Federal health officials indicate frozen fruit from China appears to be the cause of multiple outbreaks of norovirus which occurred on cruise ships last year.
In the U.S. Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report published last week, cruise ship norovirus outbreaks which sickened hundreds of people were linked to fruit smoothies made from frozen fruit products.
At least 10 European cruises from the same cruise line experienced a spate of passenger illnesses last summer, which were marked by rapid onset of diarrhea, vomiting and fever. The cruise line, which was not named in the report, investigated the illnesses to no avail.
Different ships from the same cruise line were also linked to reports of gastroenteritis illnesses and more than 3% of passengers experienced the same symptoms between July to September 2019.
Finally, in September 2019, a cruise ship from the same line sailed to the United States, and the Vessel Sanitation Program was informed of an outbreak on that ship, which sickened 117 passengers and 8 crew members. Stool samples were taken from passengers, and the agency was able to confirm norovirus as the illness, but the source of the outbreak remained unknown at the time.
After two more outbreaks occurred on other ships from the same line in October 2019, which impacted at least 85 passengers and 10 crew members on one ship, and 83 passengers and 10 crew members on the other ship, food questionnaires were given the passengers.
The findings revealed 80% of passengers ate a smoothie made from frozen fruits and berries.
The U.S. Food and Drug Administration was enlisted to help with the investigation and collected frozen fruit and berry items from the ships and tested 16 samples. Three samples tested positive for norovirus, including frozen raspberries, tropical fruit cocktail, and berry mix. The cruise line had purchased 22,000 pounds of frozen fruit from a supplier in China.
After the contamination was discovered, the fruit items were removed and no more illnesses occurred. The World Health Organization later issued a recall for the frozen fruit in November 2019.
Norovirus is a type of gastrointestinal illness that is very contagious. It causes stomach upset, diarrhea, and vomiting. It can be spread from person to person or by touching contaminated surfaces. Contaminated drinks or food can also spread the virus; however, people typically recover within 1 to 3 days.