An unusual pattern of avian flu cases in Egypt — almost all are in toddlers, all of whom have survived — has led some flu-tracking Web sites to speculate that dozens of silent cases are circulating there.
That would be an alarming development, but other experts, including those at the World Health Organization, say such fears are exaggerated. Although thousands of Egyptians have rushed their children to hospitals this flu season, there is no evidence yet of asymptomatic avian flu cases or any significant mutation in the H5N1 virus.
“Right now, it’s all hot air,” said Dr. Robert G. Webster, a flu expert at St. Jude Children’s Research Hospital in Memphis. “I hope to hell it’s not happening, because it would mean the virus is adapting to humans. But there’s not a shred of data.”