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Childhood Tuberculosis (TB) is a staggering problem. In India, approximately 3.42 lakh children (0-14 years of age) are estimated to get TB every year, accounting for about 6% of total TB cases reported to NTEP in 2020[1]. In 2020, approximately one lakh children with TB (0 to 14 years of age) were reported to the NTEP, while an additional 1.4 lakh children were reported to the NTEP in the age group of 15-18 years[2]. Consistently, children constitute 6-7% of all the patients treated under NTEP annually. Nevertheless, there are some variations in the case reporting across the states, attributed to differences in the burden of disease, health-seeking behaviour, and availability of services.

Nearly a third of the children with TB globally are from India, despite an estimated detection gap of about 56%. Children up to the age of 14 years constitute 35% of the population in our country and are estimated to contribute approximately 10% of the caseload. However, reported numbers may be low as many children are treated outside the National TB programme. Pulmonary TB is the most common form of TB in children; however, extra-pulmonary TB (EPTB) in children forms a more significant proportion of cases than adults. Adults comprise the largest proportion of TB cases as the adulthood span is far longer than paediatric. In addition, TB control does not figure prominently as one of the child survival strategies. The child survival strategies are expectedly focused on the diseases with the highest mortality among the under-five, including premature birth, perinatal asphyxia and injuries, pneumonia and diarrhoea. Among the other causes of childhood, mortality is TB, albeit unrecognised yet important. However, the exact contribution of TB to ‘Under-5 Mortality’ is unknown. Many TB related deaths are possibly reported as pneumonia due to similar respiratory symptoms, and autopsy studies from few African nations support this contention. As a singular organism, Mycobacterium tuberculosis (M.tb) contributes to most death of under-five among the world’s middle and lower-income countries.

               Although the principles of diagnosis and treatment remain similar in children and adults, the differences in the type of disease and specific host characteristics bring up some challenging variations. Adults and older children more often have the infectious form of TB, which may be confirmed by testing sputum, while in general, younger children have forms of TB that show up poorly on sputum smears. Moreover, difficulties in accessing the specimen from children who swallow rather than bring out sputum add further challenge. Whereas alternative methods to collect respiratory samples are more invasive and require professional skills. Confirmation of TB and its drug sensitivity does require microbiological testing but the sophistication of diagnosis among children often makes it challenging to decentralise it to the community level.

Rapid molecular diagnostic methods like newer generation cartridge-based nucleic acid amplification tests (Xpert-RifTM /TruenatTM) and Line Probe Assays (LPA) have been approved and employed by the National TB elimination Program (NTEP). These tests can rapidly identify Mycobacterium tuberculosis with much-improved sensitivity compared to conventional smear testing, even among specimens from children but are far more expensive when pursued in the private sector. Nevertheless, the final yield of TB testing is better if the microbiological confirmation is done on good quality specimens from cases with high suspicion of TB based on clinical and radiological abnormalities. As the symptoms suggestive of pulmonary TB are non-specific and overlapping, initial screening with chest imaging helps prioritise cases for testing by NAAT. 

Furthermore, newer molecular tests can simultaneously detect much critical rifampicin resistance as they are nested or two-step automated Polymerase Chain Reaction (PCR), leading to a significant shift in diagnostic strategy. Such diagnostic modalities have paved ways for Universal drug sensitivity testing (U-DST), the core programmatic strategy and refers to upfront testing of all TB cases for Rifampicin resistance and further for Fluoroquinolones and Isoniazid (INH). Therefore, all TB cases (new or retreatment) must now be tested for drug resistance upfront and instituted specific treatment as per the resistance pattern detected.

In addition, several changes have come up in the treatment of TB. Firstly, for children, dosages of anti TB drugs have been revised upwardly to achieve optimal drug levels, and now the Fixed Drug Combinations (FDCs) are used to decrease the risk of missing a particular drug from the prescribed regimen. Secondly, awareness about high initial Isoniazid resistance and its contribution to the failure of the retreatment regimen has led to the use of a third companion drug (Ethambutol) in the continuation phase of the first-line therapy. Lastly, the standard retreatment regimen, commonly known as category II therapy, has been withdrawn.

The current decade has witnessed a revitalisation in new activities led by recent innovations in TB with a renewed commitment to eliminate the disease from the world.  Understanding the disease, drug therapy and its pharmacokinetics, resistance amplification, and newer diagnostics and drugs have created an opportunity to use this knowledge to improve child TB care in specific and child health care in particular. The present updated guidelines capture the use of newer diagnostics and therapy modifications for managing TB in children to achieve the goal of early diagnosis, prompt and effective therapy guided by the sensitivity pattern to key drugs.

 


[1] Central TB Division, 2020. India TB Report - 2020. National Tuberculosis Elimination Program - Annual Report. New Delhi: Central TB Division, Ministry of Health and Family Welfare, Government of India.

[2] Central TB Division, 2021, Nikshay Data from National Tuberculosis Elimination Program, Ministry of Health and Family Welfare, Government of India.