Neglected infectious disease (NID) experts discussed opportunities for and challenges to integrating HIV/AIDS and NID control and prevention interventions Tuesday at the 60th Annual Meeting of the American Society of Tropical Medicine and Hygiene in Philadelphia.
While both are important, NIDs affect one-third of the world’s population,” said Judd Walson, MD, MPH of the University of Washington. The difference in funding for the two, however, is quite different: there was $5.7 billion in proposed funding for HIV/AIDS in 2011, and the global investment in NIDs was $155 million, or three percent of the total HIV/AIDS budget.
Walson showed that the geographical overlap of the major NIDs and HIV/AIDS is great – in sub-Saharan Africa (SSA), where the HIV/AIDS burden is greatest, more than five NIDs are often affecting the countries at one time. As an example of how to successfully target NID and HIV programmatic overlap, Walson recounted a program in Kisumu, Kenya that had very low levels of people coming in for HIV testing. They came up with the idea of offering free bed nets (for malaria prevention) and water filtration devices (for prevention of diarrheal disease) to those who came in for free HIV testing. Over six days, more than 10,000 people came out to be tested, Walson said, and more than 1100 people were identified as HIV-infected. Moreover, they identified 500 people to participate in a research study they planned to conduct among HIV–infected persons.
“If we are creative and we think about ways to leverage the opportunity that the HIV/AIDS response has had, we may be able to have a more profound impact on many of the individuals living around the world,” Walson said.
The U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) push to put more HIV-infected individuals on antiretroviral treatment (ART) tends to set up a little “island of excellence in a sea of mediocrity,” said Sten Vermund, MD, PhD, of Vanderbilt University, agreeing with Walson that there is a lot of opportunity here. Vermund exemplified his point by showing a picture of a typical rural health clinic in Africa that lacked access to either electricity or running water. Nevertheless, Vermund noted that more than half of those clinically eligible to receive ART by World Health Organization treatment guideline standards are not receiving it.
While it is well-studied and well-appreciated that HIV infection worsens the natural history of co-infection with many diseases, it is not widely studied nor appreciated that HIV transmission and progression can be exacerbated by the coinfection, Vermund said. This spurred Vermund and a colleague to undertake a systematic literature review on the impact of co-infection treatment on viral load in 2010.
“The overall impression was very much a case of a protection for viral load – a diminution of viral load if you either cured for curable parasites and STDs or TB, or treated the non-curable [diseases],” he said, noting that it was the consistency of these findings that was very reassuring. However, after eliminating studies due to lack of relevance, only 19 studies were analyzed, highlighting the need for much more data. A variety of studies have documented that very minimal changes in markers of HIV disease have a profound effect on transmission of HIV and progression of HIV.
An area with much potential overlap was discussed by Dr. Alan Fenwick of the Imperial College of London, who covered schistosomiasis elimination as an HIV/AIDS control strategy. Recent estimates show that 440 million people alive today have had or currently have schistosomiasis – a parasitic worm infection caused by a blood fluke. Approximately 90 percent of those infected live in sub-Saharan Africa, again a big overlap with the HIV/AIDS pandemic. One of the most common types – female genital schistosomiasis – causes genital lesions that increase a woman’s susceptibility to HIV infection. Some suggest it is a big catalyst of HIV infection.
The tricky part is treating females early, before they develop lesions, the panelists agreed. Schistosomiasis is effectively treated with the drug praziquantel but people must be treated annually and although it prevents lesions from worsening, praziquantel does not heal the lesions and therefore could only help quell the transmission of HIV/AIDS if used on very young girls yet to develop them.
Integrating schistosomiasis control with PEPFAR would make sense, Fenwick argued, as 10 of the 15 PEPFAR countries in Africa have huge schistosomiasis prevalence and populations at risk. “Just by treating every schoolage female in Africa in endemic areas we really would be able to prevent schistosomiasis in 100 million women, “ he said, regardless of whether or not they would later develop HIV.