Natural Hosts of the Hepatitis A Virus

Hepatitis A Virus and Its Natural Hosts

The natural hosts of Hepatitis A virus or HAV is represented by man and a number of species of non-human primates such as chimpanzee, African vervet, aotus and other classifications of monkeys. These non-human primates are reported to contain spontaneous hepatitis A infections. The sera, or the clear and pale yellow fluid of newly captured monkeys with anti-HAV antibody, show that infection can spread throughout their natural habitat.

There are four separate monkey HAVs that are native to each species, which are varied from each other and from human HAV strains. Each virus represents evolutionary relationships among HAVs and their hosts in the classification of these primates.

Role of Non-human Primates in HAV transmission

The species of monkeys susceptible to hepatitis A virus are chimpanzees, cynomolgus monkeys (aka crab-eating macaques), owl monkeys, stump-tailed monkeys, rhesus monkeys, tamarins, marmosets, squirrel monkeys and African green monkeys. HAV-induced disorder in these non-human primates is similar to human disease but can be milder with full recovery.

The natural transmission of human hepatitis A virus from experimentally infected animals to humans show the susceptibility of humans to monkey HAV strains. If ape strains don’t induce disease in humans despite virus reproduction and ensuing sera conversion, monkey strains may be used as vaccines.

Even if HAV-immune people introduced to monkey strains developed signs of hepatitis, a global immunization program can never attain the suppression of HAV, as monkeys would constantly pose as the main viral host.

Hepatitis A Virus Infection               

HAV enters the bloodstream through the intestine right after ingestion.

Then, the blood carries the virus to the liver where it multiplies within the liver. Complete viral particles are secreted into the bile which is released via stool. For about 11 days earlier from the manifestation of anti-HAV antibodies or symptoms in the blood, HAV is excreted in huge amounts.

Generally, it has 15 to 50 days incubation period with less than 0.5 percent mortality. The virus needs an integral eukaryote-initiating factor to shut down host protein synthesis for the beginning of translation. The poor growth of the virus in cell culture is due to its inefficient competing for the cellular translational mechanism.

The hepatitis A virus structure is “non-enveloped” and consists of a single-stranded RNA (ribonucleic acid) within a protein shell. The virus has only one serotype or the set of antigens but several genotypes or genetic makeup of cells exist.

Symptoms and Hosts of Hepatitis A

Hepatitis A virus infection symptoms appear two to six weeks with an average of 28 days after initial infection.

In children, symptoms aren’t noticeable at all and can’t even be seen as an HAV carrier. There is more than 80 percent of adults which show signs of symptoms compatible with the acute viral hepatitis as the risk is directly related to age for the symptomatic infection. Some people can be ailing for six months, but generally, symptoms usually last for less than two months. The symptoms include the following:

  • Fever
  • Nausea
  • Fatigue
  • Appetite loss
  • Bile has dark amber color
  • Jaundice or the yellowing of the skin or whites of the eyes
  • Diarrhea and other related conditions

HAV Prevention

Hepatitis A virus can be avoided through proper hygiene, sanitation, and vaccine. The vaccine has two types, the first one contains inactivated hepatitis A virus and the other contains a live attenuated virus. Both vaccine types provide active immunity from future infection. Through injection, the vaccine is given with an initial dose that gives protection beginning two to four weeks after the vaccination. The second (booster) dose is given six to twelve months later, which gives protection for a period of twenty years.

Although there’s no surefire treatment for hepatitis, patients are advised to avoid alcohol and fatty foods, take some rest, stay hydrated and eat a balanced diet. Hepatitis A is a highly contagious liver infection t caused by the hepatitis A virus. The virus causes inflammation that affects the liver’s ability to function.

Environmental Control of the Hepatitis A Virus

The source of infection must always be sought to prevent future contamination. There should be keen attention to toilet hygiene and ensure that soap and clean water are available for regular washing of hands. Cleanup of food premises that are potentially infective of hepatitis A must also be done because contaminated food can be a chief source of the virus.

The virus can be acquired from contaminated water or food or from close contact with someone who’s already damaged by the virus, although infected individuals can recover fully with no liver damage. It is highly recommended that people should practice frequent washing not only to avoid acquiring the virus but also to prevent it from spreading elsewhere. Aside from the non-human primates, humans are the viral host. Thus, proper precautions should always be observed.


Balayan MS. Natural hosts of hepatitis A virus. Vaccine. 1992;10 Suppl 1:S27-31.

Namsai A, Louisirirotchanakul S, Wongchinda N, Siripanyaphinyo U, Virulhakul P, Puthavathana P, Myint KS, Gannarong M, Ittapong R. Surveillance of hepatitis A and E viruses contamination in shellfish in Thailand. Lett Appl Microbiol. 2011 Dec;53(6):608-13.

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