Avian Influenza Makes a Comeback, Reviving Pandemic Worries

Most virologists believed the question wasn't whether the bird virus H5N1 would return, but when. They were right. In the past 2 weeks, China, Vietnam, and Thailand have all reported new outbreaks of the strain that scientists fear could evolve into a global catastrophe if unchecked. Meanwhile, the World Health Organization (WHO), frustrated by a lack of cooperation, stepped up pressure last week on countries to provide samples that could be used to monitor the gathering threat.