In February 1999, an outbreak of listeriosis caused by Listeria monocytogenes serotype 3a occurred in Finland. All isolates were identical. The outbreak strain was first isolated in 1997 in dairy butter. This dairy began delivery to a tertiary care hospital (TCH) in June 1998. From June 1998 to April 1999, 25 case patients were identified (20 with sepsis, 4 with meningitis, and 1 with abscess; 6 patients died). Patients with the outbreak strain were more likely to have been admitted to the TCH than were patients with other strains of L. monocytogenes (60% vs. 8%; odds ratio, 17.3; 95% confidence interval, 2.8-136.8). Case patients admitted to the TCH had been hospitalized longer before cultures tested positive than had matched controls (median, 31 vs. 10 days; P=.008). An investigation found the outbreak strain in packaged butter served at the TCH and at the source dairy. Recall of the product ended the outbreak.
The purpose of the present study was to establish the occurrence of infertility in Finnish women aged 30, 35 and 40 years. The study is based on an interview by questionnaire carried out on women participating in screening for cancer by Pap smear. The participation rate is generally about 60%. A total of 4,879 women were interviewed between May 1981 and April 1982. 149 incomplete replies were discarded and an additional 528 women not at risk of conception were excluded. The final analysis included 4,202 women. Actual infertility, i.e., failure to establish pregnancy at the time of interview, occurred in 438 women (10.4%). The overall infertility rate was 15.4%. The primary infertility rate (5%) seems to be similar in all the age groups interviewed. Secondary infertility increased among women aged 30-40 years, from 4.1 to 9.9%. Actual infertility increased highly significantly between the age groups 30 and 40 years. A limited number of women are permanently infertile, but the percentage of those who at some point in their lives are involuntarily childless is higher.
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.
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.
A total of 80 human infections by Escherichia coli O157:H7 were documented in Finland in 1997 and 1998. Most were sporadic and their sources undetermined. Five cases not associated with one another, one of which led to secondary transmission within a family, could be traced to five different dairy farms. These five case patients (age range 2-17 years, median age 3 years) were hospitalised with bloody diarrhoea; two of them developed haemolytic uraemic syndrome. All nine human isolates obtained were sorbitol negative, carried the verocytotoxin 2 and eae genes, and produced verocytotoxin and enterohaemolysin. The phage and pulsed-field gel electrophoresis types of the human and bovine isolates from the corresponding farms were indistinguishable. The cattle (20-70 animals per farm) were monitored for up to 2 years after the human cases. The proportion of cattle excreting the type that caused the human infections varied from 3.2 to 66.7% when sampled soon after the human cases, and from 0.0 to 5.3% about a year or so later. On most of the farms, the animals excreted the pathogen intermittently. On one farm, Escherichia coli O157 isolates with other characteristics were also occasionally isolated. Although the infections were traced back to the farms, it could not be established whether the source was unpasteurised milk or direct or indirect contact with cattle. The results of this study emphasise the need for special recommendations for children visiting or living on a farm to prevent these infections.