Prevalence Of anti-HAV Antibodies Research Articles

Superinfection of other hepatitis viruses on top of chronic hepatitis B: The more, the worse

Superinfection of other hepatitis viruses on top of chronic hepatitis B: The more, the worse

P-50 PREVALENCE OF HEPATITIS AMONG STUDENTS AND HEALTH PROFESSIONALS AT THE FEDERAL UNIVERSITY OF BAHIA

Hepatitis A virus (HAV) is a hepatotrophic virus of fecal-oral transmission. Occupational exposure in the health area is not considered a risk of HAV contagion. Adults are more likely to develop fulminant hepatitis. In Brazil, those over 20 years of age have a high prevalence of anti-HAV antibodies (IgGHAV). To study the prevalence of IgGHAV in college students (group 1) and professionals (group 2) of the health area of the Federal University of Bahia. The sample consisted of 335 individuals who completed an epidemiological questionnaire and in whom IgGHAV was studied in sera. IgGHAV was present in 56.9% of all individuals, being 43.9% susceptible. IgGHAV was in 94.4% of group 2 and in 48.8% of group 1 (p = 0.000). There were no statistical differences between ethnicities. There was an association between professional category and report of exposure to biological material (p = 0.017), but not between seropositivity and report of this exposure. These data reflect both occupational and environmental exposure. Greater seropositivity in older professionals can also mean greater environmental exposure throughout life. In this study, curiously, greater exposure to biological material did not have a significant association with seropositivity for HAV, recalling the importance of exposure also in the extra-academic community. This study showed that 43.9% of the individuals who start studies in the health area of our university are susceptible to contracting HAV infection, which generates an epidemiological reconsideration of the need for vaccination in this population in the vaccine calendar from Brazil concerning the last VHA outbreaks in special population as MSM. CAPES and CNPq.

Increasing Burden of Hepatitis A in Adolescents and Adults and the Need for Long-Term Protection: A Review from the Indian Subcontinent.

Hepatitis A, an acute inflammatory liver disease caused by hepatitis A virus (HAV) infection from close contact with infected people, is highly endemic in the Indian subcontinent. Due to poor sanitary conditions, most of the population is exposed to the virus in childhood. At this age, the disease is asymptomatic and provides life-long protection against the disease. Due to rapid socioeconomic development in some areas, however, pockets of the population are reaching adolescence/adulthood without prior exposure to the virus and are thus susceptible to infection. At these ages, infection carries a higher risk of symptomatic disease and complications including mortality. This review of epidemiology and burden of disease studies in the Indian subcontinent, published since 2005, shows increasing evidence of a shift from high to intermediate endemicity in high-income—typically urban—populations. The prevalence of anti-HAV antibodies (previously reported at > 90%) is lower now in adolescents and young adults (e.g., around 80% in Bangladesh and 55% in 5–15 years in India). As a result, HAV is responsible for more acute viral hepatitis predominantly in this age group (e.g., > 15 years: 3.4% in 1999 to 12.3% in 2003 or high socioeconomic status 13–20 years: 27% in 1999 to 62% in 2003), with a greater clinical and economic burden. Numerous outbreaks due to HAV have been reported [e.g., Sri Lanka (2009–2010): > 13,000 affected; Kashmir (2015–2017): 12 outbreaks; Kerala (2012–2016): 84 outbreaks] from water or food contamination. Due to current shifts in endemicity, a growing proportion of the population is no longer exposed in childhood. As the disease remains highly endemic, it also provides a source for more severe disease in susceptible people at an older age and for outbreaks. Well-tolerated and effective vaccines are available and help prevent disease burden and provide long-term protection. These should now be used more widely to protect more patients from the growing disease burden of hepatitis A.FundingGlaxoSmithKline Biologicals SA.Plain Language SummaryPlain language summary available for this article—please see Fig. 1 and the following link: 10.6084/m9.figshare.9963044.Fig. 1Plain Language Summary. Highlights the context of the article, the endemicity shift and the burden of hepatitis A in adolescents and adults and steps to be taken to address the impact of this diseaseElectronic supplementary materialThe online version of this article (10.1007/s40121-019-00270-9) contains supplementary material, which is available to authorized users.

Decreasing risk of hepatitis A infection in León, Nicaragua: evidence from cross-sectional and longitudinal seroepidemiology studies.

Background and ObjectivesNicaragua is highly endemic for hepatitis A. We aimed to provide an estimate of the change in the age-specific risk of hepatitis A virus (HAV) infection based on serological data from cross-sectional and longitudinal samples collected in León, Nicaragua, in 1995/96 (n = 979) and 2003 (n = 494).MethodsThe observed age-specific prevalence of anti-HAV antibodies was correlated to the age-specific risk of infection by calculating the probability of freedom from infection at a specific age.ResultsThe proportion of seropositive children aged 1.5 to 6 years was 42% in 2003 compared to 67% in 1995/96. Estimated annual risk of infection for a 3-year old child was 30% (95% CI: 27.0%, 33.1%) in 1995 and 15.5% (95% CI: 12.4%, 19.0%) in 2003. There was good agreement between estimates based on cross-sectional and longitudinal data. The age-specific geometric mean of the quantified anti-HAV antibody levels assessed in 2003 was highest at age 4 and decreased steadily up to age 40.ConclusionsThe substantially lower risk of HAV infection in 2003 than in 1995 for young children indicates a beginning transition from high to intermediate endemicity in León, Nicaragua. Consecutive age-stratified serosurveys are useful to assess changes in risk of infection following public health interventions. The decreasing age-specific GMC of anti-HAV antibodies during adulthood in a country with endemic HAV indirectly suggests that ongoing HAV exposure in the community has marginal boosting effect on antibody levels once protective immunity has been established by natural infection.

Prevalence of antibodies against hepatitis A virus among children and adolescents in Germany

Since hepatitis A virus (HAV) infection during childhood is mostly asymptomatic, only seroprevalence studies can provide reliable information on incidence of HAV infection in children. The prevalence of anti-HAV antibodies was determined in sera taken in 2008 to 2010 from 1,645 children aged 0-17 years and in sera taken in 2010-2011 from 400 adult blood donors in Germany. For examination of trend over time, 715 sera collected between 1999 and 2006 from children at the age of 0-17 years within the federal state Thuringia were included. Antibody testing was carried out using the test kits ETI-AB-HAVK PLUS and ETI-HA-IGMK PLUS from DiaSorin. In children, the overall prevalence of antibodies was 10.8 %. After the seroprevalence declined from 8.8 % among the 0-2 year-olds to 2.4 % among the 3-4 year-olds, there was a significant increase to 20.5 % in the group of the 15-17 year-olds. Boys had with 12.7 % a significantly higher seroprevalence of anti-HAV antibodies compared to 8.8 % among girls. In adult blood donors, there was a HAV seroprevalence of 19.3 %. The likelihood of past infection or immunization within the age groups of children from 0 to 12 years differed significantly from that of adults. In conclusion, in Germany, only a small number of HAV infections occur in children, especially up to the age of 12 years. The proportion of susceptible children is greater than the proportion of susceptible adults. Thus, during outbreaks, the rate of infection among children would usually be higher than the rate among adults.

Declining prevalence of hepatitis A virus antibodies among children from low socioeconomic groups reinforces the need for the implementation of hepatitis A vaccination in Brazil

Age-related seroprevalence studies that have been conducted in Brazil have indicated a transition from a high to a medium endemicity of hepatitis A virus (HAV) infection in the population. However, most of these studies have focused on urban populations that experience lower incidence rates of HAV infection. In the current study, the prevalence of anti-HAV antibodies was investigated in children with a low socioeconomic status (SES) that live on the periphery of three capital cities in Brazil. A total of 1,162 dried blood spot samples were collected from individuals whose ages ranged from one-18 years and tested for anti-HAV antibodies. A large number of children under five years old (74.1-90%) were identified to be susceptible to HAV infection. The anti-HAV antibody prevalence reached ≥ 50% among those that were 10-14 years of age or older. The anti-HAV prevalence rates observed were characteristics of regions with intermediate level of hepatitis A endemicity. These data indicated that a large proportion of children with a low SES that live at the periphery of urban cities might be at risk of contracting an HAV infection. The hepatitis A vaccine that is currently offered in Brazil is only available for high-risk groups or at private clinics and is unaffordable for individuals with a lower SES. The results from this study suggest that the hepatitis A vaccine should be included in the Brazilian National Program for Immunisation.

Seroepidemiology of hepatitis a in the croatian population.

Hepatitis A virus (HAV) has a worldwide distribution, although this distribution tends to be uneven among geographical regions and population groups. The prevalence of anti-HAV antibodies in the general population varies widely among countries. In Europe, the seroprevalence of HAV is reported to range from 32% to 88%. The aim of this study was to determine the seroprevalence of HAV among the general Croatian population. During a 2-year period (2008-2009), a total of 791 serum samples were tested for the presence of anti-HAV total (IgM+IgG) and anti-HAV IgM antibodies using an automated enzyme-linked fluorescent assay (Mini Vidas; bioMérieux, Marcy l'Etoile, France). The overall anti-HAV seroprevalence was 41.6%. The observed difference in the seroprevalence rates among male and female patients was not statistically significant (44% vs. 39.6%, P = 0.218). A marked increase in anti-HAV seropositivity with age was observed (P < 0.001). The seroprevalence did not differ significantly between participants residing in rural regions (45.3%) and those residing in urban regions (40.6%, P = 0.292). Our results corroborate those of seroprevalence studies in other developed countries. More than half of the Croatian population (59.4%) is susceptible to HAV infection. Older age is an important predictor for being anti-HAV positive.

The use of dried blood spots for assessing antibody response to hepatitis A virus after natural infection and vaccination

During recent years, vaccination against hepatitis A has been implemented in several countries. It is expected that the increase in mass vaccination against hepatitis A will eventually result in a decreased prevalence of anti-HAV antibodies in the general population. For this reason, a suitable clinical sample for diagnosis of hepatitis A must be sufficiently sensitive to enable detection of lower antibodies titers. In this study, the feasibility of using dried blood spots (DBS) was assessed for the detection of anti-HAV antibodies after a natural infection and vaccination. Seventy-four DBS and paired plasma samples were obtained from a group of college students for a cross-sectional hepatitis A seroepidemiological study. Forty-six students seronegative for anti-HAV were selected randomly and immunized with an inactivated hepatitis A vaccine using an 0-6 month schedule. Seroconversion was monitored in paired plasma and DBS samples 6 months after the first dose followed by a period of 8 and 24 months after the second dose. A strong correlation between OD/CO rates of paired plasma and DBS samples for the detection of anti-HAV was observed. The sensitivity and specificity of the DBS compared with plasma for the detection of anti-HAV antibodies after natural infection was 100%. The sensitivity of DBS in samples collected 24 months after the second dose of hepatitis A vaccine was 95.4%. The results showed that DBS samples can be used for the detection of anti-HAV antibodies both after natural infection or vaccination.

Prévalence des anticorps de l’hépatite A chez l’enfant dans la région de Marrakech

To determine the prevalence of anti-hepatitis A virus (HAV) antibodies among Moroccan children and to examine some of the factors influencing its transmission. 150 children, aged six months to 14 years, were tested for anti-HAV IgG (indicating past infection). A questionnaire concerning personal and epidemiological data relating to hepatitis A was completed. The overall prevalence of anti-HAV antibodies was 51%. There was no significant difference between male and female children. The proportions of children positive for HAV-IgG varied significantly with age: 70.3% in the 7-14 age range were positive compared with 45.2% aged 6 years and less. Urban inhabitants did not have a higher prevalence than rural residents did. Socioeconomic factors were significantly correlated with the prevalence of anti-HAV-IgG, the father's level of education having the strongest influence. The high overall HAV prevalence in children confirms that Morocco is an intermediately endemic area for HAV infection. Morocco is entering a transitional phase and the introduction of hepatitis A vaccination in early childhood may reduce the prevalence of this infection and prevent outbreaks.

Hepatitis A seroprevalence in Tuscany, Italy

Information regarding the current seroprevalence of hepatitis A virus (HAV) is useful for the control of HAV infections. The objective of our study was to evaluate the prevalence of anti-HAV antibodies among children (1-5 years old) and young adults (15-20 years old) in Tuscany, in central Italy. A total of 565 sera were collected in three years 1992, 1998 and 2004, equally distributed between the two age groups. The overal proportion of those that tested positive for anti-HAV antibodies was 8.3%. The proportion of immune children (1-5 years old) statistically significantly increased over the years. The percentage of immune subjects among 15-20-year-old young adults varied over the years, not showing a significant statistical trend, nevertheless our findings indicate that in a low endemicity area, adolescents and young adults are becoming increasingly susceptible to HAV infection. On-going monitoring of immunity to HAV is necessary for detecting trends over time.

Seroprevalence of hepatitis A virus infection in persons with HIV infection in Taiwan: implications for hepatitis A vaccination

To retrospectively determine the prevalence of anti-hepatitis A virus (HAV) antibody in HIV-positive persons with different routes of HIV exposure and to describe its characteristics in order to guide vaccination policy. The prevalence of anti-HAV antibody was compared between 1580 HIV-positive persons seeking medical attention and 2581 HIV-negative controls seeking health check-ups, who had undergone anti-HAV tests between 2004 and 2007. Comparisons were also made among groups of the HIV-positive patients who had acquired HIV via different routes of transmission. A multivariate logistic regression model was built to identify independent variables associated with anti-HAV seropositivity. The overall prevalence of anti-HAV antibody was 60.9% in the HIV-positive and 48.0% in the controls (p<0.001). The overall adjusted odds ratio (AOR) for positive anti-HAV antibody was 2.604 (95% confidence interval (CI) 2.106-3.219) in HIV-positive persons compared with HIV-negative persons. In addition, HIV-positive men who have sex with men (MSM), heterosexuals, and injecting drug users (IDU) all had significantly higher AOR for positive anti-HAV antibody than HIV-negative persons. In HIV-positive persons, older age (AOR 1.284, 95% CI 1.246-1.322) and IDU (AOR 5.137, 95% CI 3.499-7.542) were independently associated with an increased prevalence of anti-HAV antibody. Nearly 90% of the IDU had become seropositive for HAV after age 36-40 years, compared with heterosexuals and MSM after age 46-50 years, and controls after age 51-55 years. Our findings suggest that age groups to be targeted for HAV vaccination vary with the different routes of HIV exposure.

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

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.

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

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.

Changes in Hepatitis a Virus Seroepidemiology in Hiv-Infected Brazilian Patients

Shifting of hepatitis A virus (HAV) epidemiology from a high towards an intermediate endemicity pattern and use of antiretroviral therapy increased the risk of HIV/HAV coinfection in developing countries. The aim of this study was to investigate the presence of HAV markers in a cohort of HIV-infected patients from 1988 to 2004. The presence of serum anti-HAV antibodies and HAV-RNA by real-time polymerase chain reaction was investigated in 581 patients. Total anti-HAV antibodies was found in 464/581 (79.8%) patients, however, a changing epidemiologic pattern of hepatitis A among HIV-infected patients from 1988 to 2004 was observed. Among patients susceptible to HAV (n = 117), 5 (4.2%) were coinfected with HAV, all of them had IgM anti-HAV antibodies and were serum HAV-RNA-positive. The high prevalence of anti-HAV antibodies in HIV-infected patients suggests that screening tests for anti-HAV antibodies should be performed before implementation of hepatitis A vaccination, especially in those patients from endemic countries.

Prevalence of anti-HAV antibodies in multitransfused patients with beta-thalassemia

To detect the prevalence of anti-HAV IgG antibodies in adult multitransfused beta-thalassemic patients. We studied 182 adult beta-thalassemic patients and 209 controls matched for age and sex from the same geographic area, at the same time. Anti-HAV IgG antibodies, viral markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection were evaluated. Anti-HAV IgG antibodies were detected more frequently in thalassemic patients (133/182; 73.1%) than in healthy controls (38/209; 18.2%, P < 0.0005). When we retrospectively evaluated the prevalence of anti-HAV IgG antibodies in 176/182 (96.7%) thalassemic patients, whose medical history was available for the previous ten years, it was found that 83 (47.2%) of them were continuously anti-HAV IgG positive, 16 (9.1%) acquired anti-HAV IgG antibody during the previous ten years, 49 (27.8%) presented anti-HAV positivity intermittently and 28 (15.9%) were anti-HAV negative continuously. Multitransfused adult beta-thalassemic patients present higher frequency of anti-HAV IgG antibodies than normal population of the same geographic area. This difference is difficult to explain, but it can be attributed to the higher vulnerability of thalassemics to HAV infection and to passive transfer of anti-HAV antibodies by blood transfusions.

Shifting Seroepidemiology of Hepatitis A in Japan, 1973–2003

Hepatitis A infection is caused by hepatitis A virus (HAV) contracted through fecal-oral transmission. Life-long immunity is conferred after infection. Improved sanitary conditions have generally resulted in a significant decline in the incidence of hepatitis A. However, a low incidence of infection results in increased HAV susceptibility. The present study investigates the prevalence of anti-HAV antibody and clarifies the current HAV status and HAV susceptibility in Japan at 2003. A total of 2,430 serum specimens collected during 2003 from Japanese individuals ranging in age from 0-92 years, were tested for anti-HAV antibody using an inhibition enzyme linked immunosorbent assay. All specimens were obtained from the WHO and the National Serum Reference Bank/National Institute of Infectious Diseases, Tokyo, Japan. The overall seroprevalence was 12.2%. Anti-HAV antibodies were rarely detected in individuals between 0-44 years of age. Starting from the age of 45-49 years, seropositivity gradually increased through age 65 years and above. Seroprevalence was not affected by gender, and geographic distribution did not affect age-specific seroprevalence until the age of 60 years. HAV susceptibility in Japan is increasing annually. Particularly, the prevalence of anti-HAV antibody in individuals older than 50 years in 2003 was 50.3%, which is significantly lower than that of corresponding studies in 1994 (74.3%), 1984 (96.9%) and 1973 (96.9%). The growing susceptible population of advanced age results in more frequent HAV infection among them. The surveillance of anti-HAV antibody prevalence is useful for implementing preventive measures and for controlling the spread of HAV.

Participant-collected, Mail-delivered Oral Fluid Specimens Can Replace Traditional Serosurveys

Although population-based serosurveys offer an optimal measure of cumulative infection rates, they are seldom performed due to high cost and complex logistics. Use of participant self-collected oral fluid as a diagnostic specimen and mail for specimen delivery has the potential of generating reliable, population-representative data at limited cost. A survey of oral fluid HAV-specific immunoglobulin G (an indicator of past HAV infection) was undertaken in a provincially representative sample of 20–39 year olds as a pilot study. A provincial administrative database served as the sampling frame. Potential participants were invited by mail to collect oral fluid and complete a questionnaire at home and return both by mail. Additional telephone prompting was directed at slow responders. Oral fluid was tested using a validated ELISA. From among 2,448 potential participants, contact by mail or telephone was made with 1,009 eligible subjects; 59% (585) participated. Materials withstood mailing and the quality of self-collected specimens was excellent. A positive test result was found in 22.1% overall and in 15.7% of self-reported non-vaccinated subjects. Among Canadian-born, non-vaccinated individuals, the positive test rate increased progressively from 1.2% (95% CI: 0–6.3) in 20–24 year olds to 16.4% (95% CI: 9.5–23.3) in 35–39 year olds. Antibody prevalence was higher among Canadian-born non-immunized 20–29 year olds who reported travel to developing countries (33.3%, 95% CI: 11.6–55.1) than in non-travellers (2.5%, 95% CI: 0.7-6.2). Mail-based population surveys of infection markers in oral fluid are feasible provided an appropriate sampling frame is used. This survey revealed a high anti-HAV antibody prevalence in young Canadian adults, increasing with age and travel to developing countries.

Prevalence of anti-hepatits A antibodies in children of different socioeconomic conditions in Vila Velha, ES

This report describes the prevalence of anti-HAV antibodies in children from elementary school in the Municipality of Vila Velha, ES, Brazil. Anti-HAV antibodies were investigated by ELISA method in the serum of 606 children (four to fourteen years old) from three elementary schools, located in neighborhoods with varying household monthly income levels: São José School, 200 children, household income higher than US$700; São Torquato School, 273 children, US$200 to 300; and Cobi School, 133 children, less than US$200. From each children data on age, gender, skin color, sanitary conditions, frequency of contact with sea or river water and family history of hepatitis were recorded. Anti-HAV antibodies were present in 38.6% of all children, 9% in São José School, 49.1% in São Torquato School and 61.7% in Cobi School. Logistic regression analysis demonstrated a positive correlation of positive anti-HAV test with age, non white color of the skin, absence of sewage treatment and domestic water filter, and a past history of hepatitis. The prevalence of anti-HAV antibodies in school children in Vila Velha, ES, was lower than that observed in the same age group in North and Northeast Brazil and was significantly higher in children from families with low socioeconomic status. In addition the results indicate a changing epidemiologic pattern of hepatitis A in our country, with an increasing number of children and adolescents with high risk for HAV infection, mainly in high socioeconomic class. A consideration must be given to the feasibility of vaccination programs for children and adolescents in our country.

Estudio seroepidemiológico de la hepatitis A en la comunidad de Madrid durante el año 2002

The aim of this study was to investigate the prevalence and risk factors associated with hepatitis A virus (HAV) infection in a representative population sample to determine who can benefit from vaccination strategies and to investigate the age limit at which previous HAV antibody screening is not required. From April to September 2002, we studied a total of 557 patients, 90 children and 467 blood donors, aged 1-65 years. Information on demographic variables (age, gender, place of residence and education level) was recorded. Patients with history of hepatitis or other liver diseases were excluded. Anti-HAV antibodies (IgG) were determined with an automated enzyme immunoassay (AxSYM, Abbott Diagnostics). The chi-square and Mantel-Haenszel tests were used for the statistical analysis. The overall prevalence of HAV infection was 41.5%. There was a significant increase in prevalence with age (chi-square TL:205, P < .0001), with rates from the youngest to oldest groups of 5.5%, 23.5%, 28.1%, 64.2% and 93.2%, respectively. Apart from age, the only other risk factor independently associated with prevalence was the level of education, with higher prevalence at the lower education levels (OR 5 2.7; chi-square = 32.11, P < .0001). The prevalence of anti-HAV antibodies has decreased in recent years in the community of Madrid. Among the population less than 35 years of age, 75% of individuals are susceptible to the infection and could benefit from universal vaccination without previous screening for anti-HAV antibodies.

The need of vaccination against hepatitis A in patients with chronic liver disease : fact or fancy?

Purpose: It has been suggested that there is an ongoing change in recent years, in the prevalence of anti HAV antibody among portuguese population, particularly related to overall improvement in sanitary conditions, both in urban and rural areas in the last 3 decades. This lower prevalence would be related with the lower infection rate in children, adolescents and young adults.