HealthDay News — The incidence of developing tuberculosis is high among exposed infants and young children, according to a review published in the March 21 issue of The Lancet.
Leonardo Martinez, Ph.D., from Stanford University School of Medicine in California, and colleagues conducted a systematic review and meta-analysis to examine the development of tuberculosis in children closely exposed to a tuberculosis case and followed for incident disease. Data were analyzed from 46 cohort studies in 34 countries.
A total of 137,647 tuberculosis-exposed children were assessed at baseline, and 130,512 were followed for 429,538 person-years. The researchers identified 1,299 prevalent and 999 incident tuberculosis cases during follow-up. Compared with children with a negative result for tuberculosis infection, those not receiving preventive therapy with a positive result for tuberculosis infection had a significantly higher two-year cumulative tuberculosis incidence; this incidence was highest for children younger than 5 years of age (19 percent). The effectiveness of preventive therapy was 63 and 91 percent among all exposed children and among those with a positive result for tuberculosis infection, respectively (adjusted hazard ratios, 0.37 and 0.09, respectively). Eighty-three percent of all children aged younger than 5 years who developed tuberculosis were diagnosed within 90 days of the baseline visit.
“Our estimates indicate that many exposed children, especially those with recent infection, are at substantial risk of developing tuberculosis and must be prioritized by development of new prevention and early case finding strategies,” the authors write.