An outbreak of monophasic Salmonella Typhimurium associated with raw pork sausage and other pork products, Denmark 2018-19.

In Denmark, outbreaks of salmonella with more than 20 cases have become rare. In November 2018, an outbreak of monophasic Salmonella Typhimurium was detected and an investigation initiated with the aim of identifying the source and controlling the outbreak. Outbreak cases were defined based on core genome multilocus sequence types. We conducted hypothesis-generating interviews, a matched case-control study, food sampling and trace-back investigations. We identified 49 cases distributed across Denmark. In univariable analyses a traditional form of raw Danish pork sausage (medister sausage), pork chops and ground veal/pork showed matched odds ratio of 26 (95% CI 3-207), 4 (95% CI 1-13) and 4 (95% CI 1-10), respectively. In a multivariable analysis, only medister sausage remained significant. Several patients described tasting or eating the sausage raw or undercooked. Samples of medister sausage analysed were negative for salmonella and investigations at the production site did not reveal the mechanism of contamination. In conclusion, in spite of having eliminated salmonella in the egg and broiler industry, Denmark is still at risk of major salmonella outbreaks. We identified a raw pork sausage as a particular risk product that needs to be thoroughly cooked before consumption. Tasting raw meat or eating undercooked pork should be discouraged.

A national register-based study of paediatric varicella hospitalizations in Denmark 2010-2016.

Varicella, usually a mild disease of childhood, can also cause complications and hospitalization. Universal varicella immunization is implemented in several countries worldwide, but not in Denmark. Taking advantage of unique national registers, we aimed to estimate the incidence of paediatric varicella hospitalizations and assess determinants for hospitalization. For this purpose, we designed a nationwide, retrospective register study of paediatric varicella hospitalizations and applied a case-cohort design and logistic regression analysis comparing hospitalized varicella patients to a sample of the entire paediatric population in Denmark. Varicella patients were identified in The Danish National Patient Register and referents were randomly selected from the Danish Civil Registration System. The incidence of paediatric varicella admissions was 11/100 000 children 0-18 years of age/year. Of admitted children 67·1% had complications and 30·0% had underlying disease. All categories of underlying disease significantly increased the odds of hospitalization as well as male gender and not having been born in Denmark. In conclusion, we found a considerable burden of paediatric varicella disease in Danish hospitals, of similar magnitude as in other European countries comparable to Denmark. With this study we have provided epidemiological data needed for considering implementation of varicella vaccine in Denmark.

Varicella-zoster immunoglobulin treatment in pregnant women in Denmark from 2005 to 2015: descriptive epidemiology and follow-up.

Primary infection with varicella-zoster virus in pregnancy poses a risk of severe infection and embryopathies. Upon exposure, seronegative women are candidates for varicella-zoster immunoglobulin (VZIG). The aim of this paper was to describe risk factors for VZIG treatment including sources of varicella exposure and to study how many women developed clinical infection and received postpartum vaccination. We identified all pregnant women who received VZIG from December 2005 to March 2015. Additional information was obtained from Danish registers and a follow-up questionnaire. A total of 104 women were included and 88 completed the questionnaire. Significantly more women had 'other country of origin' than Denmark. They were more often second para (57%) and had most commonly been exposed to varicella by their own child (58%). Five women developed clinical varicella infection, and only 26·5% were vaccinated after delivery. The study concludes that few women developed infection after VZIG and none developed pneumonia. General practitioners should be particularly aware of obtaining varicella anamnesis in parous women from non-temperate countries in order to perform selective vaccination prior to pregnancy. In case of varicella exposure during pregnancy in a seronegative woman, postpartum vaccination is crucial.