The Organization, Content, and Case-Finding Effectiveness of HIV Assisted Partner Services in High HIV Morbidity Areas of the U.S

Background: Assisted partner services (APS) are a longstanding component of public health efforts to control HIV in the United States, but their contemporary effectiveness is uncertain. Methods: The study surveyed U.S. state and local health departments that reported > 300 new HIV diagnoses in 2018 and were participating in phase 1 of the Ending the Epidemic Initiative. The study collected data on the content and organization of APS and aggregate data on APS outcomes for 2019. Analyses defined the APS continuum, contact and case-finding indices (i.e., sex partners named and newly diagnosed per index case receiving APS), and estimated staff case-finding productivity. Findings: Fifteen (79%) of 19 jurisdictions responded to the survey, providing APS outcome data for 13 (68%) areas. Most health departments integrated APS with efforts to link index cases and partners to HIV care (93%) and pre-exposure prophylaxis (86%). A total of 18,833 persons were newly diagnosed with HIV in the 13 areas. Health departments initiated APS investigations on 13,899 (74%) cases and offered and provided APS to 12,338 (66%) and 9,733 (52%) index cases, respectively. Cases named 6,704 partners (contact index=0.69), of whom 2,650 (39%) had previously diagnosed HIV, 2,134 (32%) tested HIV negative, 516 (7.7% of named and 19% of tested partners) were newly diagnosed with HIV, and 2,239 (33%) were not known to have tested. Across all jurisdictions, the case-finding index was 0.053 (median=0.047, range 0.015-0.10). Health departments employed 288 full-time equivalent staff to provide APS. These staff interviewed a mean of 43 index cases annually, identifying a median of 1.8 new HIV infections in partners per staff per year. APS accounted for 2.7% of new diagnoses in 2019. Interpretation: HIV case-finding resulting from APS in the U.S. is low, reflecting low contact elicitation and attrition at each step along the continuum from case initiation to partner testing. Funding Information: Research was supported by NIH award AI027757. Declaration of Interests: None to declare. Ethics Approval Statement: The University of Washington institutional review board (IRB) defined the study as exempt from the need for IRB review.