The non-specific symptoms and signs of tuberculosis in children and the difficulty in obtaining quality sputum samples — particularly in very young children — are major contributing factors to the burden of childhood TB in India, according to the recently released ‘India TB Report 2024’.
The number of pediatric tuberculosis cases notified in the country went up from 135,921 in 2022 to 143,174 in 2023.
The report pointed out that children face a higher risk of acquiring and developing TB, with infants and young children being more prone to life-threatening forms of the illness, contributing to significant morbidity and mortality.
Diagnosing childhood TB
The major diagnostic challenges include the diagnosis of the bacteria, collection of sputum sample and drug dosing.
Agreeing with the report’s findings, Dr Bharath Reddy, director and consultant pediatric pulmonologist, Shishuka Children’s Speciality Hospital, Bangalore, says that one major challenge with childhood TB cases is diagnosis.
“Pediatric TB is paucibacillary, which means the bacteria are relatively fewer in number compared to in adult TB, where the bacilli are many more in number. So, the chances of detection of that bacterium are much lesser in childhood TB cases,” he says.
Dr Reddy adds that as per national guidelines, you must first identify the bacteria to make a diagnosis of TB. “Once you document that a particular bacillus is identified, you have to report it, and then only start the TB medication,” he says. “So, this reporting process is difficult in pediatric TB cases because it is not possible to isolate the bacteria since they are lesser in number. This, however, does not mean that the person does not have tuberculosis.”
The diagnosis of TB in children is more complex because doctors can’t rely only on the identification or isolation of the bacteria.
Dr Reddy says that things have improved a little on the diagnosis front, thanks to rapid molecular diagnostic tests — such as the cartridge-based nucleic acid amplification test (CBNAAT) and GeneXpert MTB/RIF assay — for tuberculosis diagnosis. These tests improve the chances of identifying bacteria even if they are fewer in number.
TB in children: Challenge starts from sample collection
Dr Reddy says that another challenge in diagnosing pediatric TB is sample collection, mainly because children do not produce sputum like adults.
Dr Naveen Dutt, additional professor, pulmonary medicine, AIIMS, Jodhpur, Rajasthan, says the smaller the child, the more difficult it becomes to interpret the symptoms and collect sputum samples. “Younger children are not able to expectorate the sputum for testing,” he says.
Dr Reddy adds: “The child may not even produce the sputum or even if they produce it, they are not going to bring it out. So, getting the sample is a very big challenge for us.”
Doctors employ a procedure known as gastric lavage in children under 10. In this, doctors take out the mucus from the stomach using a nasogastric tube (NG tube) and then send the sample for testing.
“In more complex cases, we may do a bronchoscopy, where you go into the lung directly, take out the mucus from inside the lung and send it for testing,” he says.
Dr Reddy adds that tuberculosis in children is often extrapulmonary, which means that there may be involvement of multiple organs other than the lungs.
The drug dosing problem
The third biggest challenge is in terms of the drug dosing.
There are fixed combinations of medications for adults. “But in pediatrics, each combination for each child is different,” says Dr Reddy. “We often have to dilute the tablet, sometimes we powder the tablet, divide it and then adjust the doses as per the child’s weight.”
Pediatric TB: Long-term effects
A 2022 study published in the American Journal of Respiratory and Critical Care Medicine showed that children five years or younger who developed pulmonary TB were more at risk for wheezing and poor lung function later on in life.
The lung damage in children with TB depends on how early the treatment is started. “In cases where the diagnosis is grossly delayed, the TB ends up damaging the lung to an extent, leading to bronchiectasis,” says Dr Reddy. In many cases, the lung damage would be severe by the time the child — especially from places far from cities — is brought to a tertiary care centre, he adds.
A CT scan is done to assess the degree of damage. “If the TB is in the earlier stages, it is still reversible,” says Dr Reddy. “But not in the later stages.”
Takeaways
Children face a higher risk of acquiring and developing TB, with infants and young children being more prone to life-threatening forms of the illness. The non-specific symptoms and the difficulty in sputum sample collection are among the challenges in diagnosing childhood TB, say experts.
