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Research in Focus: The STAMP study

It is well known that the brunt of the global AIDS epidemic has been felt by people in sub-Saharan Africa. According to the 2014 UNAIDS GAP Report, there are currently 24.7 million people living with HIV in the region; this accounts for 71% of all people living with HIV worldwide. Furthermore, there were an estimated 1.1 million deaths due to AIDS in sub-Saharan Africa last year.

Tuberculosis (TB) remains the leading cause of AIDS-related illness and deaths worldwide and three quarters of all TB cases occur in sub-Saharan Africa. Studies have shown that up to two-thirds of HIV+ adult patients who die in hospitals have TB. Most of these cases were neither clinically suspected nor diagnosed before death, illustrating a stark failure of the current approaches in properly diagnosing patients.

“People often die of TB without even having a diagnosis,” says Dignitas International’s Medical and Research Director, Dr. Joep van Oosterhout.

Detecting TB in patients is not easy. The current standard approach for TB detection in Malawi is a laboratory test called Xpert MTB/RIF. This test requires a patient sputum sample and getting the results back to the patients can take a few days. Several studies have shown fewer than 50% of patients could produce a sputum sample due to illness. Furthermore, TB often involves organs other than the lungs and therefore is not always caught using the Xpert test.

A new bedside urine test has shown promise in increasing the detection of TB. This test, called TB-LAM, can diagnose TB within 30 minutes. While the use of this urine test has shown increased TB detection, there is no evidence yet that it will reduce HIV-TB mortality. In addition, the cost-effectiveness of this new diagnostic tool has not been proven.

Along with the London School of Hygiene and Tropical Medicine and the Malawi College of Medicine , Dignitas will be undertaking the STAMP study, aimed at improving treatment for patients with HIV and TB. The objective of the study will be to determine whether adding urine testing (using the TB-LAM and Xpert tests), to the routine TB diagnosis strategy (sputum Xpert test) reduces mortality in TB-HIV co-infected patients. In addition, the study will evaluate whether the diagnostic tool is cost effective in sub-Saharan Africa and other resource-limited settings.

The STAMP trial aims to address a really important problem. There is still a high mortality from TB amongst people living with HIV. With improved access to antiretroviral therapy, the risk of death has dropped but it is still much higher than in the general population.

“If we add urine diagnostics to the current sputum diagnostics, we may be able to detect far more TB cases and diagnose far earlier,” says Joep. The hope is that with an earlier diagnosis, patients will start TB treatment sooner and achieve better health outcomes.

The three-year study, which is being funded by the UK Department for International Development, Wellcome Trust and the Medical Research Council, will be conducted in both Malawi and South Africa. Dignitas will lead the Malawi segment of the study, which will start next year and conclude in late 2017. If the study shows positive results, there is a strong potential for improving the health outcomes of people with HIV in sub-Saharan Africa and other resource-limited settings.

Dignitas InternationalResearch in Focus: The STAMP study