Tuberculosis in health care workers in Malawi

Although sub-Saharan Africa has the highest rates of tuberculosis (TB) and human immunodeficiency virus (HIV) infection in the world, the rates of TB amongst its health care workers (HCWs) are poorly documented. We therefore conducted a country-wide investigation. All district/government and mission hospitals in Malawi that diagnose and care for TB patients were visited in order to obtain information on hospital-based HCWs and their incidence of TB in 1996. Hospital TB case loads, country-wide TB notification numbers an d national population estimates for 1996 were obtained, which enabled TB ca se notification rates to be calculated. In 1996, 108 (3.6%) of 3042 HCWs fr om 40 hospitals were registered and treated for TB: 22 with smear-positive pulmonary TB (PTB), 40 with smear-negative PTB and 46 with extrapulmonary T B. The overall case fatality rate was 24%. Compared with the adult general population aged greater than or equal to 15 years, the relative risk [95% c onfidence interval (CI)] in HCWs of all types of TB was 11.9 [9.8-14.4], of smear-positive PTB 5.9 [3.9-9.0], of smear-negative PTB 13.0 [9.5-17.7] an d of extrapulmonary TB 18.4 [13.8-24.6], P < 0.05. The 1996 hospital TB cas e load ranged from 29 to 915: there were no cases of TB in HCWs in hospital s whose case load was is less than or equal to 100 patients, while the TB c ase rate among HCWs was similar in hospitals with annual case loads of 101- 300 or >300. The annual risk of TB was high among all categories of HCW, es pecially clinical officers. This study shows a high rate of TB in HCWs in M alawi, and emphasizes the need for practical and affordable control measure s for the protection of HCWs from TB in low-income countries.