Lower lungfield tuberculosis in a rural African population.

An analysis of 500 consecutive pulmonary tuberculosis cases shows that lower lungfield tuberculosis occurs in 6.8 percent of the negroid population studied and therefore shows no racial predelection. The ratio of female to male involvement was 3:1. A clear association with young women and with pregnancy with or without other infections was demonstrated. Affected men were in the much older age group. Some association with diabetes and heart failure were also observed. The initial diagnosis of most of these patients was basal pneumonia or lung abscess. Therefore, the most useful clinical pointers were productive cough with or without haemoptysis unresponsive to various conventional antibiotics. The right base was most favoured and cavitation with fluid levels were frequent. We believe that the aetiological factors would include stress as could occur with pregnancies and poor basal tissue oxygenation due to diminished basal expansion in abdominal distension or cardiac failure.