Hepatitis A Virus Seroprevalence Research Articles

Prevalence of hepatitis A virus among migrant workers in Qatar: A national study.

Hepatitis A virus (HAV) is the predominant cause of acute viral hepatitis worldwide; however, data on HAV antibody prevalence (seroprevalence) among migrant populations are limited. This study aimed to investigate HAV seroprevalence among Qatar's migrant craft and manual workers (CMWs), constituting approximately 60% of the country's population. HAV antibody testing was conducted on stored serum specimens obtained from CMWs during a nationwide severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) population-based cross-sectional survey between July 26 and September 9, 2020. Associations with HAV infection were investigated through regression analyses. Of the 2,607 specimens with HAV antibody test results, 2,393 were positive, and 214 were negative. The estimated HAV seroprevalence among CMWs was 92.0% (95% CI: 90.9-93.1%). HAV seroprevalence was generally high but exhibited some variation, ranging from 70.9% (95% CI: 62.4-78.2%) among Sri Lankans to 99.8% (95% CI: 98.2-99.9%) among Pakistanis. The multivariable regression analysis identified age, nationality, and educational attainment as statistically significant factors associated with HAV infection. Relative to CMWs aged ≤29 years, the adjusted relative risk (ARR) was 1.06 (95% CI: 1.03-1.10) in CMWs aged 30-39 years and reached 1.15 (95% CI: 1.10-1.19) in those aged ≥50 years. In comparison to Indians, the ARR was lower among Sri Lankans, assessed at 0.81 (95% CI: 0.72-0.91), but higher among Nepalese at 1.07 (95% CI: 1.04-1.11), Bangladeshis at 1.10 (95% CI: 1.07-1.13), Pakistanis at 1.12 (95% CI: 1.09-1.15), and Egyptians at 1.15 (95% CI: 1.08-1.23). No evidence for differences was found by geographic location or occupation. HAV seroprevalence among Qatar's CMW population is very high, with over nine out of every ten individuals having been exposed to this infection, likely during childhood.

Hepatitis A seroprevalence and demographic risk factors in the susceptible population: a cross-sectional study.

The epidemiology of hepatitis A virus (HAV) infection is influenced by variables such as age, sex, environmental conditions, and vaccination status. This study aimed to evaluate HAV seropositivity after the inclusion of hepatitis A vaccination in the national childhood immunization program and identify demographic risk factors of the susceptible population before routine vaccination.This cross-sectional epidemiological study was conducted by retrospectively examining the laboratory records of patients who underwent HAV serology testing in a tertiary care center in eastern Turkey between 2008 and 2019.Overall immunity to HAV was 81.6%. According to birthplace and year, the rate of anti-HAV positivity was higher among people born before 2006 in the Southeast and Eastern Anatolia regions. For those born in 2012 or later, the lowest seropositivity was among those born in the Southeast region, while it was over 60% in the other regions. When analyzed by year of birth, the lowest seropositivity was in those born between 1994 and 2011, and the frequency of seropositivity increased with age. Of those born between 1982 and 1999, the seropositivity rate was higher among men than women. Rural dwellers born before 2012 had higher seropositivity than urban dwellers. Among those born before the introduction of routine childhood HAV vaccination, female sex, urban dwelling, and each additional year of age were identified as independent demographic risk factors for HAV susceptibility.Socioeconomic development and immunization programs have altered HAV seroprevalence patterns. Planning catch-up vaccinations, especially in adolescents and young adults (born in 1994-2011) with low seropositivity and ensuring the continuity of hygiene and sanitation practices are important to protect the susceptible population.

Prevalence of Hepatitis A Virus and Hepatitis E Virus in a tertiary care hospital, East Delhi, India.

Background & Aim: Acute viral hepatitis (AVH) is a condition that is known to be caused by enterically transmitting Hepatitis A virus (HAV) and Hepatitis E virus (HEV). Usually, they result in self-limiting disease but can be seriously threatening if complications arise. This study was done to determine the prevalence rate of HAV and HEV in a tertiary care hospital in East Delhi, India.
 Material & Methods: The retrospective and observational study of 2-year duration was conducted in the Department of Microbiology at UCMS and GTBH Delhi, India. A total of 410 samples from patients presenting with a clinical diagnosis of acute hepatitis were considered in the study. The serum samples were analysed for IgM anti-HAV and IgM anti-HEV, respectively, using commercially available ELISA kits.
 Results: The seroprevalence of HAV and HEV were 2.19% and 0.24%, respectively. No case was found to be reactive for both parameters, indicating no case of co-infection. The majority of clinical samples were from female patients.
 Conclusion: The incidence of HEV and HAV illnesses suggests that East Delhi has a lower prevalence rate of the reported viral illnesses. This finding suggests one of the following: limited circulation of the agents, good sanitary conditions, and/or protective immunity among the population tested. Nonetheless, we should continue to assess the ongoing conditions and take measures to improve them.

1240. Hepatitis A in Latin America and the Caribbean: a Systematic Literature Review on Endemicity Patterns and Immunization Programs

Abstract Background In 2019, hepatitis A virus (HAV) infections caused around 39,600 deaths worldwide. Age-specific seroprevalence is used as a marker to classify endemicity. In countries with intermediate endemicity, WHO recommends universal HAV vaccination for children ≥1 year considering local disease burden and cost-effectiveness analyses. This review aimed to describe the endemicity patterns and HAV immunization programs in Latin America and the Caribbean (LAC). Methods We conducted a systematic literature review using MEDLINE, Embase, CENTRAL, CDRS, Lilacs, and Scopus from January 2005 to December 2021. Additionally, we searched grey literature, including Pan American Health Organization/WHO country profiles and official government websites in January 2022. The main outcomes were HAV seroprevalence and characteristics of HAV immunization programs. Results We identified 30 studies containing data on HAV seroprevalence in LAC and 13 records from grey literature on HAV vaccination program. As of January 2022, among 33 countries, 8 had public universal childhood HAV vaccination program and 12 had programs for at least one population at-risk (Figure 1 and Table 1). Only 7 countries had seroprevalence data available (Figure 2). Using WHO criteria, 5 countries were classified as intermediate endemicity; 2 have already introduced HAV vaccination in the NIP (Brazil and Colombia) and 3 have not introduced yet (Bolivia, Mexico, and Peru). In Argentina and Brazil, studies conducted in certain populations at risk, such as men who have sex with men and healthcare workers aged between 20-40 years, showed higher susceptibility to infection (seroprevalence: 40%-60%). Figure 1.Hepatitis A routine immunization schedule in national immunization programs in Latin America and the Caribbean, 2022 a Available for Guatemalan Social Security Institute (employed people in formal sector), which represents 17% of total population. b Countries that included in national immunization program for at least one population at risk Table 1.Characteristics of hepatitis A immunization programs in Latin America and the Caribbeana Populations at risk: 2-dose schedule; b Partial introduction in 2014 in endemic areas; c only available for Guatemalan Social Security Institute (formally employed population), which represents 17% of total populationFigure 2.Hepatitis A endemicity level in studies conducted in Latin America and the Caribbean based on WHO classification criteriaa general population; b premarital exam; c health care workers; d children school; e liver cirrhosis; f national survey; g samples from labs, h beauticians; i population-based survey; j chronic HCV infection; k rural settlement; l low socioeconomic groups; m chronic HCV infection; n men who have sex with men/ transgender women. Mantovani 2015 and Pereira 2016 are included in the review and not showed here (description of prevalence < 5 y) Conclusion Eight countries had universal HAV vaccination program and 12 offered for at least one population at-risk. LAC countries where HAV seroprevalence was available showed predominance of intermediate endemicity. Bolivia, Mexico, and Peru would benefit from universal childhood vaccination, and Argentina and Brazil should evaluate increasing susceptibility among adults at-risk to expand access to vaccination. In countries without recent data, surveillance of acute cases/outbreaks and seroprevalence studies are needed to guide the HAV vaccination implementation. Disclosures Cintia I. Parellada, MD, PhD, MSD Brazil: Employee of MSD Brazil, a subsidiary of Merck & Co., Inc.,|MSD Brazil: Stocks/Bonds Emilia Prieto, MD, MSc, MSD Colombia: Employee of MSD Colombia, a subsidiary of Merck & Co., Inc.,|MSD Colombia: Stocks/Bonds Cristina Carias, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds Martha Carolina Valderrama, MD, Msc, IQVIA: Advisor/Consultant|IQVIA: Employee of IQVIA who received funding to execute this study Daniel Samacá-Samacá, Msc, IQVIA: Advisor/Consultant|IQVIA: Employee of IQVIA who received funding to execute this study Fabian Hernandez, BSPharm, Msc, IQVIA: Employee of IQVIA who received funding to execute this study Homero Monsanto, PhD, Merck & Co., Inc.: Employee.

Hepatitis A virus seroprevalence among children and adolescents in a high-burden HIV setting in urban South Africa

Hepatitis A virus (HAV) infection is one of the most important global causes of viral hepatitis. Recent reviews suggested that HAV endemicity in South Africa could shift from high to intermediate. A hospital-based HAV seroprevalence study was conducted between February 2018 and December 2019 in Pretoria, South Africa. Systematic sampling was performed on children and adolescents (1–15 years) who attended outpatient services. Participants with a known HIV status and valid HAV serology results were included. Of the 1220 participants, the median age was 7 years (IQR: 4–11), with 648 (53.11%) males and 572 (46.89%) females. Of 628 (51.48%) HIV-infected participants, most (329, 71.83%) were both immunologically and virologically controlled or had low-level viremia (74, 16.16%). Almost three-quarters (894, 73.28%) were living in formal dwellings, and just over half (688, 56.39%) had access to clean water sources inside the house. Increasing age was associated with testing HAV IgG-positive (OR 1.25; 95% CI 1.20–1.30, p < 0.001), with 19.8% of participants one year of age compared with 86.7% of participants 15 years of age. This study suggests that South Africa has an intermediate HAV seroprevalence, with rates < 90% by 10 years of age (68.6%). Increased age and informal dwellings are statistically associated with HAV seropositivity, while HIV status does not significantly influence HAV seropositivity.

Dynamic Changes in Hepatitis A Immunity in Regions with Different Vaccination Strategies and Different Vaccination Coverage.

The data on hepatitis A virus (HAV) seroprevalence are critical for the implementation of a universal mass vaccination (UMV) strategy. The latter has not been implemented in Russia; however, regional child vaccination programs have been adopted in some parts of the country. The aim of this study is to assess changes in HAV immunity within the last decade in regions of Russia with different vaccination strategies and different vaccination coverage rates. In regions where UMV has not been implemented and HAV vaccination coverage rates do not exceed the national average, the 50% seroprevalence threshold has shifted in the Moscow region from people aged under 40 years in 2008 to people aged over 59 years in 2020, and from people aged under 30 years to people aged over 40 years in the Khabarovsk region. In two regions (Yakutia and Sverdlovsk), a two-dose-based UMV scheme has been in place since 2011 and 2003, respectively, and in Tuva single-dose child immunization was launched in 2012. These regional programs have resulted in a significant increase in HAV seroprevalence in children and adolescents. In Yakutia, 50% herd immunity had been achieved by 2020 in age groups under 20 years, compared to 20–30% seroprevalence rates in 2008. In the Sverdlovsk region, HAV immunity has increased to >65% over the decade in children aged over 10 years, adolescents and young adults, whereas it declined in older age groups. However, a three-fold drop in HAV immunity has occurred in children under 10 years of age, reflecting a significant decline in vaccination coverage. In Tuva, HAV immunity rates in children under 10 years old increased two-fold to exceed 50% by 2020. These data suggest that UMV should be implemented on a national level. Measures to control vaccination coverage and catch-up vaccination campaigns are recommended in order to maintain the effectiveness of existing HAV vaccination programs.

Systematic Review and Meta-Analysis: Seroprevalence, Vaccination Rates, and Response for Hepatitis A in Inflammatory Bowel Disease

Introduction Guidelines recommend hepatitis A virus (HAV) vaccination in individuals with inflammatory bowel disease (IBD). We performed a systematic review to inform the clinical practice regarding this guidance. Methods After a PubMed and Embase search, duplicates were removed and the remaining titles screened for studies reporting relevant outcomes. Pooled seroprevalence rates for HAV, pooled vaccination rates, and pooled seroconversion rates were calculated. We also calculated pooled relative risk of seroprevalence for HAV among IBD and control population. Heterogeneity was investigated using subgroup analysis. Results The pooled seroprevalence of HAV antibodies in patients with IBD (14 studies, 2,370 patients) was 0.36 (95% confidence interval [CI]: 0.22–0.53, I 2 = 95%). On comparing the seroprevalence of HAV in IBD with controls (4 studies), the pooled relative risk was not different between the two (0.94, 95% CI: 0.66–1.34, I 2 = 76%). The pooled seroconversion rate after two doses of HAV vaccination (5 studies, 221 patients) was 0.93 (95% CI: 0.88–0.96, I 2 = 0%). Three studies (104 patients) reported on the seroconversion after a single dose of HAV vaccination and the pooled seroconversion rate was 0.47 (95% CI: 0.35–0.59, I 2 = 20%). The pooled vaccination rate for hepatitis A among patients with IBD (18 studies, 9,521 patients) was 0.21 (95% CI: 0.14–0.30, I 2 = 99%). Conclusion Hepatitis A vaccine has good immunogenicity in patients with IBD. The decision to routinely vaccinate IBD patients may be made in light of underlying seroprevalence of HAV.

Seroprevalence and incidence of hepatitis A in Southeast Asia: A systematic review.

A previous review on hepatitis A virus (HAV) seroprevalence in 2005 categorized Southeast Asia as a low HAV endemicity region. In 2010, the World Health Organization modified this from low to low/medium endemicity, pointing out that these estimates were based on limited evidence. Since then, there has been no attempt to review HAV epidemiology from this region. We conducted a systematic review of literature to collect information on HAV incidence and seroprevalence in select countries in the Southeast Asian region, specifically, The Association of Southeast Asian Nations over the last 20 years. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. From the relevant articles, we extracted data and conducted a risk of bias assessment of individual studies. The search yielded 22 and 13 publications on HAV seroprevalence and incidence, respectively. Overall, our findings point to a very low HAV endemicity profile in Thailand and Singapore and evidence of a shift towards low HAV endemicity in Indonesia, Lao People's Democratic Republic, Malaysia, the Philippines, and Vietnam. Only Singapore, Thailand, Malaysia, and the Philippines have existing HAV disease surveillance and reported incidence rates below 1 per 100,000. Several outbreaks with varying magnitude documented in the region provide insights into the evolving epidemiology of HAV in the region. Risk of bias assessment of studies revealed that the individual studies were of low to medium risk. The available HAV endemicity profiles in Southeast Asian countries, aside from Thailand, are limited and outdated, but suggest an endemicity shift in the region that is not fully documented yet. These findings highlight the need to update information on HAV epidemiology through strengthening of disease surveillance mechanisms to confirm the shift in HAV endemicity in the region.

Status of Immunity Against the Hepatitis A Virus in Healthy Population: A Report from Southeastern Iran

Background: Recently, epidemiological studies on hepatitis A virus (HAV) infection showed the seroprevalence has been changing due to changes in lifestyle. To the best of our knowledge, there have been no published data on the seropositivity of HAV in Zahedan, southeastern Iran. Objectives: This study aimed to investigate the seroprevalence of HAV immunoglobulin G (IgG) antibody in Zahedan, southeastern Iran, to provide the required information for better planning in preventive strategies. Methods: In this cross-sectional study, using the available sampling method, a total of 250 serum samples (18 years and above) in both the urban and rural areas of Zahedan were evaluated for anti-HAV IgG by enzyme-linked immunosorbent assay. Results: Based on the results, it was observed that 228 out of 250 (91.2%) serum samples were positive for HAV IgG antibody. Male gender, family size, parents’ education, mother’s occupation, and history of jaundice before the age of 12 years were associated with positive HAV antibody (P &lt; 0.001). The seroprevalence HAV rates were not statistically different between the residents of urban and rural regions. Conclusions: The seropositivity of HAV is high in both the urban and rural areas of Zahedan, Iran. Therefore, the HAV vaccination of the general population is not necessary. It is recommended to monitor HAV seroprevalence in the general population to determine high-risk groups, including anti-HAV seronegative individuals, for HAV vaccination in the residents of the southeast border.

Hepatitis A Outbreak in a Facility for the Disabled, Gyeonggi Province, Korea: An Epidemiological Investigation.

Objectives:The number of cases of hepatitis A virus (HAV) infections has sharply increased in Korea, especially among young adults. In this study, an HAV outbreak in a facility for disabled people was investigated, and we found epidemiological differences both between 2 different generations and between generally abled and disabled groups.Methods:We analyzed the incubation period and attack rate of an HAV outbreak and investigated the prevalence of HAV antibodies among the staff and residents of a facility for the disabled. We performed a retrospective cohort study during the HAV outbreak, which lasted from February 8 to 25, 2019, including examinations of HAV antibody tests and post-exposure HAV vaccination for the staff or residents of the facility.Results:There were 9 confirmed cases in 2 staff members and 7 residents. Among 53 people (30 staff and 23 residents), except for the 9 confirmed cases and 1 staff member with a known history of HAV infection, HAV seroprevalence was seen in 16.7% of the staff under 40 years of age and 95.2% of those over 40 years of age, while the corresponding rates in the residents were 0.0% and 58.8%, respectively.Conclusions:This result implies that it is necessary to prioritize HAV vaccination for vulnerable groups and workers of residential care facilities.

Tracking the Epidemiologic Shifts in Hepatitis A Sero-Prevalence Using Age Stratification: A Cross-Sectional Study at Jordan University Hospital.

The study of hepatitis A virus (HAV) epidemiology and sero-prevalence has important public health implications. Changes in the epidemiology of hepatitis A can result in a larger pool of susceptible persons in countries with improved sanitation and hygienic conditions if vaccination is not provided. The aim of this study was to investigate the prevalence of HAV immunoglobulin G (IgG) in Jordan. In addition, we aimed to identify the potential differences in HAV sero-prevalence based on age, among other variables. We recruited the study participants at Jordan University Hospital in Amman, Jordan, during October 2020–June 2021. Assessment of participants’ socio-demographic variables was done using a paper-based questionnaire. Testing for HAV IgG was based on a competitive enzyme linked immunosorbent assay (ELISA). The study population comprised 360 individuals with a median age of 18 years. The overall sero-prevalence of HAV in our study sample was 38.3%. Divided by age, the sero-prevalence of HAV was 8.2%, 12.3%, and 20.8% among individuals aged 10 years or less, 15 years or less, and 30 years or less, respectively. The estimated age at mid-population immunity was between 21 and 30 years. Besides age, individuals residing outside the Central region of Jordan had a significantly higher HAV sero-prevalence. Additionally, the use of filtered municipal water was associated with a lower sero-prevalence of HAV compared with the use of unfiltered municipal water among individuals aged 15 years or less. The results of this study suggest an intermediate to low endemicity of HAV in Jordan. An epidemiologic shift of HAV sero-prevalence with a declining rate of positivity for HAV IgG was noticed in this study. This highlights the importance of the recently introduced HAV vaccination in Jordan. Future research to evaluate the public health benefits of HAV vaccination in Jordan is recommended.

English

BACKGROUND Hepatitis A &amp; E viruses are enterically transmitted viruses responsible for acute viral hepatitis in developing countries. Hepatitis A virus (HAV) has worldwide distribution while hepatitis E virus (HEV) is restricted to tropical countries. HAV affects infants and young children while HEV affects older children and young adults. This study was conducted to determine the seroprevalence of HAV and HEV and their co-infection in patients presenting with acute viral hepatitis (AVH). METHODS 200 sera of patients suffering from suspected acute viral hepatitis (AVH) attending tertiary care rural hospital JNMC Sawangi, Wardha were included in the study. Serum samples were tested for IgM anti HAV and IgM anti - HEV for the detection of acute hepatitis A and acute hepatitis E using commercially available ELISA kit &amp; Immunochromatography test (ICT) for comparison of ELISA and ICT. RESULTS The overall seroprevalence of HAV and HEV infection was found to be 19 %. The seroprevalence of HAV infection was found to be 13 %, HEV infection 5 % and HAV - HEV co - infection 1 %. HAV infection in males and females was found to be 16.07 % and 9.09 % respectively &amp; HEV infection was found to be 5.35 % and 4.54 % respectively. In case of detection of HAV IgM, two serum samples were negative by ICT but positive by ELISA &amp; for HEV IgM, one serum sample was negative by ICT but positive by ELISA. The sensitivity, specificity, positive predictive value and negative predictive value of HAV IgM was found to be 96 %, 98.8 %, 92.30 % &amp; 99.43 % and for HEV IgM was found to be 90 %, 99.47 %, 90 % &amp; 99.47 % respectively. CONCLUSIONS It is evident from this study that infection with enteric hepatitis viruses is not infrequent. Findings from this study emphasize the need to establish regular seroepidemiological surveys to keep track of epidemiology of these viruses. Results from rapid tests are comparable to ELISA with additional advantage of ease of interpretation and neither time consuming nor requiring special instruments. KEY WORDS Hepatitis A, Hepatitis E, Seroprevalence

1433. Promoting Vaccination of Vaccine Preventable Diseases in Newly Employed Nurses and Doctors Guided by Serological Study

BackgroundVaccination after serological evaluation of healthcare workers is key component of vaccine preventable diseases (VPDs) preparedness in hospital. The aim of this study is to determine the seroprevalence of VPDs and the vaccination rates among newly employed nurses and doctors.MethodsA cross-sectional study was conducted at a referral university hospital in the Republic of Korea. All newly employed nurses and doctors without immunity were recommended to have the hepatitis B virus (HBV), varicella zoster virus (VZV), measles, mumps, and rubella (MMR), hepatitis A virus (HAV) and tetanus-diphtheria-pertussis (Tdap) vaccination. HBV, VZV, MMR vaccinations were financially supported and Tdap vaccination was recommended without testing. We investigated the seroprevalence of HAV, HBV, and VZV and vaccination rate of recommended vaccination (HAV, HBV, MMR, VZV, and Tdap) from Jan 1st, 2017 to March 31th, 2020.ResultsA total of 668 (527 female, 141 male) newly employed nurses and doctors were identified. The median age (IQR) is 25 (24-27). Seroprevalence were 59.1% (95% confidence interval [CI] 55.4-62.8) for HAV, 86.1% (95% CI 83.5-88.7) for HBV, and 92.4% (95% CI 90.4-94.4) for VZV. Vaccination rate of recommended vaccination were 24.5% (95% CI 18.5-30.5) for HAV, 23.3% (95% CI 13.6-33.0) for HBV, 48.7% (95% CI 33.0-64.4) for VZV, 30.0% (95% CI 25.5-34.5) for MMR and 33.1% (95% CI 29.0-37.2) for Tdap respectively.ConclusionSeroprevalence of HAV was lower than HBV and varicella in newly employed nurses and doctors. Although persistent effort to improve the healthcare worker’s vaccination, the actual rates were low. Further strategy promoting vaccination of newly employed nurses and doctors are needed.Disclosures All Authors: No reported disclosures

The Seroprevalence of Hepatitis A Virus (HAV) Among Blood Donors Presenting to the Iranian Blood Transfusion Organization in Sanandaj, Iran

Background: Hepatitis A virus (HAV) infection is endemic in Iran. Detection of the seroprevalence of HAV is necessary to evaluate the feasibility of infection control strategies in the population. Objectives: This study aimed to determine the seroprevalence of HAV among blood donors as a representative sample of the general population. Methods: In this cross-sectional study, 268 blood samples were randomly selected from donors, presenting to the Iranian Blood Transfusion Organization in Sanandaj, Iran, in 2019. The collected sera were measured for anti-HAV antibodies (IgG and IgM), using ELISA assays. Also, demographic data, including age, gender, marital status, education, occupation, and blood donation status, were collected. The test results and demographic data were analyzed in STATA software. Results: The mean age of the blood donors was 37.79 ± 10.64 years, and 88.43% of them were male. Out of 268 blood samples, 218 (81.34%) were positive for anti-HAV antibodies. The antibody positivity was significantly correlated with age (P = 0.014) and marital status (P = 0.027). The majority of anti-HAV positive cases were found among farmers and ranchers (93.33%) (P = 0.045). Conclusions: A large proportion of blood donors had anti-HAV antibodies and were immune to HAV infection. Therefore, HAV was endemic in the study area.

First evidence for continuous circulation of hepatitis A virus subgenotype IIA in Central Africa.

Although a high seroprevalence of antibodies against hepatitis A virus (HAV) has been estimated in Central Africa, the current status of both HAV infections and seroprevalence of anti‐HAV antibodies remains unclear due to a paucity of surveillance data available. We conducted a serological survey during 2015‐2017 in Gabon, Central Africa, and confirmed a high seroprevalence of anti‐HAV antibodies in all age groups. To identify the currently circulating HAV strains and to reveal the epidemiological and genetic characteristics of the virus, we conducted molecular surveillance in a total of 1007 patients presenting febrile illness. Through HAV detection and sequencing, we identified subgenotype IIA (HAV‐IIA) infections in the country throughout the year. A significant prevalence trend emerged in the young child population, presenting several infection peaks which appeared to be unrelated to dry or rainy seasons. Whole‐genome sequencing and phylogenetic analyses revealed local HAV‐IIA evolutionary events in Central Africa, indicating the circulation of HAV‐IIA strains of a region‐specific lineage. Recombination analysis of complete genome sequences revealed potential recombination events in Gabonese HAV strains. Interestingly, Gabonese HAV‐IIA possibly acquired the 5’‐untranslated region (5’‐UTR) of the rare subgenotype HAV‐IIB in recent years, suggesting the present existence of HAV‐IIB in Central Africa. These findings indicate a currently stable HAV‐IIA circulation in Gabon, with a high risk of infections in children aged under 5 years. Our findings will enhance the understanding of the current status of HAV infections in Central Africa and provide new insight into the molecular epidemiology and evolution of HAV genotype II.

Poor response to hepatitis A vaccination in hematopoietic stem cell transplant recipients.

Hepatitis A virus (HAV) infection is highly prevalent in developing countries. In countries experiencing a shift from intermediate/high endemicity to low endemicity, the World Health Organization recommends the incorporation of HAV vaccine into the national vaccination calendar for children aged ≥1year. Since HAV antibodies wane over time, most HSCT revaccination guidelines advise vaccination as optional, following the country recommendation. However, no study has evaluated the serological response to HAV vaccine in allogeneic HSCT recipients. We conducted a prospective study in 46 HSCT recipients who received two doses of inactivated HAV vaccine. Blood samples were taken before vaccination to determine HAV prevalence rates, and before and 4-6weeks after the second dose. Specific anti-HAV antibodies were detected by a competitive commercial enzyme immune assay. Patients received the first dose of vaccine at a median of 332.5 (120-4134) days after HSCT. Median absolute lymphocyte count at vaccination was 1947 (696-12500)/mm3 . The seroprevalence rate was 93.5% at inclusion. Although safe and well tolerated, the serological response to HAV vaccine in susceptible patients was poor (33%), and no boost effect was observed in seropositive patients. In areas with intermediate/high seroprevalence of HAV, serology should be recommended prior to referral to vaccination. The mechanisms of antibody interference and how to overcome T-cell function deficiency need to be better understood in transplant populations receiving HAV vaccine. Alternative schedules of HAV vaccination should be evaluated in prospective trials.

Declining trends in Hepatitis A seroprevalence over the past two decades, 1998–2017, in Pune, Western India

Reduction in seroprevalence of Hepatitis A virus (HAV) is known to be associated with improvements in socioeconomic conditions of the community. National Institute of Virology, Pune has been studying seroprevalence of hepatitis viruses in Pune region over the past four decades. In total, 1438 samples were collected from urban general (UGEN), urban lower socioeconomic stratum (ULSES) and rural (RURAL) populations of the Pune district. Based on estimates in previous studies, subjects were enrolled from age groups '6-10', '15-25' and '40 + ' years. HAV seroprevalence in younger population showed a significant decline. A significant decline in HAV seroprevalence in '15-25' years age group in UGEN (from 85.9% to 73.9%; OR = 0.46, 95% CI: 0.25-0.86) and RURAL (from 98.6% to 91.4%; OR = 0.15, 95% CI: 0.05-0.45) populations suggested that the trend probably started more than a decade ago. Seroprevalence of HAV among ULSES '6-10' children was found to be significantly higher (70.4%) than that among the RURAL children (44.2%; OR = 3.0, 95%CI: 1.7-5.2) and UGEN children (40.4%; OR = 3.5, 95%CI: 1.8-6.7). In view of increasing rates of urbanisation in India, ULSES population needs special consideration while designing future studies and viral hepatitis vaccination/elimination strategies. Our findings call for robust population-based studies that consider heterogeneity within populations and dynamics of socio-economic parameters in various regions of a country.

Simultaneous infection of Hepatitis A and Hepatitis E viruses amongst acute viral hepatitis patients: A hospital-based study from Uttarakhand.

Background:Enterically transmitted viral agents like Hepatitis A virus (HAV) and Hepatitis E virus (HEV) are common causes of viral hepatitis in developing countries. Double infections by both agents, as their routes of entry are similar, are common. Overall this is a major health issue for our country. This study was carried out to learn about the seroprevalence of HAV & HEV (and double infections if any) infections in acute viral hepatitis (AVH) cases attending our hospital.Materials and Methods:This is a retrospective cross-sectional study of a 2-years duration carried out in the serology lab of Dept. of Microbiology, AIIMS Rishikesh. Continuously collected samples totaling 617 cases, presenting with Acute Viral Hepatitis was included in the study. Cases with suggestive history were tested for IgM anti-HAV and IgM anti-HEVrespectively. Commercially available ELISA kits were put into use. Standard Statistical Package (SPSS 23) was put to use for statistical analysis.Results:HAV & HEV seroprevalence in AVH cases were found to be 14.7% (91/617) and 28.04% (173/617), respectively. Dual infection of HAV and HEV was found in 5.9% (32/617) of study subjects. The prevalence of HAV and HEV among males were14.2% and 34.26%, respectively while that in female were 15.36% and 21.16%, respectively. Infection was predominantly found in young adults. Distinct seasonal variation was observed, period towards the end of monsoon, and beginning of winter recorded more cases. Both year, most of the positive cases are seen in the months of August and September.Conclusion:The infection rate of HEV is higher than HAV amongst AVH cases. This and relatively high co-infection rate (5.9%) is significant in terms of the need for regular screening of HEV in pregnant women as well as the urgent need to improve hygiene amongst the population. This data will help in future vaccine strategies and sanitation programs in this part of the country.

A systematic review of the epidemiology of hepatitis A in Africa

BackgroundHepatitis A, caused by the hepatitis A virus (HAV), is a vaccine preventable disease. In Low and Middle-Income Countries (LMICs), poor hygiene and sanitation conditions are the main risk factors contributing to HAV infection. There have been, however, notable improvements in hygiene and sanitation conditions in many LMICs. As a result, there are studies showing a possible transition of some LMICs from high to intermediate HAV endemicity. The World Health Organization (WHO) recommends that countries should routinely collect, analyse and review local factors (including disease burden) to guide the development of hepatitis A vaccination programs. Up-to-date information on hepatitis A burden is, therefore, critical in aiding the development of country-specific recommendations on hepatitis A vaccination.MethodsWe conducted a systematic review to present an up-to-date, comprehensive synthesis of hepatitis A epidemiological data in Africa.ResultsThe main results of this review include: 1) the reported HAV seroprevalence data suggests that Africa, as a whole, should not be considered as a high HAV endemic region; 2) the IgM anti-HAV seroprevalence data showed similar risk of acute hepatitis A infection among all age-groups; 3) South Africa could be experiencing a possible transition from high to intermediate HAV endemicity. The results of this review should be interpreted with caution as the reported data represents research work with significant sociocultural, economic and environmental diversity from 13 out of 54 African countries.ConclusionsOur findings show that priority should be given to collecting HAV seroprevalence data and re-assessing the current hepatitis A control strategies in Africa to prevent future disease outbreaks.

Seroprevalence of Hepatitis A and Hepatitis E Viruses among Pregnant Women in Haiti.

Hepatitis E virus (HEV) infection is associated with a high fatality rate among pregnant women, and gestational complications have been reported among pregnant women infected with hepatitis A virus (HAV). The aim of this study was to determine the seroprevalence of HAV and HEV infections among pregnant women in Haiti. We stratified the population (n = 1,307) between West and non-West regions. Specimens were tested for total HAV antibody (anti-HAV), and IgM and IgG HEV antibody (anti-HEV). Overall, 96.8% pregnant women were positive for total anti-HAV, 10.3% for IgG anti-HEV, and 0.3% for IgM anti-HEV. The prevalence of IgG anti-HEV in the non-West region (12.3%) was significantly greater than that in the West region (5.3%) (P < 0.0001). Most pregnant women in Haiti had evidence of past exposure and immunity to HAV. The non-West region had a higher prevalence of HEV. Improvement in water and sanitation will help in the prevention and control of these infections in Haiti.