Differences in hepatitis A seroprevalence among geographical regions in Turkey: a need for regional vaccination recommendations

A review of the experience of childhood hepatitis A vaccination in Saudi Arabia and Turkey: implications for hepatitis A control and prevention in the Middle East and North African region

In most countries of the Middle East and Northern African (MENA) region, a high hepatitis A virus (HAV) endemicity has been documented. Few others, such as Saudi Arabia and Turkey, are transitioning from high to intermediate endemicity. There is a paucity of recently published HAV disease burden that could be useful to inform or strengthen relevant national hepatitis A vaccination policy and other prevention strategies in the region. This review summarizes information on HAV epidemiology before and after the implementation of a childhood hepatitis A vaccination program in Saudi Arabia and Turkey. In both countries, a clear shift in the age of first HAV exposure has been documented, with more homogeneous trends across regions in Saudi Arabia compared to Turkey. Utilizing the experience of Saudi Arabia and Turkey with hepatitis A vaccination, countries in the region are encouraged to foster discussions on potential vaccination strategies suitable for their own setting.

Hepatitis A virus age-specific seroprevalence after the implementation of a Toddlers' Vaccination in Turkey: Shifting susceptibility to adolescents

Aim:

In Turkey, improvements in sanitation and the implementation of a vaccination program resulted in reduced rates of childhood exposure to hepatitis A virus. The incidence of symptoms and the complications of the disease are known to be increased in later ages. We aimed to describe changes in the seroprevalence of hepatitis A virus from the pre-vaccine era (2012) to the post-vaccine era (2018) in different age groups.

Material and Methods:

Levels of anti-hepatitis A virus immunoglobulin (Ig)-G of patients with no chronic disease and who were admitted to our hospital between 2013–2018 were obtained retrospectively from a single children’s hospital database system.

Results:

A total of 3238 subjects were enrolled in the study (2820 children, 418 adults). The overall percentage of seropositivity was 60.5% in group 1 (age ≤2 years), 57.9% in group 2 (age 2–6 years), 31.2% in group 3 (age 7–11 years), 32.7% in group 4 (age 12–18 years), 44.6% in group 5 (age 19–24 years), and 73.9% in group 6 (age >25 years). Between 2013–2018, the increase in the number of seropositive individuals in group 2 (p<0.01), and the decrease in groups 3 and 4 were statistically significant from 2013 to 2018 (p=0.028, p<0.01).

Conclusion:

According to the data of this single-center children’s hospital in Turkey, hepatitis A virus seropositivity increases significantly in the preschool age group, but decreases in school-age children and adolescents after vaccination.

Hepatitis A immunity in Yozgat, Turkey

BACKGROUND

Since routine immunization could change the epidemiological profile of hepatitis A virus (HAV) infection in the future, it is important to determine the baseline immunity to HAV across Turkey.

OBJECTIVE

The aim of this study was to determine the seroprevalence of hepatitis A among individuals 6 years of age and older in Yozgat, Turkey.

DESIGN

Cross-sectional.

SETTING

Community in central region of Turkey.

PATIENTS AND METHODS

Questionnaires and blood specimens were collected and the presence of hepatitis A IgG antibodies against hepatitis A virus was determined quantitatively by ELISA.

MAIN OUTCOME MEASURES

The rates of hepatitis A immunity by age group.

SAMPLE SIZE

1862.

RESULTS

Immunity to hepatitis A was 79.1% (n=1473). The mean (SD) age was 17.1 (14.7) years in the nonimmune group and 37.8 (19.5) years in the immune group (P less than .001), and immunity increased with age. No significant difference in immunity rate was detected between gen.ders in children and adults. The seropositivity rate for subjects ages 6-19 years was lower than in subjects aged 20-96 years (52.2% versus 93.9%; P less than .001).

CONCLUSION

A catch-up vaccination program is needed for persons aged 6-19 years in Yozgat.

LIMITATIONS

Single region data which can not be generalized. For this reason, a multi-centered study that can reflect the whole country is recommended.

CONFLICT OF INTEREST

None.

Determining the persistence of maternally acquired antibodies to hepatitis A and varicella zoster during the first 2 years of life in Turkey

Vaccination should be timed to take into account the potential interference of maternal antibodies. The purpose of this study was to determine the persistence of maternally acquired antibodies to hepatitis A and varicella zoster in a group of healthy infants between 6 and 24 months of age. These infants were divided into four groups according to the age at the time of follow-up visits. The study group consisted of infants who were brought to the 6-month follow-up visit (group 1, n=100), 12-month follow-up visit (group 2, n=99), 18-month follow-up visit (group 3, n=59), and 24-month follow-up visit (group 4, n=59). Hepatitis A, varicella IgG, and IgM antibodies were analyzed qualitatively. Hepatitis A IgG seropositivity was determined as 71 % in group 1, 41.4 % in group 2, 0 % in group 3, and 8.5 % in group 4 (p<0.001). Varicella IgG seropositivity was found to be 5 % in group 1, 4 % in group 2, 4 % in group 3, and 1 % in group 4 (p>0.05).

CONCLUSION

We found that maternal hepatitis A antibodies in children disappear between 12 and 18 months, whereas maternal varicella antibodies substantially diminish following the sixth month. Therefore, the vaccination timing should be based on factors such as the interference of maternal antibodies, disease susceptibility period, and immune maturation.

Molecular epidemiology of hepatitis A virus infection in Northeast India

The present study was undertaken to screen the molecular epidemiology of Hepatitis A virus (HAV) in Northeast India (NEI) who are ethnically distinct, tribal dominated and of lower socio-economic status with almost no information available from NEI on these aspects. Briefly, 3 ml blood was collected from 324 random liver disease cases with jaundice, receiving care at Central Hospital, N.F. Railway, Guwahati, Assam with informed consent. The patients detected with HAV-IgM positive status were included and were stratified as acute viral hepatitis (AVH) and fulminant hepatitis (FHF) based on clinical profile. Viral RNA was isolated and HAV-RNA was detected by Real-time PCR using primers for the VP3-VP1 region. HAV genotyping was studied by PCR-direct sequencing-phylogenetic analysis approach using the VP1/2A region of HAV isolates. Statistical analysis was performed using SPSS13.0 software. A total of 69 cases were HAV infected with two HBV co-infected cases (n = 69 + 2 = 71), 62 cases and two co-infected cases were AVH and others were FHF cases. HAV infection was predominant in especially in the young and adult age group. HAV-RNA was detected in 28 cases, out of which 19 cases could be genotyped (12 AVH, 7 FHF); which showed the prevalence of genotype IIIA or IA only. Although HAV genotype IIIA was the major genotype in both the AVH (10/12, 83.33%) and FHF (5/7, 71.43%) group, but the difference in distribution of genotypes in AVH and FHF cases was statistically non-significant (P = 0.550). HAV genotype IIIA is associated with the majority of HAV infected cases and severity in NEI.

Hepatitis A virus in the Middle East and North Africa region: a new challenge

During the past three decades, a gradual shift in the age of infection with hepatitis A virus (HAV) from early childhood to adulthood has been observed. There is a general lack of updated data on HAV burden of disease, incidence and age-specific seroprevalence in countries of the Middle East and North Africa (MENA) region. The aim of this article is to review the published data on anti-HAV seroprevalence, an important tool to monitor infections rates, in countries of the MENA region and associated risk factors including water and socioeconomic data when available. Data on anti-HAV seroprevalence were found for 12 of 25 MENA countries. We show that MENA countries, similar to other areas in the world, have a clear shift in HAV incidence with a decline among young age groups and an increase among adults and older individuals. This would likely be associated with increased morbidity and increased risks of outbreaks among younger age groups. Consequently, the continuous surveillance of hepatitis A cases and the inclusion of hepatitis A vaccine in the expanded immunization programmes are needed in countries of the MENA.

Prevalence of hepatitis A antibodies in Eastern Bolivia: a population-based study

The seroprevalence of hepatitis A virus (HAV) is changing from high to intermediate endemicity in several Latin American countries, but the pattern in the Andean Latin American countries is unknown. A seroepidemiological survey (n = 436) of HAV in schoolchildren living in the Cochabamba region of Bolivia was conducted in 2010. A questionnaire was completed by parents to obtain demographic, socio-economic, and housing data, and blood samples were collected. The overall prevalence of HAV IgG was 95.4% (95% CI 93.5-97.4). The prevalence was higher in children aged 5-10 years (97%) and pre-adolescents aged 10-13 years (97.9%). The prevalence was also higher in subjects whose parents had a low level of education (99.4-99.5%), who lived in rural areas (98.7%), lived in municipalities with low urban development (99.1-100%), had water delivered at home from a tanker (99.4%), and spoke Quechua at home (99.5%). The descriptive and bivariate analysis suggested that no change in HAV epidemiology has occurred in Cochabamba.

Seroprevalence of hepatitis A virus antibody in a population aged 0-30 years in Shanghai, China: implications for hepatitis A immunization

This study aimed to determine current seroprevalence of hepatitis A virus (HAV) antibody in subjects aged 0-30 years in Shanghai. A total of 5515 subjects were recruited through random clustering sampling in 2009. Basic clinical and demographic information and records of HAV vaccination were acquired by questionnaire interviews and review of immunization records. Serum samples were collected and tested for anti-HAV IgM and total anti-HAV. The overall seroprevalence of total anti-HAV was 52·9%. Subjects aged 20-24 years had the lowest (34·4%) anti-HAV seropositivity and subjects aged 5-9 years had the highest (74·6%) positivity. Seroprevalence was significantly greater in subjects from suburban areas than in subjects from urban areas. Subjects who had HAV immunizations had significantly greater seropositivity for total anti-HAV. Previous hepatitis A immunization policies had a significant impact on the presence of anti-HAV seroprevalence in a population aged 0-30 years from Shanghai.

Epidemiological and serological aspects of hepatitis A among children and teenagers in the city of Santos: a cross-sectional study

CONTEXT AND OBJECTIVE

Viral hepatitis A is still a concern at public health level in Brazil and around the world, due both to the number of affected subjects and the possibility of complications in the acute forms. The Brazilian Ministry of Health estimates that at least 70% of this country's population has already had contact with the hepatitis A virus (HAV). The aim here was to discover the prevalence of serological markers for the hepatitis A virus among children and teenagers at daycare facilities, kindergartens and elementary schools in the city of Santos.

DESIGN AND SETTING

Cross-sectional study in kindergartens and elementary schools within the municipal education network in several regions of the city of Santos.

METHOD

Students' family members were surveyed using a questionnaire and 4,680 finger-prick blood samples were taken and assayed by means of the ELISA technique.

RESULTS

The general prevalence of anti-HAV IgG was 9.72% and, of these cases, 74.6% were reactive to anti-HAV IgM. There was higher prevalence of anti-HAV IgG among older children, females, children who played in streams, those whose homes were not connected to the sewage system, those whose parents had low education levels, those with low household income and those who did not live along the seashore. The prevalence of anti-HAV IgM peaked in the early years and subsequently fell, and it was lower on the hills and in the Northwestern Zone.

CONCLUSION

The general prevalence of serological markers for hepatitis A was low in Santos.

Changing epidemiology of hepatitis A infection in Izmir, Turkey

The seroprevalence study was conducted in order to determine the current seroepidemiology hepatitis A in Izmir, Turkey and to evaluate the epidemiological shift in HAV serostatus. Blood samples collected from 595 subjects aged 1-60 years were analyzed for anti-HAV IgG antibodies. The current study results were compared with those of a previous study conducted in 1998 involving the same location. There was a marked decrease in the prevalence of anti-HAV between 1998 and 2008. While anti-HAV seroprevalence rates in the current study were 4.6% in children aged 1-4 years, 23% in children aged 10-14 years, and 85% in young adults aged 20-29 years, the prevalence rates were 36% in the 1-4 years age group, 65% in the 10-14 years age group, and 95% in young adults in the previous study, indicating a shift in HAV seroprevalence from the younger to the higher age groups. As HAV infection in childhood is decreasing, the pool of susceptible adolescents and young adults is increasing in Izmir, Turkey. The majority of adolescent population is susceptible to HAV infection. The potential risk of HAV epidemics still exists. The situation of Turkey, suggested to need for mass immunization. Also, introduction of hepatitis A vaccination into the national immunization schedule of Turkey should be considered.

Role of CYP2E1 gene polymorphisms association with hepatitis risk in Northeast India

AIM

To investigate hepatitis virus, genetic and environmental factors, and their interactions in predisposing patients to liver diseases in Northeast India.

METHODS

A total of 104 jaundice patients and 124 community controls were included. Serological analysis was performed by routine enzyme-linked immunosorbent assay, and nucleic acid testing for hepatitis viruses was done by polymerase chain reaction (PCR), followed by PCR direct sequencing for viral genotyping. Cytochrome P450 2E1 (CYP2E1) polymorphism was studied by PCR-restriction fragment length polymorphism. Nitrite and volatile nitrosamines in indigenous foods consumed routinely by the Northeast Indian ethnic population were estimated by Griess's reagent and GC-MS, respectively.

RESULTS

Hepatitis A virus (HAV) infection was predominantly prevalent (36.5%) in our cohort, followed by hepatitis B virus (HBV), hepatitis E virus (HEV) and hepatitis C virus. HBV genotype D and HEV genotype 1 were the most dominant. CYP2E1 c1/c2 genotype frequency was comparatively higher in alcoholic (P < 0.0001, OR = 30.5) and cryptogenic (P = 0.014, OR = 8.714) patients, and was associated with significantly higher hepatitis risk (P = 0.0.007, OR = 6.489). Mutant C allele of Cyp2E1 DraI frequency was comparatively higher in HAV (P = 0.006), alcoholic (P = 0.003) and cryptogenic (P = 0.014) cases, and was associated with overall hepatitis risk (P = 0.026, OR = 5.083). Indigenous foods, Gundruk, Kharoli, betel leaf and nuts were found to have the highest nitrite content.

CONCLUSION

Apart from viral factors, CYP2E1 polymorphism might be associated with increased risk of liver diseases in Northeast India. Indigenous foods that contain nitrite and nitrosamine might be an associated risk factor.

Hepatitis A virus seroprevalence by age and world region, 1990 and 2005

OBJECTIVE

To estimate current age-specific rates of immunity to hepatitis A virus (HAV) in world regions by conducting a systematic review and meta-analysis of published data. The estimation of the global burden of hepatitis A and policies for public health control are dependent on an understanding of the changing epidemiology of this viral infection.

METHODS

Age-specific IgG anti-HAV seroprevalence data from more than 500 published articles were pooled and used to fit estimated age-seroprevalence curves in 1990 and 2005 for each of 21 world regions (as defined by the Global Burden of Disease 2010 Study).

FINDINGS

High-income regions (Western Europe, Australia, New Zealand, Canada, the United States, Japan, the Republic of Korea, and Singapore) have very low HAV endemicity levels and a high proportion of susceptible adults, low-income regions (sub-Saharan Africa and parts of South Asia) have high endemicity levels and almost no susceptible adolescents and adults, and most middle-income regions have a mix of intermediate and low endemicity levels.

CONCLUSION

Anti-HAV prevalence estimates in this analysis suggest that middle-income regions in Asia, Latin America, Eastern Europe, and the Middle East currently have an intermediate or low level of endemicity. The countries in these regions may have an increasing burden of disease from hepatitis A, and may benefit from new or expanded vaccination programs.

Epidemiology of hepatitis A virus infections, Germany, 2007-2008

Communicating vaccination recommendations may help reduce infections.