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Protracted outbreak of S. Enteritidis PT 21c in a large Hamburg nursing home.

Frank C, Buchholz U, Maass M, Schröder A, Bracht KH, Domke PG, Rabsch W, Fell G - BMC Public Health (2007)

Bottom Line: Enteritidis isolates from patients and suspected food vehicles were phage typed and compared.Enteritidis was consistently recovered from patients' stools throughout the outbreak.Suggestions are made to nursing homes, aiding in outbreak prevention.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany. frankc@rki.de

ABSTRACT

Background: During August 2006, a protracted outbreak of Salmonella (S.) Enteritidis infections in a large Hamburg nursing home was investigated.

Methods: A site visit of the home was conducted and food suppliers' premises tested for Salmonella. Among nursing home residents a cohort study was carried out focusing on foods consumed in the three days before the first part of the outbreak. Instead of relying on residents' memory, data from the home's patient food ordering system was used as exposure data. S. Enteritidis isolates from patients and suspected food vehicles were phage typed and compared.

Results: Within a population of 822 nursing home residents, 94 case patients among residents (1 fatality) and 17 among staff members were counted 6 through 29 August. The outbreak peaked 7 through 9 August, two days after a spell of very warm summer weather. S. Enteritidis was consistently recovered from patients' stools throughout the outbreak. Among the food items served during 5 through 7 August, the cohort study pointed to afternoon cake on all three days as potential risk factors for disease. Investigation of the bakery supplying the cake yielded S. Enteritidis from cakes sampled 31 August. Comparison of the isolates by phage typing demonstrated both isolates from patients and the cake to be the exceedingly rare phage type 21c.

Conclusion: Cake (various types served on various days) contaminated with S. Enteritidis were the likely vehicle of the outbreak in the nursing home. While the cakes were probably contaminated with low pathogen dose throughout the outbreak period, high ambient summer temperatures and failure to keep the cake refrigerated led to high pathogen dose in cake on some days and in some of the housing units. This would explain the initial peak of cases, but also the drawn out nature of the outbreak with cases until the end of August. Suggestions are made to nursing homes, aiding in outbreak prevention. Early outbreak detection is crucial, such that counter measures can be swift and drawn-out outbreaks of nosocomial food-borne infections avoided.

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Related in: MedlinePlus

Food distribution system within the nursing units and other customers of the central kitchen.
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Figure 2: Food distribution system within the nursing units and other customers of the central kitchen.

Mentions: The central kitchen functioned as a clearing house for all meals served in the nursing units (for details see figure 2). Cold food items for breakfast and dinner arrived in small lots in the unit kitchens and were used there to prepare breakfast and dinner, served on trays according to residents' standing orders. Warm meals were prepared in the central kitchen, chilled, portioned and arranged on trays according to residents' orders from a weekly menu. Items for warm consumption were reheated in the unit kitchens utilizing cook-and-chill procedures.


Protracted outbreak of S. Enteritidis PT 21c in a large Hamburg nursing home.

Frank C, Buchholz U, Maass M, Schröder A, Bracht KH, Domke PG, Rabsch W, Fell G - BMC Public Health (2007)

Food distribution system within the nursing units and other customers of the central kitchen.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2194771&req=5

Figure 2: Food distribution system within the nursing units and other customers of the central kitchen.
Mentions: The central kitchen functioned as a clearing house for all meals served in the nursing units (for details see figure 2). Cold food items for breakfast and dinner arrived in small lots in the unit kitchens and were used there to prepare breakfast and dinner, served on trays according to residents' standing orders. Warm meals were prepared in the central kitchen, chilled, portioned and arranged on trays according to residents' orders from a weekly menu. Items for warm consumption were reheated in the unit kitchens utilizing cook-and-chill procedures.

Bottom Line: Enteritidis isolates from patients and suspected food vehicles were phage typed and compared.Enteritidis was consistently recovered from patients' stools throughout the outbreak.Suggestions are made to nursing homes, aiding in outbreak prevention.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany. frankc@rki.de

ABSTRACT

Background: During August 2006, a protracted outbreak of Salmonella (S.) Enteritidis infections in a large Hamburg nursing home was investigated.

Methods: A site visit of the home was conducted and food suppliers' premises tested for Salmonella. Among nursing home residents a cohort study was carried out focusing on foods consumed in the three days before the first part of the outbreak. Instead of relying on residents' memory, data from the home's patient food ordering system was used as exposure data. S. Enteritidis isolates from patients and suspected food vehicles were phage typed and compared.

Results: Within a population of 822 nursing home residents, 94 case patients among residents (1 fatality) and 17 among staff members were counted 6 through 29 August. The outbreak peaked 7 through 9 August, two days after a spell of very warm summer weather. S. Enteritidis was consistently recovered from patients' stools throughout the outbreak. Among the food items served during 5 through 7 August, the cohort study pointed to afternoon cake on all three days as potential risk factors for disease. Investigation of the bakery supplying the cake yielded S. Enteritidis from cakes sampled 31 August. Comparison of the isolates by phage typing demonstrated both isolates from patients and the cake to be the exceedingly rare phage type 21c.

Conclusion: Cake (various types served on various days) contaminated with S. Enteritidis were the likely vehicle of the outbreak in the nursing home. While the cakes were probably contaminated with low pathogen dose throughout the outbreak period, high ambient summer temperatures and failure to keep the cake refrigerated led to high pathogen dose in cake on some days and in some of the housing units. This would explain the initial peak of cases, but also the drawn out nature of the outbreak with cases until the end of August. Suggestions are made to nursing homes, aiding in outbreak prevention. Early outbreak detection is crucial, such that counter measures can be swift and drawn-out outbreaks of nosocomial food-borne infections avoided.

Show MeSH
Related in: MedlinePlus