Grocery store loyalty cards help B.C. disease detectives trace hepatitis A outbreak

Hepatitis A virus can cause Hepatitis A, which is a potentially serious form of liver disease by attacking the liver. Non-travel-related hepatitis A infection is rare in North America as the virus is usually found in developing countries with very poor sanitary conditions and hygiene practices.

It often takes a long time to recognize that a food-borne disease outbreak is underway because cases can be dispersed geographically. Taking into consideration that the incubation period of hepatitis A is usually 14 to 28 days, it can be difficult to find the source since people cannot recall with precision what they ate weeks earlier.

An example of successful investigation is the recall of hepatitis A contaminated pomegranate seeds in British Columbia in early 2012 by comparing the foods the infected people had bought in previous months. Those food purchasing histories were compiled from their crockery story loyalty cards, pomegranate seeds in a frozen fruit mix were eventually identified as the source of the infection. At a very early stage, with only six cases, the investigators were able to see that the infected people had purchased the same brand of a frozen fruit mix containing blueberries, strawberries, cherries and pomegranate seeds. The following test eventually showed that on e lot of pomegranate seeds from the supplier was contaminated with hepatitis A and a recall was ordered.
“It certainly did make it easier and it allowed us to identify, to really land on a specific product really very early in the outbreak,” Dr. Helena Swinkels of Fraser Health Authority says of the access to the patients’ purchasing history through their loyalty card data, “Loyalty cards are one tool that definitely can help investigations of food-borne outbreaks.”

Although hepatitis A is rare in Canada and the few cases recorded each year generally are in people travelling in or returning from countries where the virus circulates, occasionally someone who becomes infected will transmit it to others in Canada. Therefore, it is necessary for the public to understand its transmission pathway and the prevention methods.

-Faecal-oral route
-Waterborne outbreaks, infrequent, usually associated with sewage-contaminated or inadequately treated water.
-Close physical contact with an infectious person, although casual contact among people does not spread the virus.

-Improved sanitation, food safety and immunization are the most effective ways to combat hepatitis A.
-Several hepatitis A vaccines are available internationally.