COVID-19-related excess missed HIV diagnoses in the United States in 2021.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) and related disruptions led to a significant decline in HIV diagnoses in the United States in 2020. A previous analysis estimated 18% fewer diagnoses than expected among persons with HIV (PWH) acquiring infection in 2019 or earlier, suggesting that the decline in overall diagnoses cannot be attributed solely to decreased transmission. This analysis evaluates the progress made towards closing the 2020 diagnosis deficit in 2021. METHODS: We apply previously developed methods analyzing 2021 diagnosis data from the National HIV Surveillance System to determine whether 2021 diagnosis levels of PWH infected pre-2020 are above or below the expected pre-COVID trends. Results are stratified by assigned sex at birth, transmission group, geographic region, and race/ethnicity. RESULTS: In 2021, HIV diagnoses returned to pre-COVID levels among all PWH acquiring infection 2011-2019. Among Hispanic/Latino PWH and male individuals, diagnoses returned to pre-COVID levels. White PWH, MSM, and PWH living in the south and northeast showed higher-than-expected levels of diagnosis in 2021. For the remaining populations, there were fewer HIV diagnoses in 2021 than expected. CONCLUSION: Although overall diagnoses among persons acquiring HIV pre-2020 returned to pre-COVID levels, the diagnosis gap observed in 2020 remained unclosed at the end of 2021. Fewer than expected diagnoses among certain populations indicate that COVID-19-related disruptions to HIV diagnosis trends remained in 2021. Although some groups showed higher-than-expected levels of diagnoses, such increases were smaller than corresponding 2020 decreases. Expanded testing programs designed to close these gaps are essential.

Mortality Among Persons With HIV in the United States During the COVID-19 Pandemic: A Population-Level Analysis.

BACKGROUND: Whether the COVID-19 pandemic has had a disproportionate impact on mortality among persons with diagnosed HIV (PWDH) in the United States is unclear. Through our macroscale analysis, we seek to better understand how the COVID-19 pandemic affected mortality among PWDH. METHODS: We obtained mortality and population data for the years 2018-2020 from the National HIV Surveillance System for the US PWDH population and from publicly available data for the general population. We computed mortality rates and excess mortality for both the general and PWDH populations. Stratifications by age, race/ethnicity, and sex were considered. For each group, we determined whether the 2020 mortality rates and mortality risk ratio showed a statistically significant change from 2018 to 2019. RESULTS: Approximately 1550 excess deaths occurred among PWDH in 2020, with Black, Hispanic/Latino, and PWDH aged 55 years and older comprising the majority of excess deaths. Mortality rates increased in 2020 from 2018-2019 across the general population in all groups. Among PWDH, mortality rates either increased or showed no statistically significant change. These increases were similar to, or smaller than, those observed in the general population, resulting in a 7.7% decrease in the mortality risk ratio between PWDH and the general population. CONCLUSIONS: While mortality rates among PWDH increased in 2020 relative to 2018-2019, the increases were smaller, or of similar magnitude, to those observed in the general population. We thus do not find evidence of elevated mortality risk from the COVID-19 pandemic among PWDH. These findings held across subpopulations stratified by age, sex, and racial/ethnic group.

Interstate Mobility of People With Diagnosed HIV in the United States, 2011-2019.

OBJECTIVE: Assessing mobility among people with HIV is an important consideration when measuring HIV incidence, prevalence, and the care continuum in the United States. Our aims were to measure mobility among people with HIV compared with the general population and to examine factors associated with migration among people with HIV. METHODS: We calculated state-to-state move-in and move-out migration rates for 2011 through 2019 using National HIV Surveillance System data for people with HIV and using US Census data for the general population. For people with HIV, we also assessed the association between migration and HIV care outcomes. RESULTS: From 2011 through 2019, the US general population had stable migration, whereas migration rates among people with HIV fluctuated and were higher than among the general population. Among people with HIV, migration rates in 2019 were higher among people assigned male sex at birth versus female sex at birth, among people aged ≤24 years versus ≥25 years, among people with HIV infection attributed to male-to-male sexual contact versus other transmission categories, and among non-Hispanic Other people (ie, American Indian or Alaska Native, Asian, Native Hawaiian or Other Pacific Islander, or multiple races) versus Hispanic, non-Hispanic Black, and non-Hispanic White people. Receipt of HIV medical care (90.3% vs 75.5%) and achieving viral suppression (72.1% vs 65.3%) were higher among people with HIV who migrated versus those who did not. CONCLUSIONS: People with HIV in the United States are more mobile than the general population. Determining the mobility of people with HIV can help with strategic allocation of HIV prevention and care resources.

An estimate of excess deaths among people with HIV during the coronavirus disease 2019 pandemic in the United States, 2020.

We developed an ad hoc method to estimate the number of excess deaths among persons with HIV (PWH) during the coronavirus disease 2019 (COVID-19) pandemic in the United States. Using this method, we estimated approximately 1448 excess deaths from COVID-19 among PWH in 2020 in the United States. We also developed an Excel workbook for use as a tool to quickly assess excess deaths among PWH in settings with limited surveillance data.

Isolating the Effect of COVID-19-Related Disruptions on HIV Diagnoses in the United States in 2020.

BACKGROUND: Diagnoses of HIV in the United States decreased by 17% in 2020 due to COVID-related disruptions. The extent to which this decrease is attributable to changes in HIV testing versus HIV transmission is unclear. We seek to better understand this issue by analyzing the discrepancy in expected versus observed HIV diagnoses in 2020 among persons who acquired HIV between 2010 and 2019 because changes in diagnosis patterns in this cohort cannot be attributed to changes in transmission. METHODS: We developed 3 methods based on the CD4-depletion model to estimate excess missed diagnoses in 2020 among persons with HIV (PWH) infected from 2010 to 2019. We stratified the results by transmission group, sex assigned at birth, race/ethnicity, and region to examine differences by group and confirm the reliability of our estimates. We performed similar analyses projecting diagnoses in 2019 among PWH infected from 2010 to 2018 to evaluate the accuracy of our methods against surveillance data. RESULTS: There were approximately 3100-3300 (approximately 18%) fewer diagnoses than expected in 2020 among PWH infected from 2010 to 2019. Females (at birth), heterosexuals, persons who inject drugs, and Hispanic/Latino PWH missed diagnoses at higher levels than the overall population. Validation and stratification analyses confirmed the accuracy and reliability of our estimates. CONCLUSIONS: The substantial drop in number of previously infected PWH diagnosed in 2020 suggests that changes in testing played a substantial role in the observed decrease. Levels of missed diagnoses differed substantially across population subgroups. Increasing testing efforts and innovative strategies to reach undiagnosed PWH are needed to offset this diagnosis gap. These analyses may be used to inform future estimates of HIV transmission during the COVID-19 pandemic.

Estimated time from HIV infection to diagnosis and diagnosis to first viral suppression during 2014-2018.

OBJECTIVE: To examine changes in the lengths of time from HIV infection to diagnosis (Infx-to-Dx) and from diagnosis to first viral suppression (Dx-to-VS), two periods during which HIV can be transmitted. DESIGN: Data from the National HIV Surveillance System (NHSS) for persons who were aged at least 13 years at the time of HIV diagnosis during 2014-2018 and resided in one of 33 United States jurisdictions with complete laboratory reporting. METHODS: The date of HIV infection was estimated based on a CD4+-depletion model. Date of HIV diagnosis, and dates and results of first CD4+ test and first viral suppression (<200 copies/ml) after diagnosis were reported to NHSS through December 2019. Trends for Infx-to-Dx and Dx-to-VS intervals were examined using estimated annual percentage change. RESULTS: During 2014-2018, among persons aged at least 13 years, 133 413 HIV diagnoses occurred. The median length of infx-to-Dx interval shortened from 43 months (2014) to 40 months (2018), a 1.5% annual decrease (7% relative change over the 5-year period). The median length of Dx-to-VS interval shortened from 7 months (2014) to 4 months (2018), an 11.4% annual decrease (42.9% relative change over the 5-year period). Infx-to-Dx intervals shortened in only some subgroups, whereas Dx-to-VS intervals shortened in all groups by sex, transmission category, race/ethnicity, age, and CD4+ count at diagnosis. CONCLUSION: The shortened Infx-to-Dx and Dx-to-VS intervals suggest progress in promoting HIV testing and earlier treatment; however, diagnosis delays continue to be substantial. Further shortening both intervals and eliminating disparities are needed to achieve Ending the HIV Epidemic goals.

Sexually Transmitted Infections Among US Women and Men: Prevalence and Incidence Estimates, 2018.

BACKGROUND: The most recent estimates of the number of prevalent and incident sexually transmitted infections (STIs) in the United States were for 2008. We provide updated estimates for 2018 using new methods. METHODS: We estimated the total number of prevalent and incident infections in the United States for 8 STIs: chlamydia, gonorrhea, trichomoniasis, syphilis, genital herpes, human papillomavirus, sexually transmitted hepatitis B, and sexually transmitted HIV. Updated per-capita prevalence and incidence estimates for each STI were multiplied by the 2018 full resident population estimates to calculate the number of prevalent and incident infections. STI-specific estimates were combined to generate estimates of the total number of prevalent and incident STIs overall, and by sex and age group. Primary estimates are represented by medians, and uncertainty intervals are represented by the 25th (Q1) and 75th (Q3) percentiles of the empirical frequency distributions of prevalence and incidence for each STI. RESULTS: In 2018, there were an estimated 67.6 (Q1, 66.6; Q3, 68.7) million prevalent and 26.2 (Q1, 24.0; Q3, 28.7) million incident STIs in the United States. Chlamydia, trichomoniasis, genital herpes, and human papillomavirus comprised 97.6% of all prevalent and 93.1% of all incident STIs. Persons aged 15 to 24 years comprised 18.6% (12.6 million) of all prevalent infections; however, they comprised 45.5% (11.9 million) of all incident infections. CONCLUSIONS: The burden of STIs in the United States is high. Almost half of incident STIs occurred in persons aged 15 to 24 years in 2018. Focusing on this population should be considered essential for national STI prevention efforts.

Incident and Prevalent HIV Infections Attributed to Sexual Transmission in the United States, 2018.

BACKGROUND: The Ending the HIV Epidemic: A Plan for America initiative aims to reduce new infections by 2030. Routine assessment of incident and prevalent HIV by transmission risk is essential for monitoring the impact of national, state, and local efforts to end the HIV epidemic. METHODS: Data reported to the National HIV Surveillance System were used to estimate numbers of incident and prevalent HIV infection attributed to sexual transmission in the United States in 2018. The first CD4 result after diagnosis and a CD4 depletion model were used to generate estimates by transmission category, sex at birth, age group, and race/ethnicity. RESULTS: In 2018, there were an estimated 32,600 (50% confidence interval [CI], 31,800-33,400) incident and 984,000 (50% CI, 977,000-990,900) prevalent HIV infections attributed to sexual transmission in the United States. Male-to-male sexual contact comprised 74.8% and 69.1% of incident and prevalent HIV infections, respectively. Persons aged 25 to 34 years comprised 39.6% (12,900; 50% CI, 12,400-13,400) of incident infections; however, the number of prevalent infections was highest among persons 55 years and older (29.3%; 288,300 [50% CI, 285,600-291,000]). There were racial/ethnic differences in numbers of incident and prevalent infections among both men who have sex with men and persons with HIV attributable to heterosexual contact. CONCLUSIONS: In 2018, most incident sexually transmitted HIV infections occurred in men who have sex with men, and the burden was disproportionate for persons aged 24 to 35 years, and Black/African American and Hispanic/Latino adults and adolescents. Efforts to increase the use of effective biomedical and behavioral prevention methods must be intensified to reach the goal to end the HIV epidemic in the United States.

The Estimated Number and Lifetime Medical Cost of HIV Infections Attributable to Sexually Transmitted Infections Acquired in the United States in 2018: A Compilation of Published Modeling Results.

BACKGROUND: The purpose of this study was to estimate the number and lifetime medical cost of HIV infections attributable to incident sexually transmitted infections (STIs) in the United States in 2018. METHODS: We combined data from published models regarding the number or percentage of HIV infections attributable to STIs with updated estimates of the lifetime medical cost per HIV infection. We used 2 distinct calculation methods. Our first calculation used recent estimates of the percentage of HIV infections in men who have sex with men (MSM) attributable to gonorrhea and chlamydia. Our second calculation, based on older studies, used estimates of the expected number of STI-attributable HIV infections per new STI infection, for gonorrhea, chlamydia, syphilis, and trichomoniasis. RESULTS: Our first calculation method suggested that 2489 (25th-75th percentiles, 1895-3000) HIV infections in 2018 among MSM could be attributed to gonorrhea and chlamydia, at an estimated lifetime medical cost of $1.05 billion (25th-75th percentiles, $0.79-$1.26 billion). Our second calculation method suggested that 2349 (25th-75th percentiles, 1948-2744) HIV infections in the general population (including MSM) could be attributed to chlamydia, gonorrhea, syphilis, and trichomoniasis acquired in 2018, at an estimated lifetime medical cost of $0.99 billion (25th-75th percentiles, $0.80-$1.16 billion). CONCLUSIONS: Despite ambiguity regarding the degree to which STIs affect HIV transmission, our combination of data from published STI/HIV transmission models and an HIV lifetime medical cost model can help to quantify the estimated burden of STI-attributable HIV infections in the United States.

A Surveillance Data-Based Model System for Assessing the Effects of HIV Intervention and Prevention Strategies.

OBJECTIVE: Build a dynamic model system to assess the effects of HIV intervention and prevention strategies on future annual numbers of new HIV infections, newly diagnosed cases of HIV infection, and deaths among persons infected with HIV. DESIGN AND SETTING: Model parameters are defined to quantify the putative effects of HIV prevention strategies that would increase HIV testing, thereby diagnosing infection earlier; increase linkage to care and viral suppression, thereby reducing infectiousness; and increase the use of preexposure prophylaxis, thereby protecting persons at risk of infection. Surveillance data are used to determine the initial values of the model system's variables and parameters, and the impact on the future course of various outcome measures of achieving either specified target values or specified rates of change for the model parameters is examined. PARTICIPANTS: A hypothetical population of persons with HIV infection and persons at risk of acquiring HIV infection. MAIN OUTCOME MEASURES: HIV incidence, HIV prevalence, proportion of persons infected with HIV whose infection is diagnosed, and proportion of persons with diagnosed HIV infection who are virally suppressed. RESULTS: A model system based on the basic year-to-year algebraic relationships among the model variables and relying almost exclusively on HIV surveillance data was developed to project the course of HIV disease over a specified time period. Based on the most recent HIV surveillance data in the United States-which show a relatively high proportion of infections having been diagnosed but a relatively low proportion of diagnosed persons being virally suppressed-increasing the proportion of diagnosed persons who are virally suppressed and increasing preexposure prophylaxis use appear to be the most effective ways of reducing new HIV infections and accomplishing national HIV prevention and care goals. CONCLUSIONS: Both having current and accurate information regarding the epidemiologic dynamics of HIV infection and knowing the potential impact of prevention strategies are critical in order for limited HIV prevention resources to be optimally allocated.

Geographic Distribution of HIV Transmission Networks in the United States.

BACKGROUND: Understanding geographic patterns of HIV transmission is critical to designing effective interventions. We characterized geographic proximity by transmission risk and urban-rural characteristics among people with closely related HIV strains suggestive of potential transmission relationships. METHODS: We analyzed US National HIV Surveillance System data of people diagnosed between 2010 and 2016 with a reported HIV-1 partial polymerase nucleotide sequence. We used HIV TRAnsmission Cluster Engine (HIV-TRACE) to identify sequences linked at a genetic distance of ≤0.5%. For each linked person, we assessed median distances between counties of residence at diagnosis by transmission category and urban-rural classification, weighting observations to account for persons with multiple linked sequences. RESULTS: There were 24,743 persons with viral sequence linkages to at least one other person included in this analysis. Overall, half (50.9%) of persons with linked viral sequences resided in different counties, and the median distance from persons with linked viruses was 11 km/7 miles [interquartile range (IQR), 0-145 km/90 miles]. Median distances were highest for men who have sex with men (MSM: 14 km/9 miles; IQR, 0-179 km/111 miles) and MSM who inject drugs, and median distances increased with increasing rurality (large central metro: 0 km/miles; IQR, 0-83 km/52 miles; nonmetro: 103 km/64 miles; IQR, 40 km/25 miles-316 km/196 miles). CONCLUSION: Transmission networks in the United States involving MSM, MSM who inject drugs, or persons living in small metro and nonmetro counties may be more geographically dispersed, highlighting the importance of coordinated health department efforts for comprehensive follow-up and linkage to care.

A passive and inclusive strategy to impute missing values of a composite categorical variable with an application to determine HIV transmission categories.

PURPOSE: Multiple imputation (MI) is a widely acceptable approach to missing data problems in epidemiological studies. Composite variables are often used to summarize information from multiple, correlated items. This study aims to assess and compare different MI methods for handling missing categorical composite variables. METHODS: We investigate the problem in the context of a real application: estimating the prevalence of HIV transmission category, which is a composite variable generated by applying a hierarchical algorithm to a group of binary risk source variables from a national program data set. We use simulation studies to compare and assess the performance of alternative MI strategies. These methods include the active imputation, just another variable, and the passive imputation approaches. RESULTS: Our study suggests that the passive imputation approach performs better than the direct imputation approach and the inclusive and general imputation model (i.e. passive imputation with interactions) performs the best. There is no need to embed the information from the variable-combining algorithm in the passive imputation modeling. CONCLUSION: We recommend practitioners adopting an inclusive and general passive imputation modeling strategy.

Trends in Time From HIV Diagnosis to First Viral Suppression Following Revised US HIV Treatment Guidelines, 2012-2017.

BACKGROUND: Since 2012, treatment guidelines have recommended initiating antiretroviral therapy for all persons as soon as possible after HIV diagnosis, irrespective of CD4 counts. If clinicians adopted the treatment guidelines, a shortened interval between diagnosis and first viral suppression (Dx-to-VS) would be expected, with greater declines among those with CD4 counts ≥500 cells/µL at diagnosis. METHODS: Using the National HIV Surveillance System data, we examined Dx-to-VS intervals among persons aged ≥13 years with HIV infection diagnosed during 2012-2017. Analyses were stratified by the first CD4 count: CD4 ≥500 cells/µL, 200-499 cells/µL, <200 cells/µL, and no CD4 value reported within 3 months after diagnosis. RESULTS: During 2012-2017 in the 27 US jurisdictions with complete laboratory reporting, 138,759 HIV diagnoses occurred. The median Dx-to-VS interval shortened overall for persons with HIV diagnosed in 2012 vs. 2017 from 9 to 5 months, a 12.3% annual decrease (P < 0.001) and in all CD4 groups. In 2012, the Dx-to-VS interval was longer for persons with CD4 ≥500 cells/µL than 200-499 cells/µL and <200 cells/µL (median, 9, 7, and 6 months, respectively). By 2017, the median interval was 4 months for these groups, compared with 25 months for those without a CD4 value within 3 months after diagnosis. CONCLUSION: Decreases in Dx-to-VS intervals across all CD4 groups with a greater decrease among those with CD4 ≥500 cells/µL are consistent with the implementation of treatment recommendations. The Dx-to-VS interval was longest among persons not linked to care within 3 months after diagnosis, underscoring the importance of addressing barriers to linkage to care for ending the HIV epidemic.

Estimating the probability of diagnosis within 1 year of HIV acquisition.

BACKGROUND: Early diagnosis of HIV is important for the prevention of ongoing transmission and development of HIV-related illness. The purpose of this study is to develop an outcome indicator to monitor the progress in early HIV diagnosis. METHODS: Persons diagnosed with HIV in New York City and their first CD4 test results were used to estimate the distribution of HIV diagnosis delay, based on a CD4 count depletion model. The distribution was then used to estimate the probability of diagnosis within 1 year of HIV acquisition, which is the number of cases diagnosed in a given calendar year for which diagnosis occurred within 1 year of acquisition divided by the number of incident cases in that calendar year. RESULTS: In 2012-2016, the estimated annual probability of diagnosis within 1 year of HIV acquisition in New York City was 43.0% [95% confidence interval (CI): 37.9-48.2%), 42.5% (95% CI: 36.8--48.3%), 42.8% (95% CI: 36.3--49.2%), 42.9% (95% CI: 35.4--50.3%), and 42.2% (95% CI: 33.1--51.2%), respectively. CONCLUSION: National and local health jurisdictions should consider using this new outcome indicator, the probability of diagnosis within 1 year of HIV acquisition, to monitor their progress in early HIV diagnosis.

An Innovative Approach to Assess Similarity Between Sex Partners.

We present a simple, comprehensive method for assessing similarity between sex partners of a participant and demonstrate its application using data collected in 2015 as part of CDC's National HIV behavioral surveillance (NHBS) among persons who inject drugs (PWID). We found that the pairwise similarity between sex partners of a survey participant was high. The similarity between second-to-last and third-to-last partners in the past 3 months was significantly higher than that between last and second-to-last partner in partner type, frequency of sex acts, and the contextual characteristics of sex behavior at last sexual encounter. The proposed approach provides an innovative measure of the added value of multi-partner series. The empirical analysis suggests that querying additional sex partners contributes limited data to characterize a participant's sexual behaviors among NHBS PWID. Future studies should apply the proposed method to evaluate the added value of data on multiple sex partners among other populations.

HIV Incidence, Prevalence, and Undiagnosed Infections in U.S. Men Who Have Sex With Men.

Background: HIV infection is a persistent health concern in the United States, and men who have sex with men (MSM) continue to be the most affected population. Objective: To estimate HIV incidence and prevalence and the percentage of undiagnosed HIV infections overall and among MSM. Design: Cross-sectional analysis. Setting: National HIV Surveillance System. Participants: Persons aged 13 years or older with diagnosed HIV infection. Measurements: Data on HIV diagnoses and the first CD4 test result after diagnosis were used to model HIV incidence and prevalence and the percentage of undiagnosed HIV infections from 2008 to 2015 on the basis of a well-characterized CD4 depletion model. Results: Modeled HIV incidence decreased 14.8% overall, from 45 200 infections in 2008 to 38 500 in 2015, and among all transmission risk groups except MSM. The incidence of HIV increased 3.1% (95% CI, 1.6% to 4.5%) per year among Hispanic/Latino MSM (6300 infections in 2008, 7900 in 2015), decreased 2.7% (CI, -3.8% to -1.5%) per year among white MSM (8800 infections in 2008, 7100 in 2015), and remained stable among black MSM at about 10 000 infections. The incidence decreased by 3.0% (CI, -4.2% to -1.8%) per year among MSM aged 13 to 24 years and by 4.7% (CI, -6.2% to -3.1%) per year among those aged 35 to 44 years. Among MSM aged 25 to 34 years, HIV incidence increased 5.7% (CI, 4.4% to 7.0%) per year and among MSM aged 55 years and older, HIV increased 4.1% (CI, 0.8% to 7.4%). The percentage of undiagnosed HIV infections was higher among black, Hispanic/Latino, and younger MSM than white and older MSM, respectively. Limitation: Assumptions of the CD4 depletion model and variability of CD4 values. Conclusion: Expansion of HIV screening to reduce undiagnosed infections and increased access to care and treatment to achieve viral suppression are critical to reduce HIV transmission. Access to prevention methods, such as condoms and preexposure prophylaxis, also is needed, particularly among MSM of color and young MSM. Primary Funding Source: None.

Estimation of the Percentage of Newly Diagnosed HIV-Positive Persons Linked to HIV Medical Care in CDC-Funded HIV Testing Programs.

Missing data create challenges for determining progress made in linking HIV-positive persons to HIV medical care. Statistical methods are not used to address missing program data on linkage. In 2014, 61 health department jurisdictions were funded by Centers for Disease Control and Prevention (CDC) and submitted data on HIV testing, newly diagnosed HIV-positive persons, and linkage to HIV medical care. Missing or unusable data existed in our data set. A new approach using multiple imputation to address missing linkage data was proposed, and results were compared to the current approach that uses data with complete information. There were 12,472 newly diagnosed HIV-positive persons from CDC-funded HIV testing events in 2014. Using multiple imputation, 94.1% (95% confidence interval (CI): [93.7%, 94.6%]) of newly diagnosed persons were referred to HIV medical care, 88.6% (95% CI: [88.0%, 89.1%]) were linked to care within any time frame, and 83.6% (95% CI: [83.0%, 84.3%]) were linked to care within 90 days. Multiple imputation is recommended for addressing missing linkage data in future analyses when the missing percentage is high. The use of multiple imputation for missing values can result in a better understanding of how programs are performing on key HIV testing and HIV service delivery indicators.

Vital Signs: Human Immunodeficiency Virus Testing and Diagnosis Delays - United States.

BACKGROUND: Persons unaware of their human immunodeficiency virus (HIV) infection account for approximately 40% of ongoing transmissions in the United States. Persons are unaware of their infection because of delayed HIV diagnoses that represent substantial missed opportunities to improve health outcomes and prevent HIV transmission. METHODS: Data from CDC's National HIV Surveillance System were used to estimate, among persons with HIV infection diagnosed in 2015, the median interval (and range) from infection to diagnosis (diagnosis delay), based on the first CD4 test after HIV diagnosis and a CD4 depletion model indicating disease progression and, among persons living with HIV in 2015, the percentage with undiagnosed infection. Data from CDC's National HIV Behavioral Surveillance were analyzed to determine the percentage of persons at increased risk for HIV infection who had tested in the past 12 months and who had missed opportunities for testing. RESULTS: An estimated 15% of persons living with HIV in 2015 were unaware of their infection. Among the 39,720 persons with HIV infection diagnosed in 2015, the estimated median diagnosis delay was 3.0 years (interquartile range = 0.7-7.8 years); diagnosis delay varied by race/ethnicity (from 2.2 years among whites to 4.2 years among Asians) and transmission category (from 2.0 years among females who inject drugs to 4.9 years among heterosexual males). Among persons interviewed through National HIV Behavioral Surveillance, 71% of men who have sex with men, 58% of persons who inject drugs, and 41% of heterosexual persons at increased risk for HIV infection reported testing in the past 12 months. In each risk group, at least two thirds of persons who did not have an HIV test had seen a health care provider in the past year. CONCLUSIONS: Delayed HIV diagnoses continue to be substantial for some population groups and prevent early entry to care to improve health outcomes and reduce HIV transmission to others. IMPLICATIONS FOR PUBLIC HEALTH PRACTICE: Health care providers and others providing HIV testing can reduce HIV-related adverse health outcomes and risk for HIV transmission by implementing routine and targeted HIV testing to decrease diagnosis delays.

Estimated HIV Incidence, Prevalence, and Undiagnosed Infections in US States and Washington, DC, 2010-2014.

INTRODUCTION: The burden of HIV infection and health outcomes for people living with HIV varies across the United States. New methods allow for estimating national and state-level HIV incidence, prevalence, and undiagnosed infections using surveillance data and CD4 values. METHODS: HIV surveillance data reported to the Centers for Disease Control and Prevention and the first CD4 value after diagnosis were used to estimate the distribution of delay from infection to diagnosis based on a well-characterized CD4 depletion model. This distribution was used to estimate HIV incidence, prevalence, and undiagnosed infections during 2010-2014. Estimated annual percentage changes (EAPCs) were calculated to assess trends. RESULTS: During 2010-2014, HIV incidence decreased 10.3% (EAPC = -3.1%) and the percentage of undiagnosed infection decreased from 17.1% to 15.0% (EAPC = -3.3%) in the United States; HIV prevalence increased 9.1% (EAPC = 2.2%). Among 36 jurisdictions with sufficient data to produce stable estimates, HIV incidence decreased in 3 jurisdictions (Georgia, New York, and District of Columbia) and the percentage of undiagnosed HIV infections decreased in 2 states (Texas and Georgia). HIV prevalence increased in 4 states (California, Florida, Georgia, and Texas). In 2014, southern states accounted for 50% of both new HIV infections and undiagnosed infections. CONCLUSION: HIV incidence and undiagnosed infection decreased in the United States during 2010-2014; however, outcomes varied by state and region. Progress in national HIV prevention is encouraging but intensified efforts for testing and treatment are needed in the South and states with high percentages of undiagnosed infection.

Estimated HIV Inter-test Interval Among People at High Risk for HIV Infection in the U.S.

INTRODUCTION: Knowing the HIV testing frequency and its temporal changes are central to evaluate public adherence to HIV testing recommendations and performance of HIV prevention programs. This study intended to estimate the mean HIV inter-test interval (ITI) and monitor its trends among men who have sex with men (MSM); people who inject drugs (PWID); and high-risk heterosexuals (HRH). METHODS: Using National HIV Behavioral Surveillance data collected during 2008-2015, this analysis estimated the mean HIV ITI for each year by race/ethnicity and age among MSM, PWID, and HRH who reported the most recent HIV test date. Separate statistical models based on renewal process theory were fit using PROC NLIN with Newton-Raphson method. Estimated mean HIV ITI lengths were compared using the z-test. RESULTS: Estimated HIV ITI generally decreased in the past decade among MSM, PWID, and HRH who reported the most recent HIV test date. In most recent study years, estimated HIV ITI (in months) ranged from 5.8 to 12.5 among MSM, from 9.0 to 13.1 among PWID, and from 15.3 to 26.7 among HRH. Within each risk group, estimated HIV ITI was shortest among blacks and individuals aged 18-24 years. CONCLUSIONS: People at high risk for HIV infection who ever tested for HIV tested more frequently in the past decade. Most recently, MSM and PWID largely adhered to the Centers for Disease Control and Prevention's HIV testing recommendations, but HRH tested less frequently. Identifying factors associated with infrequent testing among HRH may provide information for future HIV testing initiatives.