Hepatitis A is an acute illness caused by infection with hepatitis A virus (HAV). The virus replicates in the liver, transports through the bile, and is excreted into the feces via the biliary system.1
- What is hepatitis A?
- What are the symptoms associated with hepatitis A?
The likelihood of symptomatic illness from HAV is directly linked to age. Although more than 80% of adults with HAV infection experience symptoms, nearly 70% of children under 6 years of age are asymptomatic.1,2
For those who experience symptoms, the onset is typically abrupt and includes1:
- Loss of appetite
- Abdominal pain
- Dark urine
- How is hepatitis A transmitted?
- How long do the symptoms last for those who display symptoms?
Usually, symptoms do not last longer than 2 months; however, 10% to 15% of people with HAV experience prolonged or relapsing symptoms for up to 6 months.2
- What is the incubation period for hepatitis A?
The average incubation period for hepatitis A is approximately 28 days (range: 15–50 days).2
- Can HAV survive outside the body? How can the virus be killed?
Depending upon environmental conditions, HAV can live outside the body for months. Heating food at temperatures
>185oF (>85oC)for 1 minute or disinfecting surfaces with a dilution of household bleach and water (1:100 ratio) can inactivate HAV; however, the virus is still capable of being spread if food contamination occurs after cooking.2,3
Waterborne outbreaks of HAV in developed countries are rare; occurrences of this nature are generally attributed to sewage contamination and inadequately treated water.3
- How prevalent is hepatitis A?
Historically, hepatitis A rates vary cyclically, with nationwide increases every 10 to 15 years. The last peak was in 1995; since that time, rates of hepatitis A generally declined until 2011. In 2014, a total of 1,239 cases of hepatitis A were reported, a 30.4% decrease from 2013. The overall incidence rate in 2014 was 0.4 cases per 100,000 population. After adjusting for under-ascertainment and under-reporting, an estimated 2,500 hepatitis A cases occurred in 2014. (Data were unavailable for the District of Columbia.)4
- Who is at increased risk of acquiring HAV infection?
People who are at higher risk of infection from HAV include2:
- International travelers
- Men who have sex with men
- People who use illegal drugs
- People that have clotting factor disorders
- People with an occupational risk of infection
- Can someone who has recovered from HAV be reinfected?
No, once a person has recovered from HAV infection, anti-HAV IgG antibodies remain in the person's blood. This provides lifelong protection against HAV disease.2
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CDC=Centers for Disease Control and Prevention.
HAV=hepatitis A virus.
|1.||Centers for Disease Control and Prevention (CDC). Hepatitis A. In: Hamborsky J, Kroger A, Wolfe S, eds. Epidemiology and Prevention of Vaccine-Preventable Diseases. 13th ed. Washington, DC: Public Health Foundation; 2015:135–148. http://www.cdc.gov/vaccines/pubs/pinkbook/index.html. Accessed October 27, 2016.|
|2.||Centers for Disease Control and Prevention (CDC). Viral hepatitis—hepatitis A Information. http://www.cdc.gov/hepatitis/hav/. Updated August 27, 2015. Accessed October 27, 2016.|
|3.||Centers for Disease Control and Prevention (CDC). Prevention of hepatitis A through active or passive immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2006;55(RR-7):1–23.|
|4.||Centers for Disease Control and Prevention (CDC). Viral hepatitis surveillance —United States, 2014. http://www.cdc.gov/hepatitis/statistics/2014surveillance
/pdfs/2014hepsurveillancerpt.pdf. Updated September 26, 2016. Accessed October 27, 2016.