Hepatitis A Virus Antibodies Research Articles

Unveiling the Burden of Hepatitis A in Salerno, Italy: A Comprehensive 9-Year Retrospective Study (2015-2023) on the Seroprevalence of HAV Antibodies and Age/Sex Distribution.

Background: Hepatitis A virus (HAV) infection is a significant global cause of viral hepatitis. At present, the anti-HAV vaccine in Italy is proposed exclusively for specific high-risk groups, and a universal vaccination program is not implemented. Objectives: This study aimed to assess the level of immunity against HAV in patients of both sexes across age groups ranging from 0 to 95 years admitted to the San Giovanni di Dio e Ruggi d'Aragona Hospital in Salerno, Italy, over a 9-year period (2015-2023). Methods: The total HAV seroprevalence by chemiluminescence Vitros system immunodiagnostics (ortho-diagnostics) was obtained by database analysis, stratifying patients for gender and age group in both the pre-pandemic (2015-2019) and pandemic (2020-2023) periods. Results: Out of 28,104 samples collected in 2015-2023, 20,613 resulted positive by total HAV immune screening, with a significant reduction in the annualized proportion of events during the pandemic period compared to the pre-pandemic period. HAV was more abundant in males than females in both periods (exceeding the 70%), with a statistically significant decrease in HAV in females in 2015-2019. The 61-70-year-old age group is more susceptible for both genders, with a strong deviation from the 41-50-year-old age group compared to the 51-60-year-old group. The pandemic period affected the number of analyzed samples in 2020. Conclusions: The study revealed high HAV seroprevalence, especially in males and individuals aged 61-70 years. There was a notable decrease in seroprevalence during the pandemic compared to pre-pandemic years. These results emphasize the need for ongoing monitoring and suggest that a universal vaccination program could address regional immunity gaps and lower disease incidence.

Analysis of Inflammatory and Thyroid Hormone Levels Based on Hepatitis A and B Virus Immunity Status: Age and Sex Stratification.

This study investigated the potential associations between hepatitis virus antibody status and thyroid and inflammatory function. The C-reactive protein (CRP), thyroid-stimulating hormone (TSH), and free thyroxine (FT4) levels were measured in individuals with and without antibodies to the hepatitis A virus (HAV) and hepatitis B virus (HBV). Participants were stratified by age, sex, and HAV/HBV antibody status. Participants with and without antibodies to HAV and HBV had normal CRP, TSH, and FT4 levels. However, notable discrepancies were observed in FT4 levels among participants with HAV antibodies and in CRP and FT4 levels among those with both HAV and HBV antibodies, suggesting potential associations between viral immunity and thyroid function, especially in younger participants. Significant variations in thyroid hormone levels were noted when the sample was stratified by sex and HAV and HBV antibody status, indicating that the association between antibody status and thyroid hormone levels varied by sex. This study underscores the need for further research on the effect of viral immunity on inflammatory parameters and thyroid hormone levels.

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.

A declining trend of hepatitis A and hepatitis E at tertiary care hospital in South Gujarat

Objectives: Hepatitis A virus (HAV) and Hepatitis E virus (HEV) both are spread through the fecal-oral route and cause acute viral hepatitis (AVH) and pose a major public health problem in India. This study was done to find out the proportion of positivity of HAV and HEV in patients with AVH and its seasonal trend. Materials and Methods: A retrospective study was carried out at Surat Municipal Institute of Medical Education and Research Medical College, Department of Microbiology, Surat, Gujarat. Result of 3615 blood samples of suspected AVH patients of the past 5 years (January 2018–December 2022) were taken from hospital data records. The enzyme-linked immunosorbent assay method was used to test serum samples for immunoglobulin M (IgM) HAV and IgM HEV antibodies for HAV and HEV, respectively. All samples were evaluated for liver function as well. Results: The positivity of HAV and HEV was 15.13% and 10.26%, respectively. The coinfection rate was 2.07%. HAV and HEV both affected males more than females. Among pregnant females, HEV infection had more positivity (6.77%) than HAV, which had 1.08% positivity. HAV and HEV infections had a seasonal trend, with the highest infection rate in the monsoon. Conclusion: The declining trend of cases of HAV and HEV was found in Surat city of south Gujarat which indicates increased awareness about hepatitis among people and better public health management by the civic authorities.

Divergent Genotype of Hepatitis A Virus in Alpacas, Bolivia, 2019.

Hepatitis A virus (HAV) is a common human pathogen found exclusively in primates. In a molecular and serologic study of 64 alpacas in Bolivia, we detected RNA of distinct HAV in ≈9% of animals and HAV antibodies in ≈64%. Complete-genome analysis suggests a long association of HAV with alpacas.

Seroprevalence of hepatitis A virus antibodies among children and adolescents living in Northern Thailand: an implication for hepatitis A immunization

This cross-sectional study aimed to assess seroprevalence of hepatitis A virus (HAV) antibodies and identify factors associated with HAV seropositivity among children and adolescents aged 1–18 years who resided in Chiang Mai, Thailand. Sociodemographic characteristics, sanitation/hygiene, and history of HAV vaccination were collected. Anti-HAV IgG antibody was determined, and a level ≥ 1.0 S/CO defined HAV seropositivity. We enrolled 300 participants; median age 8.7 years, 54% male, and 13% overweight (BMI z-score: + 1 to + 2 standard deviation [SD]). Sixty-five participants (22%) were vaccinated against HAV. Overall, 84/300 participants (28%) demonstrated HAV seropositivity, of whom 55/65 (85%) and 29/235 (12%) were among vaccinated and unvaccinated participants (P < 0.001), respectively. Previous HAV vaccination (adjusted odds ratio [aOR] 47.2; 95% CI 20.0–111.8) and overweight (aOR 4.4; 95% CI 1.7–11.3, compared with normal weight [BMI z-score: − 2 to + 1 SD]) were significantly associated with seropositivity of HAV. In the stratified analyses, crowded bedroom (aOR 3.2; 95% CI 1.3–7.8, per one person increase) and overweight (aOR 5.0; 95% CI 1.8–13.7) were factors associated with HAV seropositivity among vaccinated and unvaccinated participants, respectively. Seroprevalence of HAV antibodies in healthy Thai children and adolescents was relatively low. Recommendation of HAV vaccination for these populations, particularly those with high-risk conditions, should be considered.

Prevalence of Rotavirus, Adenovirus, and Hepatitis A Virus in a Tertiary Care Hospital in Somalia

Rotavirus, one of the viral infectious agents that is transmitted mainly through the fecal-oral route and spreads easily in regions with poor sanitation conditions, is the most common causative agent of acute gastroenteritis in children under five years of age worldwide, and enteric adenoviruses are other frequently encountered causative agents of gastroenteritis in childhood. Hepatitis A virus (HAV) is also transmitted in similar routes and is endemic in regions with poor sanitation conditions and limited access to clean water and is usually acquired in early childhood in these regions. In this study conducted in Mogadishu Somalia, rotavirus and adenovirus antigen test (immunochromatographic rapid test) results in patients admitted to a tertiary hospital in the 9-month period between February 2019 and October 2019 and ELISA based HAV antibody test results studied in 2018-2019 were retrospectively examined and it was aimed to determine the distribution of positivity rates of these viruses by age, gender, and year. During the study period, 1136 patients (mean age 6.33±12.36) were tested for rotavirus and adenovirus antigens, and 362 patients (mean age 21.26±18.45) were tested for anti-HAV IgM/IgG antibodies. The positivity rates of rotavirus and adenovirus were found as 17.8% and 5.1%, respectively. The positivity rates of anti-HAV IgM and IgG antibodies were 26.5% and 85.4%. The age group with the highest rotavirus test positivity was babies under one year old (27.3%), positivity rate was also high in children aged 1-2 years old (20.9%), and this distribution was similar for adenovirus. Although a small number of patients were tested in under five years of age, anti-HAV IgG seropositivity was 60% and above in all age groups. The highest anti-HAV IgM positivity rates were observed in children 2-&lt;5 and 5-15 years of age, 52.9% and 44% respectively. Rotavirus antigen positivity was found at high levels in the three-month period covering June, July, and August 2019. In July (2019), it was observed that the number of rotavirus and adenovirus antigen test requests were increased, and also, at the same time the highest positivity rates for both viruses were observed; 31.2% and 9.5% for rotavirus and adenovirus. Rotavirus and enteric adenovirus co-infection was detected in 2.4% (27/1136) of the patients, and 23 (85.2%) of these were under five years of age children. Our study results show that children under the age of two are especially affected by rotavirus and adenovirus infections in Somalia and indicate that HAV infections are acquired at an early childhood. We can say that it may be useful to review vaccination programs as an important public health measure to reduce the burden of mortality and morbidity associated with HAV and rotavirus, which have a high prevalence and also have protective vaccines.

The Seroprevalence of Hepatitis A in Patients with Positive Human Immunodeficiency Virus.

Background: Hepatitis A virus (HAV) can have severe manifestations in adult patients with other liver diseases, particularly in those infected with human immunodeficiency virus (HIV). This study aimed to measure immunity against HAV in HIV-positive individuals to determine the necessity of vaccination against HAV in this population. Methods: This cross-sectional study investigated 171 HIV-positive patients aged 18 years or older who were tested for serum IgG anti-viral hepatitis A antibody. The prevalence and its determinants were analyzed based on patient data. Results: The average age of the patients was 44.2 years old. The prevalence of HAV antibody positivity was 97.7%. The prevalence was higher in patients older than 30 years. There was a close association between hepatitis C virus (HCV) infection (P=0.002). There were no significant correlations between antibody levels and sex, marital status, employment status, education level, economic status, smoking status, drug use status, and physical activity level. The mean and median CD4+ counts in patients with positive (reactive) antibody (Ab) levels were 458 and 404±294, respectively, while the mean and median CD4+ counts in patients with non-reactive antibody levels were 806 and 737±137, respectively, in those who tested negative for anti-HAV Ab (P=0.05). Conclusion: The prevalence of anti-hepatitis A IgG antibodies in people with HIV was very high in Shiraz. There is an increasing trend in the number of older patients and those with HCV infections. The negative association with CD4 was borderline in this study, which needs to be confirmed in larger groups.

SEROPREVALENCE OF HELICOBACTER PYLORI AND HEPATITIS A VIRUS AMONG ORPHANAGE CHILDREN IN SANA’A, YEMEN

Background: The epidemiological association between Helicobacter pylori (H. pylori) and hepatitis A virus (HAV) has been evaluated by different groups with conflicting conclusions. Aims: The aim of this study was to determine the prevalence of hepatitis A virus and H. pylori infection among children of an orphanage in Sana'a, and to identify the socio-demographic factors associated with their prevalence, both individually and simultaneously. Methods: This is a cross-sectional study carried out among 200 orphaned children who lived at Ahmed's orphanage in Sana’a City, Yemen during the period from October 2022 to February 2023. The stool and blood specimens were collected and the required data were filled in pretested questionnaire. By using the immunochromatographic assay technique, the seropositivity of the HAV antibody was screened in blood plasma while the H. pylori antigen was detected in stool. The obtained results were analyzed using SPSS software. Results: Out of 200 participants; 2(1%) were positive for anti-HAV and 63(31.5%) for H. pylori antigen. The HAV and H. pylori infections, respectively, were significantly higher in the group aged 10-12 and 13-15 years, attending a primary and preparatory school, living with 3-5 individuals/room, their family infected with hepatitis A and H. pylori, and received a blood transfusion. The high risk of hepatitis A infection was in children who their family was infected by HAV and received a blood transfusion while H. pylori was in subjects who had a history of hospitalizations and whose family infected by H. pylori. Conclusion: The high number of children suffering from both H. pylori and HAV antibodies among orphans in Sana'a indicates a high prevalence rate in the community. It is possible that this high prevalence reflects a prevalence specific to this group or age, and this connection is real. Peer Review History: Received: 26 February 2023; Revised: 11 March; Accepted: 17 April 2023, Available online: 15 May 2023 Academic Editor: Dr. Muhammad Zahid Iqbal, AIMST University, Malaysia, drmmziqbal@gmail.com Received file: Reviewer's Comments: Average Peer review marks at initial stage: 5.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Bilge Ahsen KARA, Ankara Gazi Mustafa Kemal Hospital, Turkey, ahsndkyc@gmail.com Prof. Hassan A.H. Al-Shamahy, Sana'a University, Yemen, shmahe@yemen.net.ye

Seroprevalence of hepatitis Antibodies in patients with cirrhosis of liver

Background and Aim: Patients with cirrhosis have a compromised immune system and are at increased risk of infections, including Hepatitis A virus (HAV). Acute HAV infection in patients with chronic liver disease/ cirrhosis can result in acute-on-chronic liver failure, which is associated with high mortality. Several Indian studies in the past have noted that 93.2%-99% patients with chronic liver disease or cirrhosis had evidence of past infection with HAV. We aimed to determine the seroprevalence of antibodies against HAV in adult patients with cirrhosis of liver. Methods: The study cohort included all patients (>18 years) with cirrhosis of liver seen by the author between May 2019 to December 2021. Diagnosis of cirrhosis was based on clinical, endoscopic, biochemical and radiological parameters. Patients with age <18 years and those who did not provide consent for testing were excluded. IgG anti HAV antibodies were tested using chemiluminescent magnetic microparticle immunoassay (CMIA) test. A value equal or greater than 1 was taken as reactive /positive. Results: A total of 548 adult patients with cirrhosis were seen during the study period. Three huned forty-nine consented to participate in the study. The median age of the study cohort was 43 (18-68 years) and 66.7 % (233) were males. The etiology for cirrhosis of liver included alcohol (210, 60.2%), hepatitis B (58, 16.7%), hepatitis C (11, 3.15%), non alcoholic steatophepatitis (51,14.6%) and others (10, 2.9%). Ig G anti HAV antibodies were detected in 238 (68.2%) cases. Conclusions: The results highlight that seroprevalence of anti HAV antibodies in cirrhotic patients is 68.2% which is much lower than previously reported in Indian studies.

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.

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.

Role of hepatitis A virus in diabetes mellitus.

BACKGROUNDAlthough much information is available regarding hepatitis C virus infection and diabetes, less is known about the relationship between hepatitis A virus (HAV) infection and diabetes. AIMTo examine the roles of HAV in diabetes risk.METHODSThis cross-sectional study population included data from the National Health and Nutrition Examination Survey collected between 2005-2012. Adult subjects (≥ 20 years old) with available body mass index measurements, defined diabetes status, history of HAV vaccination, and HAV serology were included. HAV vaccination was based on self-reported history. Successful HAV immunization was defined as the presence of both vaccination and anti-HAV antibody. HAV infection was defined by the absence of vaccination but presence of anti-hepatitis A antibody. The odds ratio (OR) for diabetes with 95% confidence intervals (95%CI) was calculated for each HAV status and then adjusted for covariates. Sensitivity tests, based on different definitions of diabetes, were performed to verify the results. RESULTSAmong 19942 subjects, 4229 subjects (21.21%) received HAV vaccination and HAV antibody was present in 9224 subjects (46.25%). Although HAV infection was associated with an increased risk of diabetes (OR: 1.13; 95%CI: 1.08-1.18), HAV vaccination was not associated with diabetes (OR: 1.06; 95%CI: 0.95-1.18), and successful HAV immunization had no impact on the risk of diabetes (OR: 1.11; 95%CI: 0.97-1.27). Thus, HAV infection was an unlikely cause of diabetes. Alternatively, in non-vaccinated subjects, diabetes increased the risk of HAV infection by 40% (OR: 1.40, 95%CI: 1.27-1.54). CONCLUSIONAn association between HAV infection and diabetes is observed which is best explained by an increased risk of HAV infection in diabetic patients. Diabetic subjects are more susceptible to HAV. Thus, HAV vaccination is highly recommended in diabetic patients.

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.

Prevalece of Hepatitis A Virus in Libian Children

Hepatitis A virus (HAV) is the most hepatotropic. This virus is responsible for the most forms of acute and benign hepatitis although fulminant hepatic failure can occur in 1% more often in adults. It is a member of Picornaviridae famil, it is a heat stable and has limited host range. The incidence of infection by Hepatitis A virus shows regional variation being highest in developing countries. Determination of age specific Hepatitis A virus (HAV) seroprevalence and the associated risk factors would help better plan for national preventive strategies including vaccination. We carried out a cross-sectional study on 315 children from Tripoli and Gharian cities in Libya during the years 2018-2020. The age range of the patients was 1-18 years and were from different socioeconomic status (SES) families.....attending teaching hospitals casualty seeking medical help and checkup. The indicators of SES included employment status, residence, number of family members, source of drinking water and social status. Serum samples were collected and investigated for HAV antibodies. The data were statistically analyzed. HAV antibodies were positive in 113 patients (36%) Males were 161(53%) while Females were 154 (49%). HAV antibodies was significantly higher among children of low SES,60 % by the age of 18 years compared to children of high SES, 35% by the same age. Crowded household and parental education were significantly associated with high seropositivity and seronegativity respectively. There is significant rate of seronegativity amongst the studied population especially those from richer backgrounds making them more susceptible to severe infection in future with concomitant complications. We propose that revision of national vaccination program should be considered to include Hepatitis A vaccination

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

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. 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 4years of age, 70% at 10years, and 90% at 59years; incidence was 52/100,000 and peaked at 4years. In 2006, after >10years of private sector vaccination, HepA coverage was <30% among children <5years, and incidence was 5.4/100,000 with a peak at 10years. In 2014, coverage was >90% among children under 5years; 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. 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.

Susceptibility to Hepatitis A Virus Infection in the United States, 2007-2016.

Despite national immunization efforts, including universal childhood hepatitis A (HepA) vaccination recommendations in 2006, hepatitis A virus (HAV)-associated outbreaks have increased in the United States. Unvaccinated or previously uninfected persons are susceptible to HAV infection, yet the susceptibility in the US population is not well known. Using National Health and Nutrition Examination Survey 2007-2016 data, we estimated HAV susceptibility prevalence (total HAV antibody negative) among persons aged ≥2 years. Among US-born adults aged ≥20 years, we examined prevalence, predictors, and age-adjusted trends of HAV susceptibility by sociodemographic characteristics. We assessed HAV susceptibility and self-reported nonvaccination to HepA among risk groups and the "immunization cohort" (those born in or after 2004). Among US-born adults aged ≥20 years, HAV susceptibility prevalence was 74.1% (95% confidence interval, 72.9-75.3%) during 2007-2016. Predictors of HAV susceptibility were age group 30-49 years, non-Hispanic white/black, 130% above the poverty level, and no health insurance. Prevalences of HAV susceptibility and nonvaccination to HepA, respectively, were 72.9% and 73.1% among persons who reported injection drug use, 67.5% and 65.2% among men who had sex with men, 55.2% and 75.1% among persons with hepatitis B or hepatitis C, and 22.6% and 25.9% among the immunization cohort. Susceptibility and nonvaccination decreased over time among the immunization cohort but remained stable among risk groups. During 2007-2016, approximately three-fourths of US-born adults remained HAV susceptible. Enhanced vaccination efforts are critically needed, particularly targeting adults at highest risk for HAV infection, to mitigate the current outbreaks.

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.

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.

Serological Evidence and Risk Factors of Hepatitis A Virus among Blood Donors in 3 Tertiary Hospitals in Sokoto, Nigeria

Background and study aim: Globally, Hepatitis-A Virus (HAV) is a major etiology of acute hepatitis. Though, enterically transmitted, there is evidence HAV being transmitted through of blood transfusion. The presence of HAV antibodies may indicate infectious threat to blood transfusion safety. In view of these, the present study was aimed to determine the seroprevalence and associated risk factors of HAV among blood donors in three tertiary Hospitals in Sokoto State, Nigeria. Materials and Methods: Blood samples were collected from one hundred and sixty eight (168) blood donors >20 years. Sera from these samples were investigated for anti-HAV specific IgG and IgM antibodies using a commercial enzyme immunosorbent assay (ELISA) Kits. Structured question-naires were used to access socio-demographic variables of subjects. Results: Seroprevalence of HAV- specific IgG and IgM were 86.3.1% and 0.0%, respectively. Of 168 blood donors, 145 had previous exposure to HAV [IgG (+) IgM (-), and none had recent infection [IgG (-) IgM (+)], 23 were susceptible to HAV [IgG (-) IgM (-). There was no significant association between sero-prevalence and any of the risk factors and sociodemographic variables studied (p>0.05). Findings from this study revealed that larger proportion of blood donors are already immune to HAV infection, while none of them had active HAV infection. Conclusion: The high prevalence of Hepatitis A antibodies among the studied subject reflects a high HAV transmission rate in this area. Hence, determination of HAV should be taken into consideration before blood transfusion.