Estimating hepatitis C prevalence in the United States, 2017-2020.

BACKGROUND AND AIMS: The National Health and Nutrition Examination Survey (NHANES) underestimates the true prevalence of HCV infection. By accounting for populations inadequately represented in NHANES, we created 2 models to estimate the national hepatitis C prevalence among US adults during 2017-2020. APPROACH AND RESULTS: The first approach (NHANES+) replicated previous methodology by supplementing hepatitis C prevalence estimates among the US noninstitutionalized civilian population with a literature review and meta-analysis of hepatitis C prevalence among populations not included in the NHANES sampling frame. In the second approach (persons who injected drugs [PWID] adjustment), we developed a model to account for the underrepresentation of PWID in NHANES by incorporating the estimated number of adult PWID in the United States and applying PWID-specific hepatitis C prevalence estimates. Using the NHANES+ model, we estimated HCV RNA prevalence of 1.0% (95% CI: 0.5%-1.4%) among US adults in 2017-2020, corresponding to 2,463,700 (95% CI: 1,321,700-3,629,400) current HCV infections. Using the PWID adjustment model, we estimated HCV RNA prevalence of 1.6% (95% CI: 0.9%-2.2%), corresponding to 4,043,200 (95% CI: 2,401,800-5,607,100) current HCV infections. CONCLUSIONS: Despite years of an effective cure, the estimated prevalence of hepatitis C in 2017-2020 remains unchanged from 2013 to 2016 when using a comparable methodology. When accounting for increased injection drug use, the estimated prevalence of hepatitis C is substantially higher than previously reported. National action is urgently needed to expand testing, increase access to treatment, and improve surveillance, especially among medically underserved populations, to support hepatitis C elimination goals.

Development of a University-Government Partnership for Public Health Response and Workforce Development in the State of Oregon.

The COVID-19 pandemic exposed and exacerbated a public health workforce shortage and national strategies have called for the development of clear occupational pathways for students to enter the public health workforce and meaningful public health careers. In response to the immediate need for public health workers during the pandemic, several universities and academic hospitals rapidly mobilized students and employees and partnered with local or state health departments. However, many of those partnerships were based on short-term volunteer effort to support critical COVID-19 public health efforts. In this article, we document the development of Oregon's Public Health Practice Team, a student, staff, and faculty workforce developed at the Oregon Health & Science University-Portland State University (OHSU-PSU) School of Public Health in close collaboration with the Oregon Health Authority (OHA). This project contributed significant effort to several phases of Oregon's statewide public health response to COVID-19, and over time developed into a lasting, multi-purpose, inter-agency collaborative public health practice program. Health equity has been centered at every stage of this work. We describe the phases of the partnership development, the current team structure and operations, and highlight key challenges and lessons learned. This provides a case-study of how an innovative and flexible university-government partnership can contribute to immediate pandemic response needs, and also support ongoing public health responses to emerging needs, while contributing to the development of a skilled and diverse public health workforce.

Estimated Number of People Who Inject Drugs in the United States.

BACKGROUND: Public health data signal increases in the number of people who inject drugs (PWID) in the United States during the past decade. An updated PWID population size estimate is critical for informing interventions and policies aiming to reduce injection-associated infections and overdose, as well as to provide a baseline for assessments of pandemic-related changes in injection drug use. METHODS: We used a modified multiplier approach to estimate the number of adults who injected drugs in the United States in 2018. We deduced the estimated number of nonfatal overdose events among PWID from 2 of our previously published estimates: the number of injection-involved overdose deaths and the meta-analyzed ratio of nonfatal to fatal overdose. The number of nonfatal overdose events was divided by prevalence of nonfatal overdose among current PWID for a population size estimate. RESULTS: There were an estimated 3 694 500 (95% confidence interval [CI], 1 872 700-7 273 300) PWID in the United States in 2018, representing 1.46% (95% CI, .74-2.87) of the adult population. The estimated prevalence of injection drug use was highest among males (2.1%; 95% CI, 1.1-4.2), non-Hispanic Whites (1.8%; 95% CI, .9-3.6), and adults aged 18-39 years (1.8%; 95% CI, .9-3.6). CONCLUSIONS: Using transparent, replicable methods and largely publicly available data, we provide the first update to the number of people who inject drugs in the United States in nearly 10 years. Findings suggest the population size of PWID has substantially grown in the past decade and that prevention services for PWID should be proportionally increased.

Cost-Effectiveness of Strategies to Identify Children with Perinatally Acquired Hepatitis C Infection.

OBJECTIVE: To determine the optimal testing strategy to identify children with perinatally acquired hepatitis C virus (HCV) infection. STUDY DESIGN: We used a decision-tree framework with a Markov disease progression model to conduct an economic analysis of 4 strategies, based on combinations of type and timing of test: anti-HCV with reflex to HCV RNA at 18 months among children known to be perinatally exposed (ie, baseline comparison strategy); HCV RNA testing at 2-6 months among infants known to be perinatally exposed (test strategy 1); universal anti-HCV with reflex to HCV RNA at 18 months among all children (test strategy 2); and universal HCV RNA testing at 2-6 months among all infants (test strategy 3). We estimated total cost, quality-adjusted life years, and disease sequalae for each strategy. RESULTS: Each of the 3 alternative testing strategies resulted in an increased number of children tested and improved health outcomes. HCV RNA testing at 2-6 months (test strategy 1) was cost-saving and resulted in a population-level difference in cost of $469 671. The 2 universal testing strategies resulted in an increase in quality-adjusted life years and an increase in total costs. CONCLUSIONS: Testing of perinatally exposed infants at age 2-6 months with a single HCV RNA test will reduce costs and improve health outcomes, preventing morbidity and mortality associated with complications from perinatal HCV infections.

Assessing the Cost-Utility of Universal Hepatitis B Vaccination Among Adults.

BACKGROUND: Although effective against hepatitis B virus (HBV) infection, hepatitis B (HepB) vaccination is only recommended for infants, children, and adults at higher risk. We conducted an economic evaluation of universal HepB vaccination among US adults. METHODS: Using a decision analytic model with Markov disease progression, we compared current vaccination recommendations (baseline) with either 3-dose or 2-dose universal HepB vaccination (intervention strategies). In simulated modeling of 1 million adults distributed by age and risk groups, we quantified health benefits (quality-adjusted life years, QALYs) and costs for each strategy. Multivariable probabilistic sensitivity analyses identified key inputs. All costs reported in 2019 US dollars. RESULTS: With incremental base-case vaccination coverage up to 50% among persons at lower risk and 0% increment among persons at higher risk, each of 2 intervention strategies averted nearly one-quarter of acute HBV infections (3-dose strategy, 24.8%; 2-dose strategy, 24.6%). Societal incremental cost per QALY gained of $152 722 (interquartile range, $119 113-$235 086) and $155 429 (interquartile range, $120 302-$242 226) were estimated for 3-dose and 2-dose strategies, respectively. Risk of acute HBV infection showed the strongest influence. CONCLUSIONS: Universal adult vaccination against HBV may be an appropriate strategy for reducing HBV incidence and improving resulting health outcomes.

Cumulative Incidence of SARS-CoV-2 Infections Among Adults in Georgia, United States, August to December 2020.

BACKGROUND: Reported coronavirus disease 2019 (COVID-19) cases underestimate true severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Data on all infections, including asymptomatic infections, are needed. To minimize biases in estimates from reported cases and seroprevalence surveys, we conducted a household-based probability survey and estimated cumulative incidence of SARS-CoV-2 infections adjusted for antibody waning. METHODS: From August to December 2020, we mailed specimen collection kits (nasal swabs and blood spots) to a random sample of Georgia addresses. One household adult completed a survey and returned specimens for virus and antibody testing. We estimated cumulative incidence of SARS-CoV-2 infections adjusted for waning antibodies, reported fraction, and infection fatality ratio (IFR). Differences in seropositivity among demographic, geographic, and clinical subgroups were explored with weighted prevalence ratios (PR). RESULTS: Among 1370 participants, adjusted cumulative incidence of SARS-CoV-2 was 16.1% (95% credible interval [CrI], 13.5%-19.2%) as of 16 November 2020. The reported fraction was 26.6% and IFR was 0.78%. Non-Hispanic black (PR, 2.03; 95% confidence interval [CI], 1.0-4.1) and Hispanic adults (PR, 1.98; 95% CI, .74-5.31) were more likely than non-Hispanic white adults to be seropositive. CONCLUSIONS: As of mid-November 2020, 1 in 6 adults in Georgia had been infected with SARS-CoV-2. The COVID-19 epidemic in Georgia is likely substantially underestimated by reported cases.

Severe Acute Respiratory Syndrome Coronavirus 2 Cumulative Incidence, United States, August 2020-December 2020.

BACKGROUND: Reported coronavirus disease 2019 (COVID-19) cases underestimate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. We conducted a national probability survey of US households to estimate cumulative incidence adjusted for antibody waning. METHODS: From August-December 2020 a random sample of US addresses were mailed a survey and self-collected nasal swabs and dried blood spot cards. One adult household member completed the survey and mail specimens for viral detection and total (immunoglobulin [Ig] A, IgM, IgG) nucleocapsid antibody by a commercial, emergency use authorization-approved antigen capture assay. We estimated cumulative incidence of SARS-CoV-2 adjusted for waning antibodies and calculated reported fraction (RF) and infection fatality ratio (IFR). Differences in seropositivity among demographic, geographic, and clinical subgroups were explored. RESULTS: Among 39 500 sampled households, 4654 respondents provided responses. Cumulative incidence adjusted for waning was 11.9% (95% credible interval [CrI], 10.5%-13.5%) as of 30 October 2020. We estimated 30 332 842 (CrI, 26 703 753-34 335 338) total infections in the US adult population by 30 October 2020. RF was 22.3% and IFR was 0.85% among adults. Black non-Hispanics (Prevalence ratio (PR) 2.2) and Hispanics (PR, 3.1) were more likely than White non-Hispanics to be seropositive. CONCLUSIONS: One in 8 US adults had been infected with SARS-CoV-2 by October 2020; however, few had been accounted for in public health reporting. The COVID-19 pandemic is likely substantially underestimated by reported cases. Disparities in COVID-19 by race observed among reported cases cannot be attributed to differential diagnosis or reporting of infections in population subgroups.

Evaluating the cost-effectiveness of hepatitis B vaccination strategies in high-impact settings for adults.

Adults at increased risk for hepatitis B virus (HBV) infection are recommended to receive vaccination. We conducted a cost utility analysis to evaluate approaches for implementing that recommendation in selected high-risk settings: community outreach events with a large proportion of immigrants, syringe service programs, substance use treatment centres, sexually transmitted infection (STI) clinics, tuberculosis (TB) clinics and jails. We utilized a decision tree framework with a Markov disease progression model to compare quality adjusted life-years and cost in 2021 United States dollars from four strategies: a 3-dose vaccination regimen with prevaccination screening and testing (PVST; baseline comparison); PVST at the initial encounter followed by a 2-dose series (Intervention 1); PVST with the first dose of a 2-dose vaccination series at the initial encounter (Intervention 2); and a 2-dose vaccination series without PVST (Intervention 3). In all settings, Intervention 1 resulted in worse health outcomes compared with the baseline strategy. Intervention 2 averted incident chronic HBV infections in all settings (range -9.4% in TB clinics, -14.8% in syringe service programs) and was a cost-saving approach in settings with higher risk of infection (i.e. jails, -$266 per person; syringe service programs, -$597; substance use treatment centres, -$130). Providing a 2-dose vaccination series without any screening (Intervention 3) averted incident HBV infections and was cost-saving in all settings but resulted in more HBV-related deaths in settings with higher HBV prevalence. These results demonstrate a 2-dose vaccine series is a cost-effective approach in these high-impact settings, even if prevaccination testing is not possible.

County-Level Variation in Hepatitis C Virus Mortality and Trends in the United States, 2005-2017.

BACKGROUND AND AIMS: Since 2013, the national hepatitis C virus (HCV) death rate has steadily declined, but this decline has not been quantified or described on a local level. APPROACH AND RESULTS: We estimated county-level HCV death rates and assessed trends in HCV mortality from 2005 to 2013 and from 2013 to 2017. We used mortality data from the National Vital Statistics System and used a Bayesian multivariate space-time conditional autoregressive model to estimate age-standardized HCV death rates from 2005 through 2017 for 3,115 U.S. counties. Additionally, we estimated county-level, age-standardized rates for persons <40 and 40+ years of age. We used log-linear regression models to estimate the average annual percent change in HCV mortality during periods of interest and compared county-level trends with national trends. Nationally, the age-adjusted HCV death rate peaked in 2013 at 5.20 HCV deaths per 100,000 persons (95% credible interval [CI], 5.12, 5.26) before decreasing to 4.34 per 100,000 persons (95% CI, 4.28, 4.41) in 2017 (average annual percent change = -4.69; 95% CI, -5.01, -4.33). County-level rates revealed heterogeneity in HCV mortality (2017 median rate = 3.6; interdecile range, 2.19, 6.77), with the highest rates being concentrated in the West, Southwest, Appalachia, and northern Florida. Between 2013 and 2017, HCV mortality decreased in 80.0% (n = 2,274) of all U.S. counties with a reliable trend estimate, with 25.8% (n = 803) of all counties experiencing a decrease larger than the national decline. CONCLUSIONS: Although many counties have experienced a shift in HCV mortality trends since 2013, the magnitude and composition of that shift have varied by place. These data provide a better understanding of geographic differences in HCV mortality and can be used by local jurisdictions to evaluate HCV mortality in their areas relative to surrounding areas and the nation.

Universal Hepatitis B Vaccination in Adults Aged 19-59 Years: Updated Recommendations of the Advisory Committee on Immunization Practices - United States, 2022.

Hepatitis B (HepB) vaccines have demonstrated safety, immunogenicity, and efficacy during the past 4 decades (1,2). However, vaccination coverage among adults has been suboptimal, limiting further reduction in hepatitis B virus (HBV) infections in the United States. This Advisory Committee on Immunization Practices (ACIP) recommendation expands the indicated age range for universal HepB vaccination to now include adults aged 19-59 years. Removing the risk factor assessment previously recommended to determine vaccine eligibility in this adult age group (2) could increase vaccination coverage and decrease hepatitis B cases.

Monitoring Coronavirus Disease 2019 (COVID-19) Through Trends in Influenza-like Illness, Laboratory-confirmed Influenza, and COVID-19-New York State, Excluding New York City, 1 January 2020-12 April 2020.

Innovative monitoring approaches are needed to track the coronavirus disease 2019 (COVID-19) epidemic and potentially assess the impact of community mitigation interventions. We present temporal data on influenza-like illness, influenza diagnosis, and COVID-19 cases for all 4 regions of New York State through the first 6 weeks of the outbreak.

COVID-19 Testing, Epidemic Features, Hospital Outcomes, and Household Prevalence, New York State-March 2020.

BACKGROUND: The US' coronavirus disease 2019 (COVID-19) epidemic has grown extensively since February 2020, with substantial associated hospitalizations and mortality; New York State has emerged as the national epicenter. We report on the extent of testing and test results during the month of March in New York State, along with risk factors, outcomes, and household prevalence among initial cases subject to in-depth investigations. METHODS: Specimen collection for COVID-19 testing was conducted in healthcare settings, community-based collection sites, and by home testing teams. Information on demographics, risk factors, and hospital outcomes of cases was obtained through epidemiological investigations and an electronic medical records match, and summarized descriptively. Active testing of initial case's households enabled estimation of household prevalence. RESULTS: During March in New York State, outside of New York City, a total of 47 326 persons tested positive for severe acute respiratory syndrome coronavirus 2, out of 141 495 tests (33% test-positive), with the highest number of cases located in the metropolitan region counties. Among 229 initial cases diagnosed through 12 March, by 30 March 13% were hospitalized and 2% died. Testing conducted among 498 members of these case's households found prevalent infection among 57%, excluding first-reported cases 38%. In these homes, we found a significant age gradient in prevalence, from 23% among those < 5 years to 68% among those ≥ 65 years (P < .0001). CONCLUSIONS: New York State faced a substantial and increasing COVID-19 outbreak during March 2020. The earliest cases had high levels of infection in their households and by the end of the month, the risks of hospitalization and death were high.

Estimating Prevalence of Hepatitis C Virus Infection in the United States, 2013-2016.

Hepatitis C virus (HCV) infection is the most commonly reported bloodborne infection in the United States, causing substantial morbidity and mortality and costing billions of dollars annually. To update the estimated HCV prevalence among all adults aged ≥18 years in the United States, we analyzed 2013-2016 data from the National Health and Nutrition Examination Survey (NHANES) to estimate the prevalence of HCV in the noninstitutionalized civilian population and used a combination of literature reviews and population size estimation approaches to estimate the HCV prevalence and population sizes for four additional populations: incarcerated people, unsheltered homeless people, active-duty military personnel, and nursing home residents. We estimated that during 2013-2016 1.7% (95% confidence interval [CI], 1.4-2.0%) of all adults in the United States, approximately 4.1 (3.4-4.9) million persons, were HCV antibody-positive (indicating past or current infection) and that 1.0% (95% CI, 0.8-1.1%) of all adults, approximately 2.4 (2.0-2.8) million persons, were HCV RNA-positive (indicating current infection). This includes 3.7 million noninstitutionalized civilian adults in the United States with HCV antibodies and 2.1 million with HCV RNA and an estimated 0.38 million HCV antibody-positive persons and 0.25 million HCV RNA-positive persons not part of the 2013-2016 NHANES sampling frame. Conclusion: Over 2 million people in the United States had current HCV infection during 2013-2016; compared to past estimates based on similar methodology, HCV antibody prevalence may have increased, while RNA prevalence may have decreased, likely reflecting the combination of the opioid crisis, curative treatment for HCV infection, and mortality among the HCV-infected population; efforts on multiple fronts are needed to combat the evolving HCV epidemic, including increasing capacity for and access to HCV testing, linkage to care, and cure.

Similarities and Differences in COVID-19 Awareness, Concern, and Symptoms by Race and Ethnicity in the United States: Cross-Sectional Survey.

BACKGROUND: Existing health disparities based on race and ethnicity in the United States are contributing to disparities in morbidity and mortality during the coronavirus disease (COVID-19) pandemic. We conducted an online survey of American adults to assess similarities and differences by race and ethnicity with respect to COVID-19 symptoms, estimates of the extent of the pandemic, knowledge of control measures, and stigma. OBJECTIVE: The aim of this study was to describe similarities and differences in COVID-19 symptoms, knowledge, and beliefs by race and ethnicity among adults in the United States. METHODS: We conducted a cross-sectional survey from March 27, 2020 through April 1, 2020. Participants were recruited on social media platforms and completed the survey on a secure web-based survey platform. We used chi-square tests to compare characteristics related to COVID-19 by race and ethnicity. Statistical tests were corrected using the Holm Bonferroni correction to account for multiple comparisons. RESULTS: A total of 1435 participants completed the survey; 52 (3.6%) were Asian, 158 (11.0%) were non-Hispanic Black, 548 (38.2%) were Hispanic, 587 (40.9%) were non-Hispanic White, and 90 (6.3%) identified as other or multiple races. Only one symptom (sore throat) was found to be different based on race and ethnicity (P=.003); this symptom was less frequently reported by Asian (3/52, 5.8%), non-Hispanic Black (9/158, 5.7%), and other/multiple race (8/90, 8.9%) participants compared to those who were Hispanic (99/548, 18.1%) or non-Hispanic White (95/587, 16.2%). Non-Hispanic White and Asian participants were more likely to estimate that the number of current cases was at least 100,000 (P=.004) and were more likely to answer all 14 COVID-19 knowledge scale questions correctly (Asian participants, 13/52, 25.0%; non-Hispanic White participants, 180/587, 30.7%) compared to Hispanic (108/548, 19.7%) and non-Hispanic Black (25/158, 15.8%) participants. CONCLUSIONS: We observed differences with respect to knowledge of appropriate methods to prevent infection by the novel coronavirus that causes COVID-19. Deficits in knowledge of proper control methods may further exacerbate existing race/ethnicity disparities. Additional research is needed to identify trusted sources of information in Hispanic and non-Hispanic Black communities and create effective messaging to disseminate correct COVID-19 prevention and treatment information.

Stagnating National Declines in Stroke Mortality Mask Widespread County-Level Increases, 2010-2016.

Background and Purpose- Recent national and state-level trends show a stalling or reversal of previously declining stroke death rates. These national trends may mask local geographic variation and changes in stroke mortality. We assessed county-level trends in stroke mortality among adults aged 35 to 64 and ≥65 years. Methods- We used data from National Vital Statistics Systems and a Bayesian multivariate space-time conditional autoregressive model to estimate age-standardized annual stroke death rates for 2010 through 2016 among middle-aged adults (35-64 years) and older adults (≥65 years) in US counties. We used log-linear regression models to estimate average annual and total percent change in stroke mortality during the period. Results- Nationally, the annual percent change in stroke mortality from 2010 to 2016 was -0.7% (95% CI, -4.2% to 3.0%) among middle-aged adults and -3.5% (95% CI, -10.7% to 4.3%) among older adults, resulting in 2016 rates of 15.0 per 100 000 and 259.8 per 100 000, respectively. Increasing county-level stroke mortality was more prevalent among middle-aged adults (56.6% of counties) compared with among older adults (26.1% of counties). About half (48.3%) of middle-aged adults, representing 60.2 million individuals, lived in counties in which stroke mortality increased. Conclusions- County-level increases in stroke mortality clarify previously reported national and state-level trends, particularly among middle-aged adults. Roughly 3×as many counties experienced increases in stroke death rates for middle-aged adults compared with older adults. This highlights a need to address stroke prevention and treatment for middle-aged adults while continuing efforts to reduce stroke mortality among the more highly burdened older adults. Efforts to reverse these troubling local trends will likely require joint public health and clinical efforts to develop innovative and integrated approaches for stroke prevention and care, with a focus on community-level characteristics that support stroke-free living for all.

Estimates of state-level chronic hepatitis C virus infection, stratified by race and sex, United States, 2010.

BACKGROUND: Hepatitis C virus (HCV) is the most common blood-borne viral infection in the United States. Previously, we used data from the National Health and Nutrition Examination Survey (NHANES) and mortality data from the National Vital Statistics System (NVSS) to estimate the prevalence of HCV antibodies (anti-HCV) and HCV RNA among all U.S. states. However, demographic differences in HCV burden at the state-level have not been systematically described. This analysis quantified the HCV burden stratified by sex and race (and associated disparities) for each U.S. state. METHODS: Building on our previous method, we used three publicly available data sources to estimate HCV RNA prevalence among noninstitutionalized adults stratified by sex and race group. We used a small-area estimation approach that included direct standardization of NHANES demographic data with logistic regression modeling of HCV-related mortality data as an adjustment factor to estimate the state-level prevalence and total persons with chronic HCV infection for sex and race groups in all U.S. states. RESULTS: Nationally, males had an estimated HCV RNA prevalence of 1.56% (95% CI: 1.37-1.84%) and females had a prevalence of 0.75% (95% CI: 0.63-0.96%). Stratified by race, national estimated prevalence of HCV RNA was highest among non-Hispanic black (2.43, 95% CI: 2.10-2.90%), followed by non-Hispanic white (1.05, 95% CI: 0.90-1.27%) and Hispanic/other (0.74, 95% CI: 0.59-1.04%). Males in most jurisdictions (41/51) have an HCV RNA prevalence that is between 1.5 and 2.5 times higher than their female counterparts. CONCLUSIONS: HCV infection disparities by sex are mostly consistent across the country. However, race differences in HCV infection differ by state and tailored prevention and treatment efforts specific to the local HCV epidemic are needed to reduce race disparities.

Estimation of State-Level Prevalence of Hepatitis C Virus Infection, US States and District of Columbia, 2010.

BACKGROUND.: Hepatitis C virus (HCV) infection is the most common chronic blood-borne infection in the United States and a leading cause of morbidity and mortality. Previous analyses of the US National Health and Nutrition Examination Survey (NHANES) indicated approximately 3.6 million noninstitutionalized persons with antibody to HCV (anti-HCV). However, state-level prevalence remains less understood and cannot be estimated reliably from NHANES alone. METHODS.: We used 3 publicly available government data sources to estimate anti-HCV prevalence in each US state among noninstitutionalized persons aged ≥18 years. A small-area estimation model combined indirect standardization of NHANES-based prevalence with logistic regression modeling of mortality data, listing acute or chronic HCV infection as a cause of death, from the National Vital Statistics System during 1999-2012. Model results were combined with US Census population sizes to estimate total number and prevalence of persons with antibody to HCV in 2010. RESULTS.: National anti-HCV prevalence was 1.67% (95% confidence interval [CI], 1.53-1.90), or 3 911 800 (95% CI, 3 589 400- 4 447 500) adults in 2010. State-specific prevalence ranged from 0.71% (Illinois) to 3.34% (Oklahoma). The West census region had the highest region-specific prevalence (2.14% [95% CI, 1.96-2.48]); 10 of 13 states had rates above the national average. The South had the highest number of persons with anti-HCV (n = 1561600 [95% CI, 1 427 700-1 768 900]). The Midwest had the lowest region-specific prevalence (1.14% [95% CI, 1.04%-1.30%]). CONCLUSIONS.: States in the US West and South have been most impacted by hepatitis C. Estimates of HCV infection burden are essential to guide policy and programs to optimally prevent, detect, and cure infection.