Two New Analyses Raise Questions About Fatality Rate Of Bird Flu
In an analysis (.pdf) published Thursday in the online edition of the journal Science, a team led by virologist Peter Palese of Mount Sinai School of Medicine in New York raises questions about the WHO’s estimated fatality rate from H5N1 bird flu, saying the rate of 59 percent is based on “an estimate of human bird flu cases that is simply too low,” Reuters reports. The WHO has recorded 586 cases of people infected by bird flu, and of those, 346 have died, the news agency notes (Begley, 2/23). Palese and colleagues say “it is not possible to determine an accurate fatality rate for H5N1 infections based on” available data, but “if one assumes a one to two percent infection rate in exposed populations, this would likely translate into millions of people who have been infected, worldwide” (Wang et al., 2/24). And in a paper published Friday in mBio, the journal of the American Society for Microbiology, Michael Osterholm of the University of Minnesota and a member of the U.S. National Science Advisory Board for Biosecurity (NSABB) and a colleague conclude that “[t]he available seroepidemiologic data for human H5N1 infection support the current WHO-reported case-fatality rates of 30% to 80%” (Osterholm/Kelley, 2/24).
The studies “ad[d] fuel to the heated controversy over publication of bird flu research” in the journals Science and Nature describing how two teams created H5N1 strains that are easily transmissible among ferrets, which are used as lab models for humans, Reuters writes (2/23). Fears that terrorists possibly could use the information prompted the U.S. National Science Advisory Board for Biosecurity in December to request the scientists redact some information prior to publishing their study results and investigators in January to institute a 60-day moratorium on bird flu research, USA Today’s “Your Life” notes. “A WHO summit that ended this week called for full publication of the two studies and for an extended halt to such research until stronger safety measures were assured in labs,” the blog writes (Vergano, 2/23).