The overall goal of this project is to implement and evaluate a community-level, structured approach to enhance HIV care access and retention for drug users in San Juan, Puerto Rico. The "Enhanced HIV Care Access and Retention Intervention" will: 1) identify drug users living with HIV who either do not know their HIV status and/or are not engaged in HIV care; 2) provide direct HIV care services through a mobile health van; and 3) support identified HIV-infected drug users with patient navigators to enhance their ability to engage in HIV care and substance abuse treatment, to initiate antiretroviral therapy, and maintain adherence to their treatment regimens. The structural enhanced care approach will be evaluated through a randomized roll-out design, a refinement of the stepped-wedge design. The community-level success of the intervention will be assessed by evaluating virologic suppression (primary biological outcome), increased attendance to HIV care visits, uptake of antiretroviral therapy, adherence to HIV treatment regimens, and decreased substance use (as secondary behavioral outcomes) in an independent cohort of HIV-positive individuals drawn from each of the neighborhoods included in the intervention. The investigators will also evaluate the implementation process and cost of the enhanced care approach including implications for cost-effectiveness, feasibility of expansion, and sustainability.

Recent scientific advances demonstrate that for people living with HIV, antiretroviral therapy (ART) is the most effective strategy to improve immune function, reduce morbidity, improve quality of life, prolong survival, and prevent HIV transmission. Translating this knowledge into practice, however, requires prompt diagnosis and linkage to care, entry into care with timely ART initiation, and engagement in care, support for ART adherence, and retention to promote durable viral suppression. Addressing failures in this cascade of care, often referred to as the "Seek, Test, Treat, and Retain (STTR)" paradigm, has become a major part of the National HIV/AIDS strategy in the United States. To date, much of the research and discussion surrounding this strategy has focused on expanding HIV testing to improve the early identification of new cases. There has been less attention focused on linkage to, engagement in, and retention in care. Specifically, little attention has focused on identifying HIV-positive individuals who, despite being aware of their diagnosis, have never been in HIV care, are intermittent users of care, or have dropped out of care.

HIV-infected injection drug users (IDUs) are a particularly difficult subpopulation to link to and retain in HIV care. They face a myriad of challenges that can impede retention in care including substance use disorders (both alcohol and drugs), mental health problems and poverty-related issues such as unstable housing and food insecurity. If IDUs adhere to their treatment regimens, however, studies have demonstrated they realize similar survival benefits from antiretroviral therapy as persons without a history of injection drug use. In contrast to the majority of communities in the U.S., in Puerto Rico, drug use, particularly injection drug use, continues to fuel a fast-growing HIV epidemic. Puerto Rico has an estimated incidence rate of 45 HIV cases per 100,000 population, twice the rate for the 50 U.S. states, and almost 40% of new infections are associated with injection drug use. In contrast, only 12% of new infections in the 50 U.S. states are among IDUs.

The overall goal of this project is to implement and evaluate a community-level, structured enhanced approach, the Enhanced HIV Care Access and Retention Intervention, for substance users in San Juan, Puerto Rico. It will bring HIV care directly to five San Juan zones in which a high proportion of HIV-infected substance users reside. The significance of the study is threefold.f care, or have dropped out of care.

HIV Testing Campaign

Inclusion Criteria:

1. be 18 years of age or older
2. report having injected drugs (opioid or stimulants) at least once in the past 30 days
3. provide written informed consent

HIV Care Cohort

Inclusion Criteria:

1. be 18 years of age or older
2. test HIV-seropositive through rapid testing (confirmed with Western Blot or immunofluorescence assay)
3. report having injected drugs more than once per week for the past 30 days
4. self-report that they have not been in HIV care for the past 6 months
5. agree to have their blood drawn for CD4 and HIV plasma RNA testing
6. live in one of the San Juan neighborhoods targeted for intervention
7. provide basic contact information for follow-up
8. sign a HIPAA Authorization/medical record release form
9. provide written informed consent

Assessment Cohort

Inclusion Criteria:

1. be 18 years of age or older
2. test HIV-seropositive through rapid testing (confirmed with Western Blot or immunofluorescence assay)
3. report having injected drugs more than once per week for the past 30 days
4. self-report that they have not been in HIV care for the past 6 months
5. agree to have their blood drawn for CD4 and HIV plasma RNA testing
6. live in one of the San Juan neighborhoods targeted for intervention
7. provide basic contact information for follow-up
8. sign a HIPAA Authorization/medical record release form
9. provide written informed consent

Exclusion Criteria (for all study components mentioned above):

1. do not meet any one or more of the above-described inclusion criteria
2. have significant cognitive or developmental impairment to the extent that they are unable to provide informed consent
3. are terminated via Site PI decision