Hepatitis A is a vaccine-preventable disease that typically causes mild illness. Hepatitis A outbreaks associated with person-to-person transmission have been widespread in the United States since 2016. We used public-use US Multiple Cause of Death data to compare characteristics and listed comorbidities among decedents with hepatitis A-listed deaths during non-outbreak (2011-2015) and outbreak (2017-2021) periods and assessed the median age at death among decedents with and without hepatitis A-listed deaths during the outbreak period. From the non-outbreak period to the outbreak period, hepatitis A-listed deaths more than doubled (from 369 to 801), while the hepatitis A-listed age-adjusted mortality rate increased 150% (p < 0.001). When compared with the non-outbreak period, hepatitis A-listed decedents during the outbreak period were more frequently male, aged 18-49 years, non-Hispanic White, died in an inpatient setting, and had hepatitis A listed as their underlying cause of death. The median age at death for hepatitis A-listed decedents was significantly younger during the outbreak period overall and among females (62 and 66 years, respectively) compared with the non-outbreak period (64 and 72 years, respectively, p < 0.001). During the outbreak period, median age at death for hepatitis A-listed decedents was 14 years younger than decedents without hepatitis A listed. Compared with the general US population, decedents with hepatitis A listed on the death certificate died at younger ages during 2017-2021. Efforts are needed to improve hepatitis A vaccination coverage among adults recommended for hepatitis A vaccination to prevent additional premature hepatitis A deaths.

OBJECTIVES: In the United States, hepatitis C is the most commonly reported bloodborne infection. It is a leading cause of liver cancer and death from liver disease and imposes a substantial burden of hospitalization. We sought to describe regional differences in hepatitis C virus (HCV)-related hospitalizations during 2012 through 2019 to guide planning for hepatitis C elimination. METHODS: We analyzed discharge data from the National Inpatient Sample for 2012 through 2019. We considered hospitalizations to be HCV-related if (1) hepatitis C was the primary diagnosis or (2) hepatitis C was any secondary diagnosis and the primary diagnosis was a liver disease-related condition. We analyzed demographic and clinical characteristics of HCV-related hospitalizations and modeled the annual percentage change in HCV-related hospitalization rates, nationally and according to the 9 US Census Bureau geographic divisions. RESULTS: During 2012-2019, an estimated 553 900 HCV-related hospitalizations occurred in the United States. The highest hospitalization rate (34.7 per 100 000 population) was in the West South Central region, while the lowest (17.6 per 100 000 population) was in the West North Central region. During 2012-2019, annual hospitalization rates decreased in each region, with decreases ranging from 15.3% in the East South Central region to 48.8% in the Pacific region. By type of health insurance, Medicaid had the highest hospitalization rate nationally and in all but 1 geographic region. CONCLUSIONS: HCV-related hospitalization rates decreased nationally and in each geographic region during 2012-2019; however, decreases were not uniform. Expanded access to direct-acting antiviral treatment in early-stage hepatitis C would reduce future hospitalizations related to advanced liver disease and interrupt HCV transmission.

We evaluated factors associated with the presence of hepatitis A virus antibodies 23 years after initiating vaccination at ages 6-15 months. Among 67 participants, 86% (42/49) of those vaccinated at ages 12-15 months and 61% (11/18) of those vaccinated at 6 months remained seropositive at 23 years. Lack of maternal antibodies at enrollment and higher initial vaccine response were independently associated with higher antibody concentrations at 23 years. Further research is needed to assess the duration of hepatitis A vaccine protection and possible need for a booster dose.

BACKGROUND AIMS: The National Health and Nutrition Examination Survey (NHANES) underestimates the true prevalence of hepatitis C virus (HCV) infection. By accounting for populations inadequately represented in NHANES, we created two models to estimate the national hepatitis C prevalence among US adults during 2017-2020. APPROACH 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 inject drugs [PWID] adjustment), we developed a model to account for 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% confidence interval [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, estimated prevalence of hepatitis C in 2017-2020 remains unchanged from 2013-2016 when using comparable methodology. When accounting for increased injection drug use, 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.

Hepatitis A is acquired through the fecal-oral route and is preventable by a safe and effective vaccine. Although hepatitis A is generally mild and self-limited, serious complications, including death, can occur. Since 2016, widespread hepatitis A outbreaks have been reported in 37 U.S. states, primarily among persons who use drugs and those experiencing homelessness. Nearly twice as many hepatitis A-related deaths were reported during 2016-2022 compared with 2009-2015. CDC analyzed data from 27 hepatitis A outbreak-affected states* that contributed data during August 1, 2016-October 31, 2022, to characterize demographic, risk factor, clinical, and cause-of-death data among 315 outbreak-related hepatitis A deaths from those states. Hepatitis A was documented as an underlying or contributing cause of death on 60% of available death certificates. Outbreak-related deaths peaked in 2019, and then decreased annually through 2022. The median age at death was 55 years; most deaths occurred among males (73%) and non-Hispanic White persons (84%). Nearly two thirds (63%) of decedents had at least one documented indication for hepatitis A vaccination, including drug use (41%), homelessness (16%), or coinfection with hepatitis B (12%) or hepatitis C (31%); only 12 (4%) had evidence of previous hepatitis A vaccination. Increasing vaccination coverage among adults at increased risk for infection with hepatitis A virus or for severe disease from infection is critical to preventing future hepatitis A-related deaths.

BACKGROUND: Hospitalization burden related to hepatitis C virus (HCV) infection is substantial. We sought to describe temporal trends in hospitalization rates before and after release of direct-acting antiviral (DAA) agents. METHODS: We analyzed 2000-2019 data from adults aged ≥18 years in the National Inpatient Sample. Hospitalizations were HCV-related if 1) hepatitis C was the primary diagnosis, or 2) hepatitis C was any secondary diagnosis with a liver-related primary diagnosis. We analyzed characteristics of HCV-related hospitalizations nationally, and examined trends in age-adjusted hospitalization rates. RESULTS: During 2000-2019, there were an estimated 1,286,397 HCV-related hospitalizations in the United States. The annual age-adjusted hospitalization rate was lowest in 2019 (18.7/100,000 population) and highest in 2012 (29.6/100,000 population). Most hospitalizations occurred among persons aged 45-64 (71.8%), males (67.1%), white non-Hispanic persons (60.5%), and Medicaid/Medicare recipients (64.0%). The national age-adjusted hospitalization rate increased during 2000-2003 (annual percent change [APC] 9.4%, P<.001) and 2003-2013 (APC 1.8%, P<.001) before decreasing during 2013-2019 (APC -7.6%, P<.001). Comparing 2000 to 2019, the largest increases in hospitalization rates occurred among persons aged 55-64 years (132.9%), Medicaid recipients (41.6%), and black non-Hispanic persons (22.3%). CONCLUSIONS: Although multiple factors likely contributed, overall HCV-related hospitalization rates declined steadily after 2013, coinciding with the release of DAAs. However, the declines were not observed equally among age, race/ethnicity, or insurance categories. Expanded access to DAA treatment is needed, particularly among Medicaid and Medicare recipients, to reduce disparities and morbidity, and eliminate hepatitis C as a public health threat.

Donor-derived transmission of infections is a rare complication of kidney transplant. Hepatitis A virus (HAV) is a common cause of acute viral hepatitis worldwide, but donor-derived transmission to organ recipients has been reported in the literature only twice previously. The timeline for HAV incubation and clearance in transplant recipients is not well understood. METHODS: In 2018, 2 kidneys and a liver were procured from a deceased donor resident of Kentucky, one of many states that was experiencing an HAV outbreak associated with person-to-person transmission through close contact, primarily among people who reported drug use. Both kidney recipients, residents of Virginia, subsequently developed acute HAV infections. We report the results of an investigation to determine the source of transmission and describe the clinical course of HAV infection in the infected kidney recipients. RESULTS: The liver recipient had evidence of immunity to HAV and did not become infected. The donor and both kidney recipients were found to have a genetically identical strain of HAV using a next-generation sequencing-based cyber molecular assay (Global Hepatitis Outbreak Surveillance Technology), confirming donor-derived HAV infections in kidney recipients. At least 1 kidney recipient experienced delayed development of detectable hepatitis A anti-IgM antibodies. By 383 and 198 d posttransplant, HAV RNA was no longer detectable in stool specimens from the left and right kidney recipients, respectively. CONCLUSIONS: Adherence to current guidance for hepatitis A vaccination may prevent future morbidity due to HAV among organ recipients. http://links.lww.com/TXD/A548.

OBJECTIVES: The incidence of hepatitis A declined in the United States following the introduction of hepatitis A vaccines, before increasing in the setting of recent widespread outbreaks associated with person-to-person transmission. We describe the hepatitis A epidemiology in the United States, identify susceptible populations over time, and demonstrate the need for improved hepatitis A vaccination coverage, especially among adults at increased risk for hepatitis A. METHODS: We calculated the hepatitis A incidence rates for sociodemographic characteristics and percentages for risk factors and clinical outcomes for hepatitis A cases reported to the National Notifiable Diseases Surveillance System during 1990-2020. We generated nationally representative estimates and 95% CIs of hepatitis A seroprevalence during 1976-March 2020 and self-reported hepatitis A vaccination coverage during 1999-March 2020 for the noninstitutionalized civilian US population using data from the National Health and Nutrition Examination Survey. RESULTS: Overall, the rate per 100 000 population of reported cases of hepatitis A virus infection in the United States declined 17.3-fold, from 10.4 during 1990-1998 to 0.6 during 2007-2015, and then increased to 2.8 during 2016-2020. The overall hepatitis A seroprevalence in the United States increased from 38.2% (95% CI, 36.2%-40.1%) during 1976-1980 to 47.3% (95% CI, 45.4%-49.2%) during 2015-March 2020. The prevalence of self-reported hepatitis A vaccination coverage in the United States increased more than 2.5-fold, from 16.3% (95% CI, 15.0%-17.7%) during 1999-2006 to 41.9% (95% CI, 40.2%-43.7%) during 2015-March 2020. CONCLUSIONS: Hepatitis A epidemiology in the United States changed substantially during 1976-2020. Improved vaccination coverage, especially among adults recommended for vaccination by the Advisory Committee on Immunization Practices, is vital to stop current hepatitis A outbreaks associated with person-to-person transmission in the United States and prevent similar future recurrences.

Chronic hepatitis B virus (HBV) infection can lead to substantial morbidity and mortality. Although treatment is not considered curative, antiviral treatment, monitoring, and liver cancer surveillance can reduce morbidity and mortality. Effective vaccines to prevent hepatitis B are available. This report updates and expands CDC's previously published Recommendations for Identification and Public Health Management of Persons with Chronic Hepatitis B Virus Infection (MMWR Recomm Rep 2008;57[No. RR-8]) regarding screening for HBV infection in the United States. New recommendations include hepatitis B screening using three laboratory tests at least once during a lifetime for adults aged ≥18 years. The report also expands risk-based testing recommendations to include the following populations, activities, exposures, or conditions associated with increased risk for HBV infection: persons incarcerated or formerly incarcerated in a jail, prison, or other detention setting; persons with a history of sexually transmitted infections or multiple sex partners; and persons with a history of hepatitis C virus infection. In addition, to provide increased access to testing, anyone who requests HBV testing should receive it, regardless of disclosure of risk, because many persons might be reluctant to disclose stigmatizing risks.

BACKGROUND: People who use drugs are at increased risk for hepatitis A virus infection. Since 1996, the Advisory Committee on Immunization Practices has recommended hepatitis A vaccination for people who use drugs. Since 2016, the U.S. has experienced widespread hepatitis A outbreaks associated with person-to-person transmission. PURPOSE: To describe the prevalence of drug use, route of use, and drugs used among hepatitis A outbreak-associated patients. METHODS: State outbreak and medical records were reviewed to describe the prevalence, type, and route of drug use among a random sample of 812 adult outbreak-associated hepatitis A patients from Kentucky, Michigan, and West Virginia during 2016-2019. Differences in drug-use status were analyzed by demographic and risk-factor characteristics using the X (2) test. RESULTS: Among all patients, residents of Kentucky (55.6%), Michigan (51.1%), and West Virginia (60.1%) reported any drug use, respectively. Among patients that reported any drug use, methamphetamine was the most frequently reported drug used in Kentucky (42.3%) and West Virginia (42.1%); however, opioids were the most frequently reported drug used in Michigan (46.8%). Hepatitis A patients with documented drug use were more likely (p<0.05) to be experiencing homelessness/unstable housing, have been currently or recently incarcerated, and be aged 18-39 years compared to those patients without documented drug use. IMPLICATIONS: Drug use was prevalent among person-to-person hepatitis A outbreak-associated patients, and more likely among younger patients and patients experiencing homelessness or incarceration. Increased hepatitis A vaccination coverage is critical to prevent similar outbreaks in the future.

In November 2021, CDC was notified of a cluster of previously healthy children with hepatitis of unknown etiology evaluated at a single U.S. hospital (1). On April 21, 2022, following an investigation of this cluster and reports of similar cases in Europe (2,3), a health advisory* was issued requesting U.S. providers to report pediatric cases(†) of hepatitis of unknown etiology to public health authorities. In the United States and Europe, many of these patients have also received positive adenovirus test results (1,3). Typed specimens have indicated adenovirus type 41, which typically causes gastroenteritis (1,3). Although adenovirus hepatitis has been reported in immunocompromised persons, adenovirus is not a recognized cause of hepatitis in healthy children (4). Because neither acute hepatitis of unknown etiology nor adenovirus type 41 is reportable in the United States, it is unclear whether either has recently increased above historical levels. Data from four sources were analyzed to assess trends in hepatitis-associated emergency department (ED) visits and hospitalizations, liver transplants, and adenovirus stool testing results among children in the United States. Because of potential changes in health care-seeking behavior during 2020-2021, data from October 2021-March 2022 were compared with a pre-COVID-19 pandemic baseline. These data do not suggest an increase in pediatric hepatitis or adenovirus types 40/41 above baseline levels. Pediatric hepatitis is rare, and the relatively low weekly and monthly counts of associated outcomes limit the ability to interpret small changes in incidence. Ongoing assessment of trends, in addition to enhanced epidemiologic investigations, will help contextualize reported cases of acute hepatitis of unknown etiology in U.S. children.

BACKGROUND: Safe and effective hepatitis A vaccines have been recommended in the United States for at-risk adults since 1996; however, adult vaccination coverage is low. METHODS: Among a random sample of adult outbreak-associated hepatitis A cases from three states that were heavily affected by person-to-person hepatitis A outbreaks, we assessed the presence of documented Advisory Committee on Immunization Practices (ACIP) indications for hepatitis A vaccination, hepatitis A vaccination status, and whether cases that were epidemiologically linked to an outbreak-associated hepatitis A case had received postexposure prophylaxis (PEP). RESULTS: Overall, 74.1% of cases had a documented ACIP indication for hepatitis A vaccination. Fewer than 20% of epidemiologically linked cases received PEP. CONCLUSIONS: Efforts are needed to increase provider awareness of and adherence to ACIP childhood and adult hepatitis A vaccination and PEP recommendations in order to stop the current person-to-person hepatitis A outbreaks and prevent similar outbreaks in the future.

Traditional models of preventive care rely heavily on delivering services in established clinical settings. These settings might provide incomplete access for certain medically underserved populations, such as people who use drugs (PWUD), people experiencing homelessness (PEH), and people who are incarcerated or detained, because of either barriers in accessing care or past experiences of stigma and discrimination. Missed opportunities for delivering preventive vaccination services to medically underserved populations can lead to increased transmission, morbidity, and mortality. Between 2016 and 2021, widespread person-to-person outbreaks of hepatitis A across the United States—disproportionately affecting PWUD and PEH—highlighted both the challenges encountered and innovative solutions required in bringing preventive services to medically underserved populations. 1

During 1995-2011, the overall incidence of hepatitis A decreased by 95% in the United States from 12 cases per 100,000 population during 1995 to 0.4 cases per 100,000 population during 2011, and then plateaued during 2012─2015. The incidence increased by 294% during 2016-2018 compared with the incidence during 2013-2015, with most cases occurring among populations at high risk for hepatitis A infection, including persons who use illicit drugs (injection and noninjection), persons who experience homelessness, and men who have sex with men (MSM) (1-3). Previous outbreaks among persons who use illicit drugs and MSM led to recommendations issued in 1996 by the Advisory Committee on Immunization Practices (ACIP) for routine hepatitis A vaccination of persons in these populations (4). Despite these long-standing recommendations, vaccination coverage rates among MSM remain low (5). In 2017, the New York City Department of Health and Mental Hygiene contacted CDC after public health officials noted an increase in hepatitis A infections among MSM. Laboratory testing* of clinical specimens identified strains of the hepatitis A virus (HAV) that subsequently matched strains recovered from MSM in other states. During January 1, 2017-October 31, 2018, CDC received reports of 260 cases of hepatitis A among MSM from health departments in eight states, a substantial increase from the 16 cases reported from all 50 states during 2013-2015. Forty-eight percent (124 of 258) of MSM patients were hospitalized for a median of 3 days. No deaths were reported. In response to these cases, CDC supported state and local health departments with public health intervention efforts to decrease HAV transmission among MSM populations. These efforts included organizing multistate calls among health departments to share information, providing guidance on developing targeted outreach and managing supplies for vaccine campaigns, and conducting laboratory testing of clinical specimens. Targeted outreach for MSM to increase awareness about hepatitis A infection and improve access to vaccination services, such as providing convenient locations for vaccination, are needed to prevent outbreaks among MSM.

Hepatitis A is a vaccine-preventable disease caused by the hepatitis A virus (HAV). Transmission of the virus most commonly occurs through the fecal-oral route after close contact with an infected person. Widespread outbreaks of hepatitis A among persons who use illicit drugs (injection and noninjection drugs) have increased in recent years (1). The Advisory Committee on Immunization Practices (ACIP) recommends routine hepatitis A vaccination for children and persons at increased risk for infection or severe disease, and, since 1996, has recommended hepatitis A vaccination for persons who use illicit drugs (2). Vaccinating persons who are at-risk for HAV infection is a mainstay of the public health response for stopping ongoing person-to-person transmission and preventing future outbreaks (1). In response to a large hepatitis A outbreak in West Virginia, an analysis was conducted to assess total hepatitis A-related medical costs during January 1, 2018-July 31, 2019, among West Virginia Medicaid beneficiaries with a confirmed diagnosis of HAV infection. Among the analysis population, direct clinical costs ranged from an estimated $1.4 million to $5.6 million. Direct clinical costs among a subset of the Medicaid population with a diagnosis of a comorbid substance use disorder ranged from an estimated $1.0 million to $4.4 million during the study period. In addition to insight on preventing illness, hospitalization, and death, the results from this study highlight the potential financial cost jurisdictions might incur when ACIP recommendations for hepatitis A vaccination, especially among persons who use illicit drugs, are not followed (2).

BACKGROUND & AIMS: During 2016-2020, the United States experienced person-to-person hepatitis A outbreaks that are unprecedented in the vaccine era, during which case-fatality ratios reported by some jurisdictions exceeded those historically associated with hepatitis A. APPROACH & RESULTS: To identify factors associated with hepatitis A-related mortality, we performed a matched case-control study (matched on age [±5 years] and county of residence in a 1:4 ratio) using data collected from health department and hospital medical records of outbreak-associated patients in Kentucky, Michigan, and West Virginia. Controls were hepatitis A outbreak-associated patients who did not die. There were 110 cases (mean age 53.6 years) and 414 matched controls (mean age 51.9 years); most cases (68.2%) and controls (63.8%) were male. Significantly (p<0.05) higher odds of mortality were associated with pre-existing non-viral liver disease (adjusted odds ratio [aOR] 5.2), history of hepatitis B (aOR 2.4), diabetes (aOR 2.2), and cardiovascular disease (aOR 2.2), as well as initial MELD score ≥30 (aOR 10.0), AST/ALT ratio >2 (aOR 10.3), and platelet count <150,000/uL (aOR 3.7) among hepatitis A outbreak-associated patients in the independent multivariable conditional logistic regression analyses (each model adjusted for sex). CONCLUSIONS: Pre-existing liver disease, diabetes, cardiovascular disease, and initial MELD score ≥30, AST/ALT ratio ≥1, or platelet count <150,000/uL among hepatitis A patients were independently associated with higher odds of mortality. Providers should be vigilant for such features and have a low threshold to escalate care and consider consultation for liver transplantation. Our findings support the Advisory Committee on Immunization Practices recommendation to vaccinate persons with chronic liver disease, though future recommendations to include adults with diabetes and cardiovascular disease should be considered.

BACKGROUND: Since 2016, the US has experienced person-to-person hepatitis A outbreaks unprecedented in the vaccine era. The proportion of cases hospitalized in these outbreaks exceeds historical national surveillance data. METHODS: We described the epidemiology, characterized the reported increased morbidity, and identified factors associated with hospitalization during the outbreaks by reviewing a 10% random sample of outbreak-associated hepatitis A cases in Kentucky, Michigan, and West Virginia-three heavily affected states. We calculated descriptive statistics and conducted age-adjusted log-binomial regression analyses to identify factors associated with hospitalization. RESULTS: Participants in the random sample (n=817) were primarily male (62.5%) with mean age of 39.0 years; 51.8% were hospitalized. Among those with available information, 73.2% reported drug use, 14.0% were experiencing homelessness, 29.7% were currently or recently incarcerated, and 61.6% were epidemiologically linked to a known outbreak-associated case. Residence in Michigan (adjusted risk ratio [aRR] 1.8), being a man who has sex with men (aRR 1.5), non-injection drug use (aRR 1.3), and homelessness (aRR 1.3) were significantly (p<0.05) associated with hepatitis A-related hospitalization. CONCLUSIONS: Our findings support current Advisory Committee on Immunization Practices recommendations to vaccinate all persons who use drugs, men who have sex with men, and persons experiencing homelessness against hepatitis A.

Hepatitis a is a vaccine-preventable, communicable disease of the liver caused by the hepatitis a virus (hav). The infection is transmitted via the fecal-oral route, usually from direct person-to-person contact or consumption of contaminated food or water. Hepatitis a is an acute, self-limited disease that does not result in chronic infection. Hav antibodies (immunoglobulin g [igg] anti-hav) produced in response to hav infection persist for life and protect against reinfection; igg anti-hav produced after vaccination confer long-term immunity. This report supplants and summarizes previously published recommendations from the advisory committee on immunization practices (acip) regarding the prevention of hav infection in the united states. Acip recommends routine vaccination of children aged 12-23 months and catch-up vaccination for children and adolescents aged 2-18 years who have not previously received hepatitis a (hepa) vaccine at any age. Acip recommends hepa vaccination for adults at risk for hav infection or severe disease from hav infection and for adults requesting protection against hav without acknowledgment of a risk factor. These recommendations also provide guidance for vaccination before travel, for postexposure prophylaxis, in settings providing services to adults, and during outbreaks.

The United States is in the midst of unprecedented person-to-person hepatitis A outbreaks. By using Healthcare Cost and Utilization Project data, we estimated the average costs per hepatitis A-related hospitalization in 2017. These estimates can guide investment in outbreak prevention efforts to stop the spread of this vaccine-preventable disease.

The United States is experiencing person-to-person outbreaks of hepatitis A in unprecedented numbers during the vaccine era (1). As of May 2020, 33 states had reported hepatitis A outbreaks involving approximately 32,500 cases, 19,800 (61%) hospitalizations, and 320 deaths since 2016 (1). These infections are spreading primarily through close contact among persons who use drugs and persons experiencing homelessness, as well as among men who have sex with men (MSM) (2). | | During these outbreaks, hepatitis A infections occurring among food handlers have raised public alarm and resulted in calls for vaccinating all food handlers, often prompting health departments to divert limited resources away from populations at risk. However, the risk for secondary transmission from hepatitis A–infected food handlers to food establishment patrons is not well understood. To characterize this risk, a novel, structured survey was developed and conducted using Research Electronic Data Capture (REDCap) (version 9.5.13; Vanderbilt University); among 30 state health departments reporting person-to-person hepatitis A outbreaks during July 1, 2016–September 13, 2019, 29 states responded (3,4).

In September 2017, Namibia’s Ministry of Health and Social Services (MoHSS) identified an increase in cases of acute jaundice in Khomas region, which includes the capital city of Windhoek. Hepatitis E is a liver disease caused by hepatitis E virus, which is transmitted by the fecal-oral route, causing symptoms consistent with acute jaundice syndrome (1). Hepatitis E is rarely fatal; however, the disease can be severe in pregnant women, resulting in fulminant hepatic failure and death (2).

We appreciate Dr. Spaulding and colleagues’ thoughtful commentary on our article. We used national data to provide the most accurate estimate possible of the prevalence of hepatitis C among adults in the United States, but our estimate was dependent on the quality and completeness of the available data. We corrected for the omission of several high-prevalence populations from the National Health and Nutrition Examination Survey (NHANES), but no nationally representative studies of these populations exist. Spaulding and her colleagues raise a number of reasons why our study may underestimate the true prevalence of hepatitis C among incarcerated persons, but unfortunately, no nationwide data exist to assess the magnitude of these potential biases. According to 2016 Bureau of Justice Statistics data, most people arrested are detained in jails for short periods of time(1); thus, most of the number of persons cited in Dr. Spaulding’s reply would be eligible for NHANES sampling. We could not further adjust estimates for potential nonresponse bias beyond those addressed through standard NHANES sample weights without risk of double-counting prevalent cases. | | Varan et al.(2) data were excluded because we decided a priori to include only articles published more recently than those included in the incarcerated prevalence analysis from the Edlin et al. 2015(3) national hepatitis C virus prevalence estimate. With respect to the differential treatment of North Carolina and South Carolina from Schoenbachler et al. (4) (“study 6”), South Carolina data were excluded because “Initially, the South Carolina program targeted detainees…who had obtained tattoos in non-professional or unregulated settings.” Although testing was eventually expanded to include other detainees, Shoenbachler et al. did not indicate at what point that transition occurred or whether the expansion applied to all four South Carolina jails in the study or just one.(4) We determined that the targeted risk-based screening employed met our “sampling higher-risk subpopulations selectively” exclusion criteria, and consequently only included North Carolina data from Schoenbachler et al. in our analysis. | | Incarcerated populations bear a large and disproportionate hepatitis C burden, and incarceration provides an important opportunity to identify cases, provide life-saving curative treatment, and prevent transmission. The Centers for Disease Control and Prevention (CDC) is looking to other systems to collect data for prevention planning and providing more support to traditional and nontraditional surveillance systems both within and outside correctional facilities. Regardless of the exact number, prevention, testing, care, and treatment of incarcerated persons with or at risk for hepatitis C is an important priority for CDC and the nation.

BACKGROUND: Hepatitis A is a vaccine-preventable viral disease transmitted by the fecal-oral route. During 2016-2018, the County of San Diego investigated an outbreak of hepatitis A infections primarily among people experiencing homelessness (PEH) to identify risk factors and support control measures. At the time of the outbreak, homelessness was not recognized as an independent risk factor for the disease. METHODS: We tested the association between homelessness and infection with hepatitis A virus (HAV) using a test-negative study design comparing patients with laboratory-confirmed hepatitis A with control subjects who tested negative for HAV infection. We assessed risk factors for severe hepatitis A disease outcomes, including hospitalization and death, using multivariable logistic regression. We measured the frequency of indications for hepatitis A vaccination according to Advisory Committee on Immunization Practice (ACIP) guidelines. RESULTS: Among 589 outbreak-associated cases reported, 291 (49%) occurred among PEH. Compared with those who were not homeless, PEH were at 3.3 (95% CI: 1.5-7.9) times higher odds of HAV infection, 2.5 (95% CI: 1.7-3.9) times higher odds of hospitalization, and 3.9 (95% CI: 1.1-16.9) times higher odds of death associated with hepatitis A. Among PEH, 212 (73%) patients recorded other ACIP indications for hepatitis A vaccination. CONCLUSIONS: PEH were at higher risk for infection with HAV and higher risk for severe hepatitis A disease outcomes compared with those not experiencing homelessness. Approximately one-fourth of PEH had no other ACIP indication for hepatitis A vaccination. These findings support the recent ACIP recommendation to add homelessness as an indication for hepatitis A vaccination.

Hepatitis A virus (HAV) is primarily transmitted fecal-orally after close contact with an infected person (1); it is the most common cause of viral hepatitis worldwide, typically causing acute and self-limited symptoms, although rarely liver failure and death can occur (1). Rates of hepatitis A had declined by approximately 95% during 1996-2011; however, during 2016-2018, CDC received approximately 15,000 reports of HAV infections from U.S. states and territories, indicating a recent increase in transmission (2,3). Since 2017, the vast majority of these reports were related to multiple outbreaks of infections among persons reporting drug use or homelessness (4). In addition, increases of HAV infections have also occurred among men who have sex with men (MSM) and, to a much lesser degree, in association with consumption of imported HAV-contaminated food (5,6). Overall, reports of hepatitis A cases increased 294% during 2016-2018 compared with 2013-2015. During 2016-2018, CDC tested 4,282 specimens, of which 3,877 (91%) had detectable HAV RNA; 565 (15%), 3,255 (84%), and 57 (<1%) of these specimens were genotype IA, IB, or IIIA, respectively. Adherence to the Advisory Committee on Immunization Practices (ACIP) recommendations to vaccinate populations at risk can help control the current increases and prevent future outbreaks of hepatitis A in the United States (7).

In March 2018, the Kanawha-Charleston Health Department (KCHD) in West Virginia began investigating a cluster of reported hepatitis A virus (HAV) infections. Twelve specimens tested by CDC’s Division of Viral Hepatitis laboratory confirmed that patients were infected with an HAV strain (genotype 1B) reported in ongoing hepatitis A outbreaks in multiple states, primarily among persons who use drugs and persons experiencing homelessness (1). In August 2018, because of ongoing reporting of cases, the West Virginia Bureau of Public Health requested epidemiologic assistance from CDC in responding to the outbreak.

Importance: Infection with hepatitis C virus (HCV) is a major cause of morbidity and mortality in the United States, and incidence has increased rapidly in recent years, likely owing to increased injection drug use. Current estimates of prevalence at the state level are needed to guide prevention and care efforts but are not available through existing disease surveillance systems. Objective: To estimate the prevalence of current HCV infection among adults in each US state and the District of Columbia during the years 2013 to 2016. Design, Setting, and Participants: This survey study used a statistical model to allocate nationally representative HCV prevalence from the National Health and Nutrition Examination Survey (NHANES) according to the spatial demographics and distributions of HCV mortality and narcotic overdose mortality in all National Vital Statistics System death records from 1999 to 2016. Additional literature review and analyses estimated state-level HCV infections among populations not included in the National Health and Nutrition Examination Survey sampling frame. Exposures: State, accounting for birth cohort, biological sex, race/ethnicity, federal poverty level, and year. Main Outcomes and Measures: State-level prevalence estimates of current HCV RNA. Results: In this study, the estimated national prevalence of HCV from 2013 to 2016 was 0.84% (95% CI, 0.75%-0.96%) among adults in the noninstitutionalized US population represented in the NHANES sampling frame, corresponding to 2035100 (95% CI, 1803600-2318000) persons with current infection; accounting for populations not included in NHANES, there were 231600 additional persons with HCV, adjusting prevalence to 0.93%. Nine states contained 51.9% of all persons living with HCV infection (California [318900], Texas [202500], Florida [151000], New York [116000], Pennsylvania [93900], Ohio [89600], Michigan [69100], Tennessee [69100], and North Carolina [66400]); 5 of these states were in Appalachia. Jurisdiction-level median (range) HCV RNA prevalence was 0.88% (0.45%-2.34%). Of 13 states in the western United States, 10 were above this median. Three of 10 states with the highest HCV prevalence were in Appalachia. Conclusions and Relevance: Using extensive national survey and vital statistics data from an 18-year period, this study found higher prevalence of HCV in the West and Appalachian states for 2013 to 2016 compared with other areas. These estimates can guide state prevention and treatment efforts.

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.

Postexposure prophylaxis (PEP) with hepatitis A (HepA) vaccine or immune globulin (IG) effectively prevents infection with hepatitis A virus (HAV) when administered within 2 weeks of exposure. Preexposure prophylaxis against HAV infection through the administration of HepA vaccine or IG provides protection for unvaccinated persons traveling to or working in countries that have high or intermediate HAV endemicity. The Advisory Committee on Immunization Practices (ACIP) Hepatitis Vaccines Work Group conducted a systematic review of the evidence for administering vaccine for PEP to persons aged >40 years and reviewed the HepA vaccine efficacy and safety in infants and the benefits of protection against HAV before international travel. The February 21, 2018, ACIP recommendations update and supersede previous ACIP recommendations for HepA vaccine for PEP and for international travel. Current recommendations include that HepA vaccine should be administered to all persons aged >/=12 months for PEP. In addition to HepA vaccine, IG may be administered to persons aged >40 years depending on the provider's risk assessment. ACIP also recommended that HepA vaccine be administered to infants aged 6-11 months traveling outside the United States when protection against HAV is recommended. The travel-related dose for infants aged 6-11 months should not be counted toward the routine 2-dose series. The dosage of IG has been updated where applicable (0.1 mL/kg). HepA vaccine for PEP provides advantages over IG, including induction of active immunity, longer duration of protection, ease of administration, and greater acceptability and availability.

During the summer of 2016, the Hawaii Department of Health responded to the second-largest domestic foodborne hepatitis A virus (HAV) outbreak in the post-vaccine era. The epidemiological investigation included case finding and investigation, sequencing of RNA positive clinical specimens, product trace-back and virologic testing and sequencing of HAV RNA from the product. Additionally, an online survey open to all Hawaii residents was conducted to estimate baseline commercial food consumption. We identified 292 confirmed HAV cases, of whom 11 (4%) were possible secondary cases. Seventy-four (25%) were hospitalised and there were two deaths. Among all cases, 94% reported eating at Oahu or Kauai Island branches of Restaurant Chain A, with 86% of those cases reporting raw scallop consumption. In contrast, a food consumption survey conducted during the outbreak indicated 25% of Oahu residents patronised Restaurant Chain A in the 7 weeks before the survey. Product trace-back revealed a single distributor that supplied scallops imported from the Philippines to Restaurant Chain A. Recovery, amplification and sequence comparison of HAV recovered from scallops revealed viral sequences matching those from case-patients. Removal of product from implicated restaurants and vaccination of those potentially exposed led to the cessation of the outbreak. This outbreak further highlights the need for improved imported food safety.

There are many similarities in the epidemiology and transmission of hepatitis A virus (HAV) and hepatitis E virus (HEV) genotype (gt)3 infections in the United States. Both viruses are enterically transmitted, although specific routes of transmission are more clearly established for HAV than for HEV: HAV is restricted to humans and primarily spread through the fecal-oral route, while HEV is zoonotic with poorly understood modes of transmission in the United States. New cases of HAV infection have decreased dramatically in the United States since infant vaccination was recommended in 1996. In recent years, however, outbreaks have occurred among an increasingly susceptible adult population. Although HEV is the most common cause of acute viral hepatitis in developing countries, it is rarely diagnosed in the United States.