Tuberculosis kills approximately 1.4 million people every year, and the world spends billions of dollars in public and private money annually to combat it.
Growing evidence points to links between diabetes and TB, and two researchers writing in this week’s PLoS Medicine say funding and research also should be focused on treating the two diseases together as a way to cut the TB death rate.
Earth Institute Fellow Yanis Ben Amor trains laboratory technicians in Rwanda how to conduct a Line Probe Assay, a test that detects the presence of the bacteria that causes tuberculosis. Photo: The National Reference Laboratory, Kigali
In a Policy Forum article, Timothy Sullivan from Mount Sinai Hospital in New York and Yanis Ben Amor from the Earth Institute at Columbia University explain that patients with diabetes are at increased risk of developing active TB, and have higher rates of treatment failure and death, even when receiving appropriate treatment for TB.
The authors propose that all patients confirmed to have TB be systematically screened for diabetes, and that all patients with diabetes be screened for TB when they develop related symptoms, particularly in developing countries where both diseases are common.
Reversing the incidence of TB worldwide is one of the United Nations’ Millennium Development Goals. Progress has been made on that front – the goal has probably already been met – but nonetheless, an estimated 8.8 million new cases turn up each year.
People living with HIV/AIDS are far more likely to contract TB, and treatment programs have responded by trying to coordinate their approach. Ben Amor and Sullivan say the same should be done for diabetes.
“This link may become even more meaningful in coming years, as the prevalence of diabetes is expected to rise dramatically in the resource-poor areas where TB thrives,” they say.
The authors use figures of the global incidence of tuberculosis to estimate the additional costs of associated diabetes care—$3 million to $56 million per year in Africa and $5 million to $92 million per year in South East Asia. The range of possible costs reflects a wide range of estimates of how many diabetes cases would be detected through screening TB patients.
“The additional yield of diabetes cases will vary from region to region,” Ben Amor said. “For each region, the range is actually much more limited.”
Although expanding TB treatment to include diabetes care would be expensive, the authors argue that existing health systems used for TB could be adapted to diabetes management, which may help control costs.
Before such funding begins, though, research should be done to show whether controlling diabetes can reliably improve TB outcomes – and whether it warrants using scarce funds available for global TB efforts, the authors say.
The authors propose strategies for funding and implementing efforts to simultaneously control tuberculosis and diabetes in low-income countries and conclude: “Even if the management of these complex illnesses cannot be readily integrated, it is clear that the growing burden of diabetes and its effect on TB in developing countries should not be ignored.”
While other risk factors can affect TB rates, the focus on HIV and diabetes makes sense because of similarities in the treatment protocols, said Ben Amor, who is technical advisor for TB and HIV/AIDS for the Millennium Villages Project, and the director of the Tropical Laboratory Initiative at the Center for Global Health and Economic Development.
Copies of the paper, “The Co-Management of Tuberculosis and Diabetes: Challenges and Opportunities in the Developing World,” are available at the PLoS Medicine open access site.
Author contacts: Yanis Ben Amor: firstname.lastname@example.org
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