Primary drug resistance in women with lung tuberculosis diagnosed during pregnancy, after delivery and within following 3 years

Primary drug resistance (PDR) of MBT in mothers is clinically and epidemiologically significant due to high risk of transmission to infants. We studied PDR in women with lung tuberculosis (TB) diagnosed during pregnancy, after delivery and following 3 years in Gomel region in 2013-2019 and counted percentage of TB cases with different PDR with 95% CI. We investigated all new cases of TB with bacteriological confirmation (n=54, including 6 patients with negative sputum tests in which MBT was obtained from biopsy material). Concerning the time of case-finding 7 TB cases were found in pregnant women, 16 cases were found within first month after delivery and 31 cases were found during following 3 years. Acid fast microscopy was positive in 20.4% (10.6-33.5) patients. Xpert MTB/RIF test was used in 43 patients and was positive in 76.7% (61.4-88.2) ones including all patients with biopsy MDR confirmation. Rifampicin-resistance was detected in 51.0% (36.3-65.6) of the patients with positive sputum tests and 66.7% (22.3-95.7) of the patients with biopsy confirmation. The only one Xpert MTB/RIF test was discordant with further culture and molecular line-probe assay results. Using all drug susceptibility tests multiple PDR was detected in 66.7% (52.5-78.9) patients including 5.6% (1.2-15.4) with extensive PDR-TB. Thus, level of multiple/extensive PDR in women with TB diagnosed during pregnancy, after delivery and following 3 years was found significantly higher than regional level of PDR (p<0.05). Xpert MTB/RIF is highly valuable for TB confirmation and drug susceptibility testing in the contingent due to smear negativity and high level of PDR.