Respiratory tract infection due to Chlamydia pneumoniae in military personnel.

The objective of this investigation was to determine whether Chlamydia pneumoniae was involved in an outbreak of respiratory disease among military recruits, 92 patients (average age 20.1 years) were included in the study if they had a sore throat or cough for more than 1 week. In addition to sore throat and cough, fatigue, headache, dyspnoea and vertigo were the most frequent symptoms. The patients received standard treatment with 100 mg of doxycycline b.i.d. for 14 days. In 38.8% of cases symptoms were alleviated after 1-2 weeks of treatment, and in 22.4% of cases after 2-3 weeks of treatment. Pretreatment throat washings and sera were sampled for Chlamydia. Sera were drawn for Chlamydia, Mycoplasma and adenovirus serology. Cell culture (Hep-2) and 3 different serological methods-microimmunofluorescence (MIF), enzyme immunoassay with a recombinant glycoconjugate antigen (r-EIA) and immunoperoxidase assay (IPA)-were used. Cell culture was found to have too low a sensitivity to be of diagnostic value. Acute infection was demonstrated in 13% by MIF IgM and in an additional 21% by MIF IgG (titre rises). Enzyme immunoassay IgM was found in 17% and IPA IgM in 19% of individuals without MIF IgM antibodies. Microimmunofluorescence was found to be the most useful test for serodiagnosis. The combination of serological methods showed that 40 out of 52 (76.9%) had an acute infection with possible chlamydial aetiology. In conclusion, methodological improvements are necessary for the aetiological diagnosis of chlamydial respiratory infections.