Saturday, January 31, 2009

Is H5N1 On the Way?

While the U.S. dwells on the unprecedented failure of financialization of its economy another specter, a possible panademic seems to be looming. While largely ignored in American media reports out of Asia suggest that H5N1 influenza is showing signs of living up to its potential as a human to human communicable disease transmitted by asymptomatic bird populations. This disease, which has a reported mortality rate of 50-60%, has been seen in Chinese cases in which the vector seems to have been asymptomatic birds carrying the clade 7 version of the virus for which there is no current vaccine. As per recombinomics:

"The sequencing comments above are from the OIE report on the H5N1 from the Jiangsu outbreaks last month, and are followed by the most recent confirmed human case in China (see updated map), who died yesterday. The “virus variant” is clade 7, as seen in phylogenetic analysis of A/chicken Shanxi/02/2006 in the latest WHO on vaccine targets. On the same branch is A/Beijing/01/2003, which was isolated from the first H5N1 confirmed case in mainland China.

It is likely that the latest case was also infected by clade 7 H5N1, which is vaccine resistant, because most vaccines target clade 1 or 2, which are significantly different than clade 7.

The details of the Jiangsu outbreaks are unclear. Some local media reports suggested the outbreak was large, and involved dead poultry that was shipped to market. Other reports acknowledged the H5N1 infection, but noted that the infected birds were asymptomatic and identified through routine screening.

However, if the latest case was fatally infected by clade 7 from an asymptomatic duck, then the potential for additional cases is high, because the virus can travel and disperse undetected. Moreover, since clade 7 is resistant to the most common vaccines, it could be widespread.

Clade 7 was also reported in Vietnam in August, and a clade 7 target was recently identified by the WHO. There currently is no clade 7 pandemic vaccine, and the selected target is only proposed as a target, as indicated in the most recent WHO vaccine update. The earlier presence of clade 7 in Vietnam may be related to the recent confirmed human case in northern Vietnam, which was announced today."

The potential for for a larger epidemic will take some time to manifest itself but given the recent Chinese New Year holidays and travel one could expect more widespread diffuse outbreaks in the very near future.If this happens the Pandemic Information News offers a chilling scenario for the U.S. which, quite frankly, is in no position to deal with even a minor league catastrophe:

"The world is celebrating Barack Obama as President of the United States � while a new threat appears on the horizon: There are severe signs that the long expected pandemic avian influenza could be on its way to conquer the world. First deaths in Asia concern little children, which from virological point of view is a rather new aspect, and could be the evidence for a new spread. While scientists expect this pandemic to happen in the near future, the new President should also stay alert: A coming influenza pandemic would deteriorate the global economy even without financial crisis or recession......

"However, the situation in the United States is more alerting, according to the Centers for Disease Control and Prevention (CDC). A new University of Colorado at Boulder study showed the resistance of the avian flu virus to a major class of antiviral drugs "is increasing through positive evolutionary selection, with researchers documenting the trend in more than 30 percent of the samples tested", as the scientists report. Even if the expected influenza pandemic did not start yet, there is no doubt about the comeback of the lethal virus: The first Pandemic Influenza occurred in three waves in the United States - exactly 90 years ago, between 1918 and 1919."

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