Setting: Laboratories performing sputum smear microscopy for tuberculosis in Benin, Malawi, Nicaragua and Senegal.
Methods: Analysis of computerized laboratory registers to ascertain workload, yield from serial smear examination, and demographic characteristics of examinees.
Results: Data from more than 60,000 examinees in 42 laboratories showed that the average number of smears examined per day ranged from 4 to 19 (mean 6) per country. To find one case of tuberculosis, on average 21 smears of suspects were examined (range 8 to 50). Of all cases with ultimately at least one positive result, 87% were already positive on the first examination. Demographic characteristics of cases differed considerably by country and gender. In 35 of 42 laboratories, males were more frequently found to be cases than females, and with increasing age an increasingly larger number of female than male suspects had to be examined to identify one case.
Conclusions: This study demonstrates the usefulness of a standardized recording system for results of acid-fast microscopy in obtaining essential information for program management and on demographic characteristics of persons presenting for examination.