Limited nosocomial transmission of drug-resistant-tuberculosis, R. Moldova

We aimed to detect transmission events of multidrug-resistant/rifampicin-resistant (MDR/RR) strains of Mycobacterium tuberculosis-complex (Mtbc) at a TB-hospital in Chisinau, R. Moldova. Ward, room and bed for each in-patient were recorded and in-hospital transfers monitored over one year. Whole-genome-sequencing (WGS) was performed from MDR/RR Mtbc-strains to identify putative index patients of in-patients who developed MDR/RR-TB during a 2-year follow-up. 307/2490 12.3% patients were diagnosed with MDR/RR-TB. 41 patients with MDR/RR-TB initially spent 631 days on non-MDR-TB wards before transferred to a MDR-TB ward. MDR/RR-Mtbc isolates belonged to lineage 2 (43.3%) or lineage 4 (56.7%). 124/268 (46.3%) patients were assigned to one of 28 clusters, including 7/17 patients with a putative hospital-acquired MDR/RR-TB. Only 2/17 patients had a plausible direct link in the hospital. Detailed molecular and patient surveillance revealed a low rate of nosocomial transmission of MDR/RR Mtbc-strains, suggesting that transmission of drug-resistant TB in R. Moldova occurs outside the hospital.