Over 250 individuals fell ill in five outbreaks caused by Cryptosporidium parvum in Finland, October-November 2012. The cases were connected by lunch meals at restaurants in four different cities. In two outbreaks, the same C. parvumIIdA17G1 subtype was found in patients' stool samples which supports a single source of infection. Frisée salad was the only common food item served at the restaurants, and consumption of lunch salad containing the frisée salad was associated with the illness. Lunch customers who responded that they had eaten lunch salad were three times more likely to have become ill than those who had not answered whether they had eaten the salad or not (RR 2.66; 95% Cl 1.02-6.9, P-value <0.01). Cryptosporidiosis should be considered as a causal agent in long-lasting watery diarrhoea combined with abdominal cramps, and clinical samples should be tested for Cryptosporidium at the same time bacteria and viruses are tested. Measures to prevent contamination of 'ready-to-eat vegetables' with Cryptosporidium oocysts and methods to test frozen food samples should be developed.

In 2010, a marked increase in listeriosis incidence was observed in Finland. Listeria monocytogenes PFGE profile 96 was responsible for one-fifth of the reported cases and a cluster of PFGE profile 62 was also detected. Investigations revealed two fishery production plants with persistent Listeria contamination. It appears likely that the plants were at least partly responsible for the increase of listeriosis. Epidemiological investigation revealed that 57% (31/54) of cases with underlying immunosuppressive condition or medication reported eating gravad or cold-smoked fish. Two public notices were issued by THL and Evira informing which groups were most at risk from the effects of listeriosis and should therefore be cautious in consuming certain products. Systematic sampling of foods and adequate epidemiological investigation methods are required to identify the sources of Listeria infections. Continuous control measures at fishery production plants producing risk products are essential.

In March 2014, a Yersinia pseudotuberculosis (YP) outbreak was detected by a municipal authority in southern Finland. We conducted epidemiological, microbiological and traceback investigations to identify the source. We defined a case as a person with YP infection notified to the National Infectious Disease Registry between February and April 2014, or their household member, with abdominal pain and fever≥38 °C or erythema nodosum. Healthy household members were used as household-matched controls. We identified 43 cases and 50 controls. The illness was strongly associated with the consumption of raw milk from a single producer. The odds ratio of illness increased with the amount of raw milk consumed. Also previously healthy adults became infected by consuming raw milk. Identical YP strains were identified from cases' stool samples, raw milk sampled from a case's refrigerator and from the milk filter at the producer's farm. The producer fulfilled the legal requirements for raw milk production and voluntarily recalled the raw milk and stopped its production. We advised consumers to heat the raw milk to 72 °C for 15 s. Current legislation for raw milk producers should be reviewed and public awareness of health risks linked to raw milk consumption should be increased.

In October 2011 in Finland, two persons fell ill with symptoms compatible with botulism after having eaten conserved olives stuffed with almonds. One of these two died. Clostridium botulinum type B and its neurotoxin were detected in the implicated olives by PCR and mouse bioassay, respectively. The olives were traced back to an Italian manufacturer and withdrawn from the market. The public and other European countries were informed through media and Europe-wide notifications.

During one week in July 2012, two patients from the same ward at the municipal hospital in Vaasa, Finland, were diagnosed with septicaemia caused by Listeria monocytogenes. An outbreak investigation revealed eight concomitant cases of febrile gastroenteritis caused by L. monocytogenes on the same ward. Median age of the cases was 82 years and median incubation time for listerial gastroenteritis was 21 h (range 9-107). An additional 10 cases of invasive listeriosis caused by the same outbreak strain were identified across the whole country during the summer of 2012. Environmental investigation at the affected municipal hospital ward revealed ready-sliced meat jelly as the suspected source of the infection. During inspection of the meat jelly production plant, one pooled sample taken from a floor drain and a trolley wheel in the food processing environment was positive for the outbreak strain of L. monocytogenes. After the producer stopped the production of meat jelly, no further cases of listeriosis with the outbreak strain were identified via nationwide surveillance.