A bulletin for the Australian Food Industry September 1997
Contents: Training and national food hygiene legislation | ANZFA draft standard on food additives | Unusual chemical poisoning incident | Chlorfluazuron (CFZ) residues in meat | Hepatitis A transmission by foods | Garibaldi charges dropped | Cheese from unpasteurised milk | Date marking of processed foods for export | Fungi and food spoilage
Hepatitis A transmission by foods
As noted previously the main food associated with foodborne viruses including hepatitis A is molluscan shellfish. In Sydney in May an outbreak of this serious illness was linked to imported frozen prawns. Seventeen people became ill in one incident while a single case linked to frozen, imported foods was reported in a separate incident around the same time.
Proper cooking and hygienic food handling are the best safeguards against foodborne viruses. In these incidents the cooking step in two separate commercial kitchens appears to have been inadequate. Cross contamination from the original source, the prawns, to other foods not subsequently heated must also be considered a possibility.
A serious outbreak of hepatitis A in the United States involving at least 153 cases in March 1997 has been attributed to contaminated strawberries (The Lancet 349 (9058) 1997 p.1073). Since fruits are usually consumed without cooking, it is important that all care is taken to avoid viral contamination in the field and during subsequent handling and packing.
In the US incident, a strong association between illness and consumption of food items containing frozen strawberries as part of a school lunch programme was established. The strawberries were traced back from Michigan, where the outbreak occurred, to Southern California. The company in California had processed, packed and frozen the fruit in 30 pound containers a year previously. This provides a timely warning of how long some viruses can survive in the frozen condition in a sympathetic medium.
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