Gurjav U, Erkhembayar B, Burneebaatar B, Narmandakh E, Tumenbayar O, Hill-Cawthorne GA, Marais BJ, Sintchenko V. Transmission of multi-drug resistant tuberculosis in Mongolia is driven by Beijing strains of Mycobacterium tuberculosis resistant to all first-line drugs.
Tuberculosis (Edinb) 2016;
101:49-53. [PMID:
27865397 DOI:
10.1016/j.tube.2016.07.010]
[Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/17/2016] [Accepted: 07/19/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND
Mongolia has high and rising rates of multi-drug resistant tuberculosis (MDR-TB). Spatio-temporal and programmatic evidence suggests a major contribution from MDR-TB transmission, but genotypic evidence has not been assessed.
METHODS
All MDR-TB cases identified during 2012 were examined. Demographic and bacteriological data were obtained from the National Tuberculosis Reference Laboratory. Isolates of Mycobacterium tuberculosis from culture-confirmed category 1 treatment failures were genotyped using 24-loci mycobacterium interspersed repetitive unit (MIRU-24) analysis.
RESULTS
Of the 210 MDR-TB cases identified, 115 (54.8%) were treatment failures (34.8% category 1; 20.0% category 2). Streptomycin resistance was present in 156 (74.3%) cases; including 55/73 (75.3%) category 1 treatment failures who had never been exposed to streptomycin. Among category 1 treatment failures, Beijing lineage strains predominated (88.0%; 59/67 of genotyped isolates). MIRU-24 clustering was documented in 62.7% (42/67) of strains; 55.2% (37/67) remained clustered when drug susceptibility test results were considered. In total 59.5% (25/42) of clustered strains were Beijing lineage and demonstrated in-vitro resistance to all first-line drugs tested.
CONCLUSION
The MDR-TB epidemic in Mongolia appears to be driven by primary transmission of Beijing lineage strains resistant to all first-line drugs. Enhanced infection control strategies together with early MDR-TB case detection and appropriate treatment are necessary to limit escalation of the MDR-TB epidemic.
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