Countrywide audit of multidrug-resistant tuberculosis and treatment outcomes in Mongolia

Mongolia (population: 2.7 million) ranks fourth among the high tuberculosis (TB) burden countries in the World Health Organization (WHO) Western Pacific Region.1 TB is the third most common communicable disease in Mongolia after sexually transmitted infections (STIs) and viral hepatitis, and is the leading cause of mortality among all communicable diseases.2 The annual TB notification rate is 145 per 100 000 population. Treatment success for new smear-positive TB cases has been over 85% since 2000, and reached 88% in 2012. However, failure rates have been increasing, and reached 7.1% in 2012.2 This may indicate the existence of multidrug-resistant tuberculosis (MDR-TB) among new cases. MDR-TB is caused by strains of Mycobacterium tuberculosis that are resistant to at least isoniazid (H, INH) and rifampicin (R, RMP). The emergence of MDR-TB is threatening Mongolia’s progress in controlling TB. In 2007, a drug resistance survey showed that 1.4% of new TB cases and 28% of retreatment TB cases had MDR-TB.3 Between 2006 and 2012, a total of 1171 MDR-TB cases were diagnosed. A drug resistance survey in 2007 showed a rate of any drug resistance of 7.5% (95% confidence interval [CI] 5.9–9.5), with respectively 1.4% (95%CI 0.7–1.6) and 27.5% (95%CI 21.8–34.1) among patients with and without a history of treatment. The MDR-TB case detection rate among retreatment cases was 68% of that estimated (129 notified/170 estimated), and is >200% of that estimated among new cases (56 notified/33 estimated), according to the 2007 drug resistance survey, questioning the accuracy of the 2007 estimates today. Mongolia started implementing programmatic management of drug-resistant TB in 2006, and revised its national TB guidelines in 2009 to include the management of both drug-susceptible and -resistant TB.4 Attempts have since been made to scale up access to MDR-TB treatment, supported by international institutions such as the Green Light Committee (providing drugs and technical assistance) and the Global Fund to Fight AIDS, Tuberculosis and Malaria. There are several operational challenges to MDR-TB management. Diagnosis is difficult and is possible only in the capital city, incurring delays of several months; access to drugs and treatment is limited to centralised health facilities, and treatment is long (18–24 months) and involves many drugs. In addition, public road networks are poor and public transport is expensive; 39% of the rural population lives under the poverty line. Thus, although Mongolia is scaling up MDR-TB treatment, a number of barriers are likely to affect the time taken to initiate treatment and treatment outcomes. From the first ever countrywide study in Mongolia, we report on 1) the total number of MDR-TB cases detected and their resistance patterns, 2) the proportion starting treatment and the delay between diagnosis and treatment initiation, 3) characteristics of those starting treatment, and 4) the relation between treatment outcomes and drug resistance.