UK strategy could prevent 7,400 MSM HIV infections by 2020
A national prevention strategy consisting of pre-exposure prophylaxis, expanded testing and early treatment programs is estimated to prevent nearly 7,400 new HIV infections among men who have sex with men in the United Kingdom by 2020, according to an analytical model presented in The Lancet HIV.
“Current prevention efforts in the U.K. that focus on correct and consistent condom use and regular HIV testing have been falling short,” Narat Punyacharoensin, PhD, of the department of infectious diseases epidemiology at the London School of Hygiene & Tropical Medicine, said in a press release. “HIV rates among MSM remain high with around 2,800 MSM becoming infected with HIV in 2014, and the trend shows no sign of abating.
“Our results show that PrEP offers a major opportunity to curb new infections and could help reverse the HIV epidemic among MSM in the U.K.”
An estimated 103,700 people currently are living with HIV in the U.K., and approximately 2,600 MSM in England and Wales are thought to have been infected annually in the past 10 years, Punyacharoensin and colleagues wrote. To predict the burden of new infections and the impact of prevention interventions, the researchers designed a deterministic, partnership-based mathematical model of HIV transmission. The target population of the model was “current” MSM aged 15 to 64 years, defined as men who reported sex with other men within the past 5 years. Demographic and behavioral data were collected from national and community-based surveys, with infectivity rates determined by disease stage, partnership status and activity. With this model, the researchers simulated the impact of seven individual and combined interventions — including PrEP use, testing, treatment, and behavior changes — on infection rates for 2014 to 2020.
Without additional interventions, Punyacharoensin and colleagues’ model estimated 16,955 (interquartile range, 13,156-21,669) new HIV infections among U.K. MSM by 2020, with 52,268 (interquartile range, 45,982-59,794) infected MSM living in the country. Assuming 100% coverage, PrEP alone would prevent 9,955 new infections, while decreasing the proportion of men with repeat sexual partners and biannual testing would individually prevent 7,263 and 7,089 new infections, respectively. Combining interventions often saw diminishing returns, with only the joint implementation of annual testing and test-and-treat programs projecting a reduction greater than the sum of the two individually. Among the more practical scenarios examined by the researchers, a combined strategy of PrEP, annual testing and a test-and-treat program among only 25% of high-activity MSM was estimated to prevent 7,399 (interquartile range, 5,587-9,813) new infections among MSM. The researchers wrote that this level of coverage is feasible, as previous data have shown that as many as half of U.K. MSM are interested in PrEP and treatment-as-prevention program participation.
“Our analysis suggests that a combination of PrEP, expansion of HIV testing and test-and-treat programs implemented in small groups of MSM in the U.K. could prevent thousands from HIV within a few years of implementation, particularly if risk-compensation behavior is successfully avoided,” Punyacharoensin and colleagues wrote. “Integration of this enhanced version of conventional interventions with novel biomedical technologies is likely to deliver the optimum approach to HIV prevention that could determine the future course of the HIV epidemic in the U.K.”
Achieving this level of protection would come with numerous practical considerations for public health, according to Emily A. Arnold, PhD, MPH, and Wayne T. Steward, PhD, MPH, both of the Center for AIDS Prevention Studies at the University of California, San Francisco. In a related editorial, they wrote the scale-up described in the study would require the public health system to greatly strengthen its relationship with community-based organization and medical providers.
“These efforts could parallel those for linking of newly diagnosed individuals from testing to care sites, but they could also take different forms, such as medical providers overseeing PrEP programs at community-based organizations,” they wrote. “The diversified expertise arising from collaboration among these different partners would better position the health care system to address the barriers to uptake and use of PrEP.” – by Dave Muoio
Disclosure: The researchers report no relevant financial disclosures.