Exotic viral hepatitis: A review on epidemiology, pathogenesis, and treatment

Certain exotic viruses are known to cause clinical diseases with potential liver involvement. These include viruses, beyond regular hepatotropic viruses (hepatitis A, -B(D), -C, -E, cytomegalovirus, Epstein Barr virus), that can be found in (sub)tropical areas and can cause exotic viral hepatitis . Transmission routes typically involve arthropods (Crimean Congo haemorrhagic fever, dengue, Rift Valley fever, yellow fever). However, some of these viruses are transmitted by the aerosolised excreta of rodents (Hantavirus, Lassa fever), or via direct contact or contact with bodily fluids (Ebola). Although some exotic viruses are associated with high fatality rates, such as Ebola for example, the clinical presentation of most exotic viruses can range from mild flu-like symptoms, in most cases, right through to being potentially fatal. A smaller percentage of people develop severe disease with haemorrhagic fever, possibly with (fulminant) hepatitis. Liver involvement is often caused by direct tropism for hepatocytes and Kupffer cells, resulting in virus-mediated and/or immune-mediated necrosis. In all exotic hepatitis viruses, PCR is the most sensitive diagnostic method. The determination of IgM/IgG antibodies is a reasonable alternative, but cross-reactivity can be a problem in the case of flaviviruses. Licenced vaccines are available for yellow fever and Ebola, and they are currently under development for dengue. Therapy for exotic viral hepatitis is predominantly supportive. To ensure that preventive measures can be introduced to control possible outbreaks, the timely detection of these viruses is very important. (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of European Association for the Study of the Liver.

Automated summary

Certain exotic viruses can cause clinical diseases with liver involvement. These viruses have various transmission routes and clinical presentations, and they may cause severe liver damage. Timely detection of these exotic hepatitis viruses is crucial.