An influenza epidemic in Egypt, 1952-3, with special reference to haemagglutination inhibition.

An influenza epidemic occurred during the winter of 1952-3 in the Sindbis Health District, 30 kilometres north of Cairo, which appears to have been due largely to type A (FM1) influenza virus. This conclusion is based on the isolation of virus and the development of HI (haemagglutination-inhibiting) antibodies in children.The development of HI antibodies to type C virus as well implies that a lower rate of infection was occurring with this virus at about the same period. Whether this virus was responsible for any of the clinical manifestations was not determined.The treatment of the sera with receptor-destroying enzyme (RDE) obtained from Vibrio cholerae materially reduced the percentage of HI positives to type A (PR8), A (FM1), and B viruses, and the seasonal curve of HI positives corresponded more closely to that of the clinical manifestations after treatment with RDE than before such treatment.