Hepatitis E virus seroepidemiology and its change during 1 year in primary school students in Ankara, Turkey

From discovery to treatment: tracing the path of hepatitis E virus

The hepatitis E virus (HEV) is a major cause of acute viral hepatitis worldwide. HEV is classified into eight genotypes, labeled HEV-1 through HEV-8. Genotypes 1 and 2 exclusively infect humans, while genotypes 3, 4, and 7 can infect both humans and animals. In contrast, genotypes 5, 6, and 8 are restricted to infecting animals. While most individuals with a strong immune system experience a self-limiting infection, those who are immunosuppressed may develop chronic hepatitis. Pregnant women are particularly vulnerable to severe illness and mortality due to HEV infection. In addition to liver-related complications, HEV can also cause extrahepatic manifestations, including neurological disorders. The immune response is vital in determining the outcome of HEV infection. Deficiencies in T cells, NK cells, and antibody responses are linked to poor prognosis. Interestingly, HEV itself contains microRNAs that regulate its replication and modify the host's antiviral response. Diagnosis of HEV infection involves the detection of HEV RNA and anti-HEV IgM/IgG antibodies. Supportive care is the mainstay of treatment for acute infection, while chronic HEV infection may be cleared with the use of ribavirin and pegylated interferon. Prevention remains the best approach against HEV, focusing on sanitation infrastructure improvements and vaccination, with one vaccine already licensed in China. This comprehensive review provides insights into the spread, genotypes, prevalence, and clinical effects of HEV. Furthermore, it emphasizes the need for further research and attention to HEV, particularly in cases of acute hepatitis, especially among solid-organ transplant recipients.

Seroprevalence of Hepatitis E Virus Infection in Middle Eastern Countries: A Systematic Review and Meta-Analysis

Hepatitis E virus (HEV) is a hepatotropic virus that is a major public health concern worldwide. Autochthonous HEV is spread through oral feces in unsanitary environments, as well as vertical and, occasionally, blood transfusion. HEV is more common in developing countries, but it has recently become more widespread in developed countries as well. The Middle East (ME) has long been an endemic location for HEV infection. Therefore, the aim of this systematic review and meta-analysis was to assess the seroprevalence of anti-HEV antibodies in ME countries. The author systematically searched five databases, namely ScienceDirect, EMBASE, Scopus, PubMed, and Google Scholar, to identify English-language articles published on or before 25 April 2022. Comprehensive meta-analysis software was used for all statistical analyses (CMA, version 3, BioStat, Englewood, CO, USA). After quality control and exclusion of irrelevant studies, 80 studies were included in the qualitative synthesis and meta-analysis. A forest plot showed that the overall pooled seroprevalence of HEV infection in ME countries in the fixed-effect and random-effect models were 21.3% (95% CI: 0.209–0.216) and 11.8% (95% CI: 0.099–0.144), respectively. Furthermore, the findings showed a high level of heterogeneity (I2 = 98.733%) among the included studies. In both fixed-effect and random-effect models, the seroprevalence of HEV infection by country was high in Egypt as compared to other regions, at 35.0% (95% CI: 0.342–0.359), and 34.7% (95% CI: 0.153–0.611), respectively. The seroprevalence of HEV infection by country was high among pregnant women, at 47.9% (95% CI: 0.459–0.499) in the fixed-effect model, and in renal transplant recipients, at 30.8% (95% CI: 0.222–0.410) in the random-effect model. The seroprevalence of HEV infection varies by country and study population in the Middle East. More research is needed to determine the disease’s incidence, morbidity, and mortality in the region, where it is prevalent.

Hepatitis E virus in Saudi Arabia: more surveillance needed

Hepatitis E virus (HEV) is a small quasi-enveloped ssRNA causing acute hepatitis. HEV is the leading cause of intermittent acute hepatitis and fulminant hepatic failure. Risk factors include drinking contaminated water in developing countries and consumption of infected animal products in developed countries. Previous reports on HEV prevalence in Saudi Arabia had small sample sizes. Nationwide systematic seroprevalence studies are needed to investigate risk factors and annual incidence. Camels play a cultural and economic role in the life of Saudi citizens with frequent human contact and potential role in zoonotic transmission. Future research needs to include larger sample-sizes and nationwide studies. Future studies should also focus on raising awareness of HEV infection and the need for wider population testing and screening.

Hepatitis E virus infection in Turkey: a systematic review

Hepatitis E virus (HEV), a non-enveloped single stranded RNA virus causes sporadic cases of hepatitis or outbreaks. The disease is generally self-limited although it may cause fulminant hepatitis in pregnant women, elderly, those with underlying chronic hepatitis, immunosuppressed, and transplant recipients. It is transmitted through fecal–oral route and zoonotic transmission. Hepatitis is a main health care problem in Turkey; HBV and HCV prevalences are 4 and 1% respectively. Hepatitis D represents another considerable hepatitis etiology with a prevalence of 5–27%. The information about HEV is not clear. In this systematic review, we aimed to analyze HEV studies reported from Turkey, to determine the current situation of the disease in the country, to delineate the limits of the studies and to determine the future study areas. The prevalence of HEV ranged from 0 to 12.4%. Children had lower prevalence than the adults. The prevalence was determined as 7–8% in pregnant women, 13% in chronic HBV patients, 54% in chronic HCV patients, 13.9–20.6% in patients with chronic renal failure, and ≈ 35% in agriculture workers. Among individuals immigrating form Turkey to Europe, HEV seroprevalence was found 10.3% in Italy and 33.4% in the Netherlands. HEV prevalence seems high in certain risk groups. Although previous studies suggest that Turkey is among the endemic countries of HEV, there are some pitfalls for the analysis of data: the studies are not powered enough to represent the whole population; they did not include immunosuppressed patients and solid organ recipients; and the prevalence of non-A non-B hepatitis was not determined.

Prevalence of hepatitis E infection in the general population of Iran: a systematic review and meta-analysis

Aim: Hepatitis E is a form of acute viral hepatitis, which is caused by hepatitis E virus (HEV). The study objective was to evaluate the prevalence of HEV to provide an overall relative frequency in Iran. Methods: In this study, databases such as PubMed and Scopus were searched using the following keywords according to MeSH, “Hepatitis E virus”, “Epidemiology”, “Enzyme-linked immunosorbent assay (ELISA)” and “Iran”. Then studies which had reported prevalence of HEV were selected. Results: We selected 36 researches out of 9246 for our study. From all the samples, the pooled estimated prevalence of HEV positive was 9.7%. It should be noted that HEV infection's relative frequency varied from 1.1% in Tehran to 46.1% in Ahvaz. Conclusion: HEV is common in Iran, although comparing to some neighboring countries, its prevalence is lower.

High prevalence of anti-hepatitis E virus antibodies in outpatients with chronic liver disease in a university medical center in Germany

AIM/OBJECTIVES/BACKGROUND

Hepatitis E virus (HEV) is an emerging disease in developed countries. HEV seroprevalence ranges from 3.2 to 10% in Europe, but is higher in endemic areas such as southern France. In Germany, an increasing incidence of HEV infections has been reported recently. Risk factors for the acquisition of HEV are incompletely understood.

METHODS

We screened 295 consecutive patients with chronic liver disease attending the outpatient department at Charité University Hospital for HEV seroprevalence. Epidemiological characteristics were analyzed and patients were questioned for risk factors using a standardized questionnaire. A total of 78 patients without known liver disease were also tested for HEV IgG.

RESULTS

Out of 295 screened patients, 62 tested positive for HEV-IgG. Overall, 50% of the HEV-positive patients were women and 23.8% had underlying liver cirrhosis. HEV-positive patients were older than HEV-negative patients (mean age 56 vs. 48.6 years). Seroprevalence increased with age from 13% in patients 30-39 years of age to 36.4% in patients 70-79 years of age. Of the total, 46.7% of HEV-IgG-positive patients had contact with domestic animals and 38.3% had received blood transfusions. A total of 50% of the HEV-IgG-positive patients had regularly consumed uncooked meat and 45% had regularly consumed wild game or wild boar, which was significantly more frequent than in HEV-IgG-negative patients.

CONCLUSION

HEV-IgG seroprevalence was 21% in a cohort of patients with chronic liver disease and 24.4% in a cohort of patients without known liver disease. The higher seroprevalence found among elderly patients suggests a lifetime accumulation of risk of exposure to HEV. The results from this study imply that regular testing should be performed for HEV in developed countries in case of liver disease of unknown etiology.

Seroprevalence of hepatitis E virus in animal workers in nonporcine consumption region of Turkey

Aim: Our aim was to investigate the prevalence of hepatitis E virus (HEV) and its potential zoonotic role in occupational groups that come into direct contact with domestic ruminants and chickens. Materials & methods: The seroprevalence of the HEV IgG antibody was determined on 92 samples using a commercial ELISA test kit. Results: The overall rate of HEV-IgG seroprevalence in the risk group was 35.9%. The control group seroprevalence was found to be 4.4%. Conclusion: HEV infection is a potential occupational hazard for people who work in jobs directly related to animals, with the exception of veterinarians, who use protective equipments to prevent the infection. Further studies should be performed with increased observation of specific risk groups in order to understand the local epidemiology and guide vaccination strategies.

Epidemiology of Hepatitis E Virus in European Countries

Over the last decade the seroprevalence of immunoglobulin (IgG) anti hepatitis E virus (HEV) has been increasing in European countries and shows significant variability among different geographical areas. In this review, we describe the serological data concerning the general population and risk groups in different European countries. Anti-HEV antibody prevalence ranged from 1.3% (blood donors in Italy) to 52% (blood donors in France). Various studies performed on risk groups in Denmark, Moldova and Sweden revealed that swine farmers have a high seroprevalence of HEV IgG (range 13%-51.1%), confirming that pigs represent an important risk factor in HEV infection in humans. Subtypes 3e,f are the main genotypes detected in the European population. Sporadic cases of autochthonous genotype 4 have been described in Spain, France, and Italy. Although most HEV infections are subclinical, in immune-suppressed and transplant patients they could provoke chronic infection. Fulminant hepatitis has rarely been observed and it was related to genotype 3. Interferon and ribavirin treatment was seen to represent the most promising therapy.

Hepatitis E virus in the countries of the Middle East and North Africa region: an awareness of an infectious threat to blood safety

PURPOSE

Hepatitis E virus (HEV) is mainly transmitted through contaminated water supplies which make the virus endemic in developing countries including countries of the Middle East and North Africa (MENA) region. Recent reports suggest potential risk of HEV transmission via blood transfusion.

METHODS

Related articles on HEV were collected by searching through the 25 countries of the MENA region using Pubmed and Medline within the past 14 years: January 2000-August 2014.

RESULTS

One hundred articles were extracted, of which 25 were not eligible. The articles discussed the seroprevalence of HEV and HEV markers in 12 countries. Eight articles provided data on HEV in blood donors. The seroprevalence of HEV in the general MENA population ranged from 2.0 to 37.5% and was higher in males than in females. Prevalence increased with age, but exposure seems to be in early life.

CONCLUSIONS

In the MENA region, the role of HEV as an infectious threat to blood safety is under-investigated. More data are needed to quantify the risk of transmission and to assess clinical outcomes. This requires, at least, surveillance screening of donors and recipients for HEV markers using sensitive and specific serological tests. At the present time, serious consideration should be given to selective screening for certain groups of patients (e.g., immunocompromised, pregnant women and others) who commonly require blood transfusion and are at high risk of hepatic failure or chronicity from HEV infection.

A systematic review of hepatitis E virus infection in children

A systematic review was conducted, seeking all literature relevant to the epidemiology, clinical and laboratory features, and outcome of hepatitis E virus (HEV) infection in children. Transmission is thought to be primarily from fecal-oral transmission, with the role of transmission from animal reservoirs not being clear in children. Worldwide, seroprevalence is <10% up to 10 years of age, with the exception of 1 of 5 studies from India and the sole study from Egypt. Seroprevalence increases with age, but it is not clear if it is increasing over time. The clinical presentation of HEV infection has broad similarities to hepatitis A virus (HAV) infection, with most cases being subclinical. However, HEV differs from HAV in that infectivity is lower, perinatal transmission can result in neonatal morbidity and even mortality, and a chronic carrier state exists, accounting for chronic hepatitis in some pediatric solid organ transplant recipients.