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

Abstract

legionellae has a worldwide distribution though the actual statistics especially in the tropics has not been established. In human history, numerous infectious diseases have emerged and re-emerged. Understanding the dynamics of emerging and reemerging infections is critical to efforts to reduce the morbidity and mortality of such infections, to establish policy related to preparedness for infectious threats, and for decisions on where to use limited resources in the fight against infections. Reports of legionnaires disease in developing countries especially from Africa have been sparse. The real magnitude of the problem is therefore unknown and it may be responsible for some of the cases of pneumonia than is generally recognized. Lack of appropriate legionella diagnostic and surveillance systems, and limited resources in Kenya and other African countries contribute to the situation. Initiation of appropriate therapy has always been associated with improved outcome therefore discovery of even a single case would be an important sentinel of indicating the likelihood of detecting undiscovered cases. This study investigated the occurrence of L.pneumophila in pneumonia patients and possible association with risk factors in the group that is positive for infection Research Hypothesis: There are cases of Legionella pneumophila infection that go undiagnosed among patients presenting at Kenyatta National Hospital with signs and symptoms suggestive of pneumoma. Objectives 1. To determine the occurrence of L.pneumophila among patients admitted at Kenyatta National Hospital medical ward with signs and symptoms suggestive of pneumoma. 2. To determine possible risk factors for those who are infected with L.pneumophila. 3. To determine the association between risk factors and infection with L.pneumophila. Study Design: A cross-sectional descriptive study was carried out between March and June, 2007. Setting: The medical ward of Kenyatta National Hospital, Nairobi. Study population: The study population comprised of patients admitted with a provisional diagnosis for pneumonia. Sample size: One hundred and twenty pneumonia patients who satisfied the inclusion criteria were obtained by consecutive sampling Ethical Consideration: Informed consent was obtained from the participants. Approval to carry out the study was obtained from the Kenyatta National Hospital Research and Ethics Committee, and the Chairman of the Department of Internal Medicine, Kenyatta National Hospital. Methodology: The ELISA technique was used to analyze the unne samples for the presence of L. pneumophila antigen .. Results The findings indicated that up to 9.2% (11 out of 120) of patients admitted at the medical ward of Kenyatta National Hospital due to signs and symptoms suggestive pneumonia between March and June were infected with L. pneumophila. At a confidence limit of 0.05, there was statistical significance In the number of pneumonia patients infected with L. pneumophila and exposure to air conditioners (p= 0.003). 22.58% of patients who were exposed to air conditioners were positive for L. pneumophila urinary antigen. There was a statistical significance between exposure to air conditioners and location of work area (p= 0.001».38.46% of those who worked indoors were exposed to air conditioners. There was also statistical significance in the number of pneumonia patients infected with L. pneumophila and a history of a past or concurrent respiratory illness (p= 0.021). 14.2% of all respondents who had a history of past or concurrent respiratory illness were positive for L. pneumophila urinary antigen. Exposure to air conditioners is a key predisposing factor to infection with L.pneumophila and there is need for public health education on routine inspection and maintenance of air conditioners and hot water systems.