ABSTRACT
We report on a salmonellosis-outbreak due to Salmonella Enteritidis phage type 14b resistant to nalidixic acid (S. Enteritidis PT14b Nx) among residents and employees of a student residence in Austria, September 2010. The outbreak was described and analysed by a retrospective cohort study, and microbiological environmental investigations were conducted to identify the outbreak source(s) and the reservoir of the outbreak strain. A total of 66 persons fulfilled the outbreak case definition including 14 laboratory-confirmed cases. Food specific cohort-analyses by day revealed that consumption of potato salad (RR: 1.65, 95%CI: 1.352.01, p=0.001) and a cheese-sausage cold plate (RR: 2.24, 95%CI: 1.293.88, p=0.002) on 14 September was associated with being an outbreak case. We hypothesised that cross-contamination with S. Enteritidis PT14b Nx positive eggs had occurred during preparation of the potato salad and cold plate as a result of preparing in parallel egg-containing breaded cutlets on 14 September. A traced laying hen holding in eastern Austria was identified as the sole source of the consumable eggs in the student residence. By applying the legally mandated sampling method for epidemiological-related laying hen farms (one pooled dust sample à 150g, two paired boot swabs cultured separately), the outbreak strain could not be detected. Our findings, that legally required sampling methods for laying hen farms failed to detect the causative pathogen in a laying hen holding, despite an epidemiological link, underline the request stated by the European Food Safety Authority Panel on Biological Hazards for a more sensitive sampling plan in epidemiologically-associated laying hen flocks.
Subject(s)
Anti-Bacterial Agents/pharmacology , Disease Outbreaks , Eggs/microbiology , Food Microbiology , Food Services , Gastroenteritis/epidemiology , Nalidixic Acid/pharmacology , Salmonella Food Poisoning/epidemiology , Salmonella enteritidis/isolation & purification , Adolescent , Animal Husbandry/legislation & jurisprudence , Animal Husbandry/standards , Animals , Austria/epidemiology , Cheese/microbiology , Chickens/microbiology , Drug Resistance, Microbial , Female , Food Handling/standards , Food Microbiology/legislation & jurisprudence , Gastroenteritis/microbiology , Humans , Male , Meat Products/microbiology , Residential Facilities , Salmonella Food Poisoning/microbiology , Salmonella Food Poisoning/transmission , Salmonella enteritidis/classification , Salmonella enteritidis/drug effects , Salmonella enteritidis/virology , Sampling Studies , Solanum tuberosum/microbiology , Young AdultABSTRACT
We describe an outbreak of hepatitis A in Lomnicka, a village in the eastern part of Slovakia. The outbreak was limited to the village and did not spread either to other districts of Slovakia or to the neighbouring countries. The number of cases reported from 28 August to 30 November 2008 was 298. All cases but one occurred in the Roma population. The outbreak was associated with low socio-economic conditions which facilitated person-to-person transmission. No common source of the outbreak was verified.
