The epidemiology of adult lung disease in Botswana.

SETTING

Republic of Botswana.

OBJECTIVES

To describe and analyse the epidemiology of adult lung disease in Botswana and provide information about risk factors.

DESIGN

Register-based retrospective study.

RESULTS

Poverty and human immunodeficiency virus (HIV) infection are major risk factors for lung disease. In 1997, TB caused 15.7%, pneumonia 8.3%, asthma/COPD 0.7% and lung cancer 0.4% of adult in-patient deaths, while 15.5% of deaths were classified as AIDS. Respiratory conditions accounted for 14.2% of hospital admissions and 18.1% of out-patient consultations. Pneumoconiosis was under-reported. Classification problems exist between AIDS, TB and pneumonia. The case fatality rate for in-patients with pneumonia was 5.6% in 1990 vs. 15.5% in 1997, and for TB patients it was 7.4% in 1990 vs. 11.2% in 1997. Morbidity rates also increased for pneumonia and TB through the 1990s. There was a steeper rise in pneumonia mortality and morbidity rates in females than males. The gender distribution in TB incidence remained unchanged, but the average age of female TB patients decreased by 7.7 years from 1983 to 1998, vs. a decrease of 5.3 years in males.

CONCLUSIONS

Pulmonary TB and pneumonia are major causes of adult mortality and morbidity in Botswana. Incidences and case fatality rates are increasing, due to co-existent HIV infection. Non-communicable lung diseases are less common causes of death, and prevalences seem to be stable.