Background:   Since November 2002, all 135 public HIV-testing sites in North Carolina have used a combined HIV antibody and RNA testing algorithm through the State Laboratory of Public Health. In the NC Department of Health and Human Services Screening & Tracing Active Transmission (STAT) program, disease intervention specialists provide urgent notification and partner counseling and referral services to all clients with RNA⁺ antibody results.

Methods:  To evaluate performance and effect of rapid STAT partner counseling and referral services in the setting of acute HIV infection, information was collected at all client interviews on index and contact symptoms, risk factors, partnership-specific behaviors, and notification, counseling, and testing outcomes. Transmission to sexual partners was documented by serial HIV testing of high-risk partners for HIV seroconversion. Transmission rates per act were estimated based on unprotected acts <45 days of acute index case diagnosis or <7 days of acute retroviral symptoms onset.

Results:  Of 227,566 public tests in NC from November 1, 2002 to October 31, 2004, 404 clients were previously HIV⁺; 1123 were newly antibody⁺; 48 additional clients were RNA⁺/antibody^­; 44 (92%) were true acute infections and 4 were false-positive RNA results. We successfully interviewed 41 true acute; index cases noted 69 anonymous and 130 named individuals who were contacts (4.85 total, 3.17 named contacts/interview). Of 130 clients, 102 (78%) named contacts who received successful partner counseling and referral services. Of the contacts, 39% were HIV⁺; 21 HIV⁺ contacts who were interviewed and counseled were classified as likely source patients (0.56 per index interview); 68% of source patients were in HIV care; and 37% had previously been on ART. Seroconversion was documented for 8 of 24 (33%) previously HIV^­ contacts to acutely infected index cases, of whom 3 were themselves acute (still antibody negative) at initial contact. HIV was transmitted by acute HIV cases at a rate >1:13 to 1:18 unprotected coital acts during acute HIV infection.

Conclusions:  Partner counseling and referral services can be highly effective in the setting of acute HIV infection, where it can be focused on individuals with extraordinary immediate risk of transmission (>5% per coital act) and large numbers of risky contacts. Partner counseling and referral services can identify source patients actively transmitting HIV for additional counseling in as many as half of cases; in North Carolina, most source patients are chronically infected.