 
several different paths to the same end. That's what makes it so efficient."