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.     

HAV and HEV infection in hospitalised hepatitis patients in Alexandria, Egypt

A total of 202 serum and stool samples from acute hepatitis patients attending the Fever Hospital of Alexandria, Egypt, have been studied to reveal markers of hepatitis virus infection. Anti-HAV IgM were detected in 21 out of 202 sera (10.4%), whereas 201 sera (99.5%) had anti-HAV IgG. The first age attack was in the class-age 0–9 years with 64.7% of anti-HAV IgM positive sera. Among 202 patients, anti-hepatitis E IgG (sample/over cut off>1.0) was identified in 90 patients (44.5%). The anti-HEV seropositivity ranged from 17.6% to 60.0% in the different age groups, with the highest level in the class-age 20–29 years. Anti-hepatitis E IgM were identified in 49 patients with the first age attack in the class-age 10–19 years (39.4%). HAV RNA was identified by nested PCR in 7 samples out of 15, whereas HEV RNA was present in 4 out of 75 stool samples. Direct DNA sequence of the latter PCR products confirmed the presence of the HEV genome; comparison of the sequences of the isolates from Egypt with those in data banks revealed the highest homology to the Burma strain. Our data confirm that HAV and HEV are common causes of acute sporadic hepatitis in Alexandria but with different peak age positivity. Occasionally, but not infrequently, dual infections (HAV–HEV and HEV-enteric viruses) were also found. The risk analysis indicates that patients living in rural areas are exposed to a higher risk of hepatitis E infection compared to the urban population, whereas the presence of anti-HEV IgG was significantly associated with consumption of common village water and use of indoor dry pit and oral therapy for schistosomiasis.     

Age-specific seroprevalence of hepatitis A infection among children visited in pediatric hospitals of Tehran, Iran

BACKGROUND: Hepatitis A is an enterically transmitted disease that still remains endemic in many developing countries. In some countries improvements in living conditions have recently led to changing in epidemiology of hepatitis A virus (HAV) infection. In our country there are very few reports on prevalence of HAV infection. OBJECTIVE: To determine the seroprevalence of anti-HAV IgG among children visited in pediatric hospitals of Tehran, Iran. METHODS: The study group included 1018 children who were 6 months-14.9 years of age. These children were visited in four major pediatric hospitals of Tehran. The children were separated to three age groups: Group 1 (6 months-4.9 years; n = 469), Group 2 (5.0-9.9 years; n = 290), and Group 3 (10.0-14.9 years; n = 259). Serum anti-HAV IgG was tested with commercial ELISA kits. The data were tested for statistical significance with chi2 test. RESULTS: In all subjects, seroprevalence of hepatitis A was 22.3% (95% CI: 19.7, 24.9). There was no significant difference between genders (22.2% vs. 22.5% in males and females, respectively) and among age groups (Group I was 22.1% and Group 3 was 25.9; p > 0.05). CONCLUSIONS: In summary, it seems that HAV infection is not highly endemic at least in some urban areas of Iran. On the basis of this epidemiologic data, post exposure prophylaxis would be necessary for children and young adults, and hepatitis A vaccination strategy should be revised.     

Hepatitis A virus infection in the United States: serologic results from the Third National Health and Nutrition Examination Survey

To determine the prevalence of hepatitis A virus (HAV) infection in the general U.S. population, sera from participants in the Third National Health and Nutrition Examination Survey (NHANES III) conducted in 1988–1994 were tested for antibody to HAV (anti-HAV). Among 21,260 participants aged ≥6 years tested, the overall prevalence of infection was 31.3%, and increased markedly with age. The age-adjusted prevalence was significantly higher among foreign- compared to U.S.-born participants, and was highest among Mexican-Americans and lowest among non-Hispanic whites. Among U.S.-born children, only Mexican-American ethnicity and income below the poverty level were associated with HAV infection in a multivariate model. During this period before hepatitis A vaccination, age, ethnicity and birthplace were the most important determinants of HAV infection in the United States.     

Seroprevalence of Hepatitis A and E Viruses Based on the Third Korea National Health and Nutrition Survey in Korea

Objectives

The purpose of this study was to investigate the seroprevalence of hepatitis A virus (HAV) and hepatitis E virus (HEV) in Korea during 2005.

Methods

Study subjects were selected from across Korea using a stratified multistage probability sampling design, and HAV and HEV seroprevalence was compared on the basis of sex, age, and residency. A total of 497 rural and urban people aged 10–99 years of age (mean ± SD age = 28.87 ± 17.63 years) were selected by two-stage cluster sampling and tested serologically for anti-HAV and anti-HEV IgG using an enzyme-linked immunosorbent assay.

Results

Among this population, the overall seroprevalence of HAV was 63.80% (55.21% aged in their 20s and 95.92% in their 30s, p < 0.01) and that of HEV was 9.40% (5.21% aged in their 20s and 7.14% in their 30s, p < 0.01). Seroprevalence also varied according to area of residence. HEV prevalence in rural areas was higher than that of urban regions based on the anti-HEV antibody, odds ratio 3.22 (95% confidence interval: 1.46–7.10, p < 0.01). There were no significant differences between male and female against anti-HAV/HEV antibodies.

Conclusion

Our study suggested that the seropositive rates of HAV and HEV might be related to age and environmental conditions.     

Age-specific seroepidemiology of hepatitis A, B, and E infections among children in Istanbul, Turkey

This study was performed for evaluation of seroprevalence of hepatitis A, B, and E among children in Istanbul, Turkey. The study group included 909 children who were 6 months–15 years of age. The children were separated to three age groups: Group 1 (6 months–4.9 years; n = 321), Group 2 (5.0–9.9 years; n = 318), and Group 3 (10.0–15.0 years; n = 270). Group 1 was divided to two subgroups for evaluation of the maternal antibody sera (6 months–2 years and over 2 years). Serum IgG anti-HAV, anti-HBc, and anti-HEV were tested by commercial ELISA kits. The data were studied by multivariant analysis. In all subjects, seroprevalence of hepatitis A, B, and E were determined as 29, 15.9, and 2.1% respectively. The prevalence of hepatitis A increased with age (p < 0.05; Group 1 15.1% and Group 3 49.6%). Anti-HBc IgG level did not significantly change with age (Group 1 18.6% and Group 3 15.4%; p > 0.05). The seroprevalence of hepatitis E virus infection was higher in Group 1 (3.7%) than Group 3 (0.3%; p < 0.05). In Group 1 first subgroup, between 6 month and 2 year, antibody levels were 12.2, 17.3, and 4.8% respectively, for anti-HAV IgG, anti-HBc IgG and anti-HEV IgG. Hepatitis A and B infection is a community health problem, but hepatitis E infection is low in children in Istanbul, Turkey. The high positive rate in Group 1 for IgG anti-HEV may be due to maternal antibodies.     

Decreasing immunity to hepatitis A virus infection among US adults: Findings from the National Health and Nutrition Examination Survey (NHANES), 1999–2012

BackgroundThe clinical course of hepatitis A virus (HAV) infection is more severe with increased age. In the United States, surveillance data reported to CDC since 2011 indicate increases in both the absolute number of cases and the mean age of cases. Total antibody to HAV (anti-HAV) is a marker of immunity.MethodsWe analyzed National Health and Nutrition Examination Survey (NHANES) data for anti-HAV from respondents aged ≥2 years collected from 2007 to 2012 and compared with data collected 10 years earlier (1999–2006). For US-born adults aged ≥20 years, we estimated age-adjusted anti-HAV prevalence by demographic and other characteristics, evaluated factors associated with anti-HAV positivity and examined anti-HAV prevalence by decade of birth.ResultsThe prevalence of anti-HAV among adults aged ≥20 years was 24.2% (95% CI 22.5–25.9) during 2007–2012, a significant decline from 29.5% (95% CI 28.0–31.1) during 1999–2006. Prevalence of anti-HAV was consistently lower in 2007–2012 compared to 1999–2006 by all characteristics examined. In 2007–2012, the lowest age-specific prevalence was among adults aged 30–49 years (16.1–17.6%). Factors significantly associated with anti-HAV positivity among adults were older age, Mexican American ethnicity, living below poverty, less education, and not having insurance. By decade of birth, the prevalence of anti-HAV was slightly lower in 2009–2012 than in 1999–2002, except among persons born from 1980 to 1989.ConclusionsNHANES data document very low prevalence of hepatitis A immunity among U.S. adults aged 30–49 years; waning of anti-HAV over time may be minimal. Improving vaccination coverage among susceptible adults should be considered.     

Seroepidemiology of hepatitis A and E virus infections in Tehran, Iran: a population based study

Hepatitis A virus (HAV) and hepatitis E virus (HEV) are enteric hepatotropic viruses and their prevalence is related to the sanitary conditions of the region under investigation. There are only a few studies on the seroepidemiology of these two viruses in the general Iranian population. The purpose of this investigation was to measure the prevalence of hepatitis A and E infections in the general population. Between 2006 and 2007, a cross sectional study was performed in Tehran, Iran. Blood specimens were collected and questionnaires were filled in for 551 persons. Patient sera were tested by ELISA for anti-HEV and anti-HAV IgGs. The χ(2) test and independent t-test were used for statistical analysis and p<0.05 was considered significant. The overall seroprevalence rates of anti-HEV IgG and anti-HAV IgG were 9.3% and 90%, respectively. The prevalence of antibodies to HAV and HEV was greater among men than women and increased with age. However, there was no significant relationship between age and gender with the existence of anti- HAV and HEV IgG antibodies. Our results show the seroprevalence of HAV and HEV antibodies are high and both viruses are endemic in this region. These findings are in accordance with results obtained from previous studies. We recommend that foreign travelers to Iran are vaccinated against HAV.     

Seroprevalence of viral hepatitis A in the Czech Republic

Over recent decades, the epidemiology of hepatitis A has changed in most European countries: the age of infection has been shifting towards older age groups. In view of this evolution and the central location of the Czech Republic in Europe, we wanted to assess current anti-hepatitis A seroprevalence. We determined the anti-hepatitis A seroprevalence among three different groups: military personnel between 1991–1995, prior to their deployment as UN troops, civilians participating in a national serological survey in 1996 and volunteers for vaccine clinical trials in 1996. The anti-HAV prevalence <20 years of age was about 4%; in the age cohort 40–49 it ranged between 47 and 51%. Only over the age of 60 years was the seroprevalence rate >85%. The risk of acquiring HAV is low for younger age groups. We could demonstrate some regional differences with higher rates in some age strata for the North Bohemian region and the lowest rates in East Bohemia and Prague. Compared to archived sera from a previous serological survey in 1984 we demonstrate a shift towards low endemicity. For the first time it is shown that an Eastern European country, i.e. the Czech Republic, is a country with a low endemicity for HAV. Substantial parts of the population are or will be at an increased risk of HAV infection and active immunisation against HAV should be considered.     

Prevalence of hepatitis virus infections in Albanian refugees

A sample of 393 Albanian refugees, including both children and adults, was tested for serological HAV, HBV, HDV and HCV markers. A high prevalence of infection with both the hepatitis A and B viruses was found, while HDV and HCV infections were uncommon. The overall prevalence of anti-HAV was 96%; it was very high in children 0-10 years, suggesting that HAV infection is largely acquired during childhood and that poor ambiental conditions influence the spreading of this viral infection.One or more serological markers of HBV infection were found in 295 Albanians (75%), confirming the endemic nature of this virus in the Albanian community. The overall prevalence of HBsAg was 19%, and the carrier rate was higher in males than in females. The high HBsAg prevalence among children suggests that HBV infection is usually acquired in early childhood.The serological data obtained in the Albanian sample examined clearly indicate the urgent need for measures to reduce the incidence of HAV and HBV infections and to avoid the further spread of HDV and HCV infections.Finally, the high prevalence of type B hepatitis indicates the necessity of vaccination against HBV for all risk groups and for all children at birth.     

Hepatitis A infection: A seroepidemiological study in young adults in North-East Italy

During the period from January to May 1994, the prevalence of antibodies to hepatitis A virus infection (anti-HAV) was tested by immunoenzyme assay in the serum samples of 620 apparently healthy subjects (81% males, 19% females), from 10 to 29 years old, resident in North-East Italy (Pordenone and surrounding district). The overall prevalence of anti-HAV was 3.7%. There was a significant lower prevalence in the group aged 10-19 than in the one aged 20–29 years (0.7% vs 6%; p < 0.001). Moreover, a significant sex difference was observed for the 20–29 year age group (p < 0.001). Among the various risk factors considered, family size and travelling abroad to endemic areas were significantly associated with HAV infection. Since a valid and effective vaccine against HAV infection has recently become available, anti-HAV vaccination campaigns can feasibly be programmed. However, different geographical regions present different epidemiological situations, so its use should be adapted to each region, with special attention to the cost-effectiveness of the immunisation programme. Our data suggest that in our region such vaccination could initially be proposed to high-risk subjects such as those travelling to endemic areas.     

Seroepidemiology of hepatitis A in voluntary blood donors from Pune, western India (2002 and 2004-2005)

Recently, a changing pattern of hepatitis A epidemiology has been reported in the Indian population indicating a rise in the rate of hepatitis A infection among adults. The study's objective was to assess anti-HAV prevalence in voluntary blood donors from middle and high socioeconomic strata. Serum samples collected from voluntary blood donors from Pune city and its suburbs in the years 2002 and 2004-2005 were tested for anti-HAV IgG antibodies. Serum samples collected during 2004-2005 were examined for anti-HAV IgM antibodies. Positive samples were tested for HAV-RNA. Agewise anti-HAV positivity was significantly low in adults aged 18-25 years (90.4%) compared to those aged >25 years (97.4%) (P<0.01). A decline in anti-HAV prevalence was significant in 2004-2005 compared to that in 2002 (96.5% vs. 92.1%) (P<0.01). Overall, in both adult age groups, the proportion of anti-HAV positivity was remarkably low in the high socioeconomic group (HSG) (88.96%) compared to that of the middle socioeconomic group (MSG) (95.86%) (P<0.01). Anti-HAV IgM positivity was not significant (~1%), however, presence of HAV-RNA in one of the samples indicated the possibility of horizontal transmission of HAV. Increase in seronegativity to HAV in HSG implicates a rise in the susceptible pool and indicates the need for vaccination against hepatitis A.     

Seroepidemiology of Hepatitis A Infection in Northeastern China,Korea, and Japan

ObjectivesThe epidemiological patterns of endemic hepatitis A virus (HAV) are unclear in northeastern Asia depending on the ethnicity of the country in question. The purpose of this study was to investigate the seroprevalence of HAV in northeastern China, South Korea, and Japan.MethodsA total of 1,500 serum samples were collected from five groups of inhabitants (300 each) who were over 40 years of age (Korean Chinese, indigenous Chinese, South Korean, Korean living in Japan, and indigenous Japanese). The samples were screened for antibodies to HAV using an enzyme-linked immunosorbent assay.ResultsPositivity for HAV antibodies was 93.7% (95% confidence interval [CI]: 90.9–96.4) in Koreans living in northeastern China, 99.7% (95% CI: 99.0–100.3) in indigenous Chinese, 98.0% (95% CI: 96.4–99.6) in indigenous Koreans, 33.3% (95% CI: 28.0–38.7) in Koreans living in Japan, and 20.4% (95% CI: 15.8–25.0) in indigenous Japanese persons. The overall anti-HAV prevalence was not significantly different between northeastern China and South Korea, but it was different in Japan.ConclusionsThese results indicate that differences in seroprevalence can be attributed to geological, environmental, and socioeconomic conditions rather than ethnicity.     

儿童普及接种甲肝疫苗对人群甲肝抗体水平的影响

目的　研究儿童中普及接种甲肝活疫苗后 ,对人群甲肝总抗体水平的影响。方法　选择浙江省台州市椒江城区 ,按不同年龄分成 7组 ,分别于 1991年疫苗接种前及 2 0 0 0年儿童普及接种疫苗后 9年 ,检测正常人群 72 0名和 80 3名甲肝总抗体。血清检测法ELISA。结果　疫苗接种后人群总抗体阳性率有显著的提高。青少年及儿童 ( 18岁以下 )抗体阳性率由接种前的 2 9 84%提高到接种后的 6 4 15 % (P <0 0 1)。成人组( 2 5～ 35岁 )抗体阳性率从 78 9%到 84 5 % ,没有显著差别 (P >0 0 5 ) ,但未见有下降趋势。结论　儿童普及接种甲肝活疫苗后显著地提高了人群的总抗体水平 ,同时没有发现疫苗接种后易感人群的后移     

中国控制甲型肝炎之前景

展望中国控制甲型肝炎 (甲肝 )之前景 ,考虑与甲肝流行相关的几个问题 :甲肝病毒 (HAV)的致病特点 ;HAV经粪 口途径传播及人群抗体水平状况。控制甲肝流行的有利因素 :HAV的基因结构稳定 ;绝大多数人HAV可归于Ⅰ型 ,株间核苷酸差异 <15 % ,且HAV只有 1个血清型 ,中和抗体可以中和不同基因型的HAV ;中国控制甲肝已取得显著的效果 ,甲肝减毒活疫苗的研究、开发与应用 10余年取得了显著的成就。在理论上甲肝是一种可用疫苗消灭的疾病 ,中国应为此做出贡献。     

Cost analysis of two strategies for preventing hepatitis A virus infection in Spanish travellers to developing countries.

Our objectives were to assess the prevalence of anti-hepatitis A (HAV) antibodies in Spanish travellers to developing countries and to carry out a cost analysis to allow the comparison of two vaccination strategies. Adult subjects were selected from among travellers to developing countries. Information was obtained on age, sex, destination, previous vaccination against HAV and having received immunoglobulin. Blood specimens were obtained for anti-HAV antibody determination. A total of 485 travellers were studied. The prevalence of anti-HAV antibody was 30.5% (95% CI 26-35). Antibody prevalence was inversely correlated with age: 9.8% in 18-25 years of age, rising to 75.4% in those 41-55 years of age. Cost analysis determined that the critical value of prevalence for vaccination with HAV vaccine was 37.5%. It was concluded that the youngest Spanish travellers lack anti-HAV antibodies. Vaccination without screening in those < or = 35 years of age and screening before vaccination for those > 35 years, are the preferred alternatives.     

高流行区甲型肝炎疫苗免疫方案研究

目的探讨甲型肝炎高流行区疫苗免疫方案。方法观察新生儿母传抗ＨＡＶ抗体的衰减及处于甲型肝炎流行不同阶段儿童甲型肝炎病毒感染率随年龄上升的规律。结果新生儿母传抗体的阳性率按ｌｏｇｉｓｔｉｃ曲线下降,１３个月内从９７．４％下降为５．０％;非流行期儿童甲型肝炎病毒感染率从１．５岁起随年龄上升,２岁前保持在１０％以内;流行期儿童甲型肝炎病毒感染率随年龄增加而起点提前,速度加快。鉴于甲型肝炎发病随年龄上升的起点滞后于感染,认为甲型肝炎高流行区新生儿甲型肝炎母传抗体向自然感染抗体转换的“窗口期”是在出生后１２～２４个月。结论根据流行情况与经济条件,儿童适宜的甲型肝炎疫苗免疫时机一般选择在１２～２４月龄     

Changes in seroprevalence to hepatitis A in Victoria, Australia: A comparison of three time points

Serological data provide an important measure of past exposure and immunity to hepatitis A virus (HAV) infection in a population. National serosurveys from developed countries have typically indicated a decline in HAV seroprevalence over time as sanitation levels improve. We examined trends in the seroepidemiology of HAV antibodies in Victoria, Australia, drawing on cross-sectional samples taken at three time points over a 20-year period. Stored sera from 1988 (n=753), 1998 (n=1091), and 2008 (n=791) from persons aged 1-69 years were obtained from the state of Victoria, Australia. The within-year population adjusted results show a significant trend of increasing population HAV seroprevalence over time from 34.3% (95% CI 31.7-36.9) in 1988, to 40.0% (95% CI 37.1-42.8) in 1998 and 55.1% (95% CI 52.1-58.1) in 2008, P<0.0001. A particularly noticeable rise in population seroprevalence was observed between 1998 and 2008 for those aged 5-39 years. The increase in HAV seropositivity over time is in contrast to the declining rates of disease notification in Australia. Based on comparisons with other Australian data, it appears the increase in population seroprevalence over the last two decades is unlikely to be due to endemic transmission of infection. Instead, other factors, including increases in travel to HAV endemic regions, migration to Australia from HAV endemic regions and vaccine uptake are more likely causes. Ongoing monitoring of serological HAV profiles in the population is required to determine future policy direction to prevent increased burden.     

Waning of anti-HAV immunity in Shijiazhuang prefecture,Hebei province,China: A comparison of seroprevalence between 1992 and 2011

Objective

To study the epidemiological patterns of hepatitis A, and immunity of entire population in Shijiazhuang prefecture, Hebei province, a former hyper-endemic area in north China.

Methods

Cross-sectional, seroprevalence surveys with two-stage cluster sampling were conducted among population older than 2-year between 1992 and 2011. During the 2011 serological survey, blood samples from infants <18 months without hepatitis A immunization history were also collected to determine maternal anti-HAV antibody. Serum samples were tested for anti-HAV antibody by domestic reagent or Abbott reagent. Viral hepatitis incidence rates and gross domestic product data were derived from local governmental statistics.

Results

Concomitant with the reduction of reported hepatitis A cases between 1992 and 1996 was a significant decline of HAV infections. The average prevalence decreased from 93.6% to 41.9%, and the average age at new infection was postponed from infancy to adolescence. This was attributed to improved socio-economic conditions. With intensive vaccination, a return of new seroconversion rate and seroprevalence was observed. A well fitted exponential regression equation (R² = 0.96, p < 0.0001) modeled that the maternal antibody would wane to <20 mIU/mL at 13 months.

Conclusion

Benefiting from the booming economy, rapid improvement in sanitation, safe water supply, and implementation of hepatitis A vaccines, the epidemiological pattern of hepatitis A moved from high to intermediate endemicity in Shijiazhuang. Policy makers should be aware of the waning of immunity in entire population, and adapt immunization strategy timely, to ensure a lifelong protection against hepatitis A virus.     

Changing patterns of hepatitis A virus infection in children in Palermo,Italy

In 1988 in Palermo, Italy the prevalence of antibodies to hepatitis A virus (anti-HAV) in a sample of 490 children 6–13 years old was 10.6%; it increased from 6.3% among children 6–10 years old to 14.7% in children 11–13 years old (P < 0.01).Compared with findings from a survey conducted in 1978 in the same area, the results of the present study show a significant (P < 0.01) reduction in the anti-HAV prevalence in both age groups.Anti-HAV prevalence was inversely related to the father's years of education and positively related to the family size. Children of fathers with less than 6 years of schooling had a 3.2-fold risk (C.I. 95% = 1.3–8.1), and children with five or more members in their households had a 2.7-fold risk (C.I. 95% = 1.1–6.4) of previous exposure to hepatitis A virus (HAV) infection.Our findings indicate that exposure of children in Palermo to HAV is decreasing significantly, probably because of improvements in socio-economic conditions during recent years; however socio-demographic factors appear to be important determinants of infection.