The Changing Epidemiology of Hepatitis C Virus Infection in the United States During the Years 2010 to 2018.

Hepatitis C virus (HCV) infection remains an important cause of morbidity and mortality throughout the world, leading to serious health problems among those who are chronically infected. Since 1992, the Centers for Disease Control and Prevention has been collecting data on the incidence of HCV infection in the United States. In 2018, more than 50 000 individuals were estimated to have acute HCV infection.The most recently reported data on the prevalence of infection indicate that approximately 2.4 million people are living with hepatitis C in the United States. Transmission of HCV occurs predominantly through sharing contaminated equipment for injecting drugs.Two major events have had a significant impact on the incidence and prevalence of hepatitis C in the past few decades: the US opioid crisis and the discovery of curative treatments for HCV infection. To better understand the impact of these events, we examine reported trends in the incidence and prevalence of infection.

Trends in Prevalence of Protective Levels of Hepatitis B Surface Antibody Among Adults Aged 18-49 Years With Risk Factors for Hepatitis B Virus Infection-United States, 2003-2014.

BACKGROUND: Hepatitis B virus (HBV) infection can be prevented through vaccination. However, previous data show that only about 24%-45% of US adults at high risk of HBV infection are protected. Our aims were to assess prevalence and trends in protective levels of hepatitis B surface antibody (anti-HBs) from 2003 to 2014 and explore factors associated with protection among adults at high risk. METHODS: Data were taken from the 2003-2014 National Health and Nutrition Examination surveys. Our sample included adults aged 18-49 years who were tested for HBV and reported at least 1 of the following infection risks: history of sexually transmitted disease, sex with men (for men), infection with human immunodeficiency virus, and injection drug use. We calculated the prevalence of anti-HBs (≥10 mIU/mL), indicative of immunity from vaccination, among respondents for three 4-year time intervals (2003-2006, 2007-2010, and 2011-2014) and applied the Cochran-Mantel-Haenszel test to assess trends. Using multivariable logistic regression, we examined factors associated with positive anti-HBs serology. RESULTS: The prevalence of positive anti-HBs serology was 23.4%. Prevalence increased from 2003-2006 (16.3%) to 2007-2010 (27.3%), but no change occurred from 2007-2010 (27.3%) to 2011-2014 (28.1%). Among factors predicting positive anti-HBs serology were young age and higher education. CONCLUSIONS: By 2014, less than one-third of adults aged 18-49 years at risk of infection exhibited protective antibodies ≥10 mIU/mL. Because these adults account for a majority of unprotected adults, targeted intervention strategies are essential to achieve the hepatitis B elimination goal.

The Hepatitis C Virus Care Continuum: Linkage to Hepatitis C Virus Care and Treatment Among Patients at an Urban Health Network, Philadelphia, PA.

Improving care and treatment for persons infected with hepatitis C virus (HCV) can reduce HCV-related morbidity and mortality. Our primary objective was to examine the HCV care continuum among patients receiving care at five federally qualified health centers (FQHCs) in Philadelphia, PA, where a testing and linkage to care program had been established. Among the five FQHCs, one served a homeless population, two served public housing residents, one served a majority Hispanic population, and the last, a "test and treat" site, also provided HCV treatment to patients. We analyzed data from electronic health records of patients tested for HCV antibody from 2012 to 2016 and calculated the percentage of patients across nine steps of the HCV care continuum ranging from diagnosis to cure. We further explored factors associated with successful patient navigation through two steps of the continuum using multivariable logistic regression. Of 885 chronically infected patients, 92.2% received their RNA-positive result, 82.7% were referred to an HCV provider, 69.4% were medically evaluated by the provider, 55.3% underwent liver disease staging, 15.0% initiated treatment, 12.0% completed treatment, 8.7% were assessed for sustained virologic response (SVR), and 8.0% achieved SVR. Regression results revealed that test and treat site patients were significantly more likely to be medically evaluated (adjusted odds ratio [aOR], 2.76; 95% confidence interval [CI], 1.82-4.17) and to undergo liver disease staging (aOR, 1.92; 95% CI, 1.02-2.86) than patients at the other FQHCs combined. Conclusion: In this US urban setting, over two thirds of HCV-infected patients were linked to care; although treatment uptake was low overall, it was highest at the test and treat site; scaling up treatment services in HCV testing settings will be vital to improve the HCV care continuum.

Increases in Acute Hepatitis C Virus Infection Related to a Growing Opioid Epidemic and Associated Injection Drug Use, United States, 2004 to 2014.

OBJECTIVES: To compare US trends in rates of injection drug use (IDU), specifically opioid injection, with national trends in the incidence of acute HCV infection to assess whether these events correlated over time. METHODS: We calculated the annual incidence rate and demographic and risk characteristics of reported cases of acute HCV infection using surveillance data from 2004 to 2014 and the annual percentage of admissions to substance use disorder treatment facilities reporting IDU for the same time period by type of drug injected and demographic characteristics. We then tested for trends. RESULTS: The annual incidence rate of acute HCV infection increased more than 2-fold (from 0.3 to 0.7 cases/100 000) from 2004 to 2014, with significant increases among select demographic subgroups. Admissions for substance use disorder attributed to injection of heroin and prescription opioid analgesics increased significantly, with an almost 4-fold increase in prescription opioid analgesic injection. Significant increases in opioid injection mirrored those for reported cases of acute HCV infection among demographic subgroups. CONCLUSIONS: These findings strongly suggest that the national increase in acute HCV infection is related to the country's opioid epidemic and associated increases in IDU.

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.

Comparison of ICD-9 Codes for Depression and Alcohol Misuse to Survey Instruments Suggests These Codes Should Be Used with Caution.

BACKGROUND: Research suggests depression and alcohol misuse are highly prevalent among chronic hepatitis C (CHC) patients, which is of clinical concern. AIMS: To compare ICD-9 codes for depression and alcohol misuse to validated survey instruments. METHODS: Among CHC patients, we assessed how well electronic ICD-9 codes for depression and alcohol misuse predicted these disorders using validated instruments. RESULTS: Of 4874 patients surveyed, 56% were male and 52% had a history of injection drug use. Based on the PHQ-8, the prevalence of depression was 30% compared to 14% based on ICD-9 codes within 12 months of survey, 37% from ICD-9 codes any time before or within 12 months after survey, and 48% from ICD-9 codes any time before or within 24 months after survey. ICD-9 codes predicting PHQ-8 depression had a sensitivity ranging from 59 to 88% and a specificity ranging from 33 to 65%. Based on the AUDIT-C, the prevalence of alcohol misuse was 21% compared to 3-23% using ICD-9 codes. The sensitivity of ICD-9 codes to predict AUDIT-C score ranged from 9 to 35% and specificity from 80 to 98%. Overall 39% of patients reported ever binge drinking, with a sensitivity of ICD-9 to predict binge drinking ranging from 7 to 33% and a specificity from 84 to 98%. More than half of patients had either an ICD-9 code for depression, a survey score indicating depression, or both (59%); more than one-third had the same patterns for alcohol misuse (36%). CONCLUSIONS: ICD-9 codes were limited in predicting current depression and alcohol misuse, suggesting that caution should be exercised when using ICD-9 codes to assess depression or alcohol misuse among CHC patients.

Annual Report to the Nation on the Status of Cancer, 1975-2012, featuring the increasing incidence of liver cancer.

BACKGROUND: Annual updates on cancer occurrence and trends in the United States are provided through an ongoing collaboration among the American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR). This annual report highlights the increasing burden of liver and intrahepatic bile duct (liver) cancers. METHODS: Cancer incidence data were obtained from the CDC, NCI, and NAACCR; data about cancer deaths were obtained from the CDC's National Center for Health Statistics (NCHS). Annual percent changes in incidence and death rates (age-adjusted to the 2000 US Standard Population) for all cancers combined and for the leading cancers among men and women were estimated by joinpoint analysis of long-term trends (incidence for 1992-2012 and mortality for 1975-2012) and short-term trends (2008-2012). In-depth analysis of liver cancer incidence included an age-period-cohort analysis and an incidence-based estimation of person-years of life lost because of the disease. By using NCHS multiple causes of death data, hepatitis C virus (HCV) and liver cancer-associated death rates were examined from 1999 through 2013. RESULTS: Among men and women of all major racial and ethnic groups, death rates continued to decline for all cancers combined and for most cancer sites; the overall cancer death rate (for both sexes combined) decreased by 1.5% per year from 2003 to 2012. Overall, incidence rates decreased among men and remained stable among women from 2003 to 2012. Among both men and women, deaths from liver cancer increased at the highest rate of all cancer sites, and liver cancer incidence rates increased sharply, second only to thyroid cancer. Men had more than twice the incidence rate of liver cancer than women, and rates increased with age for both sexes. Among non-Hispanic (NH) white, NH black, and Hispanic men and women, liver cancer incidence rates were higher for persons born after the 1938 to 1947 birth cohort. In contrast, there was a minimal birth cohort effect for NH Asian and Pacific Islanders (APIs). NH black men and Hispanic men had the lowest median age at death (60 and 62 years, respectively) and the highest average person-years of life lost per death (21 and 20 years, respectively) from liver cancer. HCV and liver cancer-associated death rates were highest among decedents who were born during 1945 through 1965. CONCLUSIONS: Overall, cancer incidence and mortality declined among men; and, although cancer incidence was stable among women, mortality declined. The burden of liver cancer is growing and is not equally distributed throughout the population. Efforts to vaccinate populations that are vulnerable to hepatitis B virus (HBV) infection and to identify and treat those living with HCV or HBV infection, metabolic conditions, alcoholic liver disease, or other causes of cirrhosis can be effective in reducing the incidence and mortality of liver cancer. Cancer 2016;122:1312-1337. © 2016 American Cancer Society.

Syringe Service Programs for Persons Who Inject Drugs in Urban, Suburban, and Rural Areas - United States, 2013.

Reducing human immunodeficiency virus (HIV) infection rates in persons who inject drugs (PWID) has been one of the major successes in HIV prevention in the United States. Estimated HIV incidence among PWID declined by approximately 80% during 1990-2006 (1). More recent data indicate that further reductions in HIV incidence are occurring in multiple areas (2). Research results for the effectiveness of risk reduction programs in preventing hepatitis C virus (HCV) infection among PWID (3) have not been as consistent as they have been for HIV; however, a marked decline in the incidence of HCV infection occurred during 1992-2005 in selected U.S. locations when targeted risk reduction efforts for the prevention of HIV were implemented (4). Because syringe service programs (SSPs)* have been one effective component of these risk reduction efforts for PWID (5), and because at least half of PWID are estimated to live outside major urban areas (6), a study was undertaken to characterize the current status of SSPs in the United States and determine whether urban, suburban, and rural SSPs differed. Data from a recent survey of SSPs(†) were analyzed to describe program characteristics (e.g., size, clients, and services), which were then compared by urban, suburban, and rural location. Substantially fewer SSPs were located in rural and suburban than in urban areas, and harm reduction services(§) were less available to PWID outside urban settings. Because increases in substance abuse treatment admissions for drug injection have been observed concurrently with increases in reported cases of acute HCV infection in rural and suburban areas (7), state and local jurisdictions could consider extending effective prevention programs, including SSPs, to populations of PWID in rural and suburban areas.

Identification and Linkage to Care of HCV-Infected Persons in Five Health Centers - Philadelphia, Pennsylvania, 2012-2014.

Approximately three million persons in the United States are infected with hepatitis C virus (HCV), a blood-borne pathogen that is an increasing cause of liver disease and mortality in the United States. Treatments for HCV are curative, of short duration, and have few associated side effects, increasing the importance of identifying HCV-infected persons. Many persons with HCV infection were infected decades ago, before implementation of prevention measures and most are unaware of their infection, regardless of when it occurred. Most newly diagnosed cases are associated with injection drug use. Persons born during 1945-1965 have a fivefold higher risk of HCV infection than other adults and the highest risk for HCV-related morbidity and mortality. CDC recommends testing for this group, for persons who inject drugs, and others at risk for HCV infection. From October 2012 through July 2014, the National Nursing Centers Consortium (NNCC) carried out a project to integrate routine HCV testing and linkage-to-care in five federally qualified health centers in Philadelphia, PA, that primarily serve homeless persons and public housing residents. During the project period, 4,514 patients across the five centers were tested for HCV. Of these, 595 (13.2%) were HCV-antibody positive and 550 (92.4%) had a confirmatory HCV-RNA test performed. Of those who had a confirmatory HCV-RNA test performed, 390 (70.9%) were identified as having current (i.e., chronic) HCV infection (overall prevalence = 8.6%). Of those currently infected with HCV, 90% were informed of their status, 78% were referred to an HCV care specialist, and 62% went to the referred specialist for care. Replicable system modifications that improved HCV testing and care included enhancements to electronic medical records (EMRs), simplification of HCV testing protocols, and addition of a linkage-to-care coordinator. Findings from this project highlight the need for innovative strategies for HCV testing, care, and treatment, as well as the important role of community health centers in expanding access for patient populations disproportionately affected by HCV infection.

Increases in hepatitis C virus infection related to injection drug use among persons aged ≤30 years - Kentucky, Tennessee, Virginia, and West Virginia, 2006-2012.

Hepatitis C virus (HCV) infection is the most common blood-borne infection in the United States, with approximately three million persons living with current infection. Percutaneous exposure to contaminated blood is the most efficient mode of transmission, and in the United States, injection drug use (IDU) is the primary risk factor for infection. State surveillance reports from the period 2006-2012 reveal a nationwide increase in reported cases of acute HCV infection, with the largest increases occurring east of the Mississippi River, particularly among states in central Appalachia. Demographic and behavioral data accompanying these reports show young persons (aged ≤30 years) from nonurban areas contributed to the majority of cases, with about 73% citing IDU as a principal risk factor. To better understand the increase in acute cases of HCV infection and its correlation to IDU, CDC examined surveillance data for acute case reports in conjunction with analyzing drug treatment admissions data from the Treatment Episode Data Set-Admissions (TEDS-A) among persons aged ≤30 years in four states (Kentucky, Tennessee, Virginia, and West Virginia) for the period 2006-2012. During this period, significant increases in cases of acute HCV infection were found among persons in both urban and nonurban areas, with a substantially higher incidence observed each year among persons residing in nonurban areas. During the same period, the proportion of treatment admissions for opioid dependency increased 21.1% in the four states, with a significant increase in the proportion of persons admitted who identified injecting as their main route of drug administration (an increase of 12.6%). Taken together, these increases indicate a geographic intersection among opioid abuse, drug injecting, and HCV infection in central Appalachia and underscore the need for integrated health services in substance abuse treatment settings to prevent HCV infection and ensure that those who are infected receive medical care.

Confronting the emerging epidemic of HCV infection among young injection drug users.

Hepatitis C virus infection is a significant public health problem in the United States and an important cause of morbidity and mortality. Recent reports document HCV infection increases among young injection drug users in several US regions, associated with America's prescription opioid abuse epidemic. Incident HCV infection increases among young injectors who have recently transitioned from oral opioid abuse present an important public health challenge requiring a comprehensive, community-based response. We summarize recommendations from a 2013 Office of HIV/AIDS and Infectious Disease Policy convening of experts in epidemiology, behavioral science, drug prevention and treatment, and other research; community service providers; and federal, state, and local government representatives. Their observations highlight gaps in our surveillance, program, and research portfolios and advocate a syndemic approach to this emerging public health problem.

Previous exposure to HCV among persons born during 1945-1965: prevalence and predictors, United States, 1999-2008.

OBJECTIVES: We examined HCV exposure prevalence and predictors among persons in the United States born during 1945-1965. METHODS: With data from the 1999-2008 National Health and Nutrition Examination Survey, we calculated the proportion of persons born during 1945-1965 who tested positive for HCV antibody (anti-HCV) and analyzed the prevalence by sociodemographic and behavioral risk factors. RESULTS: Anti-HCV prevalence in the 1945-1965 birth cohort was 3.2% (95% confidence interval [CI] = 2.8%, 3.8%), substantially higher than among other adults (0.9%). Within the cohort, anti-HCV prevalence was higher among non-Hispanic Blacks (6.4%; 95% CI = 5.3%, 7.7%), persons with injection drug use histories (56.8%; 95% CI = 48.4%, 64.8%), and persons with elevated alanine aminotransferase levels (12.7%; 95% CI = 10.7%, 15.1%). Injection drug use (adjusted odds ratio = 98.4; 95% CI = 58.8, 164.5) was the strongest anti-HCV prevalence predictor. Among anti-HCV-positive persons, 57.8% reported having 2 or more alcoholic drinks daily. CONCLUSIONS: With the high prevalence of HCV among persons born during 1945-1965, the increasing morbidity and mortality associated with HCV, and reductions in liver cancer and HCV-related mortality when HCV is eradicated, it is critically important to identify persons with HCV and link them to appropriate care.

Expanding primary care capacity to treat hepatitis C virus infection through an evidence-based care model--Arizona and Utah, 2012-2014.

Hepatitis C virus (HCV) infection is the leading reason for liver transplantation and a common cause of hepatocellular carcinoma, the most rapidly increasing cause of cancer-related deaths in the United States. Of the approximately 3 million persons living with HCV infection in the United States, an estimated 38% are linked to care, 11% are treated, and 6% achieve cure. Recent development of highly effective and well-tolerated medications, such as sofosbuvir and simeprevir, to treat chronic HCV infection shows promise in curbing rising HCV-related morbidity and mortality, with the potential to cure >90% of patients. To fully benefit from these new treatments, improvement in linkage to care and treatment is urgently needed.* Lack of provider expertise in HCV treatment and limited access to specialists are well-documented barriers to HCV treatment. In September 2012, CDC funded programs in Utah and Arizona to improve access to primary care providers with the capacity to manage and treat HCV infection. Both programs were modeled on the Extension for Community Healthcare Outcomes (Project ECHO), developed by the University of New Mexico's Health Sciences Center in 2003 to build primary care capacity to treat diseases among rural, underserved populations through videoconferencing and case-based learning in "teleECHO" clinics. To assess the effectiveness of these programs in improving primary care provider capacity and increasing the number of patients initiating treatment, process and patient outcome data for each state program were analyzed. In both states, Project ECHO was successfully implemented, training 66 primary care clinicians, predominantly from rural settings. Nearly all (93%) of the clinicians had no prior experience in care and treatment of HCV infection. In both states combined, 129 (46%) of HCV-infected patients seen in teleECHO clinics received antiviral treatment, more than doubling the proportion of patients expected to receive treatment. These findings demonstrate Project ECHO's ability to expand primary care capacity to treat HCV infection, notably among underserved populations.

Recommendations for the identification of chronic hepatitis C virus infection among persons born during 1945-1965.

Hepatitis C virus (HCV) is an increasing cause of morbidity and mortality in the United States. Many of the 2.7-3.9 million persons living with HCV infection are unaware they are infected and do not receive care (e.g., education, counseling, and medical monitoring) and treatment. CDC estimates that although persons born during 1945-1965 comprise an estimated 27% of the population, they account for approximately three fourths of all HCV infections in the United States, 73% of HCV-associated mortality, and are at greatest risk for hepatocellular carcinoma and other HCV-related liver disease. With the advent of new therapies that can halt disease progression and provide a virologic cure (i.e., sustained viral clearance following completion of treatment) in most persons, targeted testing and linkage to care for infected persons in this birth cohort is expected to reduce HCV-related morbidity and mortality. CDC is augmenting previous recommendations for HCV testing (CDC. Recommendations for prevention and control of hepatitis C virus (HCV) infection and HCV-related chronic disease. MMWR 1998;47[No. RR-19]) to recommend one-time testing without prior ascertainment of HCV risk for persons born during 1945-1965, a population with a disproportionately high prevalence of HCV infection and related disease. Persons identified as having HCV infection should receive a brief screening for alcohol use and intervention as clinically indicated, followed by referral to appropriate care for HCV infection and related conditions. These recommendations do not replace previous guidelines for HCV testing that are based on known risk factors and clinical indications. Rather, they define an additional target population for testing: persons born during 1945-1965. CDC developed these recommendations with the assistance of a work group representing diverse expertise and perspectives. The recommendations are informed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework, an approach that provides guidance and tools to define the research questions, conduct the systematic review, assess the overall quality of the evidence, and determine strength of the recommendations. This report is intended to serve as a resource for health-care professionals, public health officials, and organizations involved in the development, implementation, and evaluation of prevention and clinical services. These recommendations will be reviewed every 5 years and updated to include advances in the published evidence.

Hepatitis C virus testing of persons born during 1945-1965: recommendations from the Centers for Disease Control and Prevention.

DESCRIPTION: The Centers for Disease Control and Prevention (CDC) and a group of governmental and private sector partners developed these evidence-based recommendations to increase the proportion of hepatitis C virus (HCV)-infected persons who know their status and are linked to appropriate care and treatment. The recommendations also address brief alcohol screening, as alcohol accelerates progression of liver disease among HCV-infected individuals. These recommendations augment CDC's 1998 and 1999 recommendations based on risk and medical indications and are not meant to replace those recommendations. METHODS: These recommendations are based on systematic reviews of evidence published from 1995 through February 2012 in MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials, Sociological Abstracts, and Database of Abstracts of Reviews of Effects. Selected studies included cross-sectional and cohort studies that addressed either prevalence of hepatitis C in the United States or clinical outcomes (for example, hepatocellular carcinoma and serious adverse events) among treated patients and systematic reviews of trials that assessed effectiveness of brief screening interventions for alcohol consumption. The Grading of Recommendations Assessment, Development, and Evaluation framework was used to assess quality of the evidence. RECOMMENDATION 1: Adults born during 1945-1965 should receive 1-time testing for HCV without prior ascertainment of HCV risk. (Grade: strong recommendation; moderate-quality evidence). RECOMMENDATION 2: All persons with identified HCV infection should receive a brief alcohol screening and intervention as clinically indicated, followed by referral to appropriate care and treatment services for HCV infection and related conditions (Grade: strong recommendation; moderate-quality evidence).

Global burden of hepatitis C: considerations for healthcare providers in the United States.

An estimated 2%-3% of the world's population is living with hepatitis C virus (HCV) infection, and each year, >350 000 die of HCV-related conditions, including cirrhosis and liver cancer. The epidemiology and burden of HCV infection varies throughout the world, with country-specific prevalence ranging from <1% to >10%. In contrast to the United States and other developed countries, HCV transmission in developing countries frequently results from exposure to infected blood in healthcare and community settings. Hepatitis C prevention, care, and treatment programs must recognize country-specific epidemiology, which varies by setting and level of economic development. Awareness of the global epidemiology of HCV infection is important for US healthcare providers treating foreign-born patients from countries where HCV infection is endemic and for counseling patients who travel to these countries. Countries with a high burden of HCV infection also would benefit from establishing comprehensive prevention, care, and treatment programs.

Genotypic distribution of hepatitis B virus (HBV) among acute cases of HBV infection, selected United States counties, 1999-2005.

BACKGROUND: Knowledge of the genotypic distribution of hepatitis B virus (HBV) facilitates epidemiologic tracking and surveillance of HBV infection as well as prediction of its disease burden. In the United States, HBV genotyping studies have been conducted for chronic but not acute hepatitis B. METHODS: Serum samples were collected from patients with acute hepatitis B cases reported from the 6 counties that participated in the Sentinel Counties Study of Acute Viral Hepatitis from 1999 through 2005. Polymerase chain reaction followed by nucleotide sequencing of a 435-base pair segment of the HBV S gene was performed, and the sequences were phylogenetically analyzed. RESULTS: Of 614 patients identified with available serum samples, 75% were infected with genotype A HBV and 18% were infected with genotype D HBV. Thirty-two percent of genotype A sequences constituted a single subgenotype A2 cluster. The odds of infection with genotype A (vs with genotype D) were 5 times greater among black individuals than among Hispanic individuals (odds ratio [OR], 5; 95% confidence interval [CI], 2.3-10.7). The odds of infection with genotype A were 49, 8, and 4 times greater among patients from Jefferson County (Alabama), Pinellas County (Florida), and San Francisco (California), respectively, than among those living in Denver County (Colorado). Genotype A was less common among recent injection drug users than it was among non-injection drug users (OR, 0.2; 95% CI, 0.1-0.4). CONCLUSIONS: HBV genotype distribution was significantly associated with ethnicity, place of residence, and risk behavior.