RESUMEN
BACKGROUND: The risk of transmission of tuberculosis is high in crowded conditions. Addis Ababa has a relatively high burden of tuberculosis and its city buses are often filled with commuters. Tuberculosis is a potential occupational hazard for city bus drivers and cash collectors. OBJECTIVES: The objective of this study was to estimate the proportion of tuberculosis among city bus drivers and cash collectors. METHODS: We estimated the proportion of tuberculosis of all forms among city bus drivers and cash collectors of the Addis Ababa City Bus Organization, from January 2003 to December 2004. Study participants were screened with clinical, bacteriological and chest X-ray examination from January 2003 to December 2004. RESULTS: Sixteen cases of tuberculosis were identified among 903 study participants (466 city bus drivers and 437 cash collectors) examined, of whom 12 were already on anti-TB treatment and 4 were diagnosed during the study. The proportion of all forms of tuberculosis, smear-positive pulmonary tuberculosis and extra-pulmonary tuberculosis was 16/903 (1772/100,000), 4/903 (443/100,000) and 3/903(332/100,000), respectively. CONCLUSION AND RECOMMENDATIONS: The proportion of all forms of tuberculosis among the study population was higher than the notification case rates for Addis Ababa reported in 2003, which indicates the need for a routine screening of city bus drivers and cash collectors. Measures such as opening windows and reducing crowding in buses are recommended as a means of reducing the risk of exposure to bus drivers and cash collectors.