Targeting the use of pooled HIV RNA screening to reduce cost in health department STD clinics: New York City, 2009-2011.

OBJECTIVE: Staff at public New York City sexually transmitted disease (STD) clinics screen patients for acute HIV infection (AHI) using pooled nucleic acid amplification tests. AHI screening is expensive but important for populations at high risk of acquiring HIV. We analyzed if targeting AHI screening in STD clinics could reduce program costs while maintaining AHI case detection. METHODS: From January 2009 through May 2010, we screened all patients with negative rapid HIV tests for AHI. Using risk information on cases detected during this universal screening period, we developed criteria for targeted AHI screening and compared case yields and testing costs during 12 months of universal screening (June 2009 through May 2010) vs. 12 months of targeted screening (June 2010 through May 2011). RESULTS: During the defined period of universal screening, we identified 40 AHI cases, and during targeted screening, we identified 35 AHI cases. Because of targeting efforts, the number needed to test to find one AHI case dropped from 1,631 to 254. With targeted screening, it cost an average of $4,535 per case detected and 39.3 cases were detected per 10,000 specimens; using universal screening, $29,088 was spent per case detected and 6.1 cases were detected per 10,000 specimens processed. CONCLUSION: Targeted screening identified similar numbers of AHI cases as when screening all clinic patients seeking HIV testing, but at one-seventh the cost.

Comparison of Multispot EIA with Western blot for confirmatory serodiagnosis of HIV.

BACKGROUND: Recent improvements in the sensitivity of immunoassays (IA) used for HIV screening, coupled with increasing recognition of the importance of rapid point-of-care testing, have led to proposals to adjust the algorithm for serodiagnosis of HIV so that screening and confirmation can be performed using a dual or triple IA sequence that does not require Western blotting for confirmation. One IA that has been proposed as a second or confirmatory test is the Bio-Rad Multispot(®) Rapid HIV-1/HIV-2 Test. This test would have the added advantage of differentiating between HIV-1 and HIV-2 antibodies. OBJECTIVE: To compare the sensitivity and type-specificity of an algorithm combining a 3rd generation enzyme immunoassay (EIA) followed by a confirmatory Multispot with the conventional algorithm that combines a 3rd generation EIA (Bio-Rad GS HIV-1/HIV-2 Plus O EIA) followed by confirmatory Western blot (Bio-Rad GS HIV-1 WB). METHODS: 8760 serum specimens submitted for HIV testing to the New York City Public Health Laboratory between May 22, 2007, and April 30, 2010, tested repeatedly positive on 3rd generation HIV-1-2+O EIA screening and received parallel confirmatory testing by WB and Multispot (MS). RESULTS: 8678/8760 (99.1%) specimens tested WB-positive; 82 (0.9%) tested WB-negative or indeterminate (IND). 8690/8760 specimens (99.2%) tested MS-positive, of which 14 (17.1%) had been classified as negative or IND by WB. Among the HIV-1 WB-positive specimens, MS classified 26 (0.29%) as HIV-2. Among the HIV-1 WB negative and IND, MS detected 12 HIV-2. CONCLUSION: MS detected an additional 14 HIV-1 infections among WB negative or IND specimens, differentiated 26 HIV-1 WB positives as HIV-2, and detected 12 additional HIV-2 infections among WB negative/IND. A dual 3rd generation EIA algorithm incorporating MS had equivalent HIV-1 sensitivity to the 3rd generation EIA-WB algorithm and had the added advantage of detecting 12 HIV-2 specimens that were not HIV-1 WB cross-reactors. In this series an algorithm using EIA followed by MS would have resulted in the expedited referral of 38 specimens for HIV-2 testing and 40 specimens for nucleic acid confirmation. Further testing using a combined gold standard of nucleic acid detection and WB is needed to calculate specificity and validate the substitution of MS for WB in the diagnostic algorithm used by a large public health laboratory.

HIV type 2 in New York City, 2000-2008.

BACKGROUND: Antibody cross-reactivity complicates differential diagnosis of human immunodeficiency virus (HIV) type 2 (HIV-2) using standard serologic screening and confirmatory tests for HIV. HIV type 1 (HIV-1) viral load testing does not detect HIV-2. Although HIV-2 is, in general, less pathogenic than HIV-1, it can lead to immunosuppression and clinical AIDS, and there are important differences in the selection of antiretroviral therapy for HIV-2-related immunosuppression that make it imperative to differentiate between the 2 viruses. The New York City Department of Health (New York, NY) seeks to facilitate accurate diagnosis and surveillance of HIV-2 infection in the city. METHODS: We used routine HIV-1-2+O screening and a comprehensive algorithm to differentiate between HIV-1 and HIV-2 infection, universal HIV-related laboratory test reporting, population-based surveillance of HIV infection, and active communication with clinicians. RESULTS: Between 1 June 2000 and 31 December 2008, 62 persons received a diagnosis of confirmed or probable HIV-2 infection. The majority (60 [96.8%] of 62 individuals) were foreign-born (96.7% were born in Africa) and of black race/ethnicity (93.5%). At the time of initial diagnosis, 17.7% of patients with HIV-2 infection had AIDS. Forty (64.5%) of the patients received an initial diagnosis of HIV-1 infection. Among these patients, the median lag between initial diagnosis of HIV-1 infection and identification of HIV-2 as the infecting organism was 487.5 days. CONCLUSION: HIV-2 should be ruled out in persons presenting for HIV testing who originate in or travel to West Africa and other areas in which HIV-2 is endemic, particularly those who have negative or indeterminate results on HIV-1 Western blot testing or have atypical banding patterns and/or present with clinical signs of HIV infection or unexplained immunosuppression.