NEEMA Funded Projects by Topic Area – HIV
NEEMA 2.0 (2019-2024)
Mitigation strategies to reduce the spread of COVID-19, such as social distancing and stay-at-home orders, may impact HIV epidemiology in at least two different ways. On the one hand, stay-at-home orders may reduce opportunities for sexual transmission among people who do not live together. On the other hand, reduced access to HIV testing and possibly to care and biomedical prevention could lead to additional opportunities for transmission. This modeling project aims to disentangle these potentially differing effects, leading to a clearer understanding of the independent effects and to a proactive strategy for prevention during possible future social distancing or stay-at-home mitigation strategies.
The Ending the HIV Epidemic: A Plan for America (EHE) aims to reduce new HIV infections by 75% in five years and by 90% in 10 years. The initiative leverages critical scientific advances in HIV prevention, diagnosis, treatment, and outbreak response. This project builds on an existing network model for transmission of HIV among MSM to include interventions that would specifically identify and screen partners of MSM with HIV or at higher risk for infection. This project will model one approach to support efforts to address the fourth pillar of the EHE plan, “Respond,” to rapidly detect and respond to growing clusters of HIV infections.
Significant disparities have led to disproportionate HIV prevalence among some racial and ethnic groups. Additional improvement in viral suppression and PrEP coverage will be needed to address these disparities and achieve the EHE goals for each racial and ethnic group and the overall population. Prior agent-based models that include racial groups have focused on MSM alone and did not address the 19% of new diagnoses that occur in women. This project will integrate two agent-based network models (for heterosexual people and MSM, respectively) into a single unified population model of HIV transmission, expand those models to include additional ethnic groups (Hispanic/Latino), and determine the increase in viral suppression and PrEP coverage necessary for each racial and ethnic group to reach EHE goals over the next 10 years.
Sexually transmitted infections (STIs) can increase the risk of getting or transmitting HIV. A previous studyexternal icon found that overall, an estimated 10% of HIV infections were attributable to gonorrhea and chlamydia infection. This project builds on the previous study to estimate the probability of gonorrhea or chlamydia infection leading to an HIV infection. This project also aims to estimate the cost-effectiveness of gonorrhea and chlamydia screening programs on reducing HIV incidence among MSM in the United States.
Estimating the size of sexually active adult and adolescent populations at a sub-national level (e.g., county) would improve the local understanding of disease burden of STIs, including HIV. These estimates would also facilitate comparisons of disease rates, including syphilis and HIV, between MSM and other populations. Building on the methods used to estimate the size of the MSM population, this project will develop state and county-level estimates for the population of men who have sex with women (exclusively), women who have sex with men, and sexually active adolescent sexual minority males, overall and by race and ethnicity. These estimates can then be used to generate estimates of disease rates for each of these population groups.
In the United States, injection is an increasingly common and high-risk route of administration for prescription and illicit opioids, as well as other drugs such as methamphetamine. Unsafe injection drug use (IDU) behaviors increase risk for bloodborne infectious diseases such as hepatitis C virus and HIV, making these infectious diseases secondary but deleterious consequences of the opioid crisis for PWID. Due to the stigmatized and illicit nature of non-medical IDU, population-level prevalence is difficult to measure using survey methods typically used to monitor health-related behaviors. Estimation of the national population size of PWID is critical for informing infectious disease prevention efforts among PWID. The current national PWID population size estimate is based on household survey data from 2011 and does not reflect current opioid and methamphetamine injection. This project will update the PWID prevalence estimates nationally and for specific subpopulations of interest.
PWID are at high risk for multiple bloodborne and sexually transmitted infections, including HCV and HIV. National and state-level planning for SSPs and MOUD rely on accurate estimation of PWID population size and understanding how these interventions impact HCV and HIV transmission, as well as other bloodborne infections, among PWID. The particular structure of injection networks and sexual networks among PWID leads to heterogeneous risks of infection transmission and acquisition across the PWID population. In addition to SSPs and MOUD, many other preventive strategies are available for both HCV and HIV, including biomedical interventions (e.g., HIV pre-exposure prophylaxis, HIV treatment, HCV treatment) and behavioral interventions (e.g., promoting safer injection practices, condom use). Interventions can interact with each other and generate synergistic (or antagonistic) effects on the prevention of HCV and HIV. What determines the optimal intervention package is unknown. This project will extend the existing agent-based network model of HCV transmission among PWID to: (1) determine the levels of SSP coverage needed to reduce new HIV and HCV infections among PWID by 25%, 50% and 90%; (2) compare the population health and economic impacts of different levels of program coverage for opioid use disorder; (3) identify intervention combinations among the different prevention strategies that may produce substantial reductions in HCV and HIV burden among PWID; and (4) compare the cost-effectiveness of different intervention packages.