An outbreak of febrile gastroenteritis affected consumers of on-farm manufactured dairy products from a summer farm in Sweden. Symptoms included diarrhoea, fever, stomach cramps and vomiting in 88, 60, 54 and 21% of cases identified. The median incubation period was 31 h. A cohort study with 33 consumers showed an attack rate of 52% and an association between the total amount of product eaten and illness (P=0.07). Twenty-seven of 32 (84%) stool samples cultured for Listeria monocytogenes tested positive, although there was no association between clinical disease and the isolation of L. monocytogenes. In addition, gene sequences for VTEC and ETEC were detected in 6 and 1 subjects, respectively. Bacteriological analysis of cheese samples revealed heavy contamination with L. monocytogenes and coagulase positive staphylococci in all of them and gene markers for VTEC in one of them. Molecular profiles for L. monocytogenes isolated from dairy products, stool samples and an abscess from 1 patient who developed septic arthritis were identical. Results of both microbiological and epidemiological analyses point to L. monocytogenes as the most likely cause of this outbreak. The finding of markers for VTEC in some humans and cheese samples means that a mixed aetiology at least in some cases cannot be conclusively ruled out.

The total number of persons infected or colonised with vancomycin-resistant enterococci mandatorily reported to the Swedish Institute for Infectious Disease Control increased dramatically during 2007 and 2008. During a period of twenty months from 1 July 2007 to 28 February 2009, a total of 760 cases were reported compared with 194 cases reported during the entire period from 2000 to 2006. This rise was mainly attributed to a wide dissemination of vancomycin resistant enterococci which started in a number of hospitals in Stockholm in the autumn of 2007 and was followed by dissemination in various healthcare facilities (hospitals and homes for the elderly) in a further two Swedish counties in 2008. The majority of the cases (97%) were acquired in Sweden and among these, healthcare-acquired E. faecium vanB dominated (n=634). The majority of these isolates had identical or closely related pulsed-field gel electrophoresis patterns indicating clonal dissemination in the affected counties. The median minimum inhibitory concentration of vancomycin was 32 mg/L (ranging from 4 to >128 mg/L) and of teichoplanin 0.12 mg/L (ranging from 0.06 to 0.25 mg/L). Particular emphasis was placed on countermeasures such as screening, contact tracing, cleaning procedures, education in accurate use of infection control practices as well as increasing awareness of hygiene among patients and visitors. With these measures the dissemination rate decreased substantially, but new infections with the E. faecium vanB strain were still detected.

In a prospective study, the incidences of CMV infection and disease were 56 and 23%, respectively, during the first 6 months following kidney transplantation. Viremia was found in all patients with CMV disease and arthralgia was present in 71% prior to the development of CMV disease. The positive predictive value for CMV disease reached up to 90% for viremia and arthralgia in combination. Viruria was poorly correlated to viremia and hence CMV disease. The majority of patients (93%) who developed CMV disease had a seropositive donor, and viremia was significantly more common in patients who received CMV-seropositive kidneys. CMV disease was more common in CMV-seronegative recipients than in seropositive recipients. The 1-year graft survival rate was 75% in the entire study group. In patients with CMV viremia and disease, the rates were 78 and 73%, respectively. Antiviral treatment was initiated within 3 weeks of viremia detection in the 6 patients with CMV disease who survived. We found that the combination of arthralgia and viremia was a useful predictor of CMV disease and that recipients of CMV-seropositive allografts were at a greater risk of developing CMV disease. To obtain an early diagnosis and commence an early treatment of CMV disease, patients prone to develop CMV disease should be identified and clinical examination and viremia surveillance should be performed regularly.

Reported cases of hepatitis C (HCV) have been increasing among HIV-positive men who have sex with men (MSM) in many cities worldwide, including Stockholm, Sweden. This study was performed in order to see whether there is also an increase of HCV among HIV-negative MSM. A total number of 1008 MSM attending a clinic for sexually transmitted infections (STI) were screened for HCV. A confirmed positive HCV antibody screening test was found in five cases. Two of these also tested positive for HCV-RNA. We conclude that there is limited spread of HCV among MSM in Stockholm, and the prevalence of HCV among HIV-negative MSM is similar to that found in the general population.

Methicillin-resistant Staphylococcus aureus (MRSA) was found in a dog for the first time in Sweden in 2006. Between October 2006 and May 2007, MRSA was diagnosed in 7 more dogs that had been treated in 3 different small animal hospitals, located 150-200 km apart, in different counties of Sweden. Screening of the animal hospital staff and environment in these small animal hospitals showed 20 of 152 staff to be positive for MRSA, with rates between 2% and 18% in the different hospitals, while all 128 environmental samples were negative. All MRSA isolates from dogs and staff belonged to spa type t032, were Panton-Valentine leukocidin (PVL)-negative, and had indistinguishable pulsed-field gel electrophoresis patterns, except for 2 isolates with closely related patterns. To our knowledge, this is the first report of multiple outbreaks of MRSA in dogs caused by the same strain within a short time frame, and appearing in a country with low prevalence of MRSA in both humans and dogs. This highlights the importance of infection control programs in animal hospitals and in animal health care. Awareness of MRSA as an occupational risk for veterinary personnel is essential.