Flu experts debate study on H5N1 fatality rate

A group of leading flu experts has written an article in the journal Science rejecting the idea that millions of H5N1 infections have gone undetected.

The article was written in the midst of controversy over the publication of two studies surrounding the virus. The studies involved lab-created H5N1 viruses with airborne transmissibility. Some critics argued that the true H5N1 case-fatality ratio is probably much lower than the nearly 60 percent observed in confirmed cases, because in their view many mild or asymptomatic cases have likely been missed, CIDRAP News reports.

A team from Mount Sinai School of Medicine authored the study. Taia T. Wang, Michael K. Parides and Peter Palese concluded that the infection rate in populations exposed to H5N1 could be one percent to two percent, which would theoretically translate into millions of infections globally.

Flu experts said that Wang and her colleagues did not take into account underlying uncertainties, saying that the results were over interpreted.

"There is little evidence of millions of missed infections," said the article, according to CIDRAP News.

The article also includes a response from the Mount Sinai group that said that the combined rural population of countries where H5N1 outbreaks occur is approximately one billion. They assert that the tests used in the studies probably miss many cases.