The KIzSS network, a sentinel surveillance system for infectious diseases in day care centers: study protocol.

BACKGROUND: Day care-associated infectious diseases are widely recognized as a public health problem but rarely studied. Insights into their dynamics and their association with the day care setting are important for effective decision making in management of infectious disease control. This paper describes the purpose, design and potential of our national multi-center, day care-based sentinel surveillance network for infectious diseases (the KIzSS network). The aim of the KIzSS network is to acquire a long-term insight into the syndromic and microbiological aspects of day care-related infectious diseases and associated disease burden and to model these aspects with day care setting characteristics. METHODS/DESIGN: The KIzSS network applies a prospective cohort design, following day care centers rather than individual children or staff members over time. Data on infectious disease symptoms and related morbidity (children and staff), medical consumption, absenteeism and circulating enteric pathogens (children) are collected on a daily, weekly or monthly basis. Every two years, a survey is performed to assess the characteristics of participating day care centers. DISCUSSION: The KIzSS network offers a unique potential to study infectious disease dynamics in the day care setting over a sustained period of time. The created (bio)databases will help us to assess day care-related disease burden of infectious diseases among attending children and staff and their relation with the day care setting. This will support the much needed development of evidence-based and pragmatic guidelines for infectious disease control in day care centers.

A regional Salmonella enterica serovar Typhimurium outbreak associated with raw beef products, The Netherlands, 2010.

Between April and May 2010, several medical microbiological laboratories in the Netherlands notified a total of 90 cases of Salmonella enterica serovar Typhimurium with the same antibiogram type (resistant for ampicillin, tetracycline, and co-trimoxazol) and the same multiple locus variable number tandem repeats analysis pattern (03-16-09-NA-311) or single locus variants. Date of illness onset ranged from end of March to mid-May with a peak in the second week of April. Almost half of the cases were hospitalized. Cases completed a questionnaire about food items and other risk factors in the 7 days before illness onset. A matched case-control study was performed. Consumption of "ossenworst" (matched odds ratio 48.2 [95% confidence interval (CI): 3.9-595.9]) and filet américain (8.5 [95% CI: 1.0-73.6]) were found to be significant risk factors for illness. Eighty percent of the cases had eaten at least one or both raw meat products. The producer of the ground beef that was used to produce the "ossenworst" was identified, but no microbiological evidence was found. Consumers should be made more aware of the presence of raw meat in ready-to-eat products and of the potential risk in eating these products. Vulnerable persons such as young children, elderly, and persons with poor health should be discouraged from eating these products. Detection of this outbreak was mainly based on the antibiogram pattern that had identified possible cases 10 days before detailed typing results from the reference laboratory became available, thus facilitating early case findings.

Consumption of fresh fruit juice: how a healthy food practice caused a national outbreak of Salmonella Panama gastroenteritis.

In spring 2008, 15 Salmonella Panama laboratory-confirmed cases were reported within 2 weeks, twice the average annual number of reported cases of this infrequent serotype in The Netherlands. To identify the source responsible for this national outbreak, we carried out an epidemiological, microbiological, and trace-back investigation. In total, 33 cases were reported, and a matched case-control study (23 cases/24 controls) identified consumption of fresh (unpasteurized) fruit juice purchased from a large retailer (X) as the only significant risk factor for illness (matched odds ratio: 7.4, 95% confidence interval: 1.5-37.2). Though the bacterium could not be isolated from fruit juice, the minimal pH value for growth of the causative strain of the outbreak (3.4) was compatible with survival in fruit juice from X. The outbreak strain showed acid resistance and adaptive properties that may explain how it could have caused infection through fresh orange juice. To our knowledge, this is the first documented outbreak related to fresh fruit juice consumption in western Europe since 1922. A growing number of consumers who are seeking healthy food practices are exposed to the infectious risks related to unpasteurized fresh fruit juice. Labeling regulations should be adapted to properly indicate to the consumers that unpasteurized fresh fruit juices remain vulnerable to microbial contamination. Frequent microbiological screening and strict compliance with food safety procedures should reduce the infectious hazards of fresh fruit juices.

Salmonella enterica serotype Enteritidis phage type 4b outbreak associated with bean sprouts.

In November 2000 in the Netherlands, an outbreak of Salmonella enterica serotype Enteritidis phage type 4b was investigated. Eating bean sprouts was the only exposure associated with S. Enteritidis pt 4b infection (matched odds ratio 13.0, 95% confidence interval 2.0-552.5). Contaminated seeds were the most likely cause of contamination of the sprouts. The sprout grower applied a concentration of hypochlorite solution that was too low for seed disinfection.