Prevalence of antibodies against hepatitis A and E viruses among rural populations of the Chaco region, south-eastern Bolivia

We conducted a cross-sectional study to determine the seroprevalence of antibodies against hepatitis A and hepatitis E viruses (HAV and HEV) in the population of two rural areas, Camiri and Villa Montes, of the Chaco region, south-eastern Bolivia. HAV antibodies were detected in 461 (94.1%) of 490 serum samples tested, not differing significantly between sexes and study areas. The HAV seropositivity rate (64.7%) was high even in the youngest age group (1-5 years). The prevalence of HEV was 7.3%, with no significant differences between sexes. The prevalence of HEV antibodies in the population of the Camiri area (10.4%) was significantly higher than in the Villa Montes area (4.4%), possibly due to the better quality of drinking water in the Villa Montes area. In the population /= 31 year-old group. This is consistent with findings in other countries. This is the first report of the prevalence of HEV infection in Bolivia.     

Hepatitis A seroprevalence in children and adults in Kiev City, Ukraine

Summary.  Ukraine is a zone of moderate hepatitis A endemicity. The changing epidemiology of the disease because of improved hygiene has shifted the burden of Hepatitis A to older age groups where the disease is more severe. Outbreaks have also become more common as more of the population has become susceptible to hepatitis A virus (HAV). To help guide decisions regarding use of hepatitis A vaccine in Ukraine, we examined the presence of antibody to HAV (anti-HAV) in 1001 persons aged 1 to 85 years, visiting four municipal healthcare centres in the Ukrainian capital, Kiev. Overall, the anti-HAV prevalence was 31.9%. Anti-HAV seropositivity increased with age from 9.2% among children aged 1–5 years to 81.7% among persons over 50 years, but less than 50% of subjects less than 50 years were HAV seropositive. No children under 2 years were seropositive. HAV seropositivity was twice as high in children aged 5–11 years old in the low socio-economic status group (income less than 150 US$ per family member per month) than in the middle/high group (11.1% compared to 6.3%) but this disparity disappeared by adolescence. The prevalence of anti-HAV antibodies in adults was not different with respect to district of residence within the city. Considering the proportion of HAV seronegative subjects in all age groups under 50 years, routine vaccination against HAV of children aged 1–2 years old would appear to be an effective schedule for hepatitis A prophylaxis in Kiev.     

Seroepidemiology of antibody to hepatitis A in the rural eastern part of Thailand.

Hepatitis A is a disease commonly found in Thai children. However, there are very few reports on the age specific prevalence in Thailand. We studied the hapatitis A virus (HAV) antibody titer in a population in the rural eastern part of Thailand, using an antiHAV ELISA test (Abbott Laboratories, North Chicago Ill). Three hundred and sixty four subjects from Pong Nam Ron, Chanthaburi Province and 236 of children and adults from Bo Thong, Chon Buri Province were studied for age specific prevalence of antiHAV. The immunity against HAV increased with age. Fifty percent of Pong Nam Ron children had antiHAV antibodies at the age of 8-9 years and at the age of 12-13 years of Bo Thong children. The overall antibody prevalence rate was 67.9% in Pong Nam Ron and 59.3% in Bo Thong Districts. According to our data, less than 30 percent of children under 10 years old in the eastern part of Thailand were seropositive for HAV. This finding indicated a much lower incidence than previously reported which may reflect better personal and food hygiene.     

Hepatitis A seroprevalence in children and adolescents aged 1-18 years among a low socioeconomic population in Izmir, Turkey

The age-specific prevalence of hepatitis A virus (HAV) infection and risk factors were evaluated in a low socioeconomic population in Izmir. Children and adolescents 1-18 years of age admitted to the outpatient clinics for follow-up visits, or healthy children between April-December 2009 were investigated for anti-HAV antibodies by a cross-sectional study. A questionnaire on sociodemographic and hygiene information was obtained from the parents. All unvaccinated children against HAV were grouped according to their age. Seven hundred and twenty-nine children were enrolled in the study. Total HAV IgG seropositivity was 29.5% while age related values were as follows: 1-2 years, 21.4%; 2.1-5 years, 15.1%; 5.1-8 years, 20.1%; 8.1-11 years, 32.6%; 11.1-14 years, 44.3% and 14.1-18 years, 52.4%. The presence of anti-HAV IgG was associated significantly with low family income and lack of education of parents and living in a crowded family. HAV infection was endemic in a population of children living in Izmir. Anti-HAV vaccination should be considered for preschool children because teenagers are at risk of infection in this region.     

Age-specific seroprevalence of hepatitis a among school children in central Tunisia

Hepatitis A virus (HAV) has different epidemiologic and clinical patterns, depending on the level of endemicity in a given geographic area. Tunisia is considered a region of high endemicity for hepatitis. Improvement of socioeconomic conditions in this country has made a determination of the seroprevalence of this disease advisable. We assessed the seroprevalence of HAV in Sousse in central Tunisia. A total of 2,400 school children 5-20 years of age (mean +/- SD age = 11.7 +/- 3.5 years) were selected by two-stage cluster sampling and tested serologically for IgG antibody to HAV by using an enzyme-linked immunosorbent assay. The overall seroprevalence among this population was 60% (44%, in children < 10 years old, 58% in those 10-15 years of age, and 83% in those > 15 years of age. Seroprevalence also varied according to area of residence. At the age of 10, 21.3% of school children living in the urban areas and 87.7% of those living in rural areas had antibodies to HAV. Other factors that increased seroprevalence included non-potable water, crowding, and a low education level of parents with odds ratios of 4.37, 2.96, and 2.62, respectively. This study has shown an increase of seroprevalence with age, suggesting that transmission among younger children has decreased, particularly in urban areas. Programs to prevent hepatitis A may need to be modified based upon the changing age distribution of the disease and mass vaccination program could be indicated if additional incidence and prevalence data confirm the intermediate endemicity of HAV.     

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

Summary.  Hepatitis A is a worldwide vaccine-preventable infection. Recommendation of vaccination depends on the endemicity of the disease. The World Health Organization recommends universal hepatitis A vaccination in intermediate areas; however, there is no need of mass vaccination in high and low endemicity regions. Therefore, most of the countries are using a vaccination policy according to the endemicity characteristic representing the whole of the country. The endemicity of this infection varies due to sanitary and hygiene conditions and socioeconomic differences among the countries and in various regions of the same country. A sample of 1173 persons between the age of 0 and 91 years from nine randomly selected medical centres from five different geographical centres of Turkey were tested for the level of anti-hepatitis A virus (anti-HAV) immunoglobulin-G antibodies using an enzyme-linked immunosorbent assay. The overall prevalence of anti-HAV antibodies was 64.4% (1142/1173). While the rate of sero-positivity was over 80% in the 5–9 age group and more than 90% after 14 years of age in south-eastern and eastern regions, it was lower than 50% at the age of 5–9 years in central and western regions and remains under 80% in those areas. We conclude that the differences observed in HAV sero-positivity among various geographical regions in Turkey support a universal HAV immunization policy for children currently living in regions of intermediate endemicity.     

Prevalence of hepatitis virus infections in Kosovar refugees.

OBJECTIVES: To assess the prevalence of viral hepatitis infections in a sample of Kosovar refugees having arrived in southern Italy as a result of the 1999 war in the Balkans. METHODS: The 526 subjects who enrolled on voluntary basis from all age groups were tested for the prevalence of serologic markers for hepatitis virus types A, B, C, D, and E (HAV, HBV, HCV, HDV, HEV). RESULTS: Among the 526 refugees, the prevalence of total anti-HAV antibodies was 81%. A relevant finding was the presence of total anti-HAV antibodies in 61% of the children up to 10 years of age. The prevalence of anti-HEV antibodies was 2.5% among the subjects. Fifteen subjects (2.9%) were positive for hepatitis B surface antigen (HBsAg), whereas 17.5% tested positive for anti-hepatitis B core antigen (anti-HBc). In children up to 10 years of age, the prevalence of HBsAg and anti-HBc was found to be 0.4% and 6%, respectively. In subjects aged 11 to 20 years, 4.2% tested positive for HBsAg and 20.2% for anti-HBc. In the age group 21 to 30 years, 7.1% of the subjects were found to be HBsAg carriers, whereas 25.9% were found to be positive for anti-HBc. Among the refugees over 30 years of age, the prevalence of HBsAg was 4.2%, whereas anti-HBc was 43.7%. None of the refugees tested positive for anti-HDV. The prevalence of anti-HCV antibodies was 0.7%. CONCLUSIONS: The results of this seroepidemiologic study indicate a high circulation of HAV in the Kosovar population, whereas the prevalence of HEV antibodies was low and comparable to that of other European countries. The HBV infection seems to be at an intermediate level of endemicity and an immunization policy against HBV infection, through vaccination of all newborns and children before adolescence, may be advisable. Results of this study indicate that the level of endemicity of HCV infection in the Kosovar population is low.     

Hepatitis A seroprevalence and its relationship with environmental factors in children of different age groups in Kahramanmaras, Eastern Mediterranean region of Turkey

Hepatitis A infections are influenced by environmental and socioeconomic factors. Epidemiologic studies regarding hepatitis A virus (HAV) infection in Turkey have not previously examined these factors. We investigated HAV seroprevalence and its association with sociodemographic factors among children of various ages in the Eastern Mediterranean region of Turkey. The study included 1142 children (603 male and 539 female) between ages of 6 months and 18 years. Seropositivity in the whole group was 57.2%. HAV prevalence rates according to age groups were as follows: 35.5% in 6-23 months group, 19.2% in 2-5 years group, 74.3% in 6-10 years group, 83.0% in 11-14 years group, 92.8% in 15-18 years group. Risk factors that influenced seropositivity were; dense population, over-crowded families, excessive number of siblings, low socioeconomic status and low education of the mother. As HAV seroprevalence in children older than 6 years of age is high, we recommend hepatitis A vaccination in this region after the first year of life.     

Impact of recurrent epidemics of hepatitis a virus infection on population immunity levels: Bristol Bay,Alaska

The dynamics of population-based immunity were examined by using serologic surveys of 7 villages in rural Alaska between 2 epidemics of hepatitis A virus (HAV) and after the second epidemic (1988-1990). Among persons aged 2-30 years, the overall age-adjusted prevalence of antibody to HAV (anti-HAV) was 51% in 1983 and 49% in 1993 (P=.506). In children aged <5 years, prevalence rates were 0% and 11% in 1983 and 1993, respectively. The prevalence of HAV infection increased with age in both surveys. When examined by 5-year birth cohorts, anti-HAV prevalence increased in children born between 1979 and 1983 (P<.001). Between the 2 survey periods, 43 clinical cases of HAV infection were reported in these villages; all occurred from 1988 to 1990. Despite high overall prevalence of immunity, transmission during epidemics was facilitated by children aged <15 years susceptible to HAV. Little transmission occurred between epidemics. Vaccination of children against HAV should prevent future epidemics.     

Seroepidemiology of hepatitis A virus infection among school children in Delhi and north Indian patients with chronic liver disease: implications for HAV vaccination

BACKGROUND: Universal vaccination against hepatitis A virus (HAV) has been recommended for children because of the changing epidemiological pattern of HAV. Vaccination has also been advised for patients with chronic liver disease as HAV superinfection in these patients can result in severe or even fatal disease. In India, the indications for HAV vaccination are not clear due to contradictory seroepidemiological data in children and lack of data on HAV seroprevalence in patients with chronic liver disease. METHODS: Sera were collected from children studying in two government-run schools and from patients with chronic liver disease attending the Liver Clinic at the All India Institute of Medical Sciences (AIIMS). The sera were tested for anti-HAV antibodies. The incidence of HAV-induced acute hepatitis and acute liver failure at AIIMS over the last 10 years was also assessed. RESULTS: A total of 93.2% (1328/1424) of the school children between 4-18 years of age who were included in the study had anti-HAV antibody in their sera. Eighty percent of the children had antibodies against HAV in their sera by the age of 5 years, whereas all the children above 16 years were positive for anti-HAV antibody. A total of 256 patients with chronic liver disease (94 with cirrhosis of the liver, 160 with chronic hepatitis) were tested for the presence of anti-HAV antibody. Of them, 97.6% (248/254) had anti-HAV antibody in their sera. The annual frequency of HAV-induced acute viral hepatitis and acute liver failure at AIIMS during the last 10 years did not show any change. CONCLUSION: Mass vaccination against HAV is not required in north India because of the presence of protective antibodies against HAV in the majority of the population.     

Prevalence of hepatitis A virus antibodies in patients with chronic liver diseases.

OBJECTIVE: The age of persons with hepatitis A virus (HAV) infection in the general population has risen; these persons are at increased risk of clinically severe disease, especially patients with chronic liver disease. The aim of the present study was to analyze the prevalence of total antibodies against HAV in patients with chronic liver disease. METHODS: In a prospective study carried out between September 1998 and June 1999, 180 patients seen in the chronic liver disease outpatient department were studied. The prevalence of total anti-HAV antibodies was determined by age group, etiology and degree of histological damage, and according to the antecedents of risk for parenteral infection. A nonconditional logistic regression model was fitted with anti-HAV positivity as the dependent variable. RESULTS: Mean age was 44.1 years, with an anti-HAV prevalence of 77.2% (varying from 42.9% in the 21-25-year-old group to more than 83% in patients > 56-years old). Differences across groups regarding other categories (histological damage, etiology and history of parenteral or drug use) were not statistically significant, but the probability of anti-HAV positivity increased with age and a history of drug addiction. CONCLUSIONS: The prevalence of total anti-HAV antibodies is high among patients with chronic liver disease. We therefore recommend this test before vaccination against HAV, until current recommendations on universal childhood vaccination are implemented, in order to prevent hepatitis A epidemics in the general population.     

The prevalence of viral hepatitis among the Hmong people of northern Thailand

Sera from 269 Hmong people (102 males and 167 females, with mean age 35.4 years, range 16-63 years) were examined in order to determine the seroprevalence of hepatitis virus infection. The seroprevalence rates for HAV (hepatitis A virus), HBV (hepatitis B virus), HCV (hepatitis C virus), HDV (hepatitis D virus), HEV (hepatitis E virus), HGV (hepatitis G virus) and TTV (TT virus) infection were 87.8% (n=140), 76.0% (n=150), 2.0% (n=150), 0.7% (n=150), 6.5% (n=139), 5.3% (n=94) and 25.6% (n=121) respectively. The rate for carriers of HBV (HBsAg) was 13.8% (20.5% in males and 9.6% females) with a peak prevalence in the 21-40 year age group. A high rate of HAV seropositivity was found among the younger subjects. The rate of HEV seroprevalence was low. The prevalence of TTV-DNA was high with no difference between the sexes. HGV-RNA prevalence was low and seen primarily in males. This study indicates that the Hmong people are endemically infected with HAV and HBV infection and should be considered for targeted vaccination. The role of TTV and HGV in producing illness and hepatic disease has yet to be determined in this population.     

Association between hepatitis A virus and Helicobacter pylori in a developing country: the saga continues

BACKGROUND: The epidemiologic association between Helicobacter pylori and hepatitis A virus (HAV) has been evaluated by various different groups with conflicting conclusions. The aim of the present study was to determine the prevalence of HAV and H. pylori infection among adolescents attending high schools in Lebanon, and to identify the sociodemographic factors associated with their prevalence, individually and concurrently. METHODS: Nine hundred and two school students 14-18 years of age were selected randomly from 30 schools scattered all over Lebanon and tested for IgG antibodies against hepatitis A and H. pylori. Each student received a copy of a self-administered questionnaire to be completed by his/her parents inquiring about demographics, history of immunization, and prior viral hepatitis illness in the student. Bivariate analysis examined the association between different sociodemographic variables and prior HAV or H. pylori infection, and multivariate regression analysis was done to determine the factors independently associated with prior infection. RESULTS: Using ELISA the seroprevalence of antibodies against HAV was 71.3% as compared to 61.6% for anti-H. pylori. A total of 9.1% of those tested were negative for both agents. A multinomial regression analysis revealed that place of residence in relation to district or urban versus rural areas, in addition to mothers' education, were important determinants for the incidence of both agents. CONCLUSION: The low number of subjects negative for both H. pylori and HAV antibodies in Lebanon is indicative of their high prevalence in the country. It is possible that this high prevalence reflects an age-specific prevalence rather than a true association.     

Prevalence of hepatitis a antibodies in western Indian population: changing pattern

This report pertains to a retrospective study conducted between 1983 and 1995 at three time points to evaluate the prevalence of hepatitis A virus (HAV) infection in the population of Bhor Taluk, situated in western India. Serum samples from children and adults were tested for anti-HAV antibodies using blocking ELISA test. There was a significant decrease in anti-HAV prevalence among children aged 5-10 years in 1995 (87.36%) as compared to that of 1983 (97.58%) and 1987 (96.48%). All individuals >11 years of age were seropositive for anti-HAV antibodies. Anti-HAV prevalence was similar in the users of well water, but was significantly reduced in individuals supplied with piped water in 1995 (88.61%) compared with that in 1983 (98.77%). A significant decrease in anti-HAV positivity was noted in children from Bhor Taluk as compared to children from Pune bled in 1992. These results underline the need for periodic surveillance of seroepidemiology of hepatitis A to determine the measures for prevention and control of the disease.     

Association between seropositivity of antibodies against hepatitis a virus and Helicobacter pylori

Helicobacter pylori and hepatitis A virus (HAV) are documented to share common transmission routes including fecal-oral. This study examined the association between seropositivity of antibodies against H. pylori (anti-HP) and HAV (anti-HAV) via a community-based survey of 40 randomly selected kindergartens in 10 urban and 10 rural areas. Serum samples from 2,047 healthy preschool children and 104 teachers were screened for anti-HP by enzyme-linked immunosorbent assay, and for anti-HAV by microparticle enzyme immunoassay. In children, a low prevalence of anti-HAV (0.44%) was found, in contrast to a high prevalence in their teachers (78.8%); anti-HP seroprevalence was 6.4% for children and 30.8% for teachers. Anti-HAV and anti-HP seropositivities were significantly associated in teachers after adjustment for age, sex, and residential area through multiple logistic regression analysis (multivariate-adjusted odds ratio = 7.3; 95% confidence interval [CI] = 1.4-36.8, P < 0.001). Our findings suggest that HAV and H. pylori may have shared transmission routes in central Taiwan 15 years or more ago, but not any recently.     

Serological survey for human monkeypox infections in a selected population in Zaire

About 3460 persons living in Kole zone of East Kasai, in Zaire, were examined and their sera screened initially by a haemagglutination-inhibition test. Of these, 667 (19%) were positive. Radioimmunoassay adsorption tests for the presence of monkeypox- or vaccinia-specific antibodies gave unequivocal results in 300 of these sera; the remaining 47 were nonspecific. Monkeypox-specific antibodies were found in sera of 27 individuals, of all ages and both sexes, giving an overall prevalence rate of monkeypox virus-specific antibodies of 0.8%. The prevalence rate was four times higher in the 5 to 9 year age group (1.3%) than in children aged 0 to 4 years (0.3%), and was highest (2.4%) in the 15 to 19 year age group. There was no significant difference in the prevalence rates between the sexes. As might be expected, there are substantially higher prevalence rates in persons living in forest galleries than in those in savannah, and among those living in areas where human monkeypox cases had occurred in the past compared with those living in other localities. Nineteen children whose sera showed specific monkeypox antibodies were re-examined. Twelve showed facial and body skin changes suggesting the presence of vesiculo-pustular disease in the past; four of these had been known registered monkeypox cases. Seven children had neither signs nor history of past vesiculo-pustular disease, suggesting that they had suffered from subclinical infection with monkeypox virus.     

Changes in seroepidemiological pattern of Helicobacter pylori and hepatitis A virus over the last 20 years in Japan

OBJECTIVE: The age groups most susceptible to infection and the mode of transmission of Helicobacter pylori (H. pylori) are not yet clear. To contribute to a better understanding of this disease, this study was undertaken to evaluate changes in the seroepidemiological pattern of H. pylori in a group of Japanese people over the last 20 yr sampled in 1974, 1984, and 1994 in comparison with that of the hepatitis A virus (HAV), which was used as a marker of the fecal-oral route of transmission. METHODS: A total of 1015 serum samples were obtained from the National Institute of Infectious Diseases in Tokyo. All of these samples were from healthy persons aged 0-89 yr (442 male and 573 female; median age 35.6 yr), living in seven prefectures in the central part of Japan in 1974, 1984, and 1994. All serum samples were assayed for H. pylori IgG by means of enzyme-linked immunosorbent assay (ELISA). Further, anti-HAV antibodies were assayed by blocking ELISA in the same samples. We investigated the prevalence of H. pylori and HAV for all ages, and the positive rate of H. pylori for infants and children separately. RESULTS: The overall prevalence of H. pylori antibodies was 72.7% (CI 95%, 68.0-77.3) in 1974, 54.6% (CI 95%, 49.1-60.0) in 1984 and 39.3% (CI 95%, 34.1-44.4) in 1994. That of HAV was 57.7% (CI 95%, 52.5-62.8) in 1974, 41.7% (CI 95%, 36.3-47.0) in 1984, and 23.4% (CI 95%, 18.9-27.8) in 1994. The prevalence of both H. pylori and HAV was found to increase with age, whereas there have been clear cohort shifts in the seroepidemiological patterns of both infections over the last 20 yr in Japan. This study shows that there is a slight similarity in the concordance of positive and negative populations between H. pylori and HAV. However, it was very difficult to determine the concordance between H. pylori and HAV infection in this study. CONCLUSIONS: Our data strongly suggest that the highest infection rates for both H. pylori and HAV occur among infants and children in Japan. This study provides evidence that H. pylori and HAV may share a common mode of transmission but that changes in environmental conditions make this very difficult if not impossible to prove with seroepidemiological data.     

Loss of hepatitis A virus antibodies after bone marrow transplantation

Reimmunization guidelines have recommended the inactivated HAV vaccine for hematopoietic stem cell transplant (HSCT) recipients living in or traveling to areas where hepatitis A is endemic. As a shift from high to medium hepatitis A endemicity has been observed in several countries in Latin America, we conducted a retrospective study to evaluate the prevalence of hepatitis A pre-bone marrow transplant (BMT) and the loss of specific antibodies in consecutive stored serum samples from 77 BMT recipients followed up from 82 to 1530 days. The prevalence of HAV antibodies was 92.2% before BMT. As vaccine was not available in Brazil when the samples were taken, it was assumed that this prevalence reflects natural infection. Survival analysis showed that the probability of becoming seronegative was 4.5% (+/-2.6%), 7.9% (+/-3.4%), 10.1% (+/-4.0%), 23.4% (+/-9.6%) at 1, 2, 3 and 4 years after transplant, respectively. The loss of HAV antibodies was significantly associated with longer follow-up (P=0.0015), younger age (P=0.049) and acute graft-versus-host disease (P=0.035). As most reimmunization protocols start around day +365, in developing countries with similar HAV endemicity, BMT recipients should have serological screening before HAV vaccination and the inactivated vaccine should be advised to those seronegative.     

Prevalence of anti-hepatitis A antibodies in an urban middle class area of Argentina: some associated factors.

OBJECTIVE: This study evaluated the seroprevalence of hepatitis A virus (HAV) antibodies in 360 middle-class subjects from Buenos Aires City and its outskirts. METHODS: The study population included 360 individuals between 10 and 89 years of age, from the socioeconomic middle class in Buenos Aires City and some suburban areas of Buenos Aires province. Antibodies to hepatitis A virus were determined by enzyme immunoassay test kits. RESULTS: The overall prevalence of HAV antibodies was 42.2%. The highest percentage of seronegativity was found in the subgroup of younger people without a history of symptomatic hepatitis and living in houses with more than one bathroom (86.9%). In the subgroup aged 21 to 60 years, the highest rates of seronegativity were found in individuals with higher level of education living in houses with tap water (66.6%). In both groups, seronegativity may be correlated with a higher socioeconomic status. CONCLUSIONS: In the middle-class community studied, more than 50% of people under 30 years of age were unprotected against HAV. Thus, the use of a vaccine against hepatitis A has to be considered for the prevention of symptomatic hepatitis, especially in adults at risk of infection, such as those who travel to areas with poor sanitation, taking into consideration that the severity of the disease increases with age.