Joseph Prejean

Estimation of HIV Incidence in the United States

CONTEXT Incidence of human immunodeficiency virus (HIV) in the United States has not been directly measured. New assays that differentiate recent vs long-standing HIV infections allow improved estimation of HIV incidence. OBJECTIVE To estimate HIV incidence in the United States. DESIGN, SETTING, AND PATIENTS Remnant diagnostic serum specimens from patients 13 years or older and newly diagnosed with HIV during 2006 in 22 states were tested with the BED HIV-1 capture enzyme immunoassay to classify infections as recent or long-standing. Information on HIV cases was reported to the Centers for Disease Control and Prevention through June 2007. Incidence of HIV in the 22 states during 2006 was estimated using a statistical approach with adjustment for testing frequency and extrapolated to the United States. Results were corroborated with back-calculation of HIV incidence for 1977-2006 based on HIV diagnoses from 40 states and AIDS incidence from 50 states and the District of Columbia. MAIN OUTCOME MEASURE Estimated HIV incidence. RESULTS An estimated 39,400 persons were diagnosed with HIV in 2006 in the 22 states. Of 6864 diagnostic specimens tested using the BED assay, 2133 (31%) were classified as recent infections. Based on extrapolations from these data, the estimated number of new infections for the United States in 2006 was 56,300 (95% confidence interval [CI], 48,200-64,500); the estimated incidence rate was 22.8 per 100,000 population (95% CI, 19.5-26.1). Forty-five percent of infections were among black individuals and 53% among men who have sex with men. The back-calculation (n = 1.230 million HIV/AIDS cases reported by the end of 2006) yielded an estimate of 55,400 (95% CI, 50,000-60,800) new infections per year for 2003-2006 and indicated that HIV incidence increased in the mid-1990s, then slightly declined after 1999 and has been stable thereafter. CONCLUSIONS This study provides the first direct estimates of HIV incidence in the United States using laboratory technologies previously implemented only in clinic-based settings. New HIV infections in the United States remain concentrated among men who have sex with men and among black individuals.

Estimated HIV Incidence in the United States, 2006–2009

Background The estimated number of new HIV infections in the United States reflects the leading edge of the epidemic. Previously, CDC estimated HIV incidence in the United States in 2006 as 56,300 (95% CI: 48,200–64,500). We updated the 2006 estimate and calculated incidence for 2007–2009 using improved methodology. Methodology We estimated incidence using incidence surveillance data from 16 states and 2 cities and a modification of our previously described stratified extrapolation method based on a sample survey approach with multiple imputation, stratification, and extrapolation to account for missing data and heterogeneity of HIV testing behavior among population groups. Principal Findings Estimated HIV incidence among persons aged 13 years and older was 48,600 (95% CI: 42,400–54,700) in 2006, 56,000 (95% CI: 49,100–62,900) in 2007, 47,800 (95% CI: 41,800–53,800) in 2008 and 48,100 (95% CI: 42,200–54,000) in 2009. From 2006 to 2009 incidence did not change significantly overall or among specific race/ethnicity or risk groups. However, there was a 21% (95% CI:1.9%–39.8%; p = 0.017) increase in incidence for people aged 13–29 years, driven by a 34% (95% CI: 8.4%–60.4%) increase in young men who have sex with men (MSM). There was a 48% increase among young black/African American MSM (12.3%–83.0%; p<0.001). Among people aged 13–29, only MSM experienced significant increases in incidence, and among 13–29 year-old MSM, incidence increased significantly among young, black/African American MSM. In 2009, MSM accounted for 61% of new infections, heterosexual contact 27%, injection drug use (IDU) 9%, and MSM/IDU 3%. Conclusions/Significance Overall, HIV incidence in the United States was relatively stable 2006–2009; however, among young MSM, particularly black/African American MSM, incidence increased. HIV continues to be a major public health burden, disproportionately affecting several populations in the United States, especially MSM and racial and ethnic minorities. Expanded, improved, and targeted prevention is necessary to reduce HIV incidence.

Reemergence of the HIV epidemic among men who have sex with men in North America, Western Europe, and Australia, 1996-2005.

PURPOSE To describe and contextualize changes in rates of human immunodeficiency virus (HIV) notifications in men who have sex with men (MSM) in eight countries (Australia, Canada, France, Germany, Netherlands, Spain, United Kingdom, and United States) from 1996-2005. METHODS We analyzed trends in HIV notification rates from 1996-2000 and 2000-2005 by generalized linear regression and estimated annual percentage change (EAPC) in rates of HIV notifications. To interpret trends, we visually examined graphs of primary and secondary syphilis reports among MSM and the prevalence of recent HIV testing. RESULTS The rate of HIV notifications among MSM declined 5.2% per year (95% confidence interval [CI]: -5.8%, -4.7%) from 1996-2000, and increased 3.3% per year (95% CI: +2.9%,+3.7%) from 2000-2005. During the period of increasing HIV diagnoses, increases in primary and secondary syphilis diagnoses occurred among MSM, but recent HIV testing among MSM did not seem to increase. CONCLUSIONS After declining in the second half of the 1990s, HIV notification rates for MSM increased beginning in 2000. Increased HIV notifications in MSM are not wholly explained by changes in HIV testing. Urgent efforts are required to develop effective HIV prevention interventions for MSM, and implement them broadly in these countries.

Estimating the Population Size of Men Who Have Sex with Men in the United States to Obtain HIV and Syphilis Rates

Background: CDC has not previously calculated disease rates for men who have sex with men (MSM) because there is no single comprehensive source of data on population size. To inform prevention planning, CDC developed a national population size estimate for MSM to calculate disease metrics for HIV and syphilis. Methods: We conducted a systematic literature search and identified seven surveys that provided data on same-sex behavior in nationally representative samples. Data were pooled by three recall periods and combined using meta-analytic procedures. We applied the proportion of men reporting same-sex behavior in the past 5 years to U.S. census data to produce a population size estimate. We then calculated three disease metrics using CDC HIV and STD surveillance data and rate ratios comparing MSM to other men and to women. Results: Estimates of the proportion of men who engaged in same-sex behavior differed by recall period: past year = 2.9% (95%CI, 2.6–3.2); past five years = 3.9% (3.5–4.4); ever = 6.9% (5.1–8.6). Rates on all 3 disease metrics were much higher among MSM than among either other men or women (38 to 109 times as high). Conclusions: Estimating the population size for MSM allowed us to calculate rates for disease metrics and to develop rate ratios showing dramatically higher rates among MSM than among other men or women. These data greatly improve our understanding of the disproportionate impact of these diseases among MSM in the U.S. and help with prevention planning.

Prevalence of transmitted drug resistance associated mutations and HIV-1 subtypes in new HIV-1 diagnoses, U.S.-2006.

Objective:To determine the distribution of HIV-1 subtypes and the prevalence of transmitted drug resistance-associated mutations (TDRM) among persons newly diagnosed with HIV-1 infection in the United States. Methods:We used sequence data from Variant, Atypical, and Resistant HIV Surveillance (VARHS) collected from newly diagnosed persons in 10 states and 1 county health department in 2006. To evaluate TDRM, we used a mutation list for surveillance of TDRM appropriate for the primarily subtype B HIV epidemic in the United States. Results:Sequences were obtained from 2030 of 10 860 persons newly diagnosed with HIV in 11 surveillance areas. Mutations associated with transmitted drug resistance occurred in 292 (14.6%) persons; TDRM associated with a specific drug class occurred in 156 (7.8%) for non-nucleoside reverse transcriptase inhibitors, 111 (5.6%) for nucleoside reverse transcriptase inhibitors and 90 (4.5%) for protease inhibitors. There were no significant differences in prevalence of TDRM by demographic characteristic. The HIV-1 subtype B was the most prevalent subtype occurring in 1922 (96.2%) persons; subtype C (1.3%) was the most prevalent non-B subtype. Conclusion:We presented a clade B-optimized mutation list for evaluating surveillance of TDRM in the United States and analyzed the largest collection of sequence data obtained from individuals newly diagnosed with HIV. The prevalence of TDRM in persons newly diagnosed with HIV is higher than in previous U.S. studies; however, this is not necessarily a significant trend. Continued reporting of sequence data for public health purposes from all sources will improve representativeness and accuracy in analyzing trends in transmitted drug resistance and genetic diversity.

HIV Prevalence Rates Among Men Who Have Sex with Men in the Southern United States: Population-Based Estimates by Race/Ethnicity

States across the U.S. lack effective ways to quantify HIV prevalence rates among men who have sex with men (MSM). We estimated population-based HIV prevalence rates among MSM in the 17 southern states by race/ethnicity. Through 2007, estimated HIV prevalence rates per 100,000 MSM ranged from 2,607.6 among white (non-Hispanic) MSM in Maryland to 41,512.9 among black (non-Hispanic) MSM in the District of Columbia. Black MSM rates significantly exceeded Hispanic and white MSM rates in each state. Significant racial/ethnic disparities in rates persisted in a sensitivity analysis examining the possibility that minority MSM populations had been underestimated in each state. Compared with black, Hispanic, and white non-MSM males, respectively, rates at the regional level were 25.2 times higher for black MSM, 43.0 times higher for Hispanic MSM, and 106.0 times higher for white MSM. State-level analysis of racial/ethnic-specific MSM HIV prevalence rates can help guide resource allocation and assist advocacy.

Racial/Ethnic Disparities in HIV Diagnoses Among Persons Aged 50 Years and Older in 37 US States, 2005–2008

OBJECTIVES We examined racial/ethnic disparities in HIV diagnosis rates for persons aged 50 years and older. METHODS We analyzed surveillance data from the Centers for Disease Control and Prevention regarding HIV diagnoses during 2005 through 2008 in 37 states. Average annual rates of diagnoses were calculated for persons aged 50 years and older and compared with rates for persons aged 13 to 49 years. RESULTS The average annual rate of diagnosis (per 100,000 persons) for older persons was 9.8. Rates among older Blacks (49.2) and Hispanics/Latinos (19.5) were 12.6 and 5.0 times, respectively, the rate among older Whites (3.9); rates among younger Blacks (102.5) and Hispanics/Latinos (39.0) were 7.7 and 2.9 times, respectively, the rate among younger Whites (13.3). Older persons were more likely than younger persons to receive a late HIV diagnosis (prevalence ratio=1.5, P<.001). CONCLUSIONS Racial/ethnic disparities in HIV diagnosis rates are greater among persons aged 50 years and older than among younger persons. The greater HIV diagnosis rates in Blacks and later diagnosis among older persons of all races/ethnicities indicate a need to increase their awareness of risk factors for HIV infection.

Trends in condom use among MSM in the United States: the role of antiretroviral therapy and seroadaptive strategies.

Objective:Evaluate changes in condomless anal sex at last sex among men who have sex with men (MSM) and assess if these changes are associated with the adoption of serosorting and biomedical prevention. Design:The National HIV Behavioral Surveillance is a crosssectional survey done in up to 21 cities in 2005, 2008, 2011 and 2014. Methods:MSM were recruited through venue-based sampling. Among men reporting at least one male partner, we evaluated changes in condomless anal sex at last sex with a partner with (1) HIV-concordant (proxy for serosorting) or (2) HIV-discordant (discordant/unknown) status. We hypothesized that if concordant condomless sex was increasing while discordant was stable/declining, the increases could be driven by more men attempting to serosort. We used generalized estimating equations assuming a Poisson distribution and robust variance estimator to explore whether temporal changes in the outcomes varied by selected characteristics. We also assessed changes in condomless anal sex by antiretroviral therapy (ART) use among HIV-positive MSM. Results:Among 5371 HIV-positive MSM, there were increases in concordant (19% in 2005 to 25% in 2014, P < 0.001) and discordant condomless sex (15 to 19%, P < 0.001). The increases were not different by ART use. Among 30 547 HIV-negative MSM, concordant (21 to 27%, P < 0.001) and discordant condomless sex (8 to 13%, P < 0.001) increased. Conclusion:Our data suggest that condom use decreased among MSM and that the trends are not explained by serosorting or ART. Promotion of condoms and increased access to preexposure prophylaxis are vital to ensure that the benefits of ART in reducing transmission of HIV are not undermined.

Association Between Community Socioeconomic Position and HIV Diagnosis Rate Among Adults and Adolescents in the United States, 2005 to 2009

OBJECTIVES We examined the association between socioeconomic position (SEP) and HIV diagnosis rates in the United States and whether racial/ethnic disparities in diagnosis rates persist after control for SEP. METHODS We used cases of HIV infection among persons aged 13 years and older, diagnosed 2005 through 2009 in 37 states and reported to national HIV surveillance through June 2010, and US Census data, to examine associations between county-level SEP measures and 5-year average annual HIV diagnosis rates overall and among race/ethnicity-sex groups. RESULTS The HIV diagnosis rate was significantly higher for individuals in the low-SEP tertile than for those in the high-SEP tertile (rate ratios for low- vs high-SEP tertiles range = 1.68-3.38) except for White males and Hispanic females. The SEP disparities were larger for minorities than for Whites. Racial disparities persisted after we controlled for SEP, urbanicity, and percentage of population aged 20 to 50 years, and were high in the low-SEP tertile for males and in low- and high-SEP tertiles for females. CONCLUSIONS Findings support continued prioritization of HIV testing, prevention, and treatment to persons in economically deprived areas, and Blacks of all SEP levels.

Racial Disparity in U.S. Diagnoses of Acquired Immune Deficiency Syndrome, 2000–2009

BACKGROUND Increased attention has been focused on health disparities among racial/ethnic groups in the U.S. PURPOSE To assess the extent of progress toward meeting the targets of Healthy People 2010 objectives and eliminating disparities. METHODS All diagnoses of AIDS during 2000-2009 among people aged ≥ 13 years in the 50 states and District of Columbia, reported to national HIV surveillance through June 2010, together with census population data were used in this analysis (conducted in March 2011). This study assesses the trend in racial/ethnic disparities in rates of AIDS diagnoses both between particular groups using rate difference (RD) and rate ratio (RR) and across the entire range of racial/ethnic subgroups using three summary measures of disparity: between-group variance (BGV); Theil index (TI); and mean log deviation (MLD). RESULTS The overall racial/ethnic disparity, black-white disparity, and Hispanic-white disparity in rates of AIDS diagnoses decreased for those aged 25-64 years from 2000 to 2009. The black-white and Hispanic-white disparity in rates of AIDS diagnoses also decreased among men aged ≥ 65 years; however, the black-white disparity increased among young men aged 13-24 years (BGV: p<0.001, black-white RD: p<0.01) from 2000 to 2009. CONCLUSIONS Findings indicate overall decreases in racial/ethnic disparities in AIDS diagnoses except in young men, particularly young black men aged 13-24 years where the burden of AIDS is increasing. HIV testing, prevention, treatment and policy-making should be a priority for this group.