Changing trends in childhood tuberculosis.

Several changes have been observed in the epidemiology, clinical manifestations, diagnostic modalities and treatment of tuberculosis. Emergence of HIV epidemic and drug resistance have posed significant challenges. With increase in the number of diseased adults and spread of HIV infection, the infection rates in children are likely to increase. It is estimated that in developing countries, the annual risk of tuberculosis infection in children is 2.5%. Nearly 8-20% of the deaths caused by tuberculosis occur in children. Extra pulmonary tuberculosis has increased over last two decades. HIV infected children are at an increased risk of tuberculosis, particularly disseminated disease. In last two decades, drug resistant tuberculosis has increased gradually with emergence of MDR and XDR-TB. The rate of drug resistance to any drug varied from 20% to 80% in different geographic regions. Significant changes have occurred in TB diagnostics. Various diagnostic techniques such as fluorescence LED microscopy, improved culture techniques, antigen detection, nucleic acid amplification, line probe assays and IGRAs have been developed and evaluated to improve diagnosis of childhood tuberculosis. Serodiagnosis is an attractive investigation but till date none of the tests have desirable sensitivity and specificity. Tests based on nucleic acid amplification are a promising advance but relatively less experience in children, need for technical expertise and high cost are limiting factors for their use in children with tuberculosis. Short-course chemotherapy for childhood tuberculosis is well established. Directly observed treatment strategy (DOTS) have shown encouraging result. DOTS plus strategy has been introduced for MDR TB.