According to local newspaper Jornal das Caldas, the municipal council has since confirmed 122 people infected, after receiving a report with the results of laboratory tests.
Most of the identified cases – around 80 – are linked to an international youth football tournament organised by the company Footmania, held in the municipalities of Caldas da Rainha and Óbidos between 24 June and 8 July.
Public health authorities and ASAE (Food and Economic Safety Authority) conducted tests on the food service provided by the company, collecting samples.
However, no evidence was found to suggest that this was the source.
It is reported that the investigation is ongoing to determine the origin of the explosion.
Otherwise, norovirus is one of the most common causes of gastroenteritis and is highly contagious.
It is transmitted from one person to another through contact with contaminated objects and surfaces and also by consuming water or food.
At the beginning of summer, health authorities warned that “with heat, longer days, outdoor dining, parties, beaches, holiday clubs and family gatherings” there is a greater likelihood that some viruses will spread.