Epidemiology of hepatitis A in Finland in 1990-2007

Exploration of a new hepatitis a surveillance system in Beijing, China: based on molecular epidemiology

Background

The incidence of hepatitis A virus (HAV) infection is low in Beijing, China, but the risk of outbreaks still exists. It is difficult to identify possible sources of infection among sporadic cases based on a routine surveillance system. Therefore, a more effective surveillance system needs to be established.

Methods

The epidemiological data of hepatitis A were obtained from a routine surveillance system. Patients with HAV confirmed at the local hospitals were asked to complete a questionnaire that included additional case information and possible sources of infection. Serum and fecal specimens were also collected for testing HAV RNA by polymerase chain reaction. In addition, the 321-nucleotide segment of the VP1/2A junction region was sequenced to determine the HAV genotype.

Results

In 2019, 110 HAV cases were reported in Beijing, with an incidence rate of 0.51/100,000. 61(55.5%) of these patients were male. The greatest proportion of these patients were aged from 30 to 60 years. The rate was lower in suburban and rural areas compared to urban areas. Contaminated food consumption, particularly seafood consumption, was the primary potential source of infection. Among the 16 specimens of confirmed HAV cases that could be sequenced, 93.8% were HAV IA, and 6.3% were HAV IB. In addition, the samples collected from all HAV sequences in this investigation showed 89.4–100% nucleotide homology. Two groups (each with three sporadic cases) showed 100% nucleotide homology. The three sporadic cases in one group had the same possible source of infection: contaminated salad with raw vegetables and seafood. In the other group, the three sporadic cases did not have an epidemiological connection.

Conclusions

In a low HAV prevalent area, such as in Beijing, incorporating molecular epidemiology into the routine surveillance system could help inform possible clusters of outbreaks and provide support for earlier control of HAV transmission. Nevertheless, increased sampling from detected cases and improved specimen quality are needed to implement such a system.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06872-4.

Trajectory modelling of ambulatory care sensitive conditions in Finland in 1996-2013: assessing the development of equity in primary health care through clustering of geographic areas - an observational retrospective study

Background

Due to stagnating resources and an increase in staff workload, the quality of Finnish primary health care (PHC) is claimed to have deteriorated slowly. With a decentralised PHC organisation and lack of national stewardship, it is likely that municipalities have adopted different coping strategies, predisposing them to geographic disparities. To assess whether these disparities emerge, we analysed health centre area trajectories in hospitalisations due to ambulatory care sensitive conditions (ACSCs).

Methods

ACSCs, a proxy for PHC quality, comprises conditions in which hospitalisation could be avoided by timely care. We obtained ACSCs of the total Finnish population aged ≥20 for the years 1996–2013 from the Finnish Hospital Discharge Register, and divided them into subgroups of acute, chronic and vaccine-preventable causes, and calculated annual age-standardised ACSC rates by gender in health centre areas. Using these rates, we conducted trajectory analyses for identifying health centre area clusters using group-based trajectory modelling. Further, we applied area-level factors to describe the distribution of health centre areas on these trajectories.

Results

Three trajectories – and thus separate clusters of health centre areas – emerged with different levels and trends of ACSC rates. During the study period, chronic ACSC rates decreased (40–63%) within each of the clusters, acute ACSC rates remained stable and vaccine-preventable ACSC rates increased (1–41%). While disparities in rate differences in chronic ACSC rates between trajectories narrowed, in the two other ACSC subgroups they increased. Disparities in standardised rate ratios increased in vaccine-preventable and acute ACSC rates between northern cluster and the two other clusters. Compared to the south-western cluster, 13–16% of health centre areas, in rural northern cluster, had 47–92% higher ACSC rates – but also the highest level of morbidity, most limitations on activities of daily living and highest PHC inpatient ward usage as well as the lowest education levels and private health and dental care usage.

Conclusions

We identified three differing trajectories of time trends for ACSC rates, suggesting that the quality of care, particularly in northern Finland health centre areas, may have lagged behind the general improvements. This calls for further investments to strengthen rural area PHC.

Electronic supplementary material

The online version of this article (10.1186/s12913-019-4449-7) contains supplementary material, which is available to authorized users.

Hepatitis A seroprevalence in adolescents and young adults in Mexico: A 2012 National Health and Nutrition Survey analysis

To describe hepatitis A virus (HAV) seroprevalence and associated factors in adolescents (10-19 years) and young adults (20-25 years) in different Mexican regions, using 2012 National Health and Nutrition Survey data. A random selection of 1581 serum samples was analyzed. Weighted HAV seroprevalence with 95% confidence intervals (95%CI) and its association with sociodemographic factors were estimated. Mean weighted HAV seroprevalence was 69.3% (95%CI: 64.8-73.4) overall, with 58.8% (95%CI: 53.4-64.1) in adolescents and 83.0% (95%CI: 75.3-88.7) in young adults. By age of 10, 46.7% (95%CI: 33.9-60.0) were seropositive and by age of 15, 52.8% (95%CI: 36.5-68.5), corresponding to intermediate endemicity nationally. Factors associated with HAV seropositivity (adjusted odds ratio, aOR) included: lower socioeconomic status (SES) (aOR = 4.09 for low and aOR = 2.31 for medium versus high SES), older age (aOR = 0.29 for adolescents versus young adults), living in the South (aOR = 2.12 versus Central Mexico) or in rural areas (aOR = 2.25 versus urban areas). Regional differences and increased seroprevalence of HAV in marginalized populations present an important public health issue, as a relatively large proportion of young adults are susceptible to infection. The burden of symptomatic disease must be addressed further to support specific programs of continued sanitation and education improvement, and the possibility of vaccination in more susceptible regions.

Seroprevalence and susceptibility to hepatitis A in the European Union and European Economic Area: a systematic review

Most of the European Union (EU) and European Economic Area (EEA) is considered a region of very low hepatitis A virus (HAV) endemicity; however, geographical differences exist. We did a systematic review with the aim of describing seroprevalence and susceptibility in the general population or special groups in the EU and EEA. We searched databases and public health national institutes websites for HAV seroprevalence records published between Jan 1, 1975, and June 30, 2014, with no language restrictions. An updated search was done on Aug 10, 2016. We defined seroprevalence profiles (very low, low, and intermediate) as the proportion of the population with age-specific anti-HAV antibodies at age 15 and 30 years, and susceptibility profiles (low, moderate, high, and very high) as the proportion of susceptible individuals at age 30 and 50 years. We included 228 studies from 28 of 31 EU and EEA countries. For the period 2000-14, 24 countries had a very low seroprevalence profile, compared with five in 1975-89. The susceptibility among adults ranged between low and very high and had a geographical gradient, with three countries in the low susceptibility category. Since 1975, EU and EEA countries have shown decreasing seropositivity; however, considerable regional variability exists. The main limitations of this study are that the studies retrieved for analysis might not be representative of all EU and EEA publications about HAV and might have poor national representativeness. A large proportion of EU and EEA residents are now susceptible to HAV infection. Our Review supports the need to reconsider specific prevention and control measures, to further decrease HAV circulation while providing protection against the infection in the EU and EEA, and could be used to inform susceptible travellers visiting EU and EEA countries with different HAV endemicity levels.

Hepatitis B and A vaccination in HIV-infected adults: A review

Hepatitis B and A account for considerable morbidity and mortality worldwide. Immunization is the most effective means of preventing hepatitis B and A. However, the immune response to both hepatitis vaccines seems to be reduced in HIV-infected subjects. The aim of this review was to analyze the immunogenicity, safety, long-term protection and current recommendations of hepatitis B and A vaccination among HIV-infected adults. The factors most frequently associated with a deficient level of anti-HBs or IgG anti-HAV after vaccination are those related to immunosuppression (CD4 level and HIV RNA viral load) and to the frequency of administration and/or the amount of antigenic load per dose. The duration of the response to both HBV and HAV vaccines is associated with suppression of the viral load at vaccination and, in the case of HBV vaccination, with a higher level of antibodies after vaccination. In terms of safety, there is no evidence of more, or different, adverse effects compared with HIV-free individuals. Despite literature-based advice on the administration of alternative schedules, revaccination after the failure of primary vaccination, and the need for periodic re-evaluation of antibody levels, few firm recommendations are found in the leading guidelines.

Underdiagnosis of foodborne hepatitis A, The Netherlands, 2008-2010(1.)

Outbreaks of foodborne hepatitis A are rarely recognized as such. Detection of these infections is challenging because of the infection’s long incubation period and patients’ recall bias. Nevertheless, the complex food market might lead to reemergence of hepatitis A virus outside of disease-endemic areas. To assess the role of food as a source of infection, we combined routine surveillance with real-time strain sequencing in the Netherlands during 2008–2010. Virus RNA from serum of 248 (59%) of 421 reported case-patients could be sequenced. Without typing, foodborne transmission was suspected for only 4% of reported case-patients. With typing, foodborne transmission increased to being the most probable source of infection for 16%. We recommend routine implementation of an enhanced surveillance system that includes prompt forwarding and typing of hepatitis A virus RNA isolated from serum, standard use of questionnaires, data sharing, and centralized interpretation of data.

Changes in the epidemiology of hepatitis A outbreaks 13 years after the introduction of a mass vaccination program

A hepatitis A+B vaccine vaccination program of 12-year-olds was introduced in Catalonia in 1998. The aim of this study was to investigate the evolution of hepatitis A outbreaks in Catalonia and estimate the preventable fraction of cases associated with outbreaks as a measure of the impact of the vaccination program. Hepatitis A outbreaks reported to the Health Department between 1991 and 2012 were analyzed. The incidence rates of outbreaks, outbreak-associated cases and hospitalizations were calculated. The preventable fraction (PF) and 95% confidence intervals (CI) were estimated for the whole study period (pre-vaccination and post-vaccination) and the post-vaccination period.   One-hundred-eight (108) outbreaks (rate of 2.21 per 10(6) persons-year) were reported in the pre-vaccination period and 258 outbreaks (rate of 2.82 per 10(6) persons-year) in the post-vaccination period. The rate of cases associated with outbreaks was 1.52 per 10(5) persons-year in the pre-vaccination period and 1.28 per 10(5) persons-year in the post-vaccination period. Hospitalization rates were 0.08 and 0.75 per 10(6) persons-year, respectively. The number of person-to-person outbreaks whose index case was a school contact decreased in the post-vaccination period (aOR 2.72; 95%CI 1.35-5.48), but outbreaks whose index case was a man who has sex with men (MSM) or an immigrant increased. The PF of all outbreak-associated cases was 6.46% (95%CI 3.11-9.82) and the highest PF was in the 15-24 years age group (42.53%; 95%CI 29.30-55.75). In the 0-4 years age group, the PF was 18.35% (95%CI 9.59-27.11), suggesting a protective herd effect in unvaccinated subjects. Vaccination of immigrants traveling to endemic countries and MSM should be reinforced.

Genotypic shift of the hepatitis A virus and its clinical impact on acute hepatitis A in Korea: a nationwide multicenter study

BACKGROUND

The genotypic shift of hepatitis A virus (HAV) and its correlation with clinical course has not been evaluated in acute hepatitis A (AHA).

METHODS

From June 2007 to May 2009, we prospectively enrolled 546 AHA patients. We performed a nested reverse transcriptase polymerase chain reaction (RT-PCR) using the serum samples in addition to phylogenetic analysis, then we compared patient clinical features.

RESULTS

Among 351 successfully genotyped patients, we found genotype IIIA in 178 patients (51%) and IA in 173 patients (49%). The sequences of genotype IA are identical to previously reported Korean genotype IA, and the new IIIA genotype is closely related to NOR24/Norway. We retrospectively analyzed 41 AHA samples collected from 2000 to 2006 and found that all of them were genotype IA. Patients with genotype IIIA showed significantly higher levels of aspartate aminotransferase, higher levels of alanine aminotransferase, and lower platelet counts than patients with genotype IA when comparing baseline laboratory data or peak/lowest laboratory data during the disease course. However, there were no differences in duration of hospital stay, incidence of cholestatic hepatitis, acute kidney injury, and acute liver failure, or mortality between them.

CONCLUSIONS

A genotypic shift of the HAV was identified in Korean AHA subjects, and genotype IIIA HAV has become endemic. Although there were significant differences in the biochemical responses of AHA between genotype IA and genotype IIIA patients, we did not detect any differences in clinical outcomes such as complications or mortality.

Comparative effectiveness of two doses versus three doses of hepatitis A vaccine in human immunodeficiency virus-infected and -uninfected men who have sex with men

The purpose of this prospective cohort study was to compare the serologic response between human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) receiving two and three doses of hepatitis A virus (HAV) vaccine and HIV-uninfected MSM receiving two doses of HAV vaccine. Between June 2009 and December 2010, 582 MSM aged 18 to 40 years who were seronegative for HAV were enrolled in the study. HIV-infected MSM received either two doses of HAV vaccine (1,440 enzyme-linked immunosorbent assay units) (n = 140) with the second dose given at week 24 or three doses (n = 225) with the second and third dose given at weeks 4 and 24, respectively, while HIV-uninfected MSM (n = 217) received two doses. The primary endpoint was seroconversion at week 48. The geometric mean concentration (GMC) of anti-HAV antibody was determined at weeks 48 and 72. At week 48, the seroconversion rate was 75.7%, 77.8%, and 88.5% in intention-to-treat analysis for two-dose HIV-infected, three-dose HIV-infected, and two-dose HIV-uninfected MSM, respectively. The GMC of anti-HAV antibody at week 48 for three-dose HIV-infected MSM (2.29 ± 0.73 log10 mIU/mL) was significantly higher than that for two-dose HIV-infected MSM (1.94 ± 0.66; P < 0.01), but was lower than HIV-uninfected MSM (2.49 ± 0.42; P < 0.01). Multivariate analysis revealed higher CD4 counts (adjusted odds ratio [AOR] for per 50 cells/μL increase, 1.13; 95% confidence interval [CI], 1.05-1.21) and undetectable plasma HIV RNA load (AOR, 1.90; 95% CI, 1.10-3.28) before HAV vaccination were predictive of seroconversion in HIV-infected patients.

CONCLUSION

Serologic response rate to three and two doses of HAV vaccine was similar in HIV-infected MSM, which was lower than that in HIV-uninfected MSM receiving two doses. HAV vaccination in HIV-infected patients with a higher CD4 count and suppression of HIV replication increased the seroconversion rate.

The burden of liver disease in Europe: a review of available epidemiological data

To survey the burden of liver disease in Europe and its causes 260 epidemiological studies published in the last five years were reviewed. The incidence and prevalence of cirrhosis and primary liver cancer are key to understand the burden of liver disease. They represent the end-stage of liver pathology and thus are indicative of the associated mortality. About 0.1% of Hungarian males will die of cirrhosis every year compared with 0.001% of Greek females. WHO estimate that liver cancer is responsible for around 47,000 deaths per year in the EU. Harmful alcohol consumption, viral hepatitis B and C and metabolic syndromes related to overweight and obesity are the leading causes of cirrhosis and primary liver cancer in Europe. Chronic hepatitis B affects 0.5-0.7% of the European population. In the last decade the prevalence of chronic hepatitis C was 0.13-3.26%. It is of great concern that about 90% of people in Europe infected by viral hepatitis are unaware of their status. Available data suggest the prevalence rate of NAFLD is 2-44% in the general European population (including obese children) and 42.6-69.5% in people with type 2 diabetes. Each of these four major causes of liver disease is amenable to prevention and treatment, reducing the burden of liver disease in Europe and saving lives. Further surveys are urgently needed to implement cost-effective prevention programmes and novel treatments to tackle this problem.

Increased circulation of hepatitis A virus genotype IIIA over the last decade in St Petersburg, Russia

The current study, covering the period 2004-2009, is a part of long-term monitoring for hepatitis A virus (HAV) strains circulating in St Petersburg, Russia. The HAV RNA was isolated directly from the sera of hepatitis A patients and RT-PCR was carried out using primer pairs for VP1/2A and VP1 genomic regions. PCR products were sequenced and 324 nucleotides from VP1/2A and 332 from the VP1 region were used for phylogenetic analysis. The results show that the IA subtype was the most common circulating subtype during the follow-up period, as found in the previous study: almost 90% of the isolated HAV strains belonged to the IA subtype. The large hepatitis A food-borne outbreak in St Petersburg in 2005 was caused by HAV IA. However, the proportion of HAV isolates belonging to subtype IIIA significantly increased in the period 2001-2009 (7.9%) compared to the period 1997-2000 (none found). The subtype IIIA was first found in St Petersburg in 2001 among a group of intravenous drug users. The increase in its circulation during the decade suggests that this previously unusual genotype has been permanently introduced into the general population of St Petersburg. These results indicate the usefulness of molecular epidemiological methods for studying changes in the circulation of HAV strains.

Comparative hepatitis A seroepidemiology in 10 European countries

The WHO recommends hepatitis A virus (HAV) immunization according to level of transmission and disease burden. We aimed to identify susceptible age groups by standardized serosurveys to inform HAV vaccination policy in participating countries: Belgium, Czech Republic, England, Finland, Germany, Italy, Lithuania, Malta, Romania, and Slovakia. Each country tested national serum banks (n = 1854-6748), collected during 1996-2004, for anti-HAV antibodies. Local laboratory results were standardized to common units. Forty-one per cent of those aged <30 years and 6% of those aged ≥30 years were susceptible to HAV in Romania; compared to 70-94% and 26-71%, respectively, elsewhere. Romania reported high HAV incidence in children and young adults. Other countries reported HAV disease primarily in older risk groups. The results suggest low level of HAV transmission in most of Europe. Romania, however, appeared as an area with intermediate transmission. Vaccination of risk groups in countries with high susceptibility of young and middle-aged adults needs to be continued.

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.

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.

Hepatitis A: Epidemiology and prevention in developing countries

Hepatitis A is the most common form of acute viral hepatitis in the world. Major geographical differences in endemicity of hepatitis A are closely related to hygienic and sanitary conditions and other indicators of the level of socioeconomic development. The anti-hepatitis A virus (HAV) seroprevalence rate is presently decreasing in many parts of the world, but in less developed regions and in several developing countries, HAV infection is still very common in the first years of life and seroprevalence rates approach 100%. In areas of intermediate endemicity, the delay in the exposure to the virus has generated a huge number of susceptible adolescents and adults and significantly increased the average age at infection. As the severity of disease increases with age, this has led to outbreaks of hepatitis A. Several factors contribute to the decline of the infection rate, including rising socioeconomic levels, increased access to clean water and the availability of a hepatitis A vaccine that was developed in the 1990s. For populations with a high proportion of susceptible adults, implementing vaccination programs may be considered. In this report, we review available epidemiological data and implementation of vaccination strategies, particularly focusing on developing countries.

Seroprevalence of hepatitis virus infection in men who have sex with men aged 18-40 years in Taiwan

BACKGROUND/PURPOSE

Men who have sex with men (MSM) are at increased risk for hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections than the general population. Comparisons of the seroprevalence rates of these hepatitis viruses between HIV-positive and HIV-negative MSM are rarely performed in Taiwan.

METHODS

Between January 2009 and June 2010, data on the serologies for HAV, HBV, and HCV were collected from two groups of patients: HIV-negative MSM, aged 18-40 years, who sought voluntary counseling and testing (VCT) for HIV infection, and HIV-positive MSM of the same age group who sought HIV care at the National Taiwan University Hospital. Both groups of patients were also tested for syphilis.

RESULTS

During the 18-month study period, 690 HIV-negative MSM and 438 HIV-positive MSM were enrolled and tested for anti-HAV antibody, HBV surface antigen (HBsAg), hepatitis B core antibody (anti-HBc antibody), and anti-HCV antibody. HIV-positive MSM were older than HIV-negative MSM (30.5 ± 5.4 vs. 25.8 ± 4.7 years, p < 0.01). For HIV-positive MSM, the mean CD4 lymphocyte count was 477.6 ± 230.0 cells/μL and 46% of them had undetectable plasma HIV RNA load (< 40 copies/mL by reverse transcription-polymerase chain reaction assay). The overall seroprevalence rates of HAV, HBsAg, and HCV in HIV-positive MSM were 15.1%, 16.4%, and 5.5%, respectively, while in HIV-negative MSM, they were 7.4%, 6.2%, and 0.4%, respectively. In the multivariate analysis, age was significantly associated with seropositivity for HAV (OR [per one age group increase]: 1.96; 95% CI: 1.6-2.5), HBsAg (OR: 2.02; 95% CI: 1.6-2.6), anti-HBc (OR: 2.68; 95% CI: 2.3-3.2), anti-HCV (OR: 1.67; 95% CI: 1.0-2.7), and anti-HBs (OR: 1.25; 95% CI: 1.0-1.5). HIV infection was associated with seropositivity for HBsAg (OR: 1.73; 95% CI: 1.1-2.7), anti-HBc (OR: 2.44; 95% CI: 1.8-3.3), HCV (OR: 8.91; 95% CI: 2.5-31.4), and syphilis (OR: 11.21; 95% CI: 6.7-18.9).

CONCLUSION

HIV-positive MSM have a higher seroprevalence rate of HBV and HCV infection than HIV-negative MSM in Taiwan. Vaccination and safe-sex counseling should be provided to prevent the transmission of hepatitis viruses among MSM who may be engaged in high-risk behaviors.

Hepatitis A virus genotype and its correlation with the clinical outcome of acute hepatitis A in Korea: 2006-2008

Korea has recently experienced a nationwide outbreak of hepatitis A. This study aimed to investigate hepatitis A virus (HAV) genotypes and to compare clinical features between patients infected with HAV genotype IA and those with genotype IIIA. From September 2006 to August 2008, 595 patients with symptomatic hepatitis A were enrolled prospectively in four hospitals in Korea. Among them, 556 patients participated in this study by providing serum or stool samples for genotypic analysis. HAV RNA was detected in 499 patients (89.7%). Major genotypes included IA (n = 244, 48.9%) and IIIA (n = 244, 48.9%), and the remaining genotype was IB (n = 11, 2.2%). From September 2006 to August 2007, the distribution of genotypes IA and IIIA were 64.6% and 35.6%, respectively, which changed to 42.3% and 54.6%, respectively, from September 2007 to August 2008, indicating change of circulating HAV genotypes in the study period from IA to IIIA. Major patterns of amino acid substitution in the VP3/VP1 junction region were observed at position 512 (P → L) in genotype IA and at 520 (R → K) in genotype IIIA. Patients with genotype IIIA infection showed significantly higher aminotransferase levels, prothrombin time, and leukocyte count, with more severe symptoms than those with genotype IA at the time of admission. These results suggest the occurrence of a change of circulating HAV genotypes in recent community-wide outbreaks of hepatitis A in Korea, and genotype IIIA infection, compared with genotype IA infection, might show more severe clinical manifestations.

Evaluation of tropical water sources and mollusks in southern Brazil using microbiological, biochemical, and chemical parameters

Florianópolis, a city located in the Santa Catarina State in southern Brazil, is the national leading producer of bivalve mollusks. The quality of bivalve mollusks is closely related to the sanitary conditions of surrounding waters where they are cultivated. Presently, cultivation areas receive large amounts of effluents derived mainly from treated and non-treated domestic, rural, and urban sewage. This contributes to the contamination of mollusks with trace metals, pesticides, other organic compounds, and human pathogens such as viruses, bacteria, and protozoan. The aim of this study was to perform a thorough diagnosis of the shellfish growing areas in Florianópolis, on the coast of Santa Catarina. The contamination levels of seawater, sediments, and oysters were evaluated for their microbiological, biochemical, and chemical parameters at five sea sites in Florianópolis, namely three regular oyster cultivation areas (Sites 1, 2, and oyster supplier), a polluted site (Site 3), and a heavily polluted site (Site 4). Samples were evaluated at day zero and after 14 days. Seawater and sediment samples were collected just once, at the end of the experiment. Antioxidant defenses, which may occur in contaminated environments in response to the increased production of reactive oxygen species (ROS) by organisms, were analyzed in oysters, as well as organic compounds (in oysters and sediment samples) and microbiological contamination (in oysters and seawater samples). The results showed the presence of the following contaminants: fecal coliforms in seawater samples (four sites), human adenovirus (all sites), human noroviruses GI and GII (two sites), Hepatitis A viruses (one site), JC Polyomavirus in an oyster sample from the oyster supplier, Giardia duodenalis cysts, and Cryptosporidium sp oocysts (one site). Among organochlorine pesticides, only DDT (dichlorodiphenyltrichloroethane) and HCH (hexachlorocyclohexane) were detected in some sediment and oysters samples in very low levels; site 4 had the highest concentrations of total aliphatic hydrocarbons, PAHs, and linear alkylbenzenes (LABs) found either in oysters or in sediment samples. The major concentration of fecal sterol coprostanol was found at site 4, followed by site 3. After 14 days of allocation in the four selected sites, there was a significant difference in the enzymes analyzed at the monitored spots. The detection of different contaminants in oysters, seawater, and sediment samples in the present study shows the impact untreated or inadequately treated effluents have on coastal areas. These results highlight the need for public investment in adequate wastewater treatment and adequate treatment of oysters, ensuring safe areas for shellfish production as well as healthier bivalve mollusks for consumption.

Seroprevalence of hepatitis a and associated socioeconomic factors in young healthy korean adults

BACKGROUND/AIMS

An epidemiologic shift of hepatitis A virus (HAV) seroprevalence is expected due to an improvement in socioeconomic status in young adults in Korea. We investigated the age-specific seroprevalence and socioeconomic factors associated with HAV seropositivity in young, healthy Korean adults.

METHODS

Between March 2009 and February 2010, a total of 5,051 persons from 20 to 49 years of age presenting for a health check-up were included and responded to a questionaire. The seroprevalence of HAV was investigated by measuring immunoglobulin G (IgG) anti-HAV. A total of 984 pairs of cases and age- and sex-matched controls were analyzed for associated socioeconomic factors.

RESULTS

The prevalence of seropositive HAV was 6.2% in the 20 to 29 age range, 33.1% in the 30 to 39 range and 82.4% in the 40 to 49 range (p<0.001). There were no significant differences in any group according to gender. A multivariate analysis for paired cases indicated that HAV seropositivity was significantly higher in the low monthly income (below five million won, approximately 4,300 dollars) group and the Helicobacter pylori (H. pylori)-positive group (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.27-2.14; p<0.001; OR, 1.45; 95% CI, 1.19-1.76; p<0.001, respectively).

CONCLUSIONS

HAV seropositivity in young adults presenting for a health checkup appears to be decreasing, and the prevalence was significantly higher in the low monthly income group and the H. pylori-positive group.