Alexandra M. Oster

Interim guidelines for prevention of sexual transmission of Zika virus — United States, 2016

Zika virus is a mosquito-borne flavivirus primarily transmitted by Aedes aegypti mosquitoes (1,2). Infection with Zika virus is asymptomatic in an estimated 80% of cases (2,3), and when Zika virus does cause illness, symptoms are generally mild and self-limited. Recent evidence suggests a possible association between maternal Zika virus infection and adverse fetal outcomes, such as congenital microcephaly (4,5), as well as a possible association with Guillain-Barré syndrome. Currently, no vaccine or medication exists to prevent or treat Zika virus infection. Persons residing in or traveling to areas of active Zika virus transmission should take steps to prevent Zika virus infection through prevention of mosquito bites (http://www.cdc.gov/zika/prevention/).

Understanding disparities in HIV infection between black and white MSM in the United States.

Objective:We evaluated several hypotheses for disparities in HIV infection between black and white MSM in the United States, including incarceration, partner HIV status, circumcision, sexual networks, and duration of infectiousness. Design:The 2008 National HIV Behavioral Surveillance System (NHBS), a cross-sectional survey conducted in 21 US cities. Methods:MSM were interviewed and tested for HIV infection. For MSM not previously diagnosed with HIV infection, we used logistic regression to test associations between newly diagnosed HIV infection and incarceration history, partner HIV status, circumcision status, and sexual networks (older partners, concurrency, and partner risk behaviors). For HIV-infected MSM, we assessed factors related to duration of infectiousness. Results:Among 5183 MSM not previously diagnosed with HIV infection, incarceration history, circumcision status, and sexual networks were not independently associated with HIV infection. Having HIV-infected partners [adjusted odds ratio (AOR) = 1.9, 95% confidence interval (CI) = 1.2–3.0] or partners of unknown status (AOR = 1.4, CI = 1.1–1.7) were associated with HIV infection. Of these two factors, only one was more common among black MSM – having partners of unknown HIV status. Among previously diagnosed HIV-positive MSM, black MSM were less likely to be on antiretroviral therapy (ART). Conclusion:Less knowledge of partner HIV status and lower ART use among black MSM may partially explain differences in HIV infection between black and white MSM. Efforts to encourage discussions about HIV status between MSM and their partners and decrease barriers to ART provision among black MSM may decrease transmission.

High HIV incidence and prevalence and associated factors among young MSM, 2008

Objective:To estimate HIV prevalence, annual HIV incidence density, and factors associated with HIV infection among young MSM in the United States. Design:The 2008 National HIV Behavioral Surveillance System (NHBS), a cross-sectional survey conducted in 21 US cities. Methods:NHBS respondents included in the analysis were MSM aged 18–24 with a valid HIV test who reported at least one male sex partner in the past year. We calculated HIV prevalence and estimated annual incidence density (number of HIV infections/total number of person-years at risk). Generalized estimating equations were used to determine factors associated with testing positive for HIV. Results:Of 1889 young MSM, 198 (10%) had a positive HIV test; of these, 136 (69%) did not report previously testing HIV positive when interviewed. Estimated annual HIV incidence density was 2.9%; incidence was highest for blacks. Among young MSM who did not report being HIV infected, factors associated with testing HIV positive included black race; less than high school education; using both alcohol and drugs before or during last sex; having an HIV test more than 12 months ago; and reporting a visit to a medical provider in the past year. Conclusion:HIV prevalence and estimated incidence density for young MSM were high. Individual risk behaviors did not fully explain HIV risk, emphasizing the need to address sociodemographic and structural-level factors in public health interventions targeted toward young MSM.

Update: Interim Guidance for Health Care Providers Caring for Women of Reproductive Age with Possible Zika Virus Exposure — United States, 2016

CDC has updated its interim guidance for U.S. health care providers caring for women of reproductive age with possible Zika virus exposure to include recommendations on counseling women and men with possible Zika virus exposure who are interested in conceiving. This guidance is based on limited available data on persistence of Zika virus RNA in blood and semen. Women who have Zika virus disease should wait at least 8 weeks after symptom onset to attempt conception, and men with Zika virus disease should wait at least 6 months after symptom onset to attempt conception. Women and men with possible exposure to Zika virus but without clinical illness consistent with Zika virus disease should wait at least 8 weeks after exposure to attempt conception. Possible exposure to Zika virus is defined as travel to or residence in an area of active Zika virus transmission ( http://www.cdc.gov/zika/geo/active-countries.html), or sex (vaginal intercourse, anal intercourse, or fellatio) without a condom with a man who traveled to or resided in an area of active transmission. Women and men who reside in areas of active Zika virus transmission should talk with their health care provider about attempting conception. This guidance also provides updated recommendations on testing of pregnant women with possible Zika virus exposure. These recommendations will be updated when additional data become available.

HIV Infection and Awareness among Men Who Have Sex with Men–20 Cities, United States, 2008 and 2011

Over half of HIV infections in the United States occur among men who have sex with men (MSM). Awareness of infection is a necessary precursor to antiretroviral treatment and risk reduction among HIV-infected persons. We report data on prevalence and awareness of HIV infection among MSM in 2008 and 2011, using data from 20 cities participating in the 2008 and 2011 National HIV Behavioral Surveillance System (NHBS) among MSM. Venue-based, time-space sampling was used to recruit men for interview and HIV testing. We analyzed data for men who reported ≥1 male sex partner in the past 12 months. Participants who tested positive were considered to be aware of their infection if they reported a prior positive HIV test. We used multivariable analysis to examine differences between results from 2011 vs. 2008. HIV prevalence was 19% in 2008 and 18% in 2011 (p = 0.14). In both years, HIV prevalence was highest among older age groups, blacks, and men with lower education and income. In multivariable analysis, HIV prevalence did not change significantly from 2008 to 2011 overall (p = 0.51) or in any age or racial/ethnic category (p>0.15 in each category). Among those testing positive, a greater proportion was aware of their infection in 2011 (66%) than in 2008 (56%) (p<0.001). In both years, HIV awareness was higher for older age groups, whites, and men with higher education and income. In multivariable analysis, HIV awareness increased from 2008 to 2011 overall (p<0.001) and for all age and racial/ethnic categories (p<0.01 in each category). In both years, black MSM had the highest HIV prevalence and the lowest awareness among racial/ethnic groups. These findings suggest that HIV-positive MSM are increasingly aware of their infections.

Rapid HIV Testing in Transgender Communities by Community-Based Organizations in Three Cities

Objectives. This article describes the demographic and behavioral characteristics, human immunodeficiency virus (HIV) testing history, and results of HIV testing of transgender (TG) people recruited for rapid HIV testing by community-based organizations (CBOs) in three cities. Methods. CBOs in Miami Beach, Florida, New York City, and San Francisco offered TG people rapid HIV testing and prevention services, and conducted a brief survey. Participants were recruited in outreach settings using various strategies. The survey collected information on demographic characteristics, HIV risk behaviors, and HIV testing history. Results. Among 559 male-to-female (MTF) TG participants, 12% were newly diagnosed with HIV infection. None of the 42 female-to-male participants were newly diagnosed with HIV. A large proportion of MTF TG participants reported high-risk behaviors in the past year, including 37% who reported unprotected receptive anal intercourse and 44% who reported commercial sex work. Several factors were independently associated with increased likelihood of being newly diagnosed with HIV infection among MTF TG participants, including having a partner of unknown HIV status in the past year; being 20–29 or ≥40 years of age; having last been tested for HIV more than 12 months ago; and having been recruited at the New York City site. Conclusions. Based on the high proportion of undiagnosed HIV infection among those tested, TG people represent an important community for enhanced HIV testing and prevention efforts. MTF TG people should be encouraged to have an HIV test at least annually or more often if indicated, based upon clinical findings or risk behaviors. Efforts should continue for developing novel strategies to overcome barriers and provide HIV testing and prevention services to TG people.

Missed Opportunities for HIV Testing in Health Care Settings Among Young African American Men Who Have Sex with Men: Implications for the HIV Epidemic

Limited health care access and missed opportunities for HIV and other sexually transmitted infection (STI) education and testing in health care settings may contribute to risk of HIV infection. In 2008, we conducted a case-control study of African American men who have sex with men (MSM) in a southeastern city (Jackson, Mississippi) with an increase in numbers of newly reported HIV cases. Our aims were to evaluate associations between health care and HIV infection and to identify missed opportunities for HIV/STI testing. We queried 40 potential HIV-infected cases and 936 potential HIV-uninfected controls for participation in this study. Study enrollees included HIV-infected cases (n=30) and HIV-uninfected controls (n=95) who consented to participate and responded to a self-administered computerized survey about sexual risk behaviors and health care utilization. We used bivariate analysis and logistic regression to test for associations between potential risk factors and HIV infection. Cases were more likely than controls to lack health insurance (odds ratio [OR]=2.5; 95% confidence interval [CI]=1.1-5.7), lack a primary care provider (OR=6.3; CI=2.3-16.8), and to not have received advice about HIV or STI testing or prevention (OR=5.4; CI=1.3-21.5) or disclose their sexual identity (OR=7.0; CI=1.6-29.2) to a health care provider. In multivariate analysis, lacking a primary health care provider (adjusted odds ratio [AOR]=4.5; CI=1.4-14.7) and not disclosing sexual identity to a health care provider (AOR=8.6; CI=1.8-40.0) were independent risk factors for HIV infection among African American MSM. HIV prevention interventions for African American MSM should address access to primary health care providers for HIV/STI prevention and testing services and the need for increased discussions about sexual health, sexual identity, and sexual behaviors between providers and patients in an effort to reduce HIV incidence and HIV-related health disparities.

Using Molecular HIV Surveillance Data to Understand Transmission Between Subpopulations in the United States.

Background:Studying HIV transmission networks provides insight into the spread of HIV and opportunities for intervention. We identified transmission dynamics among risk groups and racial/ethnic groups in the United States. Methods:For HIV-1 pol sequences reported to the US National HIV Surveillance System during 2001–2012, we calculated pairwise genetic distance, identified linked pairs of sequences (those with distance ⩽1.5%), and examined transmission category and race/ethnicity of these potential transmission partners. Results:Of 40,950 sequences, 12,910 (32%) were linked to ≥1 other sequence. Of men who have sex with men (MSM) who were linked to ≥1 sequence, 88% were linked to other MSM and only 4% were linked to heterosexual women. Of heterosexual women for whom we identified potential transmission partners, 29% were linked to MSM, 21% to heterosexual men, and 12% to persons who inject drugs. Older and black MSM were more likely to be linked to heterosexual women. Assortative mixing was present for all racial/ethnic groups; 81% of blacks/African Americans linked to other blacks. Conclusions:This analysis is the first use of US surveillance data to infer an HIV transmission network. Our data suggest that HIV infections among heterosexual women predominantly originate from MSM, followed by heterosexual men. Although few MSM were linked to women, suggesting that a minority of MSM are involved in transmission with heterosexual women, these transmissions represent a substantial proportion of HIV acquisitions by heterosexual women. Interventions that reduce transmissions involving MSM are likely to also reduce HIV acquisition among other risk groups.

Update: Interim Guidance for Prevention of Sexual Transmission of Zika Virus--United States, 2016.

CDC issued interim guidance for the prevention of sexual transmission of Zika virus on February 5, 2016. The following recommendations apply to men who have traveled to or reside in areas with active Zika virus transmission and their female or male sex partners. These recommendations replace the previously issued recommendations and are updated to include time intervals after travel to areas with active Zika virus transmission or after Zika virus infection for taking precautions to reduce the risk for sexual transmission. This guidance defines potential sexual exposure to Zika virus as any person who has had sex (i.e., vaginal intercourse, anal intercourse, or fellatio) without a condom with a man who has traveled to or resides in an area with active Zika virus transmission. This guidance will be updated as more information becomes available.

Disparities in HIV transmission risk among HIV-infected black and white men who have sex with men, United States, 2009

Objective:To better understand why HIV incidence is substantially higher among black than white men who have sex with men (MSM), we present the first nationally representative estimates of factors that contribute to transmission – sexual behavior, antiretroviral therapy (ART) use, and viral suppression – among HIV-infected black and white MSM in the United States. Design:The Medical Monitoring Project (MMP) is a complex sample survey of HIV-infected adults receiving medical care in the United States. Methods:We used weighted interview and medical record data collected during June 2009 to May 2010 to estimate the prevalence of sexual behaviors, ART use, and viral suppression among sexually active HIV-infected black and white MSM. We used &khgr;2 tests to assess significant differences between races and logistic regression models to identify factors that mediated the racial differences. Results:Sexual risk behaviors among black and white MSM were similar. Black MSM were significantly less likely than white MSM to take ART (80 vs. 91%) and be durably virally suppressed (48 vs. 69%). Accounting for mediators (e.g. age, insurance, poverty, education, time since diagnosis, and disease stage) reduced, but did not eliminate, disparities in ART use and rendered differences in viral suppression among those on ART insignificant. Conclusion:Lower levels of ART use and viral suppression among HIV-infected black MSM may increase the likelihood of HIV transmission. Addressing the patient-level factors and structural inequalities that contribute to lower levels of ART use and viral suppression among this group will improve clinical outcomes and might reduce racial disparities in HIV incidence.