Mark Selby and Thomasina Miers, Wahaca's co-founders, have posted a message on the brand's website stating that a number of staff and customers were struck down by what is suspected to be the winter vomiting bug, norovirus.
Having assessed each case, it became clear they were not isolated incidents, so the firm got in touch with relevant officials at Public Health England and Environmental Health Offices.
In tandem with that, the company took its own precautionary measures – voluntarily closing affected restaurants, carrying out anti-viral deep cleaning at all of the restaurants, whether affected or not, and ensuring that any staff member who had reported illness remained off site until their symptoms had ceased for at least 48 hours.
Selby and Miers said, 'Teams have worked tirelessly to ensure that we have done everything within our power to limit any risk to our customers and team members, and the situation remains under control and we continue to work with all local authorities to monitor this closely.
'The majority of our restaurants are open and we hope to reopen the 4 remaining sites, on a case by case basis, as soon as we feel we are ready to do so.'
They concluded, 'We are incredibly sorry that people have been unwell. In the 9 years since we first opened Wahaca we have never had such an unprecedented incident, and we are doing everything we can to get to the bottom of how this may have happened.'