Persons who consume raw or undercooked oysters or other raw shellfish put themselves at an increased risk of Hepatitis A, according to Dr. Valerie A. Boaz, Health Officer for the Chattanooga-Hamilton County Health Department.
Hamilton County has had six cases of Hepatitis A reported to date in 2005. In 2004, only one case was reported, and in 2003, no cases were reported.
Hepatitis A is a viral disease that affects the liver. Transmission can occur through direct person-to-person contact; through exposure to contaminated water, ice, or shellfish harvested from sewage-contaminated water; or from fruits, vegetables, or other foods that are eaten uncooked and that were contaminated during harvesting or subsequent handling.
Three recently diagnosed cases of Hepatitis A reported eating raw oysters at a local restaurant in early August. The local Health Department has determined that the food-handling and preparation procedures at the restaurant were not a likely source of the infection. The cases were not hurricane-related.
The Health Department, the Tennessee Department of Health, the Food and Drug Administration, and the Centers for Disease Control in Atlanta are investigating these cases to identify the contamination source of the oysters.
Cases of Hepatitis A caused by shellfish consumption are usually not associated with a particular eating establishment as are cases related to an infected food handler, said Dr. Boaz. This is because the source is a food item that is known to be potentially infectious. Warnings on menus and health department alerts such as this remind patrons of the inherent dangers of eating raw or undercooked shellfish. Anyone eating raw or undercooked shellfish is taking a calculated risk, according to Dr. Boaz.
Although it is always a health risk to eat raw or undercooked oysters or other shellfish, the recent disruption of gulf coastal waters could cause an increase in the amount of contaminated seafood originating in those waters. Any time that flooding occurs; there is the potential for sewage systems to overflow into natural waterways causing them to become contaminated with bacteria and viruses from human waste of infected persons.
Oysters and other shellfish harvested from contaminated waters are capable of spreading Hepatitis A virus if they are not cooked before eating. Boiling or cooking these foods for at least 1 minute to 185°F (85°C) inactivates the Hepatitis A virus, thus reducing the possibility of infection, according to Bonnie Deakins, Director of Environmental Health.
“Watch for the shells to open. This means that they are done. Discard any that stay closed,” Ms. Deakins said.
So far this year, Tennessee has had 130 cases of Hepatitis A reported; many of these cases were reported in upper east Tennessee and are not related to shellfish consumption. Ninety-five cases were reported statewide in 2004, and 202 cases in 2003.
After exposure to the Hepatitis A virus, illness usually occurs in 28-30 days but it may take 15-50 days for symptoms to develop. The symptoms of Hepatitis A are fever, lack of appetite, nausea, and fatigue and then jaundice. Jaundice is a yellow or orange tint to the skin or whites of the eyes. Some persons with Hepatitis A will have no symptoms at all – especially children.
Hepatitis A symptoms usually last 1-2 weeks and no specific treatment is required in order to get better. Infected persons shed the virus in stool from a week or two before symptoms begin until a few days after jaundice begins. Because of this, persons who are ill with Hepatitis A should not work in restaurants, child care centers, or nursing homes until their symptoms have resolved.
Persons with suspected Hepatitis A infection should see their physician. A blood test to confirm the diagnosis may be indicated. Household and sexual contacts of persons with Hepatitis A may need an injection of immune globulin to keep them from getting the infection.
The spread of Hepatitis A can be controlled by good hygiene measures such as careful hand washing after using the bathroom, not eating raw or undercooked oysters or other shellfish and washing uncooked produce before eating. There is also a vaccine to prevent Hepatitis A infection, which may be indicated for persons with on-going exposure to the Hepatitis A virus.
For more information or to report a case of Hepatitis A, call 209-8190.