Predisposing factors associated with Mycoplasma pneumoniae respiratory tract infections

Abstract

Introduction Lower respiratory tract infections account for ~10% of worldwide burden of morbidity and mortality. Pneumonia is the 9th leading cause of hospital mortality in Sri Lanka and atypical pathogens account for 1/5th of the cases. M. pneumoniae is the predominant (50%) atypical pathogen. Knowing predisposing factors strengthen the modes of prevention. Objective Determination of predisposing-factors associated with M. pneumoniae respiratory infections in Sri Lanka. Methodology A prospective clinical study was done involving 416 adult-patients in Colombo-North Teaching-Hospital, Ragama and chest-hospital, Welisara (Pneumonia-97, acute-bronchitis-182, pharyngitis-137). M. pneumoniae specific IgG and IgM were tested in paired-sera using commercial-ELISA. Patient-interviewed-questionnaire was used to obtain data on predisposing factors and evaluated in serologically-positive and serologically-negative groups. The level of significance was considered as p < 0.05. Results There was no significant difference observed in relation to age (p-value-0.28, 0.76 and 0.2in pneumonia, bronchitis, pharyngitis respectively), gender, number of individuals/room (sleeping area) (p=0.82), having respiratory tract infections in close contacts (p=0.15), malignancies or past history of asthma (p>0.05 in both groups) with M. pneumoniae infection. However, there was significant association between M. pneumoniae pneumonia and diabetes mellitus (p<0.05). Discussion There was no specific age group detected to have M. pneumoniae infections which predominantly occur in childhood or significant gender predominance seen as with previous studies. The present study was not carried out in a setting with closed population to have significant infection amongst closed contacts. The significant association between M.pneumoniae infection and having diabetes mellitus would need further studies. Conclusion There were no identifiable strong factors predisposing to M. pneumoniae infection except diabetes mellitus.