Molecular Characterization and Seroprevalence of Hepatitis E Virus in Inflammatory Bowel Disease Patients and Solid Organ Transplant Recipients

Hepatitis E Virus (HEV) Infection Among Immunocompromised Individuals: A Brief Narrative Review

Hepatitis E virus (HEV) is a single-stranded positive-sense RNA virus that belongs to Hepeviridae family. HEV is the most common cause of acute viral hepatitis worldwide. According to the World Health Organization (WHO), there are estimated 20 million HEV infections worldwide every year, leading to estimated 3.3 million symptomatic cases of HEV infection. The WHO estimates that HEV infection caused approximately 44,000 deaths in 2015, which represents 3.3% of mortality rates due to viral hepatitis. In low-income (LI) countries and lower-middle-income (LMI) countries, HEV is a waterborne infection induced by HEV genotype (gt) 1 and HEV gt 2 that cause large outbreaks and affect young individuals with a high mortality rate in pregnant women from South Asian countries and patients with liver diseases. HEV gt 3, HEV gt 4, and HEV gt 7 are responsible for sporadic infections with zoonotic transmission mainly through the consumption of raw or undercooked meat from different animals. Acute HEV infection is relatively asymptomatic or mild clinical form, in rare cases the disease can be moderate/severe clinical forms and result in fulminant hepatitis or acute liver failure (ALF). Furthermore, HEV infection is associated with extrahepatic manifestations, including renal and neurological clinical signs and symptoms. Pregnant women, infants, older people, immunocompromised individuals, patients with comorbidities, and workers who come into close contact with HEV-infected animals are recognized as major risk groups for severe clinical form of HEV infection and fatal outcome. Chronic HEV infection can occur in immunocompromised individuals with the possibility of progression to cirrhosis.

mTOR inhibitors a potential predisposing factor for chronic hepatitis E: Results from the prospective collaborative CHES study (Chronic Hepatitis EScreening in patients with immune impairment and increased transaminases levels)

BACKGROUND

Chronic hepatitis E virus (HEV) in persons with immune impairment has a progressive course leading to a rapid progression to liver cirrhosis. However, prospective data on chronic HEV is scarce. The aim of this study was to determine the prevalence and risk factors for chronic HEV infection in subjects with immune dysfunction and elevated liver enzymes.

PATIENTS AND METHODS

CHES is a multicenter prospective study that included adults with elevated transaminases values for at least 6 months and any of these conditions: transplant recipients, HIV infection, haemodialysis, liver cirrhosis, and immunosuppressant therapy. Anti-HEV IgG/IgM (Wantai ELISA) and HEV-RNA by an automated highly sensitive assay (Roche diagnostics) were performed in all subjects. In addition, all participants answered an epidemiological survey.

RESULTS

Three hundred and eighty-one patients were included: 131 transplant recipients, 115 cirrhosis, 51 HIV-infected subjects, 87 on immunosuppressants, 4 hemodialysis. Overall, 210 subjects were on immunosuppressants. Anti-HEV IgG was found in 94 (25.6%) subjects with similar rates regardless of the cause for immune impairment. HEV-RNA was positive in 6 (1.6%), all of them transplant recipients, yielding a rate of chronic HEV of 5.8% among solid-organ recipients. In the transplant population, only therapy with mTOR inhibitors was independently associated with risk of chronic HEV, whereas also ALT values impacted in the general model.

CONCLUSIONS

Despite previous abnormal transaminases values, chronic HEV was only observed among solid-organ recipients. In this population, the rate of chronic HEV was 5.8% and only therapy with mTOR inhibitors was independently associated with chronic hepatitis E.

Evaluation of Prevalence of Hepatitis E Clinical Markers among Donors in Estonia

Hepatitis E virus (HEV) is now considered the most common cause of acute hepatitis worldwide. There are no published data about the prevalence of antibodies to HEV and RNA in donor sera in Estonia, and this precludes planning measures for preventing HEV proliferation through blood transfusion services. Here, were report data from an analysis of 1002 sera on the prevalence of anti-HEV IgG and IgM and the viral RNA. The antibodies were found in 48 donor sera (4.8%); of these, 40 (4%) harbored anti-HEV IgG, 15 (1.5%) contained anti-HEV IgM, and 7 donors had anti-HEV antibodies of both classes simultaneously. HEV RNA was not detected in any blood serum. Statistical associations of infection risk factors (gender, age, travel in the last six months, contact with pigs and/or wild boars in the last six months, consumption of thermally unprocessed/raw pork or boar meat, raw/unfiltered tap water or water from natural sources, unpasteurized farm dairy products, and unwashed berries and/or vegetables) were assessed. None of the listed factors were found to be associated with a higher or lower risk of anti-HEV antibody presence. At the same time, an increasing share of anti-HEV IgG carriers with age was found. The absence of HEV RNA in the analyzed donor plasma samples proves that HEV acute infection prevalence in Estonia does not exceed the average level of European countries. There is no urgent necessity to enter a requirement for a total screening of blood plasma for HEV RNA prevalence in Estonia.

Identification of Hepatitis E Virus Genotypes 3 and 7 in Israel: A Public Health Concern?

Background: Hepatitis E (HEV) is an emerging cause of viral hepatitis worldwide. Swine carrying hepatitis E genotype 3 (HEV-3) are responsible for the majority of chronic viral hepatitis cases in developed countries. Recently, genotype 7 (HEV-7), isolated from a dromedary camel in the United Arab Emirates, was also associated with chronic viral hepatitis in a transplant recipient. In Israel, chronic HEV infection has not yet been reported, although HEV seroprevalence in humans is ~10%. Camels and swine are >65% seropositive. Here we report on the isolation and characterization of HEV from local camels and swine. Methods: Sera from camels (n = 142), feces from swine (n = 18) and blood from patients suspected of hepatitis E (n = 101) were collected during 2017–2020 and used to detect and characterize HEV sequences. Results: HEV-3 isolated from local swine and the camel-derived HEV-7 sequence were highly similar to HEV-3f and HEV-7 sequences (88.2% and 86.4%, respectively) related to viral hepatitis. The deduced amino acid sequences of both isolates were also highly conserved (>98%). Two patients were HEV-RNA positive; acute HEV-1 infection could be confirmed in one of them. Discussion: The absence of any reported HEV-3 and HEV-7 infection in humans remains puzzling, especially considering the reported seroprevalence rates, the similarity between HEV sequences related to chronic hepatitis and the HEV genotypes identified in swine and camels in Israel.

Special Issue "Structural Variations and Molecular Genetics of Hepatitis Virus and Related Viruses"

In this special issue, we present collected updated data on the hepatitis viruses [...].