Childhood tuberculosis: public health and contact tracing.
Contact tracing is extremely useful to detect patients with latent tuberculosis (TB) infection and should be followed by preventive therapy. When properly applied it can have an impact on morbidity and mortality, especially among children. In most industrialised countries the decline in the risk of infection due to better overall health and effective TB control measures is likely to result in the disappearance of tuberculosis as a public health problem; therefore the cost-benefit of contact tracing is likely to be less than in the developing world. However, given an infection prevalence of up to 40% in adolescence and the more immediate need to target scarce resources at treating active infectious cases, developing countries cannot extend the practice of contact tracing and preventive therapy beyond the very young and groups at high risk. In developing countries more benefits are likely to arise from widespread and effective application of the DOTS strategy for the prevention and the control of tuberculosis in both adults and children. Diagnosis and treatment of known infectious cases must necessarily precede a recommendation for contact tracing, however great the perceived impact may be. In the interim, political commitment to ensure global equality in accessing health care, research to improve screening procedures, lower costs of treatment through shorter regimens and the application of comprehensive measures for tuberculosis prevention and control are desperately needed.