An explosive outbreak of Mycoplasma pneumoniae infection in a summer camp.

An outbreak of Mycoplasma pneumoniae infection occurred in the summer of 1978 in a boys' camp in northern Wisconsin and affected 139 of 196 persons (71%); 115 (59%) had laboratory evidence of infection. In 77% of the cases, onset of disease occurred within three weeks after arrival at camp, in contrast to the usually indolent spread of the disease. Attack rates decreased with increasing age. The sensitivity of serology for detecting M pneumoniae disease may have been as low as 79%. There was shorter duration of cough in those treated with erythromycin within four days after onset of symptoms.