ECOLOGY OF MYCOPLASMA PNEUMONIAE INFECTIONS IN MARINE RECRUITS AT PARRIS ISLAND, SOUTH CAROLINA1

Abstract

Three longitudinal studies of the ecology of M. pneumoniae infection in Marine recruits at Parris Island, S. C, were conducted during the spring, summer and winter of 1965–1966. Diagnosis of infection was established by isolation of the organism and/or a serologic response. The platoon was shown to be the basic epidemiologic unit for M.pneumoniae infection. An unusual ecologic feature was the marked variability in the infection pattern in different platoons. Growth-inhibiting (Gl) antibody was shown to be related to the natural history of M. pneumoniae infection in that: 1) an inverse relationship existed between levels of antibody and susceptibility and 2) the presence of antibody appeared to moderate the severity of infection. Approximately one-fourth of the men with preexisting Gl antibody developed a fourfold or greater serologic response suggesting that reinfection was not uncommon. The Gl antibody method was the most sensitive technique for detecting infection; 89% of infected recruits developed a rise in this antibody, while only 54% developed a rise in complement-fixing antibody and 42% yielded tine organism. The risk of infection with M. pneumoniae was shown to be related to the geographic bunking area within the barracks. It is hypothesized that M. pneumoniae infections are contracted principally in tine barracks and that droplet spread through close contact was the most important mode of transmission.