Lower Lung Field Tuberculosis: Observation from Yenagoa, Nigeria

Background: This study, undertaken in a major tertiary hospital in the Niger Delta region of Nigeria, was designed to examine the incidence of lower lung field tuberculosis in HIV infected and uninfected patients, and in diabetic patients as well as their AFB status and outcome of treatment.
Methods: Between January 2011 and December 2013, admission records, HIV status, chest radiographs findings, blood glucose levels and AFB status of all pulmonary tuberculosis patients seen in our hospital were retrieved and retrospectively analyzed according to HIV status, AFB status, chest radiographs findings and blood glucose levels. All the patients with pulmonary tuberculosis who had lesions below an arbitrary line across the hila region in their chest PA radiograph were included in the study as cases of lower lung field tuberculosis.
Results: Of the 596 pulmonary tuberculosis patients reviewed, 76 (12.8%) had lower lung field tuberculosis. It was more common in females (14.1%) than in males (10.9%). Majority of the patients (57.9%) were in the 24-34 years age groups. HIV infected cases had significantly higher occurrence at 46.4%. Diabetic patients had an incidence of 15.0%. Bilateral disease was more common (74.6%) and when unilateral the right side was more affected (51.4%). The main radiological findings were cavitation (44.7%), fibrosis (30.6%) and nodular opacities (22.3%).
Conclusion: HIV infection and diabetes mellitus increase the risk of lower lung field pulmonary tuberculosis.