Epidemiology of Foodborne Norovirus Outbreaks in Catalonia, Spain
Author Information
Author(s): Ana Martinez, Angela Dominguez, Nuria Torner, Laura Ruiz, Neus Camps, Irene Barrabeig, Cesar Arias, Josep Alvarez, Pere Godoy, Pilar Jorgina Balaña, Analia Pumares, Rosa Bartolome, Dolors Ferrer, Unai Perez, Rosa Pinto, Javier Buesa
Primary Institution: Department of Health, Autonomous Government of Catalonia, Barcelona, Spain
Hypothesis
What are the size and epidemiological characteristics of foodborne outbreaks of gastroenteritis due to Norovirus in Catalonia?
Conclusion
Norovirus outbreaks were larger but less frequent than bacterial outbreaks, suggesting that underreporting is greater for NoV outbreaks.
Supporting Evidence
- Norovirus was identified in 30 outbreaks, affecting 741 people.
- 66.7% of NoV outbreaks occurred in restaurants.
- Hospitalizations were more common in bacterial outbreaks (8.6%) than in NoV outbreaks (0.15%).
- Secondary cases accounted for 4% of cases in NoV outbreaks compared to 0.3% in bacterial outbreaks.
- The incidence rate for NoV was 9.9 per 100,000 person-years.
Takeaway
This study looked at how many people got sick from Norovirus outbreaks in Catalonia and found that these outbreaks were bigger but happened less often than those caused by bacteria.
Methodology
The study analyzed reported outbreaks of gastroenteritis from October 2004 to October 2005, collecting faecal samples and using various microbiological tests.
Potential Biases
Underreporting of smaller viral outbreaks may skew results.
Limitations
The study faced limitations due to the small number of samples available for diagnosis and the passive nature of outbreak reporting.
Participant Demographics
The population of Catalonia is approximately 6.9 million, with outbreaks occurring in various settings including restaurants and nursing homes.
Statistical Information
P-Value
p = 0.03
Confidence Interval
95% CI 9.2–10.7
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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