Number of food poisoning epidemics still on the increase in 2005


<div>A total of 55 food or water-borne food poisoning epidemics, involving ca. 2000 people, were recorded in 2005 in the Finnish food poisoning register. Most (91%) of the epidemics were transmitted by food. Domestic water was the cause in five (9%) epidemics. The number of food poisoning epidemics decreased in the years 2000 – 2003, but the decreasing trend stopped in 2004. In 2005 the number of epidemics was 15% higher than the year before. The most common cause of food and water-borne food poisonings was noro-virus. The increasing trend in the number of food poisoning epidemics proves that continuous hygiene training is needed.</div>

Also in 2005, the most common cause of food-borne food poisonings was noro-virus, which caused 16 (32%) epidemics. A raw material contaminated by noro-virus caused two epidemics. In one of the epidemics the virus was found in French oysters, and the other epidemic was probably caused by imported frozen raspberries. However, food-borne epidemics are in most cases caused by deficient hand hygiene and by an infected person taking part in food preparation. In more than half the cases the person who prepared the food suffered from stomach upset.

The second most common cause of epidemics was salmonella; it was the culprit in three epidemics. The rare antibiotic-resistant S. Typhimurium FT 104B bacterium caused a wide epidemic of mouse typhus in southern and western Finland in May, with Spanish icerberg lettuce confirmed as the cause. S. Typhimurium was also responsible for another epidemic of mouse typhus, transmitted through food prepared at home for a party. Two of the persons involved in the preparation of food were found to have an asymptomatic salmonella infection. Six people who dined at a Chinese restaurant caught an infection caused by S. Enteritidis. The transmitting foodstuff could not be identified, but severe deficiencies in hygiene were found in the restaurant.

The most significant factor contributing to epidemics was an erroneous temperature during preparation or storage of food, and in the case of the noro-virus and salmonella epidemics, an infected kitchen employee taking part in preparation of food. Sufficient hand hygiene and correct handling of raw materials and cooked food could have prevented more than half of the food-borne epidemics.

Campylobacter was the most significant cause microbe in water-borne epidemics. It caused two wide water-borne epidemics that involved hundreds of patients. In one of the epidemics the reason was contamination of tap water due to maintenance work, and in the other the cause was a rare incident of water contaminated by squirrels in the water tower. The other three water-borne epidemics were more limited, and their cause remained unknown. All in all, however, deficiencies could be shown in hygiene of water for household consumption.

The data has been collected from The Finnish Food Safety Authority's recent publication No. 2/2006, Food poisonings in Finland in 2005. The publication has been produced by the Food Safety Authority Evira in collaboration with the National Public Health Institute, with Niskanen T., Johansson T., Kuusi M., Raahenmaa M., Siitonen A. and Tuominen P. as authors. The publication can be read at:

For more information, please contact:

Food-borne epidemics:

Senior Officer Taina Niskanen, Food Safety Authority Evira, tel. +358 (0) 2077 24318, +358 (0) 50 386 8421

Epidemiologist Markku Kuusi, National Public Health Institute, +358 (0) 9 4744 8935

Mikrobiologist Tuula Johansson, Food Safety Authority Evira +358 (0) 2077 24472

Research Professor Anja Siitonen, National Public Health Institute, +358 (0) 9 4744 8245

Epidemics transmitted by domestic water:

Scientist Ilkka Miettinen, National Public Health Institute, +358 (0) 17 201 371, 040 5725600.

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