Chlamydia pneumoniaeInfection in Patients Hospitalised for Community-acquired Pneumonia in Southern Jordan

Purpose:Chlamydia pneumoniaeis associated with human respiratory diseases. Few reports examined the involvement of this bacterium in community-acquired pneumonia (CAP) in Jordan. This study investigates for the first time the role of C. pneumoniaein the establishment of CAP among nationals residing the southern part of Jordan. Materials and Methods:Nasopharyngeal and sera samples were collected from 70 hospitalised CAP patients and 63 healthy controls from Al-Karak Governorate and examined using the microimmunofluorescence and polymerase chain reaction techniques. The overall prevalence of C. pneumoniaeinfection was estimated by detecting the chlamydial immunoglobulin G (IgG) antibodies at a titre of 1:16. Rate of acute infection was estimated by detecting chlamydial DNA in nasopharyngeal samples and IgG and IgM at titres of 1:512 and 1:16, respectively. Results:A higher overall seroprevalence of C. pneumoniaeIgG was detected in CAP patients than controls (44.3% vs. 30.2%). The rate of acute infection in the entire CAP patients, based on IgG titre of 1:512, was 7.14% compared to 1.58% in the controls. Approximately, three-fold increase in the rate of acute infection was observed in CAP cases, seropositive at IgG titre of 1:16, compared to seropositive controls (16.1% vs. 5.3%). Interestingly, chlamydial IgM antibodies were detectable in 27.1% compared to only 3.2% of the controls. The presence of chlamydial nucleic acids was confirmed in 40% of CAP patients and in 7.9% of controls. Conclusions:The present findings clearly suggest a role of C. pneumoniaein the aetiology of CAP in Southern Jordan. However, coinfections with other respiratory pathogens should not be excluded.