Improving Tuberculosis (TB) Detection in Children and People Living with HIV, a Global Priority

The aim of the Stool4TB project is to revolutionise TB diagnosis with a diagnostic tool that would benefit vulnerable populations.

Tuberculosis (TB) has long been considered a preventable and curable disease. Yet, in 2022, 10.6 million people fell ill with TB. That is almost the combined population of Madrid and Barcelona. From detection to treatment, the hurdles faced by TB patients and professionals are many, and diagnosis is only the first step.

While we usually associate TB with its most famous symptom, a persistent and sometimes bloody cough, it can manifest in many other ways, such as night sweats, fatigue, or loss of appetite. These are all symptoms that can be overlooked or confused with other illnesses. TB is more difficult to detect in some groups than others, as the mix of common symptoms and the lack of accessible and easy-to-use diagnostic tools can often delay bacteriological confirmation of TB and, therefore, treatment.

Towards a world without tuberculosis

But a group of TB experts is trying to change that. Seven institutions around the world have joined forces for the Stool4TB study, an EDCTP-funded project, aiming to validate a new molecular test that can diagnose TB in children and people living with HIV from a single stool sample.

With study sites in Eswatini, Uganda, and Mozambique, the project aims to contribute to global efforts to achieve a world free of TB. At the same time, it will ensure that the comfort of TB patients is at the heart of how we diagnose the disease, as the test will be less invasive and more accessible than those currently available.

In Mozambique alone, 15 people are working hard to make sure Stool4TB is a success. Agostinho Lima, Alberto García-Basteiro, Carlos Fernández, Catrina Bazima, Edson Mambuque, Joanna Ehrlich, Lucia Carratalá-Castro, Katia Magul, Justina Bramugy, Miguel Cumbe, Shilzia Munguambe, Sozinho Acacio, Farida Cebola, Benilde Mudumane, and Jorcelina Rungo are all using their unique skills to improve TB detection in the country.

Tuberculosis in children can be difficult to detect

The numbers paint a grim picture of why projects like Stool4TB are urgently needed. A 2017 study estimated that, of the 239,000 children under the age of 15 who died from TB worldwide, around 96% did so without treatment, and of those under 5, 80% were never even diagnosed.

In the southern Mozambican district of Manhiça, this diagnostic gap is well documented: it's estimated that the maximum case detection rate among children under the age of three is 40%. Much of the problem lies in the fact that TB in children can be difficult to detect. “The symptoms can go largely unnoticed. Sometimes TB in children just shows up as a lack of growth, or not growing at the right rate, or they are just apathetic,” explains Lucía Carratalá-Castro, Medical Research Fellow at Manhiça Tuberculosis Initiative (MTBI), and an expert on paediatric TB.

If a child is suspected of having TB, the National TB Programme refers them to the Stool4TB study. It’s then up to Carratalá-Castro and the nurses to talk to the mother or the caregiver and patiently explain the symptoms of TB in children. Carratalá-Castro often shows them the child’s growth chart and what a proper chart should look like.

Diagnosing TB in people living with HIV

It’s also challenging to get laboratory confirmation of TB in people living with HIV because they have difficulty in producing sputum samples, and when they do, only about 50% of cases are confirmed. As with children, it is necessary to induce sputum production, a process that can be quite uncomfortable. Finding simpler and less invasive ways to diagnose TB is therefore a global priority.

As Lucía Carratalá-Castro pointed out: “One of the keys to the success of a study of this kind, is the relationship that the professionals involved can build between themselves and the study participants”. That’s why, in addition to the research, health, and logistics staff, the project also relies on a social science team, led by Agostinho Lima. An anthropologist with several years of experience in understanding the relationship between local populations, disease, and medicine, Lima is now focusing his efforts on TB.

Changing the social perception of TB

The social science team is working on two fronts:

1. Researching social barriers.
2. How to overcome them, and training community members and health workers to debunk myths and spread accurate information about the disease, its prevention, and how to recognise TB symptoms.

Lima explains that although TB is an ancient disease that continues to kill thousands of people every year in this part of the world – with an estimated 14,000 deaths in 2022 alone - people still struggle to recognize the symptoms of TB or understand the importance of seeking immediate medical attention if they suspect a case of TB.

“People still neglect TB. The local community is aware of TB, and has some understanding, but for example, preliminary results from the social study showed that more than half of the participants believe that TB is a sexually transmitted disease that can spread if traditional rules are not followed or if a woman has an abortion,” he adds.

But there are less mystical reasons why people sometimes delay seeking health care. Lima and Carratalá-Castro explain that while the mortality rate in Manhiça was higher 20 years ago, the local perception today is that the situation has improved significantly. As a result, the disease is often seen as an inevitable part of life. It’s only when the severity of the symptoms becomes apparent that patients are fully convinced that they need to be tested for TB and start treatment.

In addition, the Manhiça health facility is the only one in the district with adequate equipment to make accurate TB diagnoses. If successful, Stool4TB will remove this barrier and ensure that every health facility has diagnostic tools sensitive enough to correctly diagnose the disease in some of the most vulnerable groups, who are at higher risk of poorer TB treatment outcomes. Equally important, children and people living with HIV will have access to simple and non-invasive tests without compromising quality of care.

In short, Stool4Tb is about contributing to the global effort to end TB once and for all. It focuses on populations that should have received more attention long ago and understands that the key to ending TB is working with and empowering local communities.