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.

Norovirus Infection and Disease in an Ecuadorian Birth Cohort: Association of Certain Norovirus Genotypes With Host FUT2 Secretor Status.

BACKGROUND: Although norovirus is the most common cause of gastroenteritis, there are few data on the community incidence of infection/disease or the patterns of acquired immunity or innate resistance to norovirus. METHODS: We followed a community-based birth cohort of 194 children in Ecuador with the aim to estimate (1) the incidence of norovirus gastroenteritis from birth to age 3 years, (2) the protective effect of norovirus infection against subsequent infection/disease, and (3) the association of infection and disease with FUT2 secretor status. RESULTS: Over the 3-year period, we detected a mean of 2.26 diarrheal episodes per child (range, 0-12 episodes). Norovirus was detected in 260 samples (18%) but was not found more frequently in diarrheal samples (79 of 438 [18%]), compared with diarrhea-free samples (181 of 1016 [18%]; P = .919). A total of 66% of children had at least 1 norovirus infection during the first 3 years of life, and 40% of children had 2 infections. Previous norovirus infections were not associated with the risk of subsequent infection. All genogroup II, genotype 4 (GII.4) infections were among secretor-positive children (P < .001), but higher rates of non-GII.4 infections were found in secretor-negative children (relative risk, 0.56; P = .029). CONCLUSIONS: GII.4 infections were uniquely detected in secretor-positive children, while non-GII.4 infections were more often found in secretor-negative children.