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What is Hepatitis A?
The Hepatitis A virus (HAV) belongs to a group of viruses that affect the liver. HAV is the one most commonly associated with foodborne illness. The virus causes infectious hepatitis and can infect anyone. Symptoms are most often seen in school age children and adults. In general, symptoms increase in severity with increased age; 25% of adults require hospitalization with an infection. Young children are most often affected but rarely show any clinical signs; although, they do shed the virus to infect others.
Where is Hepatitis A found?
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The virus is acquired through oral ingestion. The virus can be shed in the feces of infected individuals up to 2 weeks before they present any symptoms. Recovered individuals can shed the virus and potentially infect others for up to 3 months after symptoms have disappeared. The virus is commonly passed by:
- Unwashed hands after washroom use and diaper changing
- Contaminated water and ice, especially in developing countries
- Contaminated eating utensils
- Flies contaminating food
- Sexual contact with infective person(s), particularly involving practices that may lead to fecal matter ingestion. The virus is not passed in saliva, semen or urine.
- Shellfish can harbor the virus
- Contaminated food, especially fresh produce, and other foods consumed raw.
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What are the Symptoms of Hepatitis A?
Symptoms may include; fatigue, abdominal pain, loss of appetite, dark coloured urine, nausea and vomiting and jaundice. The onset of symptoms is 15 to 50 days (average 30 days) after infection by the virus and the infection lasts approximately 4 to 6 weeks. Reoccurring illness from the virus can persist for 6 to 12 months. There is no treatment available, but those individuals that do contract the virus become immune to the disease for life.
What conditions can it survive?
The Hepatitis A virus is hardy. It can survive in water and on surfaces for over 7 days. It can survive in acidic environments (like the stomach), and freezing to -70oC for more than 6 months. It remains infectious even after exposure to 60oC for 10 to 12 hours, but destroyed by temperatures higher than 85oC and 1% bleach solutions.
How can a Hepatitis A infection be prevented?
A preventative vaccine is available for persons over the age of 1 year. Under the age of one year and for persons with certain conditions, a special immunization called an immunoglobulin (IG) vaccine is available. The vaccine has been shown to decrease the incidence in certain high risk groups.
Those most at risk are:
- Individuals traveling to developing countries
- Children and adults living in a high prevalence area
- Individuals engaged in sexual relations involving possible fecal-oral transmission
- Individuals who have chronic liver disease
- Individuals over the age of 60 years.
What can you do if you have been exposed to the virus?
The vaccine and the immunoglobulin (IG) vaccine have both been proven effective in lessening the infection in those that have been exposed to the Hepatitis A virus.
When administered within 2 weeks of exposure to the virus, the IG vaccine is 80 to 90% effective in preventing clinical symptoms of hepatitis. If post-exposure vaccination is not given, the chances of reoccurring illness are 15 to 30%.
To clean up vomitus or a feces spill, wait about 10 minutes for aerosols (air borne particles) to settle; then clean the area using disposable towels and 1% bleach. Protect yourself by wearing disposable gloves and a mask.
Information Sources:
Centers for Disease Control and Prevention. (2007). Hepatitis Fact Sheet. Retrieved from, http://www.cdc.gov/ncidod/diseases/hepatitis/a/fact.htm
Croci, L., DeMedici, D., Scalfaro, C., Fiore, A., Toti, L. (2002). The Survival of Hepatitis A virus in fresh produce. International Journal of Food Microbiology. 73. 29-34.
Health Canada. (2001). Material Safety Data Sheet – Hepatitis A. Retrieved from, http://www.phac-aspc.gc.ca/msds-ftss/msds75e.html
Morbidity and Mortality Weekly Report. (2007). Update: Prevention of Hepatitis A After Exposure to Hepatitis A Virus and in International Travelers. Updated Recommendations of the Advisory Committee on Immunization Practices (ACIP). Retrieved from, http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5641a3.htm
Ontario Ministry of Health and Long-term Care. (2006). Diseases: Hepatitis A. Retrieved from, http://www.health.gov.on.ca/english/public/pub/disease/hepatitisa.html
Public Health Agency of Canada. (2004). Hepatitis A Fact Sheet. Retrieved from, http://www.phac-aspc.gc.ca/hcai-iamss/bbp-pts/hepatitis/hep_a_e.html
Public Health Agency of Canada. (2007). Vaccine Preventable Diseases – Hepatitis A. Retrieved from, http://www.phac-aspc.gc.ca/im/vpd-mev/hepatitis-a-eng.php