Hepatitis E virus (HEV) infection is widespread worldwide and is a major health problem, particularly in developing countries. HEV infection is associated with large outbreaks in India, Asia and Africa and is one of the most common causes of acute hepatitis worldwide. Clinically, HEV infection is usually asymptomatic, but can also cause fulminant liver failure. Depending on the HEV genotype, HEV is transmitted fecal-orally (HEV 1 and HEV 2) and was previously considered a travel-associated disease. Since 2007, a steady increase in HEV cases reported under the IfSG (Infection Protection Act) has been observed in Germany, with 73 cases reported in 2007 and 3,773 in 2023. These were primarily autochthonous infections without a travel history, which are transmitted zoonotically through the consumption of undercooked animal products (usually pork meat) contaminated by HEV 3 or HEV 4. The mortality rate of HEV infection is around 2% and can be as high as >30% in pregnant women with HEV 1 or HEV 2 infection. Since 2008, chronic HEV infections have been observed, especially in immunosuppressed patients after organ transplantation and in HIV-infected persons. Chronic HEV infection can lead to severe liver inflammation, such as cirrhosis. Since the molecular and immunological mechanisms that can contribute to different clinical courses and the chronification of HEV infection are still largely unclear, the objectives are to optimize serological and molecular detection methods, determine pathogen variability and characterize chronification mechanisms using molecular virological methods.

The human hepatitis B virus (HBV), a small, strictly hepatotrophic DNA virus, is a member of the hepadnavirus family, which differs from all known DNA viruses due to its unusual replication mechanism, similar to that of retroviruses via reverse transcription. HBV is the causative agent of hepatitis B, one of the most important serious infectious diseases globally. According to WHO estimates, around two billion people (approx. 35% of the world's population) have had contact with HBV. Depending on the immune status of the HBV infected person and other factors (e.g. virus mutants), HBV infection can develop into a chronic form in around 10% of acute cases. Globally, around 269 million people are thought to have chronic hepatitis B (WHO 2023). HBV is mainly endemic in developing countries, such as Southeast Asia, Africa and South America with 5%-10% virus carrier rates. For Germany, recent surveys have shown a hepatitis B virus carrier rate of 0.3%. The prevalence rate of HBV depends not only on geographical distribution but also on risk behavior (e.g. intravenous drug use with non-sterile injection equipment). The clinical course of hepatitis B is highly variable and ranges from asymptomatic and inapparent to fulminant and severe liver inflammation, such as liver cirrhosis and hepatocellular carcinoma (HCC). Every year, around 820,000 people worldwide die as a result of a hepatitis, mostly due to HBV-induced liver cirrhosis and HCC. Acute and chronic hepatitis B is diagnosed using virological-serological and molecular biological methods in accordance with the guidelines for hepatitis B virus infection. Vaccination prophylaxis against HBV is recommended by the Standing Committee on Vaccination (STIKO) in Germany for children and adolescents.

The hepatitis C virus (HCV), a hepatotrophic single-stranded (+)-RNA virus, belongs to the flavivirus family and was first described in 1989. In contrast to hepatitis B, hepatitis C will become chronic in more than 80% of those infected. Around 170 million people worldwide (~3% of the world's population) are chronically infected with HCV. In addition to chronic hepatitis B, the chronic form of hepatitis C is responsible for the majority of all hepatocellular carcinomas and liver cirrhosis (27% and 25%, respectively) worldwide. HCV infection occurs geographically with varying prevalence. More than 20% of virus carriers are found in Asia and Africa. Across Europe, it is estimated that around 9 million people are chronically infected with HCV. In Germany, approx. 0.6% (approx. 500,000 people) (WHO, RKI 2009) are chronically infected with HCV.

Translational research activities of the hepatitis laboratory are aimed at scientific questions on the clinical relevance and sensitive detection of virus mutants (therapy response and chronification, especially in HEV) as well as investigations on inter- and intramolecular virus-host interactions, in particular the influence of hepatitis viruses on inflammatory signal transduction. The scientific activities are carried out in close collaboration with clinics and universities as well as in cooperation with national and international institutions (e.g. Nigerian CDC).

Service offering

• Molecular detection of HEV RNA, HBV DNA, HCV RNA, HDV RNA using nucleic acid amplification techniques (PCR, RT-PCR, quantitative real time PCR)
• Molecular genetic fine characterization of virus variants, in particular HEV (fine and genotyping; mutational analysis)

Current projects (as at 01/2024)

• NiCaDe 2.0 (Nigeria Centre for Disease Control: Capacity Development for Preparedness and Response for Infectious Diseases II (NiCaDe II)); BMG funded: ZMII2-2523GHP033 (2023-2025)
• ViRGiS 2.0 (Virus detection in the heart by next-generation sequencing); Pro FIT Verbundprojekt (RKI-Charité-IKDT); Co-funded by the European Regional Development Fund (EFRE); No. 10198831 (2023-2025)