Under a new tuberculosis (TB) diagnosis strategy, people considered at high risk of TB are offered molecular TB tests, even if they do not have any symptoms. A landmark study in 2020 showed that such a strategy can help diagnose more people more quickly.
Now, writes Tiyese Jeranji in Spotlight, early indications are that it also works in the real world and South Africa’s lab service says they can cope with the increased demand.
The strategy, called targeted universal testing (TUT for short), involves routinely offering TB tests to people living with HIV, household contacts of people with TB, and people who have had TB in the past two years – all groups considered at increased risk of TB. In March 2021, Spotlight reported on a cluster randomised study conducted in South Africa in which TUT was found to improve TB case detection by 17%.
Though the exact number is highly uncertain, experts estimate around 150,000 TB cases annually go undiagnosed in South Africa. Dr Norbert Ndjeka, director of Drug-Resistant TB, TB, and HIV in the National Department of Health, in March told Spotlight that 208,000 cases of TB were diagnosed in 2020. The department aims to increase this to close to 300,000 in the 2022/2023 financial year. Ndjeka lists TUT as one of the interventions to help diagnose these 92,000 additional cases.
Ndjeka also said several TUT pilots had been conducted in Global Fund-supported districts and that the wider scale-up of TUT in the public healthcare system started in April 2022.
There are early indications that TUT is already working well under real-world conditions, compared with the more controlled environment of a clinical trial.
Think TB (an NGO) is running the TUT programme in four districts in KwaZulu-Natal – uMgungundlovu, uMkhanyakude, Amajuba and uThukela. Lynette Duckworth, Think TB Technical lead, said the programme provided technical support to the four districts as well as a team of 36 nurses supporting the Department of Health at facility level.
Duckworth says there has been good uptake of the strategy at the 59 facilities they support. “In the past six months, we tested 2,087 newly diagnosed HIV clients; 1,532 HIV positive pregnant women newly enrolled in antenatal clinics and 2,274 household contacts, for TB. From this strategy (TUT), 56 household contacts of TB patients were diagnosed with TB,” she says.
In the uMkhanyakude district, the number of people investigated for TB increased from 3,856 in March 2021 to 8 999 in March 2022, a rise of 133%. Similar comparisons for the other districts are not yet available, since Think TB has only just started supporting them.
In the Western Cape, TB/HIV Care (an NGO), is also seeing positive early signs. Amanda Fonada, TB HIV Care TB programme director, says their programmatic data suggest that the TUT strategy is particularly effective in diagnosing TB in children under five. Between various groups, she says, the yields range from 6% of all those tested testing TB positive to 43% testing TB positive.
She said TB/HIV Care focal nurses review the registers of high TB burden facilities and identify clients who are at increased risk of TB (as per the three standard TUT criteria). “The list is then shared with the community enrolled nursing assistants who go to the household for screening and on-the-spot sputum collection. This sputum specimen is then brought to the facility or sent to a laboratory for testing. The nursing assistants are responsible for tracing all patients who are diagnosed with TB but not started on treatment as well as those who have interrupted treatment,” she says.
“That the testing can be done at home also makes the experience more patient-centred and convenient,” she says, adding that between December 2021 and March 2022, 111,872 tests were conducted through the programme.
Since TUT involves testing substantial numbers of asymptomatic people who wouldn’t previously have been tested for TB, the ongoing TUT scale-up will increase the number of TB tests having to be done by the National Health Laboratory Service (NHLS – South Africa’s public laboratory service).
Dr Kamy Chetty, CEO of the NHLS, says the NHLS has vast experience in dealing with large testing volumes as it is geared to service 80% of the national population. “Due to its vast decentralised network of laboratories, the NHLS has supported many of the national priority disease programmes, such as TB and HIV,” she says.
The NHLS processes around 7m HIV viral load tests per year. South Africa, through the NHLS, has, over the past decade, been a global leader in introducing new, faster TB tests – most notably with the introduction in 2011 of the GeneXpertMTB/RIF, a type of molecular TB test. GeneXpert machines have also been used for some SARS-CoV-2 testing in South Africa.
According to Chetty, the NHLS has capacity for more than 4m GeneXpert tests per year (about 10,000 tests per day) across its network of labs. Currently, it conducts around 2m tests per year.
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