A Public Health initiative on hepatitis E virus epidemiology, safety and control in Portugal--study protocol

Hepatitis E Virus in Individuals Undergoing Heparin Therapy: An Observational Serological and Molecular Study

INTRODUCTION

Heparin is derived from swine and has been suggested as a possible source of HEV. To study the potential risk of HEV infection associated with heparin treatment, two groups of individuals were compared. Sera from heparinized (N=93) and non-heparinized individuals (N=111) were tested for markers of acute HEV infection and anti-HEV IgG seroprevalence.

METHODS

An acute HEV case was defined by the presence of anti-HEV IgM and/or HEV RNA. From the 93 heparinized individuals, one was positive for IgM and IgG anti-HEV and two were positive for HEV RNA (for both ORF3 and ORF2), and there were a total of two (2.2%) cases of current or recent HEV infection. From the 111 non-heparinized individuals, three were positive for IgM anti-HEV, one was positive for both IgM and IgG anti-HEV, and none was positive for HEV RNA, and there were a total of three (2.7%) cases of current or recent HEV infection. The difference between HEV cases in the heparinized individuals and the non-heparinized individuals was not statistically significant (2.2% vs. 2.7%; p = 0.799).

RESULTS

Concerning IgG anti-HEV, it was detected in 32 individuals from the heparinized group and in 18 from the non-heparinized control group. A statistically significant difference was observed in the presence of anti-HEV IgG in heparinized individuals and controls (p = 0.003).

CONCLUSION

This study has not found any association between heparin treatment and acute HEV infection, but has shown the use of therapeutic heparin as a risk factor for IgG anti-HEV seropositivity.

Control of Raw Pork Liver Sausage Production Can Reduce the Prevalence of HEV Infection

After an acute hepatitis E (HEV) outbreak in Southern Switzerland, in January 2017 the local public health authorities started an active program of food chain control and public education. In this retrospective study, we analysed all laboratory-confirmed acute cases of HEV infection diagnosed between 2014 and 2020. In the period before the public health intervention, the number of cases increased steadily from 2014 (4 of 40 tests, 10%) reaching a peak in the last quarter of 2016 (42 of 285 tests, 14.7 %). Afterwards, the number of positive cases decreased steadily, reaching its lowest value (0.3%) in the second quarter of 2019. There was a statistically significant difference between the frequency of positive cases and period of testing, i.e., before and after the introduction of the public health interventions. Our study shows that active public health measures to control sausages containing raw pork liver can reduce the prevalence of HEV infection.

A nationwide serosurvey of hepatitis E virus antibodies in the general population of Portugal

BACKGROUND

Evidence has shown that Hepatitis E virus (HEV) genotype 3 is autochthonous in industrialized countries due to zoonotic transmission through direct contact or consumption of raw or undercooked meat from domestic swine or wild boar. As there is lack of data on seroprevalence of HEV in the general Portuguese population, a wide survey was conducted as part of the HEPeCONTROL project (60DT2), under EEA grants funding.

METHODS

Sera from a representative sample of the Portuguese population (n = 1656) at different geographic locations (30 territorial units), and age (0-99 years) were collected between July 2015 and February 2016. The sera were tested for the presence of anti-HEV IgG and IgM by EIA using one of the two most commonly used commercial immunoassays in Europe.

RESULTS

The overall HEV IgG seroprevalence was found to be 16.3% increasing with age (P < 0.05) from 0.6% in the 0-9 years group to 30.1% in people older than 70 years. The seroprevalence also varied geographically with generally higher seropositivities (25-30%) in the most rural areas of Portugal. However, the geographical differences were not statistically significant (P > 0.05). Out of 1656 samples, 8 were positive for anti-HEV IgM indicating current of recent HEV infection but no significant differences were found concerning age groups, regions and sex.

CONCLUSIONS

The present nation-wide survey provides insight in the epidemiology of HEV in Portugal and confirms that HEV is endemic in the Portuguese population.

Seroprevalence of Hepatitis E Virus Antibodies in Portuguese Children

BACKGROUND

Hepatitis E virus (HEV) has become a growing public health concern in industrialized countries. Most of the HEV seroprevalence studies have focused on adult populations, and reports regarding HEV seroepidemiology among children are scarce in these countries. The aims of this work were to perform a nationwide seroprevalence study on HEV infection in Portuguese children and to compare the HEV seropositivity in this 2015 children cohort with results in sera performed 20 years earlier.

METHODS

Sera (N = 352) from children collected in 2015 from all regions of Portugal were screened for anti-HEV IgG and IgM using the commercial enzyme-linked immunosorbent assay recomWell HEV IgG/IgM (2015 version; Mikrogen, Neuried, Germany), and positive samples were retested by immunodot assay recomLine HEV IgG/IgM (2015 version; Mikrogen, Neuried, Germany). For the comparative assessment of HEV seropositivity of the 2 children cohorts, children's sera (N = 71) archived since 1995 were screened for anti-HEV IgG and results were compared with that of the 2015 cohort, matched by sex, age and region.

RESULTS

Anti-HEV antibodies were detected in 4 children giving an overall HEV seroprevalence in the 2015 cohort of 1.1%. A healthy 10-15-year-old female was found positive for anti-HEV IgM indicating a current or recent HEV infection. No statistically significant difference was observed in HEV seroprevalence regarding gender, age group and region of residence. Comparison of the HEV seropositivity of the 2 children cohorts showed a statistical significant decrease with time (P = 0.024).

CONCLUSIONS

This is the first national study of HEV seroprevalence in Portuguese children and the first to demonstrate a decrease of anti-HEV antibodies in this age group over time.

Hepatitis E and blood donation safety in selected European countries: a shift to screening?

The public health implications of hepatitis E virus (HEV) in Europe have changed due to increasing numbers of hepatitis E cases and recent reports of chronic, persistent HEV infections associated with progression to cirrhosis in immunosuppressed patients. The main infectious risk for such immunosuppressed patients is exposure to undercooked infected pork products and blood transfusion. We summarised the epidemiology of HEV infections among blood donors and also outlined any strategies to prevent transfusion-transmitted HEV, in 11 European countries. In response to the threat posed by HEV and related public and political concerns, most of the observed countries determined seroprevalence of HEV in donors and presence of HEV RNA in blood donations. France, Germany, Spain and the United Kingdom (UK) reported cases of transfusion-transmitted HEV. Ireland and the UK have already implemented HEV RNA screening of blood donations; the Netherlands will start in 2017. Germany and France perform screening for HEV RNA in several blood establishments or plasma donations intended for use in high-risk patients respectively and, with Switzerland, are considering implementing selective or universal screening nationwide. In Greece, Portugal, Italy and Spain, the blood authorities are evaluating the situation. Denmark decided not to implement the HEV screening of blood donations.

Prevalence of hepatitis E virus antibodies in workers occupationally exposed to swine in Portugal

The concept of zoonotic hepatitis E in industrialized countries has emerged with the discovery of swine strains of hepatitis E virus (HEV) genotype 3, closely related to human HEV. Different routes of zoonotic HEV transmission have been recognized, including contact with infected pigs. Workers occupationally exposed to swine (WOES) have been considered a risk group for HEV infection, but contradictory results have been reported. In the present study, we searched for anti-HEV IgG in WOES (butchers, slaughterhouse workers, veterinarians and pig farmers; n = 114) and in the general population (n = 804) in order to investigate the potential occupational risk of zoonotic HEV infection in this work group. A significantly higher (p = 0.008) anti-HEV IgG seroprevalence was found in WOES (30.7 %) when compared with the general population (19.9 %). Multivariate analysis showed that having professions with exposure to pigs for more than 16.5 years was a risk factor for being positive for anti-HEV IgG (aOR of 5.4, 95 % CI 1.9-15.6, p = 0.002). To our knowledge, this is the first study on the prevalence of anti-HEV IgG in WOES in Portugal, also showing increased probability for infection in this group.