MULTIPLE PATHOGENS IN ADULT PATIENTS ADMITTED WITH COMMUNITY-ACQUIREDPNEUMONIA - A ONE-YEAR PROSPECTIVE-STUDY OF 346 CONSECUTIVE PATIENTS

Background - The purpose of this study was to assess the causes of com munity-acquired pneumonia in adult patients admitted to hospital. Meth ods - A prospective study was performed on 346 consecutive adult patie nts (54% men) of mean (SD) 49.3 (19.5) years (range 17-94) admitted to a university affiliated regional hospital in southern Israel with com munity-acquired pneumonia over a period of one year. Convalescent seru m samples were obtained from 308 patients (89%). The aetiological diag nosis for community-acquired pneumonia was based on positive blood cul tures and/or significant changes in antibody titres to Streptococcus p neumoniae, Haemophilus influenzae, Moraxella catarrhalis, respiratory viruses, Coxiella burnetti, Mycoplasma pneumoniae, Chlamydia pneumonia e, and Legionella sp. Results - The aetiology of community-acquired pn eumonia was identified in 279 patients (80.6%). The distribution of ca usal agents was as follows: S pneumoniae, 148 patients (42.8%); M pneu moniae, 101 (29.2%); C pneumoniae, 62 (17.9%); Legionella sp, 56 (16.2 %); respiratory viruses, 35 (10.1%); C burnetii, 20 (5.8%); H influenz ae 19 (5.5%); and other causes, 21 patients (6.0%). In patients above the age of 55 years C pneumoniae was the second most frequent aetiolog ical agent (25.5%). In 133 patients (38.4%) more than one causal agent was found. Conclusions - The causal agents for community-acquired pne umonia in Israel are different from those described in other parts of the world. In many of the patients more than one causal agent was foun d. In all these patients treatment should include a macrolide antibiot ic, at least in the first stage of their illness.