Background: Public health strategies are required to identify more early HIV infections. Adding nucleic acid testing (NAT) to HIV antibody  testing can make routine diagnosis of antibody^- acute HIV infection possible. The CDC’s STARHS algorithm also identifies antibody⁺ clients with recent (<170d) seroconversion.

Methods:  For 1 month in 2001, and since November 2002, North Carolina’s 110 public HIV-testing sites have offered enhanced VCT. Following EIA/WB testing, antibody^- specimens are pooled 1:10:90, then screened by NucliSens NAT; only NAT⁺ pools are broken down.  Since January 2003, Biomek FX robotic pooling has been used. Antibody^- NAT⁺ clients are notified by a rapid response team providing counseling, confirmatory testing, partner notification, and entry to care.  Antibody⁺ specimens undergo STARHS testing.

Results: Of 109,788 clients tested through October 1, 2003, 622 were HIV infected (prevelance = 56.7 per 10,000). Of these, 21 had NAT⁺ antibody^- acute HIV infection (prevelance =1.9 per 10,000). Of the 591antibody⁺ retested by STARHS, 121 had recent infection (prevelance =15.0 per 10,000).  For clients not previously HIV⁺, NAT added +4.1% to the diagnostic yield of antibody testing (in jails:  +11.1%; in STD clinics:  +6.4%).  Using manual pooling 3 false positive NATs occurred (n = 22,315, PPV = 0.75, Sp = 0.9999) vs 0 with robotic pooling (n = 88,428, PPV = 1.0000, Sp = 1.0000). Of 21 clients with acute HIV infection, 19  (including 1 pregnant woman) have been entered into care and offered ART.  For North Carolina women receiving universal prenatal HIV testing, annual incidence (estimated by STARHS) was 0.08%. Testing sites with highest unadjusted incidence estimates were stand-alone testing sites (1.01%), urban community health centers (0.94%), jails (0.47%), and sexually transmitted diseases clinics (0.23%).  All cases of acute or recent HIV infection have been located and mapped. Factors significantly associated with  HIV infection in North Carolina in 2002-2003 included male gender, MSM status, African American ethnicity, and age younger than 24 years.  HIV⁺ transmitters have been characterized for most cases of acute HIV infection.  Sexual and social networks associated with active HIV transmission have been newly identified and targeted for prevention activities.

Conclusions:  With HIV VCT enhanced by NAT, public helath programs can actively monitor HIV transmission in populations by identifying incident infections in real-time. The additional cases identified by NAT are those with maximm potential for secondary spread. The Screening and Tracing Active Transmission (STAT) program is a new model for increasing effectiveness of VCT-based HIV surveillance and prevention programs.

Keywords: Voluntary Counseling and Testing; Acute/Primary HIV Infection; HIV RNA