title: The Philadelphia epidemic of Legionnaire's disease: clinical, pulmonary, and serologic findings two years later.
abstract: Clinical, pulmonary, and serologic findings in Legionnaires who attended the 1976 American Legion Convention in Philadelphia were studied 2 years after the Legionnaires' disease epidemic there. All 31 survivors of Legionnaires' disease studied became ill within 2 weeks after the convention, and 18 had not fully recovered 2 years after the epidemic. Twenty-five (28%) of 90 additional Legionnaires exposed at the convention but not diagnosed as having Legionnaires' disease became ill during the same time interval; five of these had symptoms during the next 2 years. Survivors had decreased diffusion capacities measured by the carbon monoxide single-breath method. These differences could not be accounted for by ventilation abnormalities or concurrent illness. Significant levels of IgG or IgM antibodies persisted in 94% of survivors of Legionnaires' disease and in 53% of Legionnaires exposed at the convention, which suggests a high prevalence of subclinical infection. Persistence of IgM antibody raises the question of latency or subclinical infection as part of the natural history of Legionnaires' disease.
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis; D004196:Disease Outbreaks / Q000453:epidemiology*; D005221:Fatigue; D005260:Female; D005455:Fluorescent Antibody Technique; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007877:Legionnaires' Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania; D011653:Pulmonary Diffusing Capacity; D014692:Ventilation-Perfusion Ratio
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007075:Immunoglobulin M