Transmission (1,2,3,4,5)
HAV is spread by the faeco-oral route.
It can be
- person to person - occurs between children, or in adults during certain sexual practices and when using injection drugs
- contaminated food or drink - under cooked or raw oysters and clams which are contaminated or infected food handlers who are shedding the virus
- in developed countries, person-to-person spread is the most common while in developing countries faeces-contaminated food and water are common sources of infection
Transmission to older family members in a household is common with children often being the source of infection (especially under the age of 6 years)
The virus is thought to be excreted with bile and shed in the stools of an infected person.
- peak excretion occurs approximately 14 to 21 days before the onset of jaundice and a further 8 days thereafter. The patients are most infectious during this stage.
- asymptomatic infected children may excrete the virus in their stools for up to 6 months
- immunocompromised patients may shed the virus for a longer time
Other routes of transmission include
- parenteral spread - may rarely follow transfusion of blood or blood products (factor VIII and factor IX concentrates) from a donor who is in the incubation stage of the disease
- during sexual intercourse
- intravenous drug users - outbreaks have been reported in many countries amongst IV drug users
Reference
- Koenig KL, Shastry S, Burns MJ. Hepatitis A Virus: Essential Knowledge and a Novel Identify-Isolate-Inform Tool for Frontline Healthcare Providers. West J Emerg Med. 2017 Oct;18(6):1000-1007
- Franco E, Meleleo C, Serino L, et al; Hepatitis A: Epidemiology and prevention in developing countries. World J Hepatol. 2012 Mar 27;4(3):68-73.
- Committee on Infectious Diseases, American Academy of Pediatrics; Kimberlin D, Barnett E, Lynfield R, et al. Hepatitis A. In: Red Book: 2021–2024 report of the Committee on Infectious Diseases. 32nd ed. Elk Grove Village, IL: American Academy of Pediatrics; 2021.
- Abutaleb A, Kottilil S. Hepatitis A: epidemiology, natural history, unusual clinical manifestations, and prevention. Gastroenterol Clin North Am. 2020 Jun;49(2):191-9.
- Hepatitis A: guidance, data and analysis; UK Health Security Agency - formerly Public Health England.