Improving the case detection of pulmonary tuberculosis by bleach microscopy method in the North West of Nigeria

Microscopy of direct smears for acid-fast bacilli (AFB) remains the common method for the laboratory diagnosis of pulmonary tuberculosis in most laboratories in our setting. The bleach microscopy method has been introduced and evaluated in different settings as an alternative to direct smear microscopy. However, this approach is yet to be evaluated in a typical government owned/public health laboratory in our setting thus the need for this study. This study was conducted in two Family Health International (FHI) supported health facilities in North West Nigeria. A total of 1075 sputum specimens were collected for the study, comprising of new and follow up cases, regardless of age group and sex. The sputa were examined by two methods, direct smear microscopy and household bleach and centrifugation method. Out of the 1075 sputum specimens, 171 specimens (40.3%) were positive for AFB by direct microscopy and 253 (59.7%) were positive for AFB by the household bleach method. There was a significant increase in the number of AFB positive specimens by the household bleach method (p < 0.05). The bleach method significantly increase tuberculosis (TB) case detection compared to direct smear microscopy. The National TB and Leprosy Control Program could consider supporting the use of this method.