Female genital tuberculosis in Pakistan - A retrospective review of 10-year laboratory data and analysis of 32 cases

Background: Female genital tuberculosis (FGTB) is an underobserved clinical entity owing to diagnostic challenges stemming from difficulty of obtaining diagnostic specimens and paucibacillary nature of the disease. Yet, FGTB is a cause of infertility, pelvic pain, or menstrual irregularities in high-burden countries. To assess laboratory and microbiology diagnostic utilization for FGTB in Pakistan, we have collected data from 2007 to 2016 to inform the need for improved laboratory diagnostics. The objectives of this study were to determine the proportion of FGTB as culture-confirmed extrapulmonary tuberculosis (EPTB) and to describe the characteristics of women with culture-confirmed FGTB in a nationwide laboratory network in Pakistan. Method: A retrospective database was established by accessing laboratory archives and analyzed by sex and source to determine extrapulmonary cases among women. Data were checked for quality, and after removing patient identifiers and duplicate samples, frequencies were calculated in MS Excel. Clinical characteristics of patients were derived from a linked hospital database for those patients who were diagnosed and managed at the affiliated university hospital in Karachi, Pakistan. Results: Over 10 years, 410,748 mycobacterial cultures were received from multiple geographic sites throughout Pakistan and processed at the study laboratory. The overall mean culture positivity rate was 5.9% +/- 3.5%, while the mean culture positivity rate among females was 2.8% +/- 0.8%. Among female culture-confirmed tuberculosis cases, the pulmonary-to-EPTB ratio of infection was 5. Over 10 years, a total of 32 FGTB cases were reported on the basis of positive cultures for Mycobacterium tuberculosis; 3 (9.4%) were rifampin resistant. Conclusions: FGTB currently constitutes a small but significant proportion of culture-confirmed EPTB. A fewer number of laboratory requisitions suggest the need to increase awareness and testing. The advent of high-sensitivity molecular testing on extrapulmonary specimens has the potential to improve diagnostic accuracy and improved detection of FGTB cases in high-burden regions.