Impact of Human Immunodeficiency Virus and Peripartum Period on Mycobacterium tuberculosis Infection Detection

Background. Pregnancy and human immunodeficiency virus (HIV) may influence tuberculosis infection detection using interferon (IFN)-gamma release assay (QFT-Plus; Qiagen) and tuberculin skin test (TST).Methods. Participants in Western Kenya underwent QFT-Plus and TST in pregnancy, 6 weeks postpartum (6wkPP) and 12 months postpartum (12moPP).Results. 400 participants (200 with HIV [WHIV], 200 HIV-negative) enrolled during pregnancy (median 28 weeks' gestation [interquartile range, 24-30]). QFT-Plus positivity prevalence was higher than TST in pregnancy (32.5% vs 11.6%) and through 12moPP (6wkPP, 30.9% for QFT-Plus vs 18.0% for TST; 12moPP, 29.5% vs 17.1%; all P < .001), driven primarily by QFT-Plus-positive/TST-negative discordance among HIV-negative women. Tuberculosis infection test conversion incidence was 28.4/100 person-years (PY) and higher in WHIV than HIV-negative women (35.5 vs 20.9/100 PY; hazard ratio, 1.73 [95% confidence interval, 1.04-2.88]), mostly owing to early postpartum TST conversion among WHIV. Among QFT-Plus-positive participants in pregnancy, Mycobacterium tuberculosis (Mtb)-specific IFN-gamma responses were dynamic through 12moPP and lower among WHIV than HIV-negative women with tuberculosis infection at all time points.Conclusions. QFT-Plus had higher diagnostic yield than TST in peripartum women. Peripartum QFT-Plus positivity was stable and less influenced by HIV than TST. Mtb-specific IFN-gamma responses were dynamic and lower among WHIV. Tuberculosis infection test conversion incidence was high between pregnancy and early postpartum, potentially owing to postpartum immune recovery.