Laboratory Diagnosis of HEV Infection

Screening for viral hepatitis carriage

Viral hepatitis during pregnancy is common globally. In this review, we focus on the antenatal screen for hepatitis A, B, C and E, the prevention of mother-to-child transmission (MTCT) of hepatitis B and C, and the management of hepatitis A, B, C and E during pregnancy. Neonatal timely administration of hepatitis B immunoglobulin and hepatitis B vaccine is the cornerstone for preventing MTCT of hepatitis B virus (HBV), and perinatal antiviral prophylaxis with tenofovir disoproxil fumarate in mothers with positive HBeAg or HBV DNA >2 × 105 IU/ml also plays important roles in further reducing MTCT. Avoidance of risk practices in managing labor and delivery process of women with HCV infection may be useful to reduce MTCT of HCV. Early recognition of severe hepatic injury or liver failure associated with hepatitis viruses by regular liver function tests is critical to prevent maternal mortality associated with hepatitis.

Development of a New Multispecies Protein A-Based ELISA for Serodiagnosis of Hepatitis E Infection with Validation in Domestic Swine

Hepatitis E virus (HEV) infects roughly 20 million people worldwide, causing self-limiting acute hepatic disease that can evolve into a chronic course. HEV-3, HEV-4, and HEV-7 genotypes are zoonotic and transmitted to humans by consuming raw or undercooked meat. Here, we developed an indirect ELISA based on the recombinant HEV-3 capsid and performed a seroprevalence study on domestic swine in northeastern Brazil. Our in-house ELISA was initially validated using a subset of 79 sera characterized by concordant results for two distinct commercial ELISA kits. Our ELISA exhibited excellent sensitivity (94%) and specificity (100%), with an area under the curve of 0.99 Further testing, including 212 swine sera, revealed a seroprevalence of 57.5% (95% confidence interval, 50.6-64.3%). Our findings indicate that the novel ELISA test could accurately detect specific anti-HEV antibodies in domestic pigs and should be further validated in humans and other mammals.

Viral Biology and Immune Privilege in the Development of Extrahepatic Manifestations During Hepatitis E Virus Infection

Hepatitis E virus (HEV) exhibits tropism toward hepatocytes and thus affects the liver; however, HEV may also affect other tissues, including the heart, kidneys, intestines, testicles, and central nervous system. To date, the pathophysiological links between HEV infection and extrahepatic manifestations have not yet been established. Considering that HEV infects multiple types of cells, the direct effects of virus replication in peripheral tissues represent a plausible explanation for extrahepatic manifestations. In addition, since the immune response is crucial in the development of the disease, the immune characteristics of affected tissues should be revisited to identify commonalities explaining the effects of the virus. This review summarizes the most recent advances in understanding the virus biology and immune-privileged status of specific tissues as major elements for HEV replication in diverse organs. These discoveries may open avenues to explain the multiple extrahepatic manifestations associated with HEV infection and ultimately to design effective strategies for infection control.