Are sputum samples of retreatment tuberculosis reaching the reference laboratories? A 9-year audit in Tanzania

Setting: One reference and three zonal laboratories and 500 health facilities managing retreatment tuberculosis (TB) patients in Tanzania. Objectives: The National Tuberculosis and Leprosy Programme (NTLP) requires that all notified cases of retreatment TB in Tanzania have sputum samples sent for culture and drug susceptibility testing (DST). This study determined 1) if the number of annually notified retreatment patients corresponded to the number of sputum samples received by the reference laboratories, and 2) the number of culture-positive samples and the number of cases undergoing DST. Design: Nine-year audit of country-wide programme data from 2002 to 2010. Results: Of the 40 940 retreatment TB patients notified by the NTLP, 3871 (10%) had their sputum samples received at the reference and zonal laboratories for culture and DST. A total of 3761 (97%) sputum samples were processed for culture, of which 1589 (42%) were found to be culture-positive and 1415 (89%) had DST performed. Conclusions: There is a > 90% shortfall between notified retreatment cases and numbers of sputum samples received, cultured and assessed for DST at reference and zonal laboratories. Steps needed to address this problem are discussed.