Epidemic Asian A Influenza in Naval Recruits. ∗ †

Abstract

Summary

1. An explosive outbreak of Asian influenza beginning the week ending June 15, occurred at San Diego Naval Training Center. The peak admission rate of 192.2 from the recruit population occurred the following week. After the first 3 weeks the rates subsided but continued to be 2 to 3 times the pre-epidemic levels through the first 2 weeks in November. Serological and virus isolation studies showed that approximately 75% of admissions from onset of epidemic through November were due to Asian A influenza infections. A few were due to influenza B infections. Admissions due to adenoviruses occurred also in increasing numbers during Sept., Oct. and Nov. On the basis of serological studies essentially all admissions to the Dispensary from onset of epidemic to Nov. 16 were due either to influenza or adenovirus infections. 2) The general lack of immunity to Asian influenza virus in the recruit population is reflected in the high attack rate during the first 3 weeks of the outbreak and high percentage of individuals showing an antibody response to Asian A antigen in the 3-survey companies bled before and 4 weeks after the onset of the epidemic.