Abstract:

Objective: This study was planned to determine the prevalence of smear positive pulmonary TB among patients receiving care at a tertiary reference Hospital - National Hospital Abuja, Federal Capital Territory (FCT), Nigeria.

Background: With an estimated 9.4 million new cases globally, tuberculosis (TB) continues to be a major public health concern¹. Eighty percent of all cases worldwide occur in 22 high-burdens, mainly resource-poor settings. This devastating impact of tuberculosis on vulnerable populations is also driven by its deadly synergy with HIV. Therefore, building capacity and enhancing universal access to rapid and accurate laboratory diagnostics are necessary to control TB and HIV-TB co-infections in resource-limited countries². In low income countries (Nigeria inclusive), Ziehl-Neelsen sputum smear microscopy is the only cost-effective tool for diagnosis and monitoring of patients on treatment³.

There is dearth of data on the prevalence of pulmonary tuberculosis (PTB) among patient attendees from individual Institutions and Health Care Facilities performing sputum smear microscopy in Nigeria. This retrospective study will analyze sputum smear microscopy results among pulmonary TB suspected patients presenting to National Hospital Abuja, Federal Capital Territory (FCT), Nigeria. Sputum smear microscopy for Acid Fast Bacilli (AFB) results of new suspected pulmonary TB (Diagnosis) patients and their demographic data comprising age and sex recorded from January 2010 to December 2014 were retrieved from the TB Laboratory Register of the Medical Microbiology department and analyzed.

Methods: This hospital based retrospective study analyzed sputum smear microscopy results among pulmonary TB suspected patients presenting to the National Hospital Abuja, Federal Capital Territory, Nigeria. Sputum smear microscopy for Acid Fast Bacilli (AFB) results of new suspected pulmonary TB (Diagnosis) patients and their demographic data comprising age and sex recorded from January 2010 to December 2013 were retrieved from the TB Laboratory Register of the Medical Microbiology department and analyzed. Data processing and statistical analysis were performed using SPSS software (Windows version 16.0). The results were expressed as percentage, with significance at 5%.

Results: The overall prevalence of sputum smear positive cases were 17.3% (63 0f 364) and most of the positive patients were within the age range 15 – 44 years. The highest percentage of TB was seen in the age group of 15 - 24 years compared with the lowest percentages in the age group below 14 years and above 45 years. A total of 63 (17.3%) suspects were found to have at least one positive. Of these, 56 (88.9% of those with one or more positive smears and 92% of those who fulfilled the case definition) were detected from the first specimen and 7 (11.1%) were positive on the second specimen but not the first. The third specimen did not have any additional diagnostic value for the detection of AFB.

Conclusion: The prevalence of sputum smear positive cases of 18.3% increases with age up to the age 44 years. Our result show that examining two sputa smears was sufficient for the detection of AFB in our laboratory. Further research involving different laboratories from all of the six geo-political groups in Nigeria is needed to reassess these findings.

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