An estimated 290 people are now thought to have been sickened in what has become the largest E. coli outbreak to affect Northern Ireland. Health officials announced Wednesday that 124 cases have been confirmed and a further 166 are suspected to be part of the outbreak linked to Flicks, a sit-down eatery in Belfast. The Belfast Public Health Agency (PHA) confirmed to Food Safety News that these numbers remained the same Thursday. The restaurant shut down on October 11 after being named as the outbreak source. Since E. coli only incubates for up to ten days, illnesses reported after Oct. 22 will likely have been contracted from other sick people, not the restaurant, notes PHA. The agency says it is working to determine where in the restaurant the bacteria originated. “This is a complex, evolving and detailed investigation and all aspects of the outbreak are being examined thoroughly,” said Dr. Carolyn Harper, Director of Public Health for PHA, in a statement Wednesday. “As such, it would not be appropriate to comment at this stage on any potential cause of the outbreak, but as with all outbreaks, a full report will be made publicly available when the investigation and analysis is complete.” “It is not always possible to identify a specific source in outbreaks as the mechanism of contamination of food may have been short term and corrected in subsequent cleaning, food hygiene practice, or normal disposal of food,” Harper continued. This is not the first time investigators have searched for E. coli bacteria at Flicks following an outbreak. Just two months ago, a different strain of E. coli O157:H7 that had caused a separate – much smaller – outbreak. In late August, four people fell ill with matching strains of E. coli O157:H7 infections. All four reported eating at Flicks in the days before getting sick. PHA collected environmental samples at the restaurant, but none tested positive for the bacteria. Paul Devlin, a victim of the August outbreak, says he asked PHA to shut Flicks down after he found out it was where he had contracted his illness, which began August 18 after he ate at the restaurant on both Aug. 13 and Aug. 17. “What’s quite annoying and frustrating about it is that on the 23rd of August I told them that if they didn’t close the restaurant they could potentially have an outbreak on their hands.” Devlin says he found out his infection was linked to Flicks not from PHA, which didn’t inform him of the source of his illness, but from the three other victims, who all reported eating at the restaurant to a local newspaper. The Belfast City Council, which oversees restaurant closures, made the decision not to close the restaurant. “The four cases of E. coli O157 in August which were linked to this restaurant were investigated thoroughly at the time,” the Belfast City Council and PHA in a joint statement Wednesday. “All tests on the restaurant were negative. In addition, further environmental health inspections were conducted, all of which were satisfactory.” In the days following the August outbreak, the restaurant was still listed in the UK’s online food hygiene rankings – maintained by the Food Standards Agency – with a score of 3 out of 5, as reported by Irish News (subscription only). A score of 3 translates to “generally satisfactory,” according to the agency’s website. Then, in mid-October, Devlin’s prediction of a future Flicks outbreak came true, to the tune of nearly 300 illnesses. “When it broke out, I had to pinch myself and ask myself, ‘Is this really happening?'” recalls Devlin. Flicks has since been removed from FSA’s food hygiene rating scheme, which lists scores for the more than 2,700 Belfast food establishments. This could be due to the fact that the restaurant has been temporarily shut down. According to the Belfast PHA, the current outbreak was detected because of increased surveillance in the wake of the August outbreak. “Enhanced surveillance to monitor for cases was also put in place,” said the agency of its measures following the August outbreak. “The current cases came to light through that enhanced monitoring.” A spokesperson for PHA described the new measures as “particular scrutiny  of all reports in Northern Ireland of E coli 0157 and any association or links with this restaurant” in an emailed statement to Food Safety News. Now that the outbreak has been detected, the remaining challenge is to find out where in the restaurant the contamination occurred. “I can’t understand why they haven’t found it. It’s been two weeks now.” says Devlin, a premier field engineer for Microsoft who has been working from home since  August because of continued weakness following his illness. Devlin says he’s spoken to a number of people sickened in this current outbreak, and all of them ate different dishes at the restaurant. If a common food source is not identified, investigators will likely be looking at environmental contamination on food preparation surfaces. When asked whether any environmental samples have tested positive for the outbreak strain of E. coli since the restaurant shut down, PHA told Food Safety News, “Investigation is ongoing and any further information will be released in due course.”