Dealing with TB detection in children

By Owen Nyaka*

Abandoned by her husband after living sixteen years (16) in marriage, Mphemvu Suche pseudo name of Nkhata Bay district, her husband decided to marry another woman leaving Suche struggling alone with life threatening and highly contagious Multi Drug Resistant Tuberculosis (MDR-TB) disease.

In 2003, Suche is one of the three (3) MDR-TB patients that was found under Nkhata Bay District Hospital (DHO) according to Mavuto Khomba who is TB Officer for the district. He said, in the year 2024, there were 200 cases of TB of which 16 were children.

The future of Suche’s two under five children is at stake. Suche has an aunt who locally brews alcoholic drink called mkontho but still her aunt, who is an ex-TB patient, is far from being called reliable to care for neither her niece nor her niece’s children.

Periodically, the little young children go without nutrition food. They are also exposed to open fire smoke which occurs when brewing this local beer. Sometimes their house gets overcrowded when other heavily intoxicated mkontho customers are being accommodated in their vicinity; some customers are chain-smokers of the unprocessed cigarettes called chingambwe.

Although these children are believed to have contracted the disease from their adult contact, Suche’s little ones just like many young children across appears to be invisible towards the fight in ending TB.

Suche’s children, just like most pediatrics across Malawi and beyond, face a number of challenges that continue to bedevil the diagnosis of TB in children. The most common form is pulmonary TB respiratory symptoms and diagnosis is largely confirmed by examining sputum and chest radiography. Children especially the young ones find it difficult to cough and produce sputum for examination.

National TB and Leprosy Elimination Programme (NTLEP) Deputy Director Dr. Kuzani Mbendera says it is not practical to ask a child to submit sputum especially the very young.

Granted as they get older, their ability to submit a sputum increases. It follows then that the confirmation of TB via sputum is largely for adults and much older children who are able to submit sputum. It takes a very small amount of TB organisms to cause disease in a child.  

Therefore, if a child where somehow able to submit a sputum sample, TB organisms in the sputum is so little so much that it is very difficult to detect it even with advanced testing modalities available and as such most tests for TB in children end up being negative even as the child in fact has TB. This phenomenon according to Dr. Mbendera is termed Paucibacilary TB.

Experts within NTLEP, for instance Dr. Samuel Chirwa whose specialty is on TB says chest X-rays do play a role in diagnosing TB in both adults and children. Chest X-ray however rely on visible changes that the TB might have caused within the lungs.

Dr. Chirwa says the changes can be seen on the chest X-ray and aid in TB diagnosis. However, in the face of the Paucibacilary nature of the TB in children may be very minimal or none existent.

TB diagnosis therefore is usually made on epidemiology features at presentation-epidemiological features look at those areas where TB is widespread and clinical features basically looks at the symptoms at presentation and also what is found on examination which most cases depends on the affected system of the body.

Other samples which is collected depend on presentation of the TB gastric aspirates nd other body fluids where TB meningitis is being suspected. Dr. Mbendera, however say there are techniques that is used to get sputum from a child.

“Since a child swallow’s sputum as opposed to coughing it out, a feeding tube can be inserted through the nose or mouth into the stomach to get sputum from the stomach or since the swallowed sputum will be digested nd end up in stool, stool samples can be collected and tested for TB.

“A stool method is simpler nd much more acceptable than inserting a feeding tube. However due to the paucity of TB even when such samples are obtained via these techniques, the samples are very likely to test negative and the diagnosis of TB in a child will still be made solely via a combination of signs and symptoms,” says Dr. Mbendera. 

Malawi College of Medicine Lecturer on TB diagnosis, Dr. Dominic Moyo concur with NTLEP deputy Director saying pediatric TB is common but difficult to diagnose. He said sputum is difficult to obtain in children; however where possible techniques are available to induce sputum for microscopy and culture but also recently the introduction of GeneXpert has improved TB diagnosis in children.

GeneXpert is a very sensitive test for TB as opposed to Microscopy for example because Microscopy relies on the human eye to see the bacteria while GeneXpert detects fragments of TB. In the face of an already difficult to diagnose population group, GeneXpert increases the chances at detecting TB.

Both Dr. Moyo and Dr. Mbendera said to that end it is a national policy that all samples for TB testing from children must be tested on GeneXpert platform.

Moyo who is in Cape Town, South Africa for his specialty training said there is also a non-specific test called a mantoux test which is done by introducing purified protein derivative of the bacteria that cause TB into the layer of skin and measure the reaction.

“Sometimes we can induce sputum in the children or do what we call gastric washing where we starve the child for at least 12 hours and then we introduce some fluids inside and then aspirate it back. These tests, however are not as good as you would get with sputum testing which is an ideal thing to do,” says Moyo.

Moyo, however say mantoux testing also known as Tuberculin Skin Test (TST) as recent past, is no longer routinely done in public facilities. TST which does not require specific equipment at all but is just an injection is widely used but suffers poor specifically in those receiving the bacilli Calmette-Guerim vaccine and poor sensitivity in individuals with HIV infections.

In order that no one is left behind, the National Tuberculosis and Leprosy Elimination Programme under Ministry of Health has procured over 100 digital x-rays between 2018 up to end of this year. This infrastructure is being deployed in public and CHAM facilities.

The National Tuberculosis and Leprosy Elimination Programme has a fleet of 12 trucks or Vans equipped with various digital x-ray types (ultra-portable vs. fixed) equipment with Computer Aided X-ray Reading software. In between June 2018 up to December 2024 close to 800,000 people have been screened including key vulnerable populations such as miners, prisoners, contacts, people living in high density areas and hotspots.

So through a mixture of expansion of capabilities in select health facilities and the targeted use of mobile diagnostic vans equipment with x-ray are the means in which services are being expanded to at risk and hard to reach communities such as Suche’s siblings.

*Owen Nyaka is a Contributor