A survey of legionella pneumophila among pneumonia patients at Kenyatta National Hospital

Abstract

Objective: To determine the occurrence of L. pneumophila among pneumonia patientsat Kenyatta National Hospital and any association with possible risk factors.

Design: A cross- sectional descriptive study.

Setting: The study was conducted from March to June 2007, at the medical ward ofKenyatta National Hospital. Analysis of samples was done at the University of NairobiInstitute of Tropical and Infectious Diseases (UNITID) serology laboratories.

Subjects: All adult patients who were admitted to the medical ward of the hospitalwith a provisional diagnosis of pneumonia.

Results: The study indicated that up to 9.2% (11 out of 120) of the pneumonia patientsadmitted at the hospital were infected with L.pneumophila. At a confidence limit of 0.05,there was statistical significance in the number of pneumonia patients infected withL. pneumophila and exposure to air conditioners (p= 0.003). Twenty two point five eightper cent of patients who were exposed to air conditioners were positive for L. pneumophilaurinary antigen. There was a statistical significance between exposure to air conditionersand location of work area (p= 0.001)). Thirty eight point four six per cent of those whoworked indoors were exposed to air conditioners at their places of work. There was alsostatistical significance in the number of pneumonia patients infected with L. pneumophilaand a history of a past or concurrent respiratory illness (p= 0.021).

Conclusion: Exposure to air conditioners and a history of past or concurrent respiratoryillness were found to predispose one to infection. This should raise the index ofsuspicion among clinicians as they obtain a patient’s medical history. Most of thoseexposed to air conditioners are exposed at their places of work in urban centres,hence the need for health education and public awareness on routine inspection andmaintenance of such facilities. There is need for a larger multi-centre study on theprevalence of infection by L. pneumophila in pneumonia patients (both communityacquired and nosocomial), existence of co- infection and the antibiotic susceptibilityof isolated organisms.