Molecular fingerprinting reveals familial transmission of rifampin-resistant tuberculosis in Kuwait

Tuberculosis (TB) is a major public health hazard killing nearly 2 million people worldwide each year.The emergence of multidrug-resistant Mycobacterium tuberculosis strains (MDR-TB) causing increased morbidity and mortality compared to drug-susceptible strains, has become a major obstacle in the control of TB.The MDR-TB strains evolve due to sequential accumulation of resistance-conferring mutations in target genes as a result of the selective pressure of anti-TB drugs.3 e resistance develops either during treatment due to poor follow-up and compliance with TB therapy or thepatient may be infected with an already drug-resistant strain.Outbreaks of drug-resistantTB and MDR-TB prior to 1986 were rare but have occurred more frequently since then in hospitals and institutional settings involving both human immunodeficiency virus (HIV)-infected and HIV-negative individuals.The development of drug resistance during treatment (acquired resistance) and nosocomial transmission of MDR-TB to close contacts was also demonstrated, particularly among HIV-positive patients.The mortality rates among HIV-positive pati ents with MDR-TB have also been reported to be much higher (41 to 72%) compared to those reported for HIV-negative patients (4 to 17%).