Hyperendemic pulmonary tuberculosis in peri-urban areas of Karachi, Pakistan

Abstract

BackgroundCurrently there are very limited empirical data available on the prevalence of pulmonary tuberculosis among residents of marginalized settings in Pakistan. This study assessed the prevalence of pulmonary tuberculosis through active case detection and evaluated predictors of pulmonary tuberculosis among residents of two peri-urban neighbourhoods of Karachi, Pakistan.MethodsA cross-sectional study was conducted in two peri-urban neighbourhoods from May 2002 to November 2002. Systematic sampling design was used to select households for inclusion in the study. Consenting subjects aged 15 years or more from selected households were interviewed and, whenever possible, sputum samples were obtained. Sputum samples were subjected to direct microscopy by Ziehl-Neelson method, bacterial culture and antibiotic sensitivity tests.ResultsThe prevalence (per 100,000) of pulmonary tuberculosis among the subjects aged 15 years or more, who participated in the study was 329 (95% confidence interval (CI): 195 – 519). The prevalence (per 100,000) of pulmonary tuberculosis adjusted for non-sampling was 438 (95% CI: 282 – 651). Other than cough, none of the other clinical variables was significantly associated with pulmonary tuberculosis status. Analysis of drug sensitivity pattern of 15 strains of Mycobacterium tuberculosis revealed that one strain was resistant to isoniazid alone, one to streptomycin alone and one was resistant to isoniazid and streptomycin. The remaining 12 strains were susceptible to all five drugs including streptomycin, isoniazid, rifampicin, ethambutol, and pyrazinamide.ConclusionThis study of previously undetected tuberculosis cases in an impoverished peri-urban setting reveals the poor operational performance of Pakistan's current approach to tuberculosis control; it also demonstrates a higher prevalence of pulmonary tuberculosis than current national estimates. Public health authorities may wish to augment health education efforts aimed at prompting health-seeking behaviour to facilitate more complete and earlier case detection. Such efforts to improve passive case-finding, if combined with more accessible DOTS infra-structure for treatment of detected cases, may help to diminish the high tuberculosis-related morbidity and mortality in marginalized populations. The economics of implementing a more active approach to case finding in resource-constrained setting also deserve further study.

Effect of Social Factors on Tuberculosis Patients: A Comprehensive Illness Behaviour Study

“…12 The low-income population also suffers from overcrowding or malnutrition and therefore is predisposed to developing tuberculosis. 13 Perception of illness has been found to vary with cultural, ethnicity, education, family structure and socioeconomic difference. 14 Treatment of active tuberculosis requires prolonged therapy (at least 6 months) with multiple and potentially toxic drugs which can lead to adverse reactions in a significant number of patients.…”

An evaluation of ‘Ribolola’: a household tuberculosis contact tracing programme in North West Province, South Africa

“…Barriers to programmes such as Ribolola include the belief that a significant proportion of TB suspects may not be able to provide sputum at home. 17 We found that, with education, most individuals could produce sputum, and removing the requirement to attend clinic may help overcome the attrition of contacts.…”

Longitudinal Tracking of Cytokines after Acute Exposure to Tuberculosis: Association of Distinct Cytokine Patterns with Protection and Disease Development

“…Several reports from different countries have shown that the household contacts (HCs) of patients with active pulmonary TB are at a much higher risk of infection, which ranges from 30 to 80%, depending on the intensity of TB disease transmission (1,2,5,16,24,33,40). Most of the newly infected contacts of patients with TB contain the infection and do not develop disease.…”