The Western Health Board has confirmed at least 40 people are suffering food-poisoning in North Mayo following a wedding reception in the Pontoon Bridge Hotel in Foxford.
Director of Public Health with the Western Health Board Dr Declan McKeown said it is still unclear whether the outbreak is viral or bacterial. He said all the people affected so far attended the same wedding last Saturday night.
Attention was drawn to the outbreak when GPs in the region reported an rise in the numbers attending their surgery over the past three days with similar symptoms, including abdominal pains, diarrhoea and severe sweating.
The hotel, which Dr McKeown said has fully co-operated with the health board's investigation, voluntarily closed its dining service for an indefinite period on Tuesday while the inquiry is being carried out.
It was too early to identify the exact cause of the suspected outbreak, but e-coli contamination has been found in the well-water serving the hotel, said Dr McKeown. It is also possible it could have been caused by food that went off in the hot weather, he said.
"We are contacting all the 300 guests who attended a wedding reception and birthday brunch in the hotel last Saturday night and Sunday morning," Dr McKeown said.
"We have absolutely no issues with the hotel’s sanitation record or present condition and we have absolutely no reason to criticise the hotel whatsoever".
The outbreak has been described as a gastro-intestinal disease with mild symptoms from which sufferers recover from very quickly and with no lasting damage, Dr McKeown said, adding outbreaks of this nature are not uncommon at this time of the year.