Avian flu more common than supposed

Avian flu more common but not as deadly as you assumed

25/02/2012

Probably more people around the world have been affected by bird flu infections than the official figures from the World Health Organization (WHO) suggest. This is the finding of US researchers at New York's Mount Sinai School of Medicine evaluating 20 previous studies on the spread of H5N1 virus infections.

The researchers led by Taia T. Wang and Peter Palese of the Mount Sinai School of Medicine in New York (USA) doubt in their current article in the journal „Science“ the official figures from the WHO, according to which nearly 600 infections with the avian influenza virus have been recorded worldwide since 2003 and around 60 percent of the patients have died as a result of the infection. The actual number of H5N1 infections is probably much higher and lethality accordingly lower, according to the assessment of US scientists based on the 20 studies evaluated.

Many people with bird flu infection have not been investigated
According to the US researchers, WHO is far from taking into account all cases of bird flu infections. Only serious illnesses, in which patients have to go to the hospital and have an already poor chance of survival, would be recorded. Thus, the official figures come to a significantly inflated lethality (mortality in a disease), at the same time set too low overall infection numbers. The evaluation of the studies showed that around one to two percent of the more than 12,500 study participants had evidence of a past bird flu infection in their blood. Most of them would have previously shown no flu-like symptoms of respiratory or febrile diseases, so the statement of the US scientists. Therefore, according to Taia T. Wang and Peter Palese, it is highly probable that many people with the infection will not be examined and therefore go undetected. The mild disease progression without flu-like symptoms is not considered by the WHO. According to the researchers, these undiscovered H5N1 infections primarily affect people in poorer areas who often come into contact with birds.

Already millions of bird flu infections worldwide
Indeed, if one to two percent of the researchers identified by the researchers already have H5N1 infections, that could be millions of people worldwide. In any case, the number of people who already had contact with the pathogens would be significantly higher than the information provided by the WHO. The number of bird flu-related deaths may also be significantly higher than previously known, but the death rate is likely to be well below WHO's, according to US researchers. The exact numbers can not be determined on the basis of the available data, the scientists explained and therefore demanded further large-scale investigations in order to clearly clarify the health risks caused by the pathogen.

Supervirus from the laboratory fuels fear of bioterrorism
Most recently, a laboratory-developed bird flu virus, which is also transmitted from person to person, caused a sensation and discussion worldwide. The US Biosafety Agency (NSABB) opposed the publication of Yoshihiro Kawaoka's and Ron Fouchier's findings on the newly bred avian influenza virus for fear of bioterrorism. Since then, the dispute between US authorities, the scientific journals „Nature“ and „Science“, the World Health Organization, the study authors and many different other experts. Most recently, a panel of experts from the WHO had decided to publish the research results completely - but only at a later date. (Fp)

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Gerd Altmann (picture is a tracing)