With tuberculosis both the most common opportunistic illness and leading cause of death for people living with HIV, the connection between the two diseases has been documented and observed. What has been less documented is the impact of increased HIV responses on tuberculosis rates in countries hard hit by both epidemics.
Now, a study in the Journal of Infectious Diseases published online this week shows countries that received the most intensive HIV-fighting responses saw greater drops in incidence of tuberculosis illnesses and deaths than countries receiving less intensive support. The study, Potential Impact of the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) on the Tuberculosis/HIV co-epidemic in selected Sub-Sahara African countries, examined TB incidence and death rates, in the years before and after the heightened U.S. response to global HIV. The study compares data from 12 PEPFAR “focus” countries where the program made its largest investments to prevent and treat HIV, with data from 29 countries that with generalized HIV epidemics that received less direct U.S. funding to fight HIV.
Data for both groups of countries showed people living with HIV were 20 times more likely to get sick with tuberculosis than people not living with HIV, and that people living with HIV were at least 40 times more likely to die from tuberculosis than those without HIV. Before the arrival of PEPFAR support, the median tuberculosis incidence rate across focus countries was 1139 for every 100,000 people. A median rate of 445 people of every 100,000 died of tuberculosis in the focus countries. After PEPFAR’s arrival, median incidence of tuberculosis dropped to 842 for every 100,000 people, and deaths dropped to 342 per 100,000. In whole numbers, more than half a million cases of tuberculosis illness were averted and an estimated 379,432 deaths. Both sets of numbers were lower across the 29 countries studied that were not focus countries, with median incidence of 295 tuberculosis cases for every 100,000, and median mortality of 145 deaths per 100,000 before PEPFAR’s arrival, and median incidence of 282 cases per 100,000, and median mortality of 126 deaths per 100,000 after. In both groups of countries, the toll of tuberculosis dropped, but more significantly and consistently in the focus countries. Even as HIV prevalence continued to grow in some focus countries, tuberculosis epidemics slowed, the authors noted.
While the critical role of antiretroviral medicine in not only reducing HIV-related illnesses and deaths, but in preventing transmission has been acknowledged, the authors point out, the numbers from this study highlight “the likely link between high-levels of HIV investment and broader effects on related diseases such as TB.” Learning which PEPFAR programs had the greatest impact on tuberculosis would be critical to efforts to control both epidemics, they add. The results, they say, point to the need for in-country scrutiny of access to antiretroviral medicines, the “three I’s” of intensified case finding, isoniazid preventive therapy, and infection control of TB-HIV responses, as well as other efforts.