Nav: Home

The hepatitis A virus is of animal origin

November 03, 2015

The hepatitis A virus can trigger acute liver inflammation which generally has a mild course in small children but which can become dangerous in adults. The virus, which is found worldwide, has previously been considered to be a purely human pathogen which at most is found in isolated cases in non-human primates. An international team of researchers under the direction of the University of Bonn has now discovered in a large-scale study with nearly 16,000 specimens from small mammals from various continents that the hepatitis A virus - like HIV or Ebola as well - is of likely animal origin. The results currently appear in the renowned journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

An infection with the hepatitis A virus can trigger acute inflammation of the liver which generally does not cause any symptoms in children and resolves without major complications. "In tropical regions, nearly all young children are infected with the hepatitis A virus and from that time on, they are immune to this disease," says Prof. Dr. Jan Felix Drexler from the Institute of Virology at the University of Bonn Medical Centre and the German Centre for Infection Research (DZIF). By contrast, if adults become infected with the hepatitis A virus, the symptoms can be more serious, and the disease can even have a fatal outcome. The virus has been found to date only in humans and a few non-human primates. Its origins were mysterious.

15,987 specimens from 209 different species of small mammals

Virologists from the University of Bonn Hospital, together with their colleagues from several German and international research institutes worldwide, searched for viruses related to the hepatitis A virus. They investigated a total of 15,987 specimens from 209 different species of small mammals: from rodents to shrews and bats to hedgehogs. Viruses from these mammals are very similar to the human hepatitis A virus with regard to their genetic properties, protein structures, immune response and patterns of infection. "The seemingly purely human virus is thus most likely of animal origin," says Drexler. "The study enables new perspectives for risk assessments of emerging viruses by investigating functional, ecologic and pathogenic patterns instead of phylogeny only".

The scientists' evolutionary investigations may even hint at distant ancestry of the hepatitis A virus in primordial insect viruses. "It is possible that insect viruses infected insect-eating small mammals millions of years ago and that these viruses then developed into the precursors of the hepatitis A virus," says the virologist from the University of Bonn Medical Centre.

Small mammals contribute to the preservation of the hepatitis A virus

The researcher assumes that small mammals were important hosts for the preservation and evolution of the viruses. "Otherwise the hepatitis A virus would actually have gone extinct long ago in small human populations due to the lifelong immunity of the persons once infected with it," Drexler reasons. "However, patients need not fear that they could contract a hepatitis A virus infection through bats or hedgehogs. It has likely been a very long time since humans first contracted the hepatitis A precursor virus from animals - moreover, such incidents are very rare," says the virologist from the University of Bonn Medical Centre.
-end-
Publication: Evolutionary origins of hepatitis A virus in small mammals, Proceedings of the National Academy of Sciences of the United States of America (PNAS), DOI: 10.1073/pnas.1516992112

Contact information:

Prof. Dr. Jan Felix Drexler
Institute of Virology
University of Bonn Medical Centre
German Center for Infectious Disease Research (DZIF)
Tel. ++49-228-28711697
E-Mail: drexler@virology-bonn.de
http://www.virology-bonn.de
http://www.dzif.de

University of Bonn

Related Hepatitis Articles:

Nanotechnology delivers hepatitis B vaccine
X-ray imaging shows that nanostructured silica acts as a protective vehicle to deliver intact antigen to the intestine so that it can trigger an immune response.
Checkmate for hepatitis B viruses in the liver
Researchers at Helmholtz Zentrum München and the Technical University of Munich, working in collaboration with researchers at the University Medical Center Hamburg-Eppendorf and the University Hospital Heidelberg, have for the first time succeeded in conquering a chronic infection with the hepatitis B virus in a mouse model.
How common is Hepatitis C infection in each US state?
Hepatitis C virus infection is a major cause of illness and death in the United States and injection drug use is likely fueling many new cases.
New strains of hepatitis C found in Africa
The largest population study of hepatitis C in Africa has found three new strains of the virus circulating in the general population in sub-Saharan Africa.
High stability of the hepatitis B virus
At room temperature, hepatitis B viruses (HBV) remain contagious for several weeks and they are even able to withstand temperatures of four degrees centigrade over the span of nine months.
More Hepatitis News and Hepatitis Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...