A prolonged outbreak of Salmonella Montevideo infections associated with multiple locations of a restaurant chain in Phoenix, Arizona, 2008.

An outbreak of Salmonella serotype Montevideo infections associated with multiple locations of restaurant chain A in Phoenix, AZ, was identified in July 2008. One infected individual reported eating at a chain A catered luncheon where others fell ill; we conducted a cohort study among attendees to identify the vehicle. Food and environmental samples collected at six chain A locations were cultured for Salmonella. Restaurant inspection results were compared among 18 chain A locations. Routine surveillance identified 58 Arizona residents infected with the outbreak strain. Three chain A locations, one of which catered the luncheon, were named by two or more case patients as a meal source in the week prior to illness onset. In the cohort study of luncheon attendees, 30 reported illness, 10 of which were later culture confirmed. Illness was reported by 30 (61%) of 49 attendees who ate chicken and by 0 of 7 who did not. The outbreak strain was isolated from two of these three locations from uncooked chicken in marinade, chopped cilantro, and a cutting board dedicated to cutting cooked chicken. Raw chicken, contaminated before arrival at the restaurant, was the apparent source of this outbreak. The three locations where two or more case patients ate had critical violations upon routine inspection, while 15 other locations received none. Poor hygiene likely led to cross-contamination of food and work areas. This outbreak supports the potential use of inspections in identifying restaurants at high risk of outbreaks and the need to reduce contamination of raw products at the source and prevent cross-contamination at the point of service.

Norovirus in a United States virgin islands resort: outbreak investigation, response, and costs.

BACKGROUND: During 8-20 April 2012, an outbreak of gastrointestinal illness occurred among guests and employees of a resort hotel in St. Thomas, US Virgin Islands. We describe outbreak characteristics, and estimate indirect (non-medical) costs to travellers. METHODS: Employees who met the case definition were interviewed and provided stool samples. Samples were tested for norovirus by real-time reverse-transcription polymerase chain reaction. Guests were asked to complete a survey aimed to identify and characterize cases, and to estimate quality adjusted vacation days (QAVD) lost. RESULTS: Overall, 66 persons (20 employees and 46 guests) met the probable case definition. The first reported illness onset occurred in a hotel employee on 8 April, while the first reported onset in a guest occurred on 13 April. An employee suffered a public diarrhoea incident on 13 April in the central kitchen, followed by illness onset in the next day among employees that assisted with the clean-up. On 15 April, after 10 guests reported ill, the hotel implemented an outbreak response protocol instructing ill employees to take a 3-day leave, and obtain medical clearance prior to resuming work. Ill guests were advised to self-isolate, and rapid cleaning of public areas and guest rooms where suspected contamination occurred was implemented. We estimated that 65 QAVDs were lost by 43 guests (1.5 days/guest). Using an approximate cost of $450 per vacation day, we estimated indirect illness cost at $675 per guest case. Seven (64%) of 11 cases' stool specimens were positive for norovirus genotype GII.4 Den Haag. CONCLUSIONS: A norovirus outbreak in a resort hotel resulted in substantial indirect costs and loss of vacation days to ill travellers. We recommend outbreak control measures including exclusion of ill employees, until ≥48-72 h after resolution of symptoms, self-isolation of ill guests and appropriate cleaning in hotel-associated norovirus outbreaks.