Burden of Tuberculosis in South African Children During Treatment for Underlying Malignancies: A Single-center Experience in Johannesburg.

BACKGROUND Children with cancer are immunocompromised with increased susceptibility to infections. We evaluated the burden of tuberculosis in children with cancer. METHODS Children with cancer were enrolled and screened for Mycobacterium tuberculosis infection using the tuberculin skin test and enzyme-linked immune absorbent spot (T-SPOT.TB; Oxford Immunotec Ltd, Oxford, United Kingdom). Children with physician-suspected tuberculosis were investigated for M. tuberculosis using microscopy and culture on sputum or gastric washings. RESULTS We enrolled 169 children; 10.7% were living with HIV. The tuberculin skin test was positive in 2.9% of patients, who were treated for tuberculosis and excluded from further analysis. The enzyme-linked immune absorbent spot (T-SPOT.TB) was either negative or indeterminate in the first 100 children screened. The incidence of tuberculosis was 7.6 per 100 child-years; 35.3% were culture-confirmed. Tuberculosis was diagnosed at a mean of 5.5 months from cancer diagnosis. A greater proportion of children living with HIV (44.4%) developed tuberculosis than those without (17.2%; adjusted P = 0.042). Children treated for high-risk acute lymphoblastic leukemia, advanced stage non-Hodgkin lymphoma and acute myeloid leukemia (P = 0.009) and those with a higher exposure-period (per 100 child-years) to corticosteroids courses (350 vs. 29.4; P < 0.001) had a higher incidence of tuberculosis. Twenty-six of 34 children (76.5%) with tuberculosis died; multiple infections were identified at the time of death. CONCLUSIONS Screening children for tuberculosis infection at cancer diagnosis was of limited value. The high rate of tuberculosis and poor outcomes emphasize the need for a high index of suspicion to diagnose tuberculosis and consideration for antituberculosis treatment, especially for those with identified risk factors.