Spread of TB in Africa Fueled by HIV/AIDS, Other Factors, Perspective Piece Says

Africa is facing the "worst TB epidemic since the advent of the antibiotic era," Richard Chaisson, director of the Center for Tuberculosis Research at the Johns Hopkins University School of Medicine, and Neil Martinson, deputy director of the Perinatal HIV Research Unit at the University of the Witwatersrand, write in a New England Journal of Medicine perspective piece. TB in Africa is fueled by several factors, the "most important being the HIV epidemic," the authors write, adding that TB is the "most common co-existing condition in people who die from" AIDS-related causes. The link between HIV and TB "stems from two distinct processes," according to Chaisson and Martinson. They add that in some cases, people with latent TB contract HIV, which "increases 100-fold the risk of reactivation" of TB. In other cases, HIV-positive people with weakened immune systems acquire new TB infections and are at "extraordinarily high risk for active" TB, the authors write, adding that this "cycle of infection and disease is amplified by the interaction between" people with active TB and HIV in "clinics, hospitals and the broader community."

Other factors that contribute to the spread of TB in Africa include weak health systems, inadequate laboratories, conditions that promote transmission of the disease and the emergence of drug-resistant strains, according to Chaisson and Martinson. Although 11% of the world's population lives in Africa, the continent carries 29% of global TB burden, the authors write, adding that the "challenges of controlling the disease in the region have never been greater." The global health community has increased investment in TB control and research since African health ministers declared TB an emergency in 2005, which has provided a "glimmer of hope," according to the authors. While research efforts are under way to find methods to prevent, diagnose and treat TB more effectively, Africa's health care systems can adopt existing strategies for "improving disease-control outcomes," Chaisson and Martinson write. They conclude that Africa "desperately needs" increased investment in "research, health care systems, diagnostic laboratories, human resources and public health services if it is to shed its heavy burden of suffering and death" (Chaisson/Martinson, NEJM, 3/13).

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