ABSTRACT
Mycobacteria in clinical specimens of sputum smear negative adult pulmonary tuberculosis suspects in Mulago Hospital. Background: Sputum smear negative tuberculosis is a major cause of morbidity and mortality among HIV negative and HIV positive patients attending Mulago hospital. The burden of sputum smear negative tuberculosis in Uganda is not known. a few published studies have been conducted on this subject in sub-saharan Africa where the disease burden is quite high. Objectives: The aim of the study was to determine the prevalence of culture positive but sputum smear negative pulmonary TB among adult sputum smear negative pulmonary suspects admitted to Mulago Hospital and to compare the diagnostic yield of different clinical specimens. To compare the clinical and radiological features in culture positive as well as culture negative pulmonary TB suspects above. Design: A descriptive cross-sectional study was carried out on newly admitted patients aged 15-65 years inclusive; who were sputum smear negative; had abnormal X-ray and had clinical features suggestive of pulmonary TB. Consenting patients had sputum bone marrow and blood taken off for mycobacterial cultures; review of their X-rays and HIV serlogy done. Main out come measures was culture positivity on any of the specimens; X-ray disease pattern; clinical characteristics and HIV sero-status. RESULTS: Of the 50 cultures reported; 30(15) were positive for mycobacteria tuberculosis while 2 (2) had mycobcteria other than TB reported. Sputum had the highest postive culture rates with 15 of the 16 culture positive patients; positive on sputum. Of the 63 patients recruited; HIV was found in 76.2(2) had mycobcteria other than TB reported. Sputum had the highest postive culture rates with 15 of the 16 culture positive patients; positive on sputum. Of the 63 patients recruited; HIV was found in 76.2(48) and had an average WHO clinical stage 3. By clinical history and physical findings it was difficult to differentiate between culture positive and culture negative patients although culture positive patients were more likely to have a temperature 37.2o c (P_value 0.05) as oral hairy leukoplakia (P-value 0.5). On chest X-ray a trend towards more pleural effusions and adenopathy was observed in the culture positive patients. CONCLUSION: 1. Culture positive but sputum smear negative pulmonary TB is 30prevalent among newly admitted adult sputum smear negative pulmonary TB suspects in Mulago Hospital. 2. Sputum as a specimen had the highest positive culture rate and therefore if one has to culture; he/she should use the sputum in such patients. 3. it is difficult by way of clinical and radiological features to differentiate between sputum smear negative but culture negative pulmonary TB suspects although culture positive suspects are likely to have a temperature of 37.oC as well as oral hairy leukoplakia and show a trend towards more pleural effusions and hilar adenopathy