Estimated HIV Incidence in California, 2006–2009

Susan Scheer,Chi-Sheng Chin,Dan Sun,Mark Damesyn,Anthony Buckman,Shoshanna Nakelsky,Trista Bingham,Karen E Mark,Omar Sued

doi:10.1371/journal.pone.0055002

Abstract

IntroductionAccurate estimates of HIV incidence are crucial for prioritizing, targeting, and evaluating HIV prevention efforts. Using the methodology the CDC used to estimate national HIV incidence, we estimated HIV incidence in Los Angeles County (LAC), San Francisco (SF), and California’s remaining counties.MethodsWe estimated new HIV infections in 2006–2009 among adults and adolescents in LAC, SF and the remaining California counties using the Serologic Testing Algorithm for Recent Seroconversion (STARHS). STARHS methodology uses the BED HIV-1 capture enzyme immunoassay to determine recent HIV infections by testing remnant serum from persons newly diagnosed with HIV. A population-based incidence estimate is calculated using HIV testing data from newly diagnosed cases and imputing for persons unaware of their HIV infection.ResultsFor years 2007–2009, respectively, we estimated new infections in LAC to be 2426 (95% CI 1871–2982), 1669 (CI 1309–2029) and 1898 (CI 1452–2344) (p<0.01); in SF for 2006–2009, 492 (CI 327–657), 490 (CI 335–646), 458 (CI 342–574) and 367 (CI 261–473) (p = 0.14); and in the remaining California counties in 2008–2009, 2526 (CI 1688–3364) and 2993 (CI 2141–3846) respectively. HIV infection rates among men who have sex with men (MSM) in LAC were 100 times higher than other risk populations; the SF MSM rate was 3 to 18 times higher than other demographic groups. In LAC, incidence rates among African-Americans were twice those of whites and Latinos; persons 40 years or older had lower rates of infection than younger persons.DiscussionWe report the first HIV incidence estimates for California, highlighting geographic disparities in HIV incidence and confirming national findings that MSM and African-Americans are disproportionately impacted by HIV. HIV incidence estimates can and should be used to target prevention efforts towards populations at highest risk of acquiring new HIV infections, focusing on geographic, racial and risk group disparities.

Highlights

Accurate estimates of HIV incidence are crucial for prioritizing, targeting, and evaluating HIV prevention efforts
Each jurisdiction estimated the number of persons aged 13 years or older newly infected with HIV in their geographic areas using Serologic Testing Algorithm for Recent Seroconversion (STARHS) and the stratified extrapolation method previously reported and described [3,8]
For all years San Francisco County reported the highest completeness rate for HIV testing history collection and BED test results followed by Los Angeles and all other California counties

Summary

Introduction

Accurate estimates of HIV incidence are crucial for prioritizing, targeting, and evaluating HIV prevention efforts. Using the methodology the CDC used to estimate national HIV incidence, we estimated HIV incidence in Los Angeles County (LAC), San Francisco (SF), and California’s remaining counties. One of the key goals of the NHAS is to reduce the number of new HIV infections by 25 percent by 2015. Accurate estimates of newly acquired HIV infections are crucial for prioritizing, targeting, and evaluating HIV prevention and disease control efforts. The Centers for Disease Control and Prevention (CDC) implemented a sentinelbased, national HIV Incidence Surveillance (HIS) system in 2004 to monitor the number and rates of new HIV infections in the U.S and has recently released annual incidence estimates for 2006–. Data from the three California HIS sites have not yet been included in the nationwide estimates due to the recency of California’s implementation of name-based HIV reporting in April 2006 compared with other states’ more mature systems

Methods

Results

Conclusion