Morning Briefing

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).