Acute HIV infection - New York City, 2008.

Acute human immunodeficiency virus (HIV) infection (AHI) is a highly infectious phase of disease that lasts approximately 2 months and is characterized by nonspecific clinical symptoms. AHI contributes disproportionately to HIV transmission because it is associated with a high level of viremia, despite negative or indeterminate antibody (Ab) tests. Diagnosis of AHI with individual or pooled nucleic acid amplification tests (p-NAAT) can enable infected persons to adopt behaviors that reduce HIV transmission, facilitate partner referral for counseling and testing, and identify social networks of persons with elevated rates of HIV transmission. The national HIV surveillance case definition does not distinguish AHI from other stages of HIV infection, and the frequency of AHI among reported HIV cases is unknown. In 2008, to increase detection of AHI and demonstrate the feasibility of AHI surveillance, the New York City Department of Health and Mental Hygiene (NYC DOHMH) initiated p-NAAT screening at four sexually transmitted disease (STD) clinics and enhanced citywide HIV surveillance (using a standard case definition) to differentiate AHI among newly reported cases. Seventy cases of AHI (representing 1.9% of all 3,635 HIV diagnoses reported in New York City) were identified: 53 cases from enhanced surveillance and 17 cases from p-NAAT screening (representing 9% of 198 HIV diagnoses at the four clinics). Men who have sex with men (MSM) constituted 81% of AHI cases. Screening STD clinic patients, especially MSM, with p-NAAT can identify additional cases of HIV infection. Surveillance for AHI is feasible and can identify circumstances in which HIV prevention efforts should be intensified.