Prolonged afebrile nonproductive cough illnesses in American soldiers in Korea: A serological search for causation

A serological study was undertaken to investigate infections in active-duty United States soldiers with illnesses characterized by prolonged, afebrile , nonproductive coughs. Fifty-four soldiers were enrolled with such illness of greater than or equal to 2 weeks' duration (case patients) along with 5 5 well soldiers (control subjects). Serum samples were tested for IgG and I gA antibody to 3 Bordetella pertussis antigens, pertussis agglutinins, IgM antibodies to Mycoplasma pneumoniae, IgM and IgG antibodies to Chlamydia pn eumoniae, and IgM antibody to adenoviruses. Forty-six case patients (85%) h ad evidence of recent infection with Bordetella species, M. pneumoniae, or C. pneumoniae, and many had evidence of mixed infections; there were 27 Bor detella species, 20 C. pneumoniae, and 33 M. pneumoniae recent infections. Fifteen case patients had high titers of IgG or IgA to B. pertussis filamen tous hemagglutinin without high titers of antibodies to other B. pertussis antigens, which suggested the presence of cross-reacting antibodies to M. p neumoniae and perhaps C. pneumoniae or unidentified infectious agent or age nts. Since illnesses due to Bordetella species, M. pneumoniae, and C. pneum oniae can all be treated with macrolide antibiotics and B. pertussis illnes s can be prevented by immunization, and since military readiness was affect ed in 63% of the cases, it seems important to conduct further studies in mi litary populations.