A Laboratory Analysis of the 1957-1958 Influenza Outbreak in New York City. II. A Seroepidemiological Study

Abstract

Individual serums (6741) from persons ages 15 to over 60, collected from the syphilis serology laboratory, at weekly intervals, from September, 1957 to September, 1958 were tested by hemagglutination inhibition (HI) technique for Asian, FM1, PR 8 and B/LEE antibodies. A close association was found between the excess influenza-pneumonia mortality curves for New York City and the curve depicting the percentage of individuals with HI antibodies against the Asian strain. This occurred in 2 distinct waves: October, 1957and January - March, 1958 Of the serums 35% were positive for Asian antibodies at the end of the 1st wave and 70% by the end of the 2d wave. The attack rates were between 40 and 60% for all age groups. There was a relationship between loss of the Asian antibody and age: the older age groups lost the antibody to a greater extent than the younger age groups.