Hepatitis A in Latin America: The current scenario.

This review aims to gather and disseminate updated information regarding hepatitis A virus (HAV) in Latin America (LA) in the last 11 years, including seroprevalence, post-vaccination studies, virus detection in aqueous matrices and food samples, and outbreak reports. Only 24 seroprevalence studies were published between 2012 and 2023 with 55%-100% reported prevalences of anti-HAV IgG. Among the 25 LA countries, only eight of them have introduced HAV vaccines into their immunisation programs. Outbreaks of hepatitis A occurred between 2017-2019, mainly affecting men who have sex with men in Argentina, Brazil and Chile, probably as a consequence of the abrupt decline of young adults' immunity. This could be due to that young adult have never been infected in childhood (due to socio-health improvements) and are above the cut-off ages to be included when the vaccination programs were introduced. Although scarce, studies focused on environmental and food HAV surveillance have shown viral presence in these samples. Surface waters presented HAV detections between 1.2% and 86.7%, and untreated wastewaters between 2.8% and 70.9%. Genotypes found in all cases were IA and IC. The only wastewater-based epidemiology study showed to be a useful tool as a complement of traditional epidemiological surveillance. Only four LA countries have looked for HAV in food samples, with genome detection rates between 9% and 33%. Latin American HAV circulation scenario is changing. In countries where socioeconomic and sanitary conditions have not improved, the virus persists with high endemicity and the access to the vaccine should be re-evaluated by local governments. In countries where access to clean water, better sanitary conditions and HAV immunisation programs have been implemented, the number of cases among young adults seems to be increasing, alerting health authorities.

The Burden of Hepatitis A Outbreaks in the United States: Health Outcomes, Economic Costs, and Management Strategies.

BACKGROUND: Hepatitis A (HepA) vaccines are recommended for US adults at risk of HepA. Ongoing United States (US) HepA outbreaks since 2016 have primarily spread person-to-person, especially among at-risk groups. We investigated the health outcomes, economic burden, and outbreak management considerations associated with HepA outbreaks from 2016 onwards. METHODS: A systematic literature review was conducted to assess HepA outbreak-associated health outcomes, health care resource utilization (HCRU), and economic burden. A targeted literature review evaluated HepA outbreak management considerations. RESULTS: Across 33 studies reporting on HepA outbreak-associated health outcomes/HCRU, frequently reported HepA-related morbidities included acute liver failure/injury (n = 6 studies of 33 studies) and liver transplantation (n = 5 of 33); reported case fatality rates ranged from 0% to 10.8%. Hospitalization rates reported in studies investigating person-to-person outbreaks ranged from 41.6% to 84.8%. Ten studies reported on outbreak-associated economic burden, with a national study reporting an average cost of over $16 000 per hospitalization. Thirty-four studies reported on outbreak management; challenges included difficulty reaching at-risk groups and vaccination distrust. Successes included targeted interventions and increasing public awareness. CONCLUSIONS: This review indicates a considerable clinical and economic burden of ongoing US HepA outbreaks. Targeted prevention strategies and increased public awareness and vaccination coverage are needed to reduce HepA burden and prevent future outbreaks.

Assessing vaccine-induced immunity against pneumococcus, hepatitis A and B over a 9-year follow-up in pediatric liver transplant recipients: A nationwide retrospective study.

Pediatric liver transplant recipients are particularly at risk of infections. The most cost-effective way to prevent infectious complications is through vaccination, which can potentially prevent infections due to hepatitis B (HBV) virus, hepatitis A virus (HAV), and invasive pneumococcal diseases. Here, we performed a retrospective analysis of HBV, HAV, and pneumococcal immunity in pediatric liver transplant recipients between January 1, 2009, and December 31, 2020, to collect data on immunization and vaccine serology. A total of 94% (58/62) patients had available vaccination records. At transplant, 90% (45/50) were seroprotected against HBV, 63% (19/30) against HAV, and 78% (18/23) had pneumococcal immunity, but immunity against these 3 pathogens remained suboptimal during the 9-year follow-up. A booster vaccine was administered to only 20% to 40% of patients. Children who had received >4 doses of HBV vaccine and > 2 doses of HAV vaccine pretransplant displayed a higher overall seroprotection over time post-solid organ transplant. Our findings suggest that a serology-based approach should be accompanied by a more systematic follow-up of vaccination, with special attention paid to patients with an incomplete vaccination status at time of transplant.

HIV pre-exposure prophylaxis and opportunities for vaccination against hepatitis A virus, hepatitis B virus and human papillomavirus: an analysis of the Ontario PrEP cohort study.

OBJECTIVES: Populations who seek HIV pre-exposure prophylaxis (PrEP) are disproportionately affected by hepatitis A virus (HAV), hepatitis B virus (HBV) and human papillomavirus (HPV). We examined immunity/vaccination against these infections among participants in the Ontario PrEP cohort study (ON-PrEP). METHODS: ON-PrEP is a prospective cohort of HIV-negative PrEP users from 10 Ontario clinics. We descriptively analysed baseline immunity/vaccination against HAV (IgG reactive), HBV (hepatitis B surface antibody >10) and HPV (self-reported three-dose vaccination). We further performed multivariable logistic regression to identify characteristics associated with baseline immunity/vaccination. We used cumulative incidence functions to describe vaccine uptake among participants non-immune at baseline. RESULTS: Of 633 eligible participants, 59.1% were white, 85.8% were male and 79.6% were gay. We found baseline evidence of immunity/vaccination against HAV, HBV and HPV in 69.2%, 81.2% and 16.8% of PrEP-experienced participants and 58.9%, 70.3% and 10.4% of PrEP-naïve participants, respectively. Characteristics associated with baseline HAV immunity were greater PrEP duration (adjusted OR (aOR) 1.41/year, 95% CI 1.09 to 1.84), frequent sexually transmitted and bloodborne infection (STBBI) testing (aOR 2.38, 95% CI 1.15 to 4.92) and HBV immunity (aOR 3.53, 95% CI 2.09 to 5.98). Characteristics associated with baseline HBV immunity were living in Toronto (aOR 3.54, 95% CI 1.87 to 6.70) or Ottawa (aOR 2.76, 95% CI 1.41 to 5.40), self-identifying as racialised (aOR 2.23, 95% CI 1.19 to 4.18), greater PrEP duration (aOR 1.39/year, 95% CI 1.02 to 1.90) and HAV immunity (aOR 3.75, 95% CI 2.19 to 6.41). Characteristics associated with baseline HPV vaccination were being aged ≤26 years (aOR 9.28, 95% CI 2.11 to 40.77), annual income between CAD$60 000 and CAD$119 000 (aOR 3.42, 95% CI 1.40 to 8.34), frequent STBBI testing (aOR 7.00, 95% CI 1.38 to 35.46) and HAV immunity (aOR 6.96, 95% CI 2.00 to 24.25). Among those non-immune at baseline, overall cumulative probability of immunity/vaccination was 0.70, 0.60 and 0.53 among PrEP-experienced participants and 0.93, 0.80 and 0.70 among PrEP-naïve participants for HAV, HBV and HPV, respectively. CONCLUSIONS: Baseline immunity to HAV/HBV was common, and a sizeable proportion of non-immune participants were vaccinated during follow-up. However, HPV vaccination was uncommon. Continued efforts should be made to remove barriers to HPV vaccination such as cost, inclusion in clinical guidelines and provider recommendation.

Hepatitis A Exposure Response and Outbreak Prevention in a Large Urban Jail - Los Angeles County, California, May-July 2023.

Correctional settings provide a high-risk environment for hepatitis A transmission because of the high proportion of homelessness and injection drug use among persons who are incarcerated. On May 30, 2023, Los Angeles County Department of Public Health informed the Communicable Disease Surveillance and Control (CDSC) unit of the Los Angeles County Jail system that a symptomatic incarcerated person had received a positive test result for acute hepatitis A. Upon learning the next day that the patient was a food handler, CDSC staff members identified 5,830 potential contacts of the index patient, 1,702 of whom had been released from the jail. During June 1-12, a total of 2,766 contacts who did not have a documented history of hepatitis A serology or vaccination that could be confirmed from the electronic health record or state immunization registry were identified. These persons were offered hepatitis A vaccination as postexposure prophylaxis; 1,510 (54.6%) accepted vaccination. Contacts who were food handlers without confirmed evidence of immunity and who declined vaccination were removed from food-handling duties for the duration of their potential incubation period. No additional cases were identified. Identifying contacts promptly and using immunization and serology records to ensure rapid delivery of postexposure prophylactic vaccine can help prevent hepatitis A transmission during exposures among incarcerated populations.

A Randomized Clinical Trial of 1-Dose vs Accelerated 2-Dose Schedule for Hepatitis A Virus (HAV) Revaccination Among People With Human Immunodeficiency Virus Who Were Nonresponders or Had Seroreversion After Primary HAV Vaccination.

BACKGROUND: For people with human immunodeficiency virus (PWH) who have no serological responses to their primary hepatitis A virus (HAV) vaccination or have seroreversion after successful primary vaccination, the optimal revaccination strategy remains unclear. METHODS: In this open-label, randomized clinical trial, PWH who tested negative for anti-HAV antibodies after receiving a standard 2-dose series of primary HAV vaccination were enrolled and assigned in a 1:1 ratio to receive either 1 dose (the 1-dose group) or 2 doses of HAV vaccine administered 4 weeks apart (the 2-dose group). Serological response rates and anti-HAV antibody titers were compared at weeks 24 and 48. RESULTS: Of the 153 participants (77 in the 1-dose group and 76 in the 2-dose group), the overall serological response rates at week 48 after revaccination were similar between the 2 groups (2- vs 1-dose, 80.2% vs 71.4%, P = .20). However, anti-HAV antibody titers were consistently higher in the 2-dose group than in the 1-dose group. In subgroup analysis, PWH who were nonresponders to primary HAV vaccination were significantly more likely to mount a serological response after 2-dose HAV revaccination (68.4% vs 44.1%, P = .038). No severe adverse events were reported throughout the study. CONCLUSIONS: Two-dose HAV revaccination administered 4 weeks apart yielded similar serological responses as 1-dose revaccination among PWH who were nonresponders or had seroreversion after primary HAV vaccination. The 2-dose revaccination schedule generated significantly higher anti-HAV antibody titers and was more likely to elicit serological responses at week 48 among PWH who were nonresponders to primary HAV vaccination. Clinical Trials Registration. NCT03855176.

Hepatitis A occurrence and outbreaks in Europe over the past two decades: A systematic review.

Hepatitis A (HA) is a vaccine-preventable liver disease with >170 million new cases occurring yearly. In recent outbreaks in the USA, hospitalization and case-fatality ratios were >60% and ~1%, respectively. In Europe, endemicity persists and outbreaks continue to occur. We performed a systematic literature review to understand the changes in HA occurrence in Europe over the past two decades. PubMed and Embase were systematically searched for peer-reviewed articles published between 1 January 2001 and 14 April 2021 using terms covering HA, 11 selected European countries, outbreaks, outcomes and HA virus circulation. Here, we focus on HA occurrence and outbreaks in the five countries with the largest population and the most comprehensive vaccination recommendations: France, Germany, Italy, Spain and the UK; 118 reports included data for these five European countries. Notification rates (≤9.7/100,000 population) and percentages of men among cases (≤83.0%) peaked in 2017. The number of person-to-person-transmitted cases and outbreaks decreased in children but increased in other risk groups, such as men who have sex with men (MSM). Sexually transmitted outbreaks in MSM clustered around 2017. Travel-related outbreaks were few; the proportion of travel-related cases decreased during the past two decades, while the number of domestic cases increased. Despite the existing risk-based vaccination recommendations, HA transmission shifted in proportions from travelers and children to other risk groups, such as MSM and older age groups. Because a substantial proportion of the European population is susceptible to HA, adherence to existing recommendations should be monitored more closely, and enhanced vaccination strategies should be considered.

Impact of prior HBV, HAV, and HEV infection on non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease. The association between prior hepatitis B virus (HBV), hepatitis A virus (HAV), hepatitis E virus (HEV) infection and NAFLD remains unclear. We utilized the 2017-2020 National Health and Nutrition Examination Survey (NHANES) and performed multivariable logistic regression analyses to examine the association of prior HBV, HAV and HEV infection with NAFLD, as well as high risk non-alcoholic steatohepatitis (NASH) and liver fibrosis. Our analysis included 2565 participants with available anti-HBc serology results, 1480 unvaccinated participants with anti-HAV results, and 2561 participants with anti-HEV results. Among participants with NAFLD, the age-adjusted prevalence of prior HBV, HAV and HEV infection was 3.48%, 32.08% and 7.45%, respectively. Prior infection with HBV, HAV and HEV was not associated with NAFLD (cut-off 285 dB/m) [aOR: 0.99 (95% CI, 0.77-1.29), 1.29 (95% CI, 0.95-1.75), and 0.94 (95% CI, 0.70-1.27), respectively] or high-risk NASH [aOR 0.72 (95% CI, 0.45-1.17), 0.92 (95% CI, 0.55-1.52), and 0.89 (95% CI, 0.41-1.94), respectively]. Participants with anti-HBc and anti-HAV seropositivity were more likely to have significant fibrosis [aOR: 1.53 (95% CI, 1.05-2.23) and 1.69 (95% CI, 1.16-2.47), respectively]. The odds of significant fibrosis are 53%, and 69% greater for participants with prior history of HBV and HAV infection. Healthcare providers should prioritize vaccination efforts and employ a tailored approach to NAFLD in patients with prior viral hepatitis and especially HBV or HAV infection to limit disease-related outcomes.

Hepatitis A and B vaccine uptake and immunisation among men who have sex with men seeking PrEP: a substudy of the ANRS IPERGAY trial.

Vaccination against hepatitis A virus (HAV) and hepatitis B virus (HBV) is recommended in men who have sex with men (MSM). We assessed HAV and HBV vaccine uptake in the non-immune participants and their immunisation during follow-up of the ANRS IPERGAY (Intervention Préventive de l'Exposition aux Risques avec et pour les Gays) pre-exposure prophylaxis (PrEP) trial.During the ANRS IPERGAY trial among MSM (NCT01473472), vaccination against HAV and HBV was offered free of charge to all non-immune participants at baseline. We assessed anti-HAV IgGs and anti-hepatitis B surface (HBs) antibodies (Abs) at baseline, 1-3 months after each vaccine dose and on the last follow-up visit. Vaccination uptake and immunisation were analysed in non-immune participants with at least 6 months of follow-up after the 1st vaccine dose.A total of 427 MSM with a median age of 34.8 years were analysed. Median follow-up was 2.2 years (Q1-Q3, 1.6-2.9). Absence of anti-HAV IgG at baseline (50.4%, 215/427) was associated with younger age (p=0.0001). Among HAV non-immune participants, 96.1% (197/205) received one or more vaccine doses and 91.0% (172/189) received two vaccine doses. Among HBV non-immune participants, 97.6 % (81/83) received one or more vaccine doses and 78.4% (58/74) received three doses. On the last-visit sample, anti-HAV IgG and anti-HBs Abs were respectively detected in 94.8% (95% CI 90.0% to 97.7%) and 79.6% (95% CI 66.5% to 89.4%) of participants with complete vaccination and in 80.0% (95% CI 51.9% to 95.7%) and 40.0% (95% CI 16.3% to 67.7%) of participants with incomplete vaccination.Vaccine acceptability against HAV and HBV infections was very high in MSM starting PrEP. Immunisation was high in participants with a full vaccination scheme. Physicians must consider PrEP visits as major opportunities to propose and complete HAV and HBV vaccination in at-risk non-immune subjects.

Hepatitis A and B vaccination in gbMSM in Ireland: findings from the European MSM Internet Survey 2017 (EMIS-2017).

OBJECTIVES: Gay, bisexual and other men who have sex with men (gbMSM) have a higher risk of acquiring hepatitis A and B viruses (HAV and HBV) than the general population and are recommended for vaccination against both in Ireland. This study aims to determine the prevalence of self-reported HAV and HBV infection and vaccination among gbMSM in Ireland and explore factors associated with self-reported HAV and HBV vaccination among gbMSM. METHODS: This study analysed Irish data from the European MSM Internet Survey 2017 (EMIS-2017) to measure the prevalence of self-reported HAV and HBV infection and vaccination among gbMSM in Ireland. Multivariable logistic regression was used to explore the associations between sociodemographic, healthcare-related and behavioural factors and self-reported vaccination. RESULTS: There were 2083 EMIS-2017 respondents in Ireland. Among HIV-negative gbMSM, 4.6% and 4.4% reported previous HAV and HBV infection, respectively, and 51% and 57% reported the receipt of one or more vaccine dose for HAV and HBV, respectively. In the multivariable analysis, HIV-negative gbMSM had lower odds of self-reported HAV vaccination if they lived outside the capital, Dublin (aOR 0.61, 95% CI: 0.48 to 0.78), had no third-level education (aOR 0.65, 95% CI: 0.45 to 0.92), were not tested for HIV in the last year (aOR 0.39, 95% CI: 0.31 to 0.50), had never tried to obtain pre-exposure prophylaxis (PrEP, aOR 0.60, 95% CI: 0.38 to 0.96) and had not been diagnosed with a sexually transmitted infection (STI) in the previous year (aOR 0.42, 95% CI: 0.28 to 0.63). Similar associations were observed for self-reported HBV vaccination. CONCLUSIONS: Self-reported vaccination against HAV and HBV among gbMSM in Ireland is high, but the level of vaccination remains insufficient to protect against future HAV and HBV infections and outbreaks. Efforts to increase vaccination coverage among gbMSM should focus on men who live outside the capital, have lower educational attainment and do not engage with sexual health services.

Widespread Community Transmission of Hepatitis A Virus Following an Outbreak at a Local Restaurant - Virginia, September 2021-September 2022.

Hepatitis A is a vaccine-preventable liver infection caused by the hepatitis A virus (HAV); it is transmitted through ingestion of food or drink that has been contaminated by small amounts of infected stool, or through direct contact, including sexual contact, with a person who is infected (1). After years of historically low rates of hepatitis A in the United States, the incidence began increasing in 2016, with outbreaks characterized by person-to-person HAV transmission among persons who use drugs, persons experiencing homelessness, and men who have sex with men (2,3). As of September 2022, 13 states were experiencing outbreaks, including Virginia (3). In September 2021, the Roanoke City and Alleghany Health Districts (RCAHD) in southwestern Virginia investigated an outbreak of hepatitis A. The outbreak, which resulted in 51 cases, 31 hospitalizations, and three deaths, was associated with a food handler who was infected. After the outbreak, the community experienced ongoing person-to-person transmission of HAV, predominantly among persons who use injection drugs. As of September 30, 2022,* an additional 98 cases had been reported to RCAHD. The initial outbreak and community transmission have exceeded US$3 million in estimated direct costs (4,5). This report describes the initial outbreak and the ongoing community transmission of HAV. Increasing vaccination coverage among persons with risk factors for hepatitis A infection is important, including among those who use drugs. Strengthening community partnerships between public health officials and organizations that employ persons with risk factors for acquisition of HAV could help to prevent infections and outbreaks.

Preventable Deaths During Widespread Community Hepatitis A Outbreaks - United States, 2016-2022.

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.

Catch-up vaccination and enhanced immunization against hepatitis B, hepatitis A, measles, mumps, rubella and varicella in children with idiopathic thrombocytopenic purpura.

BACKGROUND: Limited data exist about the vaccination of children with idiopathic thrombocytopenic purpura (ITP) against vaccine preventable diseases. This study identified the vaccination status of children with ITP against hepatitis A, hepatitis B, measles, mumps, rubella and varicella, completed the immunization of children with inadequate immunization, re-evaluated post-vaccination antibody titers and identified probable vaccination-related complications. PATIENTS AND METHODS: All of 46 children had chronic ITP were included. Seroconversion of hepatitis A, hepatitis B, varicella, measles, rubella and mumps vaccines was screened. All children with seronegative antibodies against vaccine preventable disease were given a vaccination appointment. Antibody levels were re-measured during a period ranging from 1 to 6 months. Potential complications were detected. RESULTS: There were 46 children with a mean age of 12.25 years. All children had chronic ITP and received intravenous immunoglobulin at least once previously. Considering the vaccination status, 50% (23 children) had vaccinations appropriate for their age, 47.8% (22 children) did not know their vaccination status and 2.2% (1 patient) did not have vaccinations. Seven children (15.2%) were seropositive for all antibody types and the remaining 39 children were scheduled for vaccination. Post-vaccination antibody titers confirmed that all children became seropositive for each disease. There was no complication in any patient. CONCLUSION: Immunization against hepatitis B, hepatitis A, measles, mumps, rubella and varicella is insufficient in a considerable number of children with ITP, Hepatitis B Virus (HBV) and Hepatitis A Virus (HAV) immunization being the most frequently inadequate. After immunization, adequate seroconversion levels were achievable without complications.

Changes in the epidemiology of hepatitis A: Clinical and preventive implications. / Cambios en la epidemiología de la hepatitis A: repercusiones clínicas y preventivas.

INTRODUCTION AND OBJECTIVES: Hepatitis A Virus Infection (HAI) has been related to the hygienic-sanitary situation of an area, the changes in the epidemiology of HAI in the province of Guadalajara between 1991 and 2017 are analyzed. MATERIALS AND METHODS: Cases of HAI declared between 1991 and 2017 in Guadalajara were included. The variables analyzed were age, sex, environment, risk factors for HAI and need for hospitalization. The incidence was compared in three periods: 1991-1999, 2000-2008 and 2009-2017. RESULTS: Two hundred and thirty-three cases of HAI were declared, the average incidence rate was 4.27 cases/100,000 inhabitants, highest between 1991 and 1999 (6.93) and lowest between 2009 and 2017 (1.92), with an increment in 2017 (5.5). The median age was 16 years (IR: 8.5-28.5 years), 58.4% were male, and the highest incidence occurred between 5 and 14 years in both sexes. The most frequent risk factors were family and non-family contact and trips to endemic areas (18.6%, 17.3% and 18.2%, respectively). The last risk factor increased after 2000 (P=.001), as did the incidence in urban areas. The MSM group showed an increase in the last period (P<.001). Hospital admissions increased progressively from the first to the third period studied (P=.001). CONCLUSIONS: HAI has a low incidence in our area. More cases related to travel or sexual practices are observed. This should be considered when establishing prevention policies, including vaccination of the most exposed people.

[Expert recommendations on hepatitis A vaccination for adults].

Hepatitis A is a significant global public health concern, with severe clinical symptoms in adult cases that can progress to acute hepatic failure. With the implementation of comprehensive prevention and control measures based on vaccination, the reported incidence of hepatitis A in children has notably decreased in China, while the incidence of hepatitis A in adults has gradually increased. Vaccination against hepatitis A in adults remains a crucial preventive measure. This recommendation is formulated based on the World Health Organization's position paper on hepatitis A vaccines (2022), incorporating the latest domestic and international research advancements and opinions from domestic experts. Its aim is to provide recommendations for hepatitis A vaccination among Chinese adults, offering evidence for public health and vaccination professionals to scientifically use hepatitis A vaccines and maximize their preventive efficacy, thereby enhancing hepatitis A prevention and control efforts.

Changing Epidemiology of Hepatitis A in China: Evidence From Three National Serological Surveys and the National Notifiable Disease Reporting System.

BACKGROUND AND AIMS: China has conducted surveillance for hepatitis A since 1990, and hepatitis A was highly-to-intermediately endemic in 1992 when a Chinese hepatitis A vaccine (HepA) was licensed and introduced as a family-pay vaccine. In 2008, HepA was introduced into the Expanded Program on Immunization as a free childhood vaccine. APPROACH AND RESULTS: Three nationally representative surveys conducted in 1992, 2006, and 2014 assessed hepatitis B serology. The 1992 survey included hepatitis A virus (HAV) serology, and we tested sera from the 2006 and 2014 surveys for HAV antibodies. We used surveillance, seroprevalence, and vaccination status data to describe the changing epidemiology of hepatitis A in China from 1990 through 2014. Before HepA licensure, anti-HAV seroprevalence was 60% at 4 years of age, 70% at 10 years, and 90% at 59 years; incidence was 52/100,000 and peaked at 4 years. In 2006, after >10 years of private sector vaccination, HepA coverage was <30% among children <5 years, and incidence was 5.4/100,000 with a peak at 10 years. In 2014, coverage was >90% among children under 5 years; incidence was 1.9/100,000. Individuals born before the national introduction of HepA (1988-2004) had lower anti-HAV seroprevalence than earlier and later birth cohorts. CONCLUSIONS: The incidence of hepatitis A declined markedly following HepA introduction and improvement of sanitation and hygiene. The emerging epidemiology is consistent with disease-induced immunity having been replaced by vaccine-induced immunity, resulting in a low incidence of hepatitis A. Catch-up HepA campaigns to close the immunity gap among the 1998-2004 birth cohorts should be considered.

Factors Associated With Hepatitis A Mortality During Person-to-Person Outbreaks: A Matched Case-Control Study-United States, 2016-2019.

BACKGROUND AND 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 AND 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 preexisting nonviral 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 Model for End-Stage Liver Disease (MELD) score ≥ 30 (aOR, 10.0), aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio > 2 (aOR, 10.3), and platelet count < 150,000/µL (aOR, 3.7) among hepatitis A outbreak-associated patients in the independent multivariable conditional logistic regression analyses (each model adjusted for sex). CONCLUSIONS: Preexisting liver disease, diabetes, cardiovascular disease, and initial MELD score ≥ 30, AST/ALT ratio ≥ 1, and platelet count < 150,000/µL 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 recommendation of the Advisory Committee on Immunization Practices to vaccinate persons with chronic liver disease, though future recommendations to include adults with diabetes and cardiovascular disease should be considered.

Robust Hepatitis A Vaccination Response Within the United States Veterans Health Administration in the Wake of State Outbreaks.

We assessed hepatitis A (HepA) vaccine receipt among susceptible individuals in outbreak and matched nonoutbreak states. Difference-in-differences models and multivariable logistic regression were used to compare HepA vaccination rates in these states. In the postoutbreak year, there was a 112% increase in HepA vaccinations in outbreak states versus a 6% decrease in nonoutbreak states. Differences persisted in our multivariable model (adjusted odds ratio = 2.53; 95% confidence interval = 2.45, 2.61). HepA vaccination rates increased dramatically in outbreak states, but many individuals susceptible to hepatitis A virus remain unvaccinated. (Am J Public Health. 2022;112(7):990-994. https://doi.org/10.2105/AJPH.2022.306845).

Widespread Hepatitis A Outbreaks Associated with Person-to-Person Transmission - United States, 2016-2020.

Hepatitis A is a vaccine-preventable disease typically acquired through fecal-oral transmission. Hepatitis A virus (HAV) infection rates in the United States declined approximately 97% during 1995-2015 after the introduction and widespread pediatric use of hepatitis A vaccines (1). Since 2016, hepatitis A outbreaks have been reported in 37 states, involving approximately 44,650 cases, 27,250 hospitalizations, and 415 deaths as of September 23, 2022 (2). A report describing early outbreaks in four states during 2017 noted that most infections occurred among persons reporting injection or noninjection drug use or experiencing homelessness; this finding signaled a shift in HAV infection epidemiology from point-source outbreaks associated with contaminated food to large community outbreaks associated with person-to-person transmission (3). CDC analyzed interim data from 33 outbreak-affected states to characterize demographic, risk factor, and clinical outcome data from 37,553 outbreak-associated hepatitis A cases reported during August 1, 2016-December 31, 2020. Among persons with available risk factor or clinical outcome information, 56% reported drug use, 14% reported experiencing homelessness, and 61% had been hospitalized; 380 outbreak-associated deaths were reported. The most effective means to prevent and control hepatitis A outbreaks is through hepatitis A vaccination, particularly for persons at increased risk for HAV infection (4). The epidemiologic shifts identified during these outbreaks led to a 2019 recommendation by the Advisory Committee on Immunization Practices (ACIP) for vaccination of persons experiencing homelessness and reinforcement of existing vaccination recommendations for persons who use drugs (4). Substantial progress in the prevention and control of hepatitis A has been made; the number of outbreak-affected states has been reduced from 37 to 13 (2). Increased hepatitis A vaccination coverage, particularly through implementation of successful, nontraditional vaccination strategies among disproportionately affected populations (5), is needed to continue progress in halting current outbreaks and preventing similar outbreaks in the future.

Changing demographics and immunity to vaccine preventable diseases in people with HIV in Ireland.

BACKGROUND: HIV infection is associated with an increased risk of morbidity and mortality from vaccine preventable infections. This research describes, in the context of changing patient demographics, the seroprevalence of vaccine preventable viral infections among attendees of the largest centre for HIV positive patients in Ireland. METHODS: Baseline serum IgG results for measles, mumps, rubella, varicella zoster virus (VZV) & hepatitis A, as well as hepatitis B sAg, cAb and sAb results, were retrieved for 2534 clinic attendees attending in 2018. Results were available for between 990 and 2363 attendees (39-93%), depending on the test, and were compared with 2013 clinic data. RESULTS: There was a 35% increase in attendees in 2018 when compared to 2013. The largest increase was in attendees of South American origin. In 2018, males accounted for 73% of the entire cohort and the HIV acquisition risk for 48% of attendees was MSM. 47% of attendees were originally from Ireland. Among those tested, 33% were susceptible to at least one component of the MMR vaccine. 5% were VZV non-immune (significantly associated with younger age and the acquisition risk status of injection drug use). 21% were hepatitis A non-immune (significantly associated with younger age and being of European or South American origin). 32% were hepatitis B cAb seropositive (significantly associated with older age, injection drug use status and being originally from Africa). 3% demonstrated hepatitis B sAg positivity. 64% had hepatitis B sAb ≥ 10mIU. CONCLUSION: In a cohort of attendees to an HIV clinic in a large urban setting, the susceptibility to several common vaccine preventable viral infections, in particular MMR and hepatitis A and B, was high. These results highlight the importance of proactive screening and immunisation to help protect this high risk patient group against vaccine preventable diseases.