Oysters can give you Hepatitis A

From 1983 to 1989, the incidence of hepatitis A in the United States reached 58 percent. Some 35,800 cases were reported in the latter year.

From 1983 to 1989, the incidence of hepatitis A in the United States reached 58 percent. Some 35,800 cases were reported in the latter year.

Many were foodborne-related outbreaks that occurred in Alaska, Florida, North Carolina, and Washington. The contaminants included, among others, an ice-slush beverage purchased from a convenience store and iced tea prepared by an infected intravenous drug user who made sandwiches and drinks in a restaurant.

Contaminated frozen strawberries from a processing plant in California were the cause of two separate hepatitis A outbreaks in Georgia and Montana. In the former,13 students and two teachers of an elementary school contracted the disease in two weeks after eating strawberry shortcake in the school cafeteria.

In the Montana episode that took place at an institution for the developmentally disabled, 13 got the disease during a three-week period following the ingestion of desserts containing frozen strawberries.

An early outbreak in London in 1989 involved more than 50 residents of a group of villages. This was traced to bread prepared in a shop and its outlets by workers with soiled hands.

The womanizing librarian Giovanni Giacomo Casanova once recommended 50 oysters for breakfast for those hungry for aphrodisiacs. But instead of getting the girl of your dreams, following that advice could give you hepatitis A.

The reason? Shellfish (oysters, mussels, cockles, or clams) are more likely to transmit the disease. This is because shellfish filter large amounts of water and tend to leave large quantities of bacteria and viruses behind, including the one responsible for hepatitis A.

This was the sad experience of China which had three separate hepatitis A epidemics in 1978, 1982 and 1988 - all attributed to eating raw shellfish. The largest outbreak occurred in Shanghai in 1988, affecting about 300,000 people with 45 fatalities, according to Stephen C. Hadler of the Center for Infectious Diseases Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia.

"The first documented .outbreak of hepatitis A due to ingestion of shellfish was reported in 1956 when 600 Swedes who had eaten oysters harvested from waters contaminated with human sewage, contracted the disease. Since that time, numerous outbreaks have been reported from Europe, the USA, Asia, and Australia. While cultivation and distribution of shellfish is often carefully regulated, the nature of the business makes policing of the laws extremely difficult. Harvests are often provided to a variety of wholesalers who, in turn, supply a number of outlets. These factors, together with the prolonged incubation period, make shellfish-associated infection difficult to investigate so that many probably go undetected," revealed Ian D. Gust in "Epidemiological Patterns of Hepatitis A in Different Parts of the World" published in the journal Vaccine.

Believe it or not swimming can make you susceptible to hepatitis A.

This was reported by Dr. Frank J. Mahoney of the CDC in an article in The Journal of Infectious Diseases.

In that article, Mahoney said 20 people aged four to 36 succumbed to hepatitis A in 1989 after swimming in contaminated water in a campground in Louisiana.

Prior to the outbreak, the victims swam in two public pools - a Jacuzzi pool and an adult pool which investigators said could have been contaminated with fecal material or raw sewage owing to the pools' unusual design and filtering system. That plus the behavior of the swimmers (who either swallowed or spit water while swimming) put them at great risk for contracting hepatitis A.

"We speculate that the pools may have been contaminated either by fecal contamination from one of the swimmers or by cross-connection with the sewage. Several people reported that children wearing diapers were allowed to swim in the pools on the weekend in question. The management at the campground reported that fecal contamination of the pools by swimmers was not uncommon," Mahoney and his colleagues said.

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