Asian flu faced U.S. disease detectives with a puzzle last week. The nation's big-city health departments were noting an upsurge in deaths due to influenza and pneumonia (meaning, mostly, pneumonia as influenza's aftermath). In Dallas the rate was 150% above normal, in New York City 85% and Chicago 75%. Yet, unlike last fall, there was no reported increase in absenteeism from work. Probable answer: the present wave is hitting mostly older people who no longer work, are particularly vulnerable to flu and pneumonia.
In their determination to find out everything worth knowing about the mysterious mutant A strain of virus, researchers had other flu postscripts:
¶ Some unvaccinated oldsters are immune to Asian flu—if they had flu in the pandemic of 1889-91. Antibodies still found in their blood show that the old and new viruses were antigenically similar.
¶ Though usually a mild disease, Asian flu can kill rapidly, without intervening pneumonia. Paradoxically, this occurs most often among young adults. One hospitalized Briton, 30, had no fever, told the house physician he "felt fine," then died within a few minutes. There has been a handful of such cases in the U.S.
¶ Where there are massive flu outbreaks there are also countless infections too mild to be detected but effective in giving immunity. Fragmentary U.S. studies confirm the experience in Hong Kong, where four out of five people had nothing worse than the sniffles, but most of them later showed protective antibodies.