Hepatitis A Virus in Marsupials

Hepatitis A Virus is a cause of acute viral hepatitis in humans, causing about 11,000 deaths worldwide per year. Hepatitis A Virus was long thought to be restricted to primates, with genotypes I to III found in humans and genotypes IV to VI, termed simian Hepatitis A Virus, found in nonhuman primates[1].

Only recently, highly diverse nonprimate hepatoviruses were discovered, suggesting that the ancestors of Hepatitis A Virus may have evolved in mammals other than primates prior to their introduction into humans. Additionally, the unique structural properties of Hepatitis A virusses, resembling those found in ancestral insect viruses, suggest that it is an ancient picornavirus[2].

The expanded genus Hepatovirus now includes at least 16 putative virus species. The majority of novel hepatoviruses were obtained from bats and rodents.

Now, scientists have discovered a novel marsupial Hepatitis A Virus in Brazilian common (or big-eared) opossum (Didelphis aurita)[3]. That is a potential problem, since opossums are commonly hunted and consumed as wild game by resource-limited (read: poor) Brazilian communities.

Because the family containing marsupial Hepatitis A Virus shares a common ancestor with human Human Hepatitis A Virus, it may hypothetically retain the ability to infect humans.

The results of this research strongly suggest that the species barriers toward Hepatitis A Virus infection seem penetrable.

[1] Cristina, Costa-Mattioli: Genetic variability and molecular evolution of hepatitis A virus in Virus Research - 2007
[2] Wang et al: Hepatitis A virus and the origins of picornaviruses in Nature - 2015
[x] de Oliveira Carneiro et al: A Novel Marsupial Hepatitis A Virus Corroborates Complex Evolutionary Patterns Shaping the Genus Hepatovirus in Journal of virology - 2018. See here.