Systematic review and meta-analysis of hepatitis E seroprevalence in Southeast Asia: a comprehensive assessment of epidemiological patterns.

The burden of hepatitis E in Southeast Asia is substantial, influenced by its distinct socio-economic and environmental factors, as well as variations in healthcare systems. The aim of this study was to assess the pooled seroprevalence of hepatitis E across countries within the Southeast Asian region by the UN division.The study analyzed 66 papers across PubMed, Web of Science, and Scopus databases, encompassing data from of 44,850 individuals focusing on anti-HEV seroprevalence. The investigation spanned nine countries, excluding Brunei and East Timor due to lack of data. The pooled prevalence of anti-HEV IgG was determined to be 21.03%, with the highest prevalence observed in Myanmar (33.46%) and the lowest in Malaysia (5.93%). IgM prevalence was highest in Indonesia (12.43%) and lowest in Malaysia (0.91%). The study stratified populations into high-risk (farm workers, chronic patients) and low-risk groups (general population, blood donors, pregnant women, hospital patients). It revealed a higher IgG-28.9%, IgM-4.42% prevalence in the former group, while the latter group exhibited figures of 17.86% and 3.15%, respectively, indicating occupational and health-related vulnerabilities to HEV.A temporal analysis (1987-2023), indicated an upward trend in both IgG and IgM prevalence, suggesting an escalating HEV burden.These findings contribute to a better understanding of HEV seroprevalence in Southeast Asia, shedding light on important public health implications and suggesting directions for further research and intervention strategies.Key pointsResearch QuestionInvestigate the seroprevalence of hepatitis E virus (HEV) in Southeast Asian countries focusing on different patterns, timelines, and population cohorts.FindingsSporadic Transmission of IgG and IgM Prevalence:• Pooled anti-HEV IgG prevalence: 21.03%• Pooled anti-HEV IgM prevalence: 3.49%Seroprevalence among specific groups:High-risk group (farm workers and chronic patients):• anti-HEV IgG: 28.9%• anti-HEV IgM: 4.42%Low-risk group (general population, blood donors, pregnant women, hospital patients):• anti-HEV IgG: 17.86%• anti-HEV IgM: 3.15%Temporal Seroprevalence of HEV:Anti-HEV IgG prevalence increased over decades (1987-1999; 2000-2010; 2011-2023): 12.47%, 18.43%, 29.17% as an anti-HEV IgM prevalence: 1.92%, 2.44%, 5.27%ImportanceProvides a comprehensive overview of HEV seroprevalence in Southeast Asia.Highlights variation in seroprevalence among different population groups.Reveals increasing trend in HEV seroprevalence over the years.Distinguishes between sporadic and epidemic cases for a better understanding of transmission dynamics.

An updated assessment of hepatitis delta prevalence among adults in Canada: A meta-analysis.

Foreign-born (FB) persons represent a large proportion of adults with chronic hepatitis B (CHB) in Canada due to higher prevalence rates in countries of birth for FB persons. Suboptimal awareness and low rates of hepatitis delta virus (HDV) testing contribute to underdiagnosis and gaps in accurate estimates of Canada HDV prevalence. We aim to provide an assessment of CHB and HDV prevalence in Canada using a comprehensive literature review and meta-analysis. A comprehensive literature review of articles reporting HBsAg seroprevalence and anti-HDV prevalence was conducted to calculate country-specific rates and pooled prevalence of CHB and HDV using meta-analyses. Country-specific CHB and HDV rate estimates were combined with number of FB persons in Canada in 2021 from Statistics Canada to estimate total numbers of FB with CHB and HDV, respectively. These estimates were combined with estimates of Canada-born persons with CHB and HDV to yield the total number of persons with CHB and HDV. In 2021, we estimated 0.550 million (M) (95% CI 0.488-0.615) persons with CHB; 0.344 M (95% CI 0.288-0.401) were FB and 0.206 M (95% CI: 0.200-0.214) were Canada-born. The weighted average HDV prevalence among FB persons in Canada was 5.19% (17,848 [95% CI 9611-26,052] persons), among whom 50% emigrated from Asia and 31% from Africa. When combined with estimates of Canada-born persons with HDV, we estimate 35,059 (95% CI: 18,744-52,083) persons with HDV in Canada. In conclusion, we estimate 0.550 M and 35,059 persons living with CHB and HDV, respectively, in Canada in 2021.

Risk assessment for hepatitis E virus infection from domestic pigs introduced into an experimental animal facility in a medical school.

Hepatitis E virus (HEV) is known to cause zoonotic infections from pigs, wild boars and deer. Domestic pigs have been used as an experimental animal model in medical research and training; however, the risks of HEV infection from pigs during animal experiments are largely unknown. Here, we retrospectively investigated the seroprevalence and detection rates of viral RNA in 73 domestic pigs (average 34.5 kg) introduced into an animal experimental facility in a medical school during 2012-2016. We detected anti-HEV immunoglobulin G antibodies in 24 of 73 plasma samples (32.9%), though none of the samples were positive for viral RNA. Plasma samples of 18 pigs were sequentially monitored and were classified into four patterns: sustained positive (5 pigs), sustained negative (5 pigs), conversion to positive (6 pigs) and conversion to negative (2 pigs). HEV genomes were detected in 2 of 4 liver samples from pigs that were transported from the same farm during 2016-2017. Two viral sequences of the overlapping open reading frame (ORF) 2/3 region (97 bp) were identical and phylogenetically fell into genotype 3. A 459-bp length of the ORF2 region of an amplified fragment from a pig transported in 2017 was clustered with the wbJYG1 isolate (subgenotype 3b) with 91.5% (420/459 bp) nucleotide identity. Based on our results, we suggest that domestic pigs introduced into animal facilities carry a potential risk of HEV infection to researchers, trainees and facility staff. Continuous surveillance and precautions are important to prevent HEV infection in animal facilities.

Performance evaluation of five commercial assays in assessing seroprevalence of HEV antibodies among blood donors.

INTRODUCTION: Although hepatitis E virus (HEV) is mainly transmitted via the faecal-oral route, the rate of HEV transmission via blood donation is on the rise. However, the seroprevalence of HEV among blood donors is not well established and is thought to be affected by the type of diagnostic assay used. We aimed to evaluate performance and correlation among widely used commercial diagnostic assays for the seroprevalence assessment of HEV-IgM/IgG among blood donors. METHODOLOGY: A total of 1049 blood donor samples were tested for HEV IgG and IgM using different enzyme immunoassays (Wantai, Eruoimmune, MP diagnostics, Mikrogen immunoblot, HEV-IgM rapid test). The performance of each assay was evaluated according to our established silver standard value based on three or more IgG concordant assay results. RESULTS: HEV seroprevalence varied considerably using these assays, ranging from 10.1 % (Euroimmune-ELISA) to 18.0 % (Wanti-ELISA) for HEV-IgG, and from 0.2 % (Wanti-ELISA) to 2.6 % (MP Rapid test) for HEV-IgM. A total of 155 of 216 (71.6%) samples tested positive for HEV-IgG by three or more concordant assays. On the other hand, IgM assays showed poor agreement as only 7.6 % (4/52) of the specimens were positive according to three or more concordant assay test results. All HEV-IgG assays revealed high sensitivity and specificity (ranging 96.5-100 %),and excellent Kappa concordance (0.88-0.95), except for Euroimmun ELISA (sensitivity=61.5 %, kappa=0.63). MP ELISA showed the highest levels of sensitivity (100 %) and specificity (98.5 %). CONCLUSIONS: Due to discrepancies in the performance of various IgG and IgM assays, seroprevalence studies should be based on furher confirmatory testing for decisive conclusions to be reached.

Seroepidemiology of HEV and HAV in two populations with different socio-economic levels and hygienic/sanitary conditions.

The epidemiological scenarios of hepatitis E virus (HEV) and hepatitis A virus (HAV) infections have changed in the last few decades, but precise epidemiological data on the prevalence of anti-HEV and anti-HAV, alone or in combination, in the general population are scanty. We investigated HEV and HAV seroprevalence comparing two population samples living in Northern (Abbiategrasso, Milan) and Southern Italy (Cittanova, Reggio Calabria), the latter being characterized by a poorer socio-economic level and hygienic/sanitary conditions. Based on census records, we randomly enrolled and tested 3,365 subjects (Abbiategrasso, n = 2,489; Cittanova, n = 876) aged 18-75 years for anti-HAV and anti-HEV. Anti-HAV (71.3 % vs 52.5 %) and anti-HEV (17.8 % vs 9.0 %) prevalence rates were higher in Southern Italy (both p < 0.001). Most anti-HEV-positive subjects also had anti-HAV. Subjects testing positive for anti-HAV, alone or with anti-HEV, were older (p < 0.001 in both populations) and showed a trend toward declining prevalence in the youngest birth cohorts. The prevalence of subjects with a positive result for anti-HEV alone did not change in birth cohorts in the two towns. Detection of anti-HEV was independently associated with anti-HAV, town, birth cohort, and education level in multivariate analysis. Low socio-economic level and hygienic/sanitary conditions are associated with high HAV and HEV seroprevalence rates in Italy. Recent improvements, especially in the South, have led to a declining prevalence of anti-HAV, alone or with anti-HEV. Seroprevalence of HEV alone is uniformly low and does not change in birth cohorts born between 1938 and 1993.

Assessment of Domestic Pigs, Wild Boars and Feral Hybrid Pigs as Reservoirs of Hepatitis E Virus in Corsica, France.

In Corsica, extensive pig breeding systems allow frequent interactions between wild boars and domestic pigs, which are suspected to act as reservoirs of several zoonotic diseases including hepatitis E virus (HEV). In this context, 370 sera and 166 liver samples were collected from phenotypically characterized as pure or hybrid wild boars, between 2009 and 2012. In addition, serum and liver from 208 domestic pigs belonging to 30 farms were collected at the abattoir during the end of 2013. Anti-HEV antibodies were detected in 26% (21%-31.6%) of the pure wild boar, 43.5% (31%-56.7%) of hybrid wild boar and 88% (82.6%-91.9%) of the domestic pig sera. In addition, HEV RNA was detected in five wild boars, three hybrid wild boars and two domestic pig livers tested. Our findings provide evidence that both domestic pig and wild boar (pure and hybrid) act as reservoirs of HEV in Corsica, representing an important zoonotic risk for Corsican hunters and farmers but also for the large population of consumers of raw pig liver specialties produced in Corsica. In addition, hybrid wild boars seem to play an important ecological role in the dissemination of HEV between domestic pig and wild boar populations, unnoticed to date, that deserves further investigation.

Hepatitis delta virus testing, epidemiology and management: a multicentre cross-sectional study of patients in London.

BACKGROUND: Hepatitis delta virus (HDV) testing is recommended for all patients with hepatitis B virus (HBV) infection. HDV infection is associated with severe liver disease and interferon is the only available treatment. OBJECTIVES: To determine the rate of anti-HDV antibody testing in HBV patients; and to describe the epidemiology, clinical characteristics and management of HDV-infected patients at four hospitals in London. STUDY DESIGN: The anti-HDV testing rate was estimated by reviewing clinical and laboratory data. Cross-sectional data collection identified HDV-infected patients who had attended the study centres between 2005 and 2012. RESULTS: At a centre with clinic-led anti-HDV testing, 40% (67/168) of HBV patients were tested. Recently diagnosed HBV patients were more likely to be screened than those under long-term follow-up (62% vs 36%, P=0.01). At a centre with reflex laboratory testing, 99.4% (3543/3563) of first hepatitis B surface antigen positive samples were tested for anti-HDV. Across the four study centres there were 55 HDV-infected patients, of whom 50 (91%) had immigrated to the UK and 27 (49%) had evidence of cirrhosis. 31 patients received interferon therapy for HDV with an end of treatment virological response observed in 10 (32%). CONCLUSIONS: The anti-HDV testing rate was low in a centre with clinic-led testing, but could not be evaluated in all centres. The HDV-infected patients were of diverse ethnicity, with extensive histological evidence of liver disease and poor therapeutic responses. Future recommendations include reflex laboratory testing algorithms and a prospective cohort study to optimise the investigation and management of these patients.

HCV antigen testing for the diagnosis of hepatitis C infection: a cost-efficient algorithm.

BACKGROUND: In North America, diagnosis of active hepatitis C virus (HCV) infection is currently performed using RNA testing which is highly sensitive and specific but is associated with three major limitations: lability of RNA molecules, higher costs, and longer turn-around time as compared with commercially-available HCV core antigen testing. In the current study, a new HCV core antigen assay product was evaluated for the diagnosis of HCV infection and its cost reducing potential. METHODS: Ninety plasma specimens positive for HCV RNA along with 25 negative HCV specimens were used for HCV antigen assay. Twenty-four specimens positive for a panel of agents were used for possible cross-reactivity. Sixty-four HCV antibody-positive specimens with negative HCV RNA and indeterminate HCV immunoblot results were also employed. RESULTS: In the first group, 78/90 (86.6%) tested positive for HCV antigen with regression analysis showing no significant deviation from linearity. None of the prenatal specimens tested positive for HCV antigen. Non-specific reactions were not observed. In the HCV antibody-indeterminate group, only 2/64 (3.1%) were antigen positive. In the last group, none of the HCV antibody very-low-positive specimens tested positive for HCV antigen. Both inter- and intra-run reproducibility of 100% were noted. The cost analysis showed a minimum of 52.13% reduction in costs associated with qualitative RNA testing. CONCLUSIONS: Considering the complexity of HCV infection diagnosis and the significant cost and turn-around time burden it imposes on clinical laboratories, HCV antigen testing seems an attractive adjunct to the current battery of laboratory diagnosis that demands more attention.

Assessment of dried blood samples as an alternative less invasive method for detection of Hepatitis E virus marker in an outbreak setting.

Hepatitis E virus (HEV) is the causative agent of hepatitis E. It can be asymptomatic, associated with acute self-limiting hepatitis or acute liver failure. The conventional diagnosis of HEV infection relies on anti-HEV IgM serology. The collection of blood samples by venepunture for laboratory confirmation is often difficult during an outbreak. Thus, testing the specimens of dried blood spots (DBS) on filter papers can prove to be a feasible alternative. The present study aimed to evaluate the applicability of anti-HEV IgM detection from DBS samples and the stability of anti-HEV IgM detection at varied time interval, at various storage temperatures. Paired blood and DBS sample were collected from 44 jaundiced patients and eight healthy controls during HEV outbreaks. The DBS were tested for anti-HEV IgM by available ELISA kit with in-house modifications. Three cut offs were determined, that is, the CO1: kit cut-off, CO2: mean of negative controls above 3SD and CO3: area under Receiver operating Curve. The sensitivity of anti-HEV IgM detection ranged from 86-91%. The maximum sensitivity (91%) and specificity (100%) was obtained using CO3. Maximum stability of anti-HEV IgM antibodies (100%) was observed till 65 days at 4°C. Storage at 37°C significantly reduced anti-HEV IgM positivity, wherein 42.85% sample became negative by 45 days. DBS showed good sensitivity and specificity for detecting anti-HEV IgM and can be considered an alternate to serum sample. Moreover, anti-HEV IgM was stable at 4°C, which makes DBS a preferred method for storage and transportation of the sample to reference laboratory.

An assessment of hepatitis E virus (HEV) in US blood donors and recipients: no detectable HEV RNA in 1939 donors tested and no evidence for HEV transmission to 362 prospectively followed recipients.

BACKGROUND: Hepatitis E virus (HEV) infection has become relevant to blood transfusion practice because isolated cases of blood transmission have been reported and because HEV has been found to cause chronic infection and severe liver disease in immunocompromised patients. STUDY DESIGN AND METHODS: We tested for immunoglobulin (Ig)G and IgM antibodies to the HEV and for HEV RNA in 1939 unselected volunteer US blood donors. Subsequently, we tested the same variables in pre- and serial posttransfusion samples from 362 prospectively followed blood recipients to assess transfusion risk. RESULTS: IgG anti-HEV seroprevalence in the total 1939 donations was 18.8%: 916 of these donations were made in 2006 at which time the seroprevalence was 21.8% and the remaining 1023 donations were in 2012 when the seroprevalence had decreased to 16.0% (p < 0.01). A significant (p < 0.001) stepwise increase in anti-HEV seroprevalence was seen with increasing age. Eight of 1939 donations (0.4%) tested anti-HEV IgM positive; no donation was HEV RNA positive. Two recipients had an apparent anti-HEV seroconversion, but temporal relationships and linked donor testing showed that these were not transfusion-transmitted HEV infections. CONCLUSION: No transfusion-transmitted HEV infections were observed in 362 prospectively followed blood recipients despite an anti-HEV seroprevalence among donations exceeding 16%.

Assessment of the cross-protective capability of recombinant capsid proteins derived from pig, rat, and avian hepatitis E viruses (HEV) against challenge with a genotype 3 HEV in pigs.

Hepatitis E virus (HEV), the causative agent of hepatitis E, is primarily transmitted via the fecal-oral route through contaminated water supplies, although many sporadic cases of hepatitis E are transmitted zoonotically via direct contact with infected animals or consumption of contaminated animal meats. Genotypes 3 and 4 HEV are zoonotic and infect humans and other animal species, whereas genotypes 1 and 2 HEV are restricted to humans. There exists a single serotype of HEV, although the cross-protective ability among the animal HEV strains is unknown. Thus, in this study we expressed and characterized N-terminal truncated ORF2 capsid antigens derived from swine, rat, and avian HEV strains and evaluated their cross-protective ability in a pig challenge model. Thirty, specific-pathogen-free, pigs were divided into 5 groups of 6 pigs each, and each group of pigs were vaccinated with 200 µg of swine HEV, rat HEV, or avian HEV ORF2 antigen or PBS buffer (2 groups) as positive and negative control groups. After a booster dose immunization at 2 weeks post-vaccination, the vaccinated animals all seroconverted to IgG anti-HEV. At 4 weeks post-vaccination, the animals were intravenously challenged with a genotype 3 mammalian HEV, and necropsied at 4 weeks post-challenge. Viremia, fecal virus shedding, and liver histological lesions were compared to assess the protective and cross-protective abilities of these antigens against HEV challenge in pigs. The results indicated that pigs vaccinated with truncated recombinant capsid antigens derived from three animal strains of HEV induced a strong IgG anti-HEV response in vaccinated pigs, but these antigens confer only partial cross-protection against a genotype 3 mammalian HEV. The results have important implications for the efficacy of current vaccines and for future vaccine development, especially against the novel zoonotic animal strains of HEV.

Prevalence of leptospira in acute hepatitis syndrome and assessment of IL-8 and TNF-alpha level in leptospiral hepatitis.

To study the prevalence of leptospira in acute hepatitis syndrome and to assess interleukin (IL)-8 and tumour necrosis factor (TNF)-alpha levels in the pathogenesis of hepatitis due to leptospiral infection. Two hundred and forty-seven consecutive cases with symptoms of acute hepatitis and 30 healthy controls were enrolled in the study and detailed clinical history was elicited from them. Enzyme-linked immunosorbent assays (ELISAs) for HAV, HBV, HCV and HEV were performed to rule out common viral aetiology of hepatitis. IgM antibodies to leptospira were detected by ELISA. IL-8 and TNF-alpha levels were estimated in leptospira-positive cases and healthy controls by ELISA. Out of 247 cases of acute hepatitis, 46 (18.62%) were observed to be positive for IgM antibodies for leptospira. The mean age of these patients was 31.99 ± 0.28 years (25 males and 21 females; M/F ratio: 1.19:1). The mean ALT, AST and ASP were raised in the majority of patients. IL-8 was found to be elevated (130.81 pg/ml) in a large majority of cases 41/46, 89.1% (P < 0.001). Patients with more severe symptoms were associated with higher levels of IL-8. One mortality was observed due to leptospira. Unpredictably, TNF-alpha level was largely suppressed (45.63 pg/ml) in most of the leptospira-positive patients in comparison with healthy controls. Leptospira-induced hepatitis should be actively looked for in patients negative for A-E viral hepatitis. IL-8 appears to play an important role in the pathogenesis of leptospiral hepatitis. High TNF-alpha should alert clinicians for aggressive in hospital management of patients.

Correlation of hepatitis C RNA and serum alanine aminotransferase in hepatitis B and C seronegative healthy blood donors.

INTRODUCTION: Historically, serum alanine transaminase (ALT) has been used as a surrogate marker in the detection of hepatitis viruses in blood donors. With the availability of newer sensitive technologies for the detection of seroconversion, the value of ALT becomes questionable but continues to be used for this purpose with subsequent discarding of ALT elevated blood units. OBJECTIVE: The present study aims to evaluate the significance and cost effectiveness of ALT as a surrogate marker for hepatitis C virus infection in healthy asymptomatic blood donors who were serologically negative. MATERIALS AND METHODS: The study was conducted at clinical laboratory of a tertiary care hospital for a period of one year from November 2006 to October 2007. All donors were screened serologically for hepatitis B, C and HIV I and II, syphilis and malaria and those tested positive were excluded from further evaluation. Gender-wise reference ranges and minimal and markedly raised results for ALT (described respectively as one and two folds increase above reference range) were defined and, accordingly, donors were grouped into three. Two hundred seronegative blood donors were randomly selected from all three groups of ALT results and tested for hepatitis C nucleic acid through Amplicor HCV RNA test. The cost of discarding an ALT -only elevated blood unit was also assessed. During the study period, 25117 subjects donated blood. EIGHT HUNDRED AND RESULTS: Seventy two donors (3.4%) were positive for one or more serological tests. ALT of all donors ranged from 0-1501 U/L (Mean +/- SD; 33.4 +/- 25.45 U/L). The donors seronegative for all disease markers were 24245 (96.6%). Of these, 21164 (87.2%) donors had their ALT within reference range while 2874 (11.8%) and 207 (0.8%) of donors had minimal and markedly elevated results. Thus, 621 blood bags (red cells, platelets and plasma) costing $ 39200.0 were discarded based on ALT results alone. Of 200 seronegative donors evaluated for hepatitis C nucleic acid, only one within markedly elevated ALT levels was found to be positive. The present work did not support a positive association between hepatitis C virus nucleic acid and elevated ALT in healthy serologically negative blood donors. CONCLUSION: We did not find serum ALT testing in donors as cost effective strategy for detection of hepatitis C virus ribonucleic acid. As the number of samples tested by us was small we suggest further work to evaluate the value of ALT levels in serologically negative donors in association with hepatitis C antigen and NAT testing to elucidate the true burden of disease in geographical regions where hepatitis C is endemic and voluntary blood donation is sparse.

Prevalence and risk factors for viral hepatitis in the Kosovarian population: implications for health policy.

The prevalence of hepatitis infection among the Kosovarian population is largely unknown. The aim of the study was to evaluate the prevalence and risk factors of hepatitis A, B, C, and D (HAV, HBV, HCV, HDV) infection among the general population and in a group of health care workers in the Kosovo region. Overall, 1,287 participants were recruited, 460 males (36%) and 827 females (64%). Health care workers accounted for 253 individuals (20%), 301 were blood donor candidates (23%), 334 were pregnant women (26%), and 399 (31%) were subjects who had been examined in two clinics for routine laboratory testing. The prevalence of total anti-HAV was 88.6% (95% CI: 86.69-90.25). Prevalence of anti-HAV among children up to 10 years was 40.5% (95% CI: 29.6-53.15), reaching 70% (95% CI: 62.25-77.10) in the 11-20 age group. Age, living in rural areas and unemployment were factors associated with higher risk of HAV infection. HBsAg was detected in 2.4% (95% CI: 1.57-3.38%) of the study sample, with a significant age trend (P-value:0.0110). Positivity for total anti-HBc was detected in 18.4% (95% CI = 16.27-20.59) of the subjects. Ninety-three subjects (7.2%) were positive for anti-HBs alone. An association between age, HSV-2 positivity, working nurses and HBV infection has been observed. One patient was HDV positive. The prevalence for HCV was 0.5% (95% CI: 0.22-1.12%). HAV infection seems to be high-intermediate, while HBV shows an intermediate endemicity. It is necessary to highlight the importance of an immunization strategy against HAV and HBV in reducing the incidence of the infection. The prevalence for HCV was very low.

Poor validity of self-reported HBV vaccination among young heroin users in Spain supports the policy "don't ask, draw a blood sample, vaccinate and try to schedule another visit".

OBJECTIVES: To assess the validity of self-reported hepatitis B virus vaccination status in young heroin users. STUDY DESIGN: Cross-sectional study among 949 street-recruited young injection heroin users (IHUs) and non-injection heroin users (NIHUs) in Madrid, Barcelona and Seville. Face-to-face interviews and dried blood spot tested for anti-HBc and anti-HBs. The validity of self-reported vaccination status was assessed comparing with the serological status. The percentage of agreement with the kappa (kappa) statistic and the positive predictive value were calculated. RESULTS: The percentage of agreement between self-reported and serologic vaccination status was 51.9% overall, with little difference by city (53.1% in Barcelona, 49.0% in Madrid and 51.5% in Seville) or between IHUs (51.3%) and NIHUs (53.0%). All the kappa scores were lower than 0.1. The positive predictive value of self-reports was less than 25% in all categories analysed, except in the city of Barcelona (37%). Among those who indicated that they had been vaccinated, 31% were actually susceptible. CONCLUSIONS: In areas with a high prevalence of infection and rising coverage of vaccination the policy "don't ask, take a blood sample, give a dose of vaccine and try to schedule another visit" should be recommended in clinical practice.

Cost/benefit of laboratory tests.

BACKGROUND: Insurers choose laboratory test requirements to maximize the relationship between cost and benefit. Traditional means of analysis, such as experience studies, take years or decades to perform. Cost/benefit models provide a more timely option by projecting possible experience according to different scenarios. METHODS: The article describes how to create a cost/benefit model. RESULTS: Hemoglobin A1c and hepatitis C virus antibody tests--and more generally tests reflexed after a prior abnormal test--often have the highest cost/benefit ratio. Mortality savings is higher for tests done on older aged applicants (except for impairments that are more common in young people) and on tobacco users. Indirect costs, such as time, overhead, delays, and false positives, decrease the cost/benefit of testing. Entire markets may follow inefficient testing strategies because insurers do not deviate from the practices of market leaders. CONCLUSION: Cost/benefit analysis helps insurers set underwriting requirements by age, gender, tobacco/nontobacco status, and policy amount.

[Hepatitis A and E virus antibodies in Chilean children of low socioeconomic status: a one year follow-up study]. / Seguimientos de anticuerpos contra hepatitis A y E en una cohorte de niños de bajo nivel socioeconómico.

BACKGROUND: The seroprevalence of antibodies against hepatitis A virus (HAV) is decreasing in many Latin American countries, along with improvements in sanitary standards. However, there is no information available about low socioeconomic status (LSE) populations. AIM: To assess the evolution of hepatitis A and E virus antibodies in a cohort of LSE Chilean children. MATERIAL AND METHODS: One hundred sixty eight children aged four years, 97 males, coming from public primary care clinics, were studied. Two blood samples were obtained with an interval of one year. Anti-HAV and anti-hepatitis E virus (HEV) antibodies, were detected by ELISA using Abbott kits. RESULTS: Anti-HAV was positive in 19 children (11.3%). After one year of follow-up, only 10 children had sustained reactivity (52.6%). Fourteen children, initially negative, became positive during the follow up (9.4%). Antibody titers to HAV were significantly higher in samples that remained positive, compared with those that lost reactivity. Anti-HEV was found positive in two children (1.2%). One remained positive and the other became negative. CONCLUSIONS: In this cohort of LSE Chilean children, the prevalence to antibodies against HAV and HEV is low. Follow-up detected loss of reactivity to HAV in nearly one half of the children, probably related to lower antibody levels.

Seguimientos de anticuerpos contra hepatitis A y E en una cohorte de niños de bajo nivel socioeconómico / Hepatitis A and E virus antibodies in Chilean children of low socioeconomic status. A one year follow-up study

Background: The seroprevalence of antibodies against hepatitis A virus (HAV) is decreasing in many Latin American countries, along with improvements in sanitary standards. However, there is no information available about low socioeconomic status (LSE) populations. Aim: To assess the evolution of hepatitis A and E virus antibodies in a cohort of LSE Chilean children. Material and methods: One hundred sixty eight children aged four years, 97 males, coming from public primary care clinics, were studied. Two blood samples were obtained with an interval of one year. Anti-HAV and anti-hepatitis E virus (HEV) antibodies, were detected by ELISA using Abbott kits. Results: Anti-HAV was positive in 19 children (11.3%). After one year of follow-up, only 10 children had sustained reactivity (52.6%). Fourteen children, initially negative, became positive during the follow up (9.4%). Antibody titers to HAV were significantly higher in samples that remained positive, compared with those that lost reactivity. Anti-HEV was found positive in two children (1.2%). One remained positive and the other became negative. Conclusions: In this cohort of LSE Chilean children, the prevalence to antibodies against HAV and HEV is low. Follow-up detected loss of reactivity to HAV in nearly one half of the children, probably related to lower antibody levels.