Abstract
In 2020–2022, a total of 139 foodborne or household waterborne outbreaks were included
in the register of foodborne and waterborne outbreaks maintained by the Finnish Food
Authority. Of these, 135 (97%) were foodborne. A total of four household waterborne
outbreaks were reported over this same period. A total of 2 543 people were reported to
have fallen ill due food and 58 by household water.
As previously in the 2000s, norovirus was the most common reported cause of foodborne
outbreaks in 2020–2022. The norovirus caused 34 (25%) foodborne outbreaks. The largest
foodborne outbreak in 2020–2022 was caused by Salmonella Typhimurium in 2021, when
728 people became ill because of lunch meals in day-care centres. The causative agent
remained unknown in 33 (24%) foodborne outbreaks.
The most reported foods vectors were vegetables and vegetable products. These caused
16 outbreaks (12%). The second most common food vectors were fish and fish products,
including shellfish and mussels (12 outbreaks, 9%). However, in most of the outbreaks,
the food vector remained unidentified, or several foods were suspected as vectors (87
outbreaks, 64%).
The participation of an infected kitchen worker in food preparation and inadequate hand
hygiene resulted in 17% of foodborne outbreaks (23 outbreaks). In nearly all these cases the
causative agent was norovirus. The use of contaminated ingredients was linked to 18 (13%)
outbreaks. In 16 (12%) of outbreaks, there were inadequacies and errors in temperatures and
storage of food. The most reported location where foodborne outbreaks happened were
restaurants, cafés or hotels (64 outbreaks, 47%) The second most common were homes (16
outbreaks, 12%). A total of 16 national outbreaks or outbreaks with multiple locations were
also reported. Noroviruses caused two outbreaks identified as household waterborne and
campylobacters one outbreak. The causative agent remained unknown in one case. The
largest household waterborne outbreak was caused by campylobacter in 2020. A total of 43
people fell ill.
In 2020–2022, three swimming waterborne outbreaks, which caused 210 people to fall ill,
were reported in Finland. Either norovirus was diagnosed in swimmers, or their symptoms
suggested an infection caused by the norovirus. Norovirus was detected in the swimming
water only in one of the outbreaks. In all outbreaks, the quantities of indicator bacteria were
low. No clear cause of swimming water contamination was identified in any of the cases.
FoodWorld 