Improving tuberculosis preventive therapy uptake: A cluster-randomized trial of symptom-based versus tuberculin skin test-based screening of household tuberculosis contacts less than 5 years of age

Background. Tuberculosis preventive therapy (TPT) is highly effective at preventing tuberculosis disease in household child contacts (<5 years), but is poorly implemented worldwide. In 2006, the World Health Organization recommended symptom-based screening as a replacement for tuberculin skin testing (TST) to simplify contact evaluation and improve implementation. We aimed to determine the effectiveness of this recommendation. Methods. We conducted a pragmatic, cluster-randomized trial to determine whether contact evaluation using symptom screening improved the proportion of identified child contacts who initiated TPT, compared to TST-based screening, in Matlosana, South Africa. We randomized 16 clinics to either symptom-based or TST-based contact evaluations. Outcome data were abstracted from customized child contact management files. Results. Contact tracing identified 550 and 467 child contacts in the symptom and TST arms, respectively (0.39 vs 0.32 per case, respectively; P =.27). There was no significant difference by arm in the adjusted proportion of identified child contacts who were screened (52% in symptom arm vs 60% in TST arm; P =.39). The adjusted proportion of identified child contacts who initiated TPT or tuberculosis treatment was 51.5% in the symptom clinics and 57.1% in the TST clinics (difference −5.6%, 95% confidence interval −23.7 to 12.6; P =.52). Based on the district's historic average of 0.7 child contacts per index case, 14% and 15% of child contacts completed 6 months of TPT in the symptom and TST arms, respectively (P =.89). Conclusions. Symptom-based screening did not improve the proportion of identified child contacts evaluated or initiated on TPT, compared to TST-based screening. Further research is needed to identify bottlenecks and evaluate interventions to ensure all child contacts receive TPT.