A recent study published in the journal Global Health Action has found that testing more people with TB symptoms at South Africa's public sector clinics is one of the most effective ways to reduce rates of TB disease and death. The study, conducted by authors from the University of Cape Town, used a mathematical model to estimate the impact of various interventions on TB cases and deaths in South Africa. The model, called Thembisa, is an existing tool that tracks HIV and TB in the country.
According to the study, South Africa has made significant progress against tuberculosis, but is not on track to meet key targets set for 2030. New TB cases in South Africa are projected to decline by 46% by 2030, relative to a 2015 baseline, while TB deaths are projected to decline by 54%. However, these projections fall short of the World Health Organisation's End TB targets, which aim for an 80% reduction in new cases and a 90% reduction in deaths.
The researchers identified several interventions that could help South Africa get closer to the End TB targets. One of the most effective interventions is increasing the percentage of people reporting with TB symptoms who are tested using new TB tests at clinics, known as point-of-care tests. According to the study, if 89% of people with TB symptoms were tested using these new tests, new TB cases could be reduced by 49% and TB deaths by 67%.
The new point-of-care TB tests, which can be run on both sputum and tongue swabs, are not yet in general use in South Africa, although they are being evaluated in pilot projects. Currently, most TB tests in South Africa involve someone producing a sputum sample, which is then transported to a lab for testing. The new tests offer quicker test results and have lower operational requirements, making them a promising solution to increase TB testing in the country.
In addition to increasing testing rates, the study also found that high rates of door-to-door testing with the new point-of-care tests could reduce new TB cases and deaths by 38% and 49% respectively. Combining high rates of door-to-door testing with digital chest X-ray screening in asymptomatic individuals could also reduce new TB cases by 17% and deaths by 21%.
The study's lead author, Dr Leigh Johnson, noted that achieving high levels of testing in people with TB symptoms is crucial to reducing TB incidence and mortality. However, this may require levels of laboratory testing beyond current capacity. The authors argue that there is a need to strengthen adherence to guidelines for systematic testing of all patients with symptoms suggestive of TB and that a larger healthcare workforce dedicated to TB diagnosis is needed.
The study was supported by the Gates Foundation, and its findings have important implications for TB control in South Africa. The authors hope that their research will inform policy and practice changes to increase TB testing and reduce TB-related deaths in the country.
Key points
- Testing more people with TB symptoms at public sector clinics can help reduce rates of TB disease and death.
- New point-of-care TB tests offer a promising solution to increase TB testing in South Africa.
- Achieving high levels of testing in people with TB symptoms is crucial to reducing TB incidence and mortality.
