Using statistical mapping strategies, UCLA researchers have found that the WHO and UNAIDS strategy to eliminate HIV in sub-Saharan Africa is not feasible because it doesn’t consider several important factors.
When it comes to HIV, researchers everywhere have channeled their efforts into promoting awareness and encouraging that individuals, especially those at higher risk, take preventive measures to protect themselves and their partners from infection. As prevention strategies grow stronger, and more individuals adhere to their treatment regimens, the spread of HIV across the United States has declined in recent years. However, in continents such as sub-Saharan Africa, this is not the case; a staggering 25 million individuals are living with the virus, and strategies to bring down this number are conflicting.
One such strategy to eliminate HIV in this area, which suggested using “treatment as prevention,” was proposed by the World Health Organization (WHO) and the Joint United Nations Program on HIV/AIDS (UNAIDS). The strategy in question strives to treat infected individuals in order to reduce their ability to transmit the infection to others. The UNAIDS goal calls for 90% of individuals to be diagnosed, that 90% of infected individuals receive antiretroviral treatment, and 90% of those who are being treated achieve viral suppression—all by the year 2020.
However, a new study conducted by researchers at University of California, Los Angeles (UCLA), has found that although the plan may be commendable in what it strives to do, it “might not be feasible.”
So, how did they reach these conclusions? They set their sights on Lesotho, which is a country within South Africa that is especially hit by the virus; in fact, 1 in 4 adults living there are infected. By using “statistical mapping techniques” the research team was able to “identify the location of all people who are HIV-infected in Lesotho.”
Co-author of the study, Justin Okano, a statistician working on a team led by Sally Blower, PhD, director of UCLA’s Center for Biomedical Modeling, said that “the HIV epidemic in Lesotho is hidden. Nobody knows where the vast majority of HIV-infected people live.” He continued, in order to find where these individuals live, they would need to test “everyone in the country,” an option that is not exactly easy.
The researchers were able to reveal this “hidden epidemic” through the combination of datasets from several different sources; these data included “settlement patterns” as well as “geographic variation in population density.” The team developed a map using HIV testing data that was taken from around 7,000 individuals in Lesotho. The map predicted not only where all HIV-infected individuals in the country lived, but also if they had been diagnosed.
In fact, according to co-author Brian Coburn, postdoctoral fellow in Dr. Blower’s team, “We estimate that almost every settlement in the country has at least one HIV-infected person, and this holds true for even the smallest and most remote settlement.” He continued, “We also found that approximately 70% of HIV-infected adults live in rural settlements.”
Ultimately, the study results suggested that the current UNAIDS HIV elimination plan is not “feasible” for Lesotho. In fact, to adequately execute that plan, they would have to find and treat “a very large number of people in remote areas where there are only two or fewer infected people per square kilometer,” a very difficult task indeed.
So, what does this mean? In a press release, Dr. Blower said, “Global health policies for HIV elimination need to be redesigned, and they need to consider settlement patterns and population density.” She continued, “Our results show that the spatial demographics of populations in predominantly rural countries in sub-Saharan Africa will significantly hinder, and may even prevent, the elimination of HIV.”
However, the team didn’t stop there; they also used the map to develop a different strategy to eliminate HIV, which would “maximize the efficiency of resource utilization.” In addition, the strategy would take into consideration important factors such as settlement patterns, and population density, as well as “spatial diffusion of the epidemic.” With their strategy, the researchers would be able to “minimize the area in Lesotho that needs to be covered” in order to both identify and treat infected individuals.
“To develop effective strategies, we need to figure out—throughout entire countries—where HIV-infected individuals live and which communities are connected to each other,” Dr. Blower said. “A spatial map can provide all kinds of insight.”
Although strategy choice really lies in the hands of African governments, global health policies and recommendations pertaining to HIV need to be revised in order to consider the new data that has been presented, Dr. Blower concluded.