Epidemiology of pertussis in children of Flanders Belgium: can healthcare professionals be involved in the infection?

Pertussis is a communicable disease whose registration incidence in the Flemish region of Belgium has increased since 2003. Originally, this increment was obvious only in the province of Antwerp, but since 2012, there has also been an increase in the registered cases of pertussis in other Flemish provinces. The overall registration incidence for pertussis in Flanders was 5·6 per 100 000 in 2012. The majority of these cases were identified among young children, but older children and adults were also affected. Increased awareness, new diagnostic tools, better registration, waning immunity, and circulation of new strains were most likely associated with the increase in reporting. Although many of the pertussis infections we studied occurred within family units, several healthcare workers who had been in contact with young children were also identified as sources of pertussis. A number of these were index cases, while others were secondary infections. Finally, a fatal neonatal pertussis case is presented to illustrate the severity of the disease in young unvaccinated children.

Usefulness of the European Epidemic Intelligence Information System in the management of an outbreak of listeriosis, Belgium, 2011.

A cluster of time-linked cases and the identification of a clonal strain suggest the occurrence of an outbreak of listeriosis in Belgium in 2011, presumably due to the consumption of hard cheese made with pasteurised milk and produced by a Belgium manufacturer. The outbreak clone was identified as Listeria monocytogenes serovar 1/2a, sensitive to arsenic and cadmium and of multilocus sequence typing MLST-type 37. Food investigation of this outbreak was facilitated by the European Epidemic Intelligence Information System and data exchanged between French and Belgium listeriosis surveillance systems.

Outbreak of Shigella sonnei infections in the Orthodox Jewish community of Antwerp, Belgium, April to August 2008.

In the beginning of April 2008 three cases of Shigella sonnei infection were identified among the Orthodox Jewish community of Antwerp, Belgium. We conducted a descriptive study and a household cohort study to identify potential risk factors. Stool samples were cultured and antibiotic susceptibility of the isolates was determined. Between April and August 2008, 42 cases were registered. All characterised isolates (n=20) shared an identical pulsed-field gel electrophoresis profile and were indistinguishable from one of the twelve main strains detected in Israel in 2008, where the index case's father had stayed before the outbreak. The secondary attack rate in households was 8.5% (95% confidence interval (CI): 4.3­12.7). Multivariate analysis identified the following risk factors for secondary spread: households with more than three children (adjusted relative risk (RR): 9.17; 95% CI: 1.21­69.13), children younger than five years (adjusted RR: 5.45; 95% CI: 2.44­12.62), and children younger than 12 years assisting in washing younger siblings (adjusted RR: 5.45; 95% CI: 2.44­12.17). Rigorous hand washing, use of disposable towels, information for parents and caregivers, and exclusion of symptomatic children from day care, preschool and school for a minimum of 48 hours were implemented.

Outbreak of verocytotoxin-producing E. coli O145 and O26 infections associated with the consumption of ice cream produced at a farm, Belgium, 2007.

In October 2007, an outbreak of verocytotoxin-producing Escherichia coli (VTEC) O145 and E. coli O26 occurred among consumers of ice cream produced and sold in September 2007 at a farm in the province of Antwerp (Belgium). The ice cream was consumed at two birthday parties and also eaten at the farm. Five children, aged between two and 11 years, developed haemolytic uraemic syndrome (HUS), and seven other co-exposed persons contracted severe diarrhoea. In three of the five HUS cases VTEC O145 infections were laboratory confirmed, one in association with VTEC O26. Identical isolates of E. coli O145 and O26 were detected with PCR and PFGE in faecal samples of patients and in ice cream leftovers from one of the birthday parties, in faecal samples taken from calves, and in samples of soiled straw from the farm at which the ice cream was produced. Ice cream was made from pasteurised milk and most likely contaminated by one of food handlers.