Acute HIV Infection -- New York City, 2008

The following feasibility study describes a pilot surveillance and screening program to detect acute HIV infection (AHI). Diagnoses of AHI can enable recently infected persons to adopt behaviors that reduce transmission, facilitate partner referral for counseling and testing, and identify high-risk social networks.

In May 2008, the city Department of Health and Mental Hygiene initiated pooled nucleic acid amplification testing (p-NAAT) at four STD clinics. Based on HIV testing volume, p-NAAT screening sites were located at clinics in Queens, Manhattan, Brooklyn, and the Bronx. In addition, the department (DOHMH) enhanced citywide HIV surveillance with a case definition to differentiate acute HIV infection (AHI) among new HIV diagnoses.

From May 5 to December 31, 2008, 70 of 3,635 reported HIV diagnoses (1.9 percent) were identified as AHI. Of the 70 AHI, 53 were found through enhanced surveillance, including 40 (75 percent) on the basis of laboratory criteria. The STD clinics performed 21,425 rapid antibody tests, of which 184 (0.9 percent) were HIV-positive. Among the 21,241 HIV-negative specimens, 17 additional AHI were discovered, for 9 percent of the clinics' 198 HIV-positive diagnoses.

Among STD clinic patients with AHI, the median age was 28 years (range: 19-42 years), and all males were men who have sex with men (MSM), including three reporting sex with men and women. The one female case reported commercial sex work and injection drug use. Seroconversion was confirmed by Western blot in all 16 patients who returned for follow-up testing and evaluation.

Nine STD clinic AHI patients were documented in the city STD registry, with seven having had previous and two having concurrent syphilis infection. Patients reported an average four sex partners, and of 44 total partners reported, 36 (82 percent) were able to be notified of HIV exposure. Among them, 16 (44 percent) reported HIV-positive status subsequently documented in the city's Surveillance Registry. Of the 20 who did not know their status, 16 agreed to testing, and one was HIV antibody-positive.

Among the 53 AHI cases found through enhanced surveillance, the median age of the 50 men and three women was 32 years (range: 15-62 years), and 23 were diagnosed at hospitals (43 percent), 17 at private physician offices (32 percent), 12 at community clinics (23 percent), and one at a college clinic (2 percent). Among the males, 41 (82 percent) reported having sex with men.

The findings confirm that "p-NAAT can increase AHI diagnoses among high-risk STD clinic patients, and indicate that AHI diagnoses can be made apart from p-NAAT screening programs," says an editorial note. "Based on the results, NYC DOHMH has expanded p-NAAT screening to all nine New York City STD clinics and improved ascertainment of AHI in routine surveillance."