ABSTRACT
Viral infections affecting the liver had a serious impact on humanity, as they have led to significant morbidity and mortality in patients with acute and chronic infections. The discovery of the viral agents of severe acute hepatitis in children triggered interest of the scientific community to establish the pathogenesis and diagnostic techniques to identify the affected population. But, WHO, together with scientists in various affected countries, are working to understand the cause of this infection that does not appear to belong to any of the known five types of hepatitis viruses: A, B, C, D and E. Many cases of severe acute hepatitis of unknown origin in children <10 years of age were reported by the International Health Regulations (IHR) was mainly by adenovirus infection, HAdV-41. Although most acute infections cause mild disease and even go undetected, some can lead to complications and turn fatal. With the rapid scientific and technological advances in the last centuries, controlling and even curing the infections became a possibility, with a large focus on preventive medicine through vaccination. The review article describes the epidemiology, pathogenesis, clinical presentation, diagnostic tools and current medication regimens for severe acute hepatitis of unknown origin in children.Copyright © 2022, Global Research Online. All rights reserved.
ABSTRACT
Hepatitis D virus (HDV) is a defective liver-tropic virus that needs the helper function of hepatitis B virus (HBV) to infect humans and replicate. HDV is transmitted sexually or by a parenteral route, in co-infection with HBV or by super-infection in HBV chronic carriers. HDV infection causes acute hepatitis that may progress to a fulminant form (7%-14% by super-infection and 2%-3% by HBV/HDV co-infection) or to chronic hepatitis (90% by HDV super-infection and 2%-5% by HBV/HDV co-infection), frequently and rapidly progressing to cirrhosis or hepatocellular carcinoma (HCC). Peg-interferon alfa the only recommended therapy, clears HDV in only 10%-20% of cases and, consequently, new treatment strategies are being explored. HDV endemicity progressively decreased over the 50 years from the identification of the virus, due to improved population lifestyles and economic levels, to the use of HBV nuclei(t)side analogues to suppress HBV replication and to the application of universal HBV vaccination programs. Further changes are expected during the severe acute respiratory syndrome coronavirus-2 pandemic, unfortunately towards increased endemicity due to the focus of healthcare towards coronavirus disease 2019 and the consequently lower possibility of screening and access to treatments, lower care for patients with severe liver diseases and a reduced impulse to the HBV vaccination policy.