Epidemiology of drug-resistant tuberculosis among children and adolescents in South Africa 2005-2010.

SOUTH AFRICA has one of the highest burdens of multidrug-resistant tuberculosis (MDR-TB; defined as TB with resistance to isoniazid [INH] and rifampin [RMP]) in the world, with 15 419 laboratory-confirmed MDR-TB cases in 2012.1 The World Health Organization (WHO) estimates that 1.8% of new cases and 6.7% of retreatment cases among adults in South Africa are MDR-TB.2 No routine surveillance data on MDR-TB among children are available globally or in South Africa. However, the proportion of MDR-TB among new and retreatment cases is believed to be similar among both adults and children in most countries, based on several mathematical models.1,3,4 In some settings, including South Africa, infants and young children may be at higher risk for MDR-TB than adults.4,5 Estimates of pediatric TB and drug-resistant TB (DR-TB; TB with resistance to any anti-tuberculosis drug) rely on limited data because TB surveillance has historically focused on sputum smear-positive disease and laboratory- confirmed drug resistance, which are much less common in children, who often have difficulty producing sputum and tend to have paucibacillary disease.4–6 The presence of drug resistance or human immunodeficiency virus (HIV) infection compounds diagnostic and treatment challenges in children.7–10 Such challenges are of concern, as infants and young children, especially those with HIV infection, are more likely than adults to progress rapidly from infection to disease and develop more severe forms of TB, such as TB meningitis.7,10–12 The few published reports that describe the epidemiology of pediatric DR-TB have been limited to small case series or cohorts in academic centers. A recent meta-analysis highlighted variations in treatment practices, time to treatment (from 2 days to 46 months), length of treatment (6–34 months), and severity of disease among children, but reported a relatively uniform treatment success rate of 80%.8,13 Studies from major academic centers in Johannesburg and the Western Cape Province provide the most comprehensive description of DR-TB among children in South Africa. In the Western Cape, results from surveys over a 17-year period showed DR-TB and MDR-TB among children with culture-confirmed TB reaching its peak during our study period, at 15.4% and 8.9%, respectively.14–16 In Johannesburg in 2008, 9% of children with a recorded drug susceptibility test (DST) result had MDR-TB.17 Treatment outcomes varied, with higher levels of mortality (31%) among children in Johannesburg than in Western Cape (12%).13,17 A better understanding of the epidemiology of DR-TB in children and adolescents across South Africa can inform whether programmatic and clinical practices meet the needs of children and adolescents. To that end, we reviewed the records of children and adolescents with DR-TB in four provinces in South Africa to describe the clinical features, management, and outcomes of DR-TB among this vulnerable population.