The council’s public health director Andy Kingdom said an increase in coronavirus cases by 22 to 42 in the Bridlington West recording area came following the outbreak.
The director added the outbreak, which has since been contained, also accounted for case increases in neighbouring Bridlington North and Bridlington East where care home staff live.
The outbreak fuelled an overall increase in East Riding coronavirus cases from the 127 recorded between Tuesday, March 30 and Monday April 5 to 139 the following week.
The seven day rolling rate per 100,000 people in the East Riding rose from 37 to 41 during the same period.
An East Riding Council spokesperson said: “We can confirm that a care home in Bridlington has coronavirus cases and can provide assurance that we are working closely with public health and all appropriate agencies to ensure that the necessary actions are being taken to keep residents and staff as safe as possible during these unprecedented times.”
Mr Kingdom said there were no signs yet that coronavirus rates had surged after restrictions on non-essential businesses including pubs and other venues eased on Monday, April 12.
But he added the care home outbreak showed coronavirus, particularly the now dominant Kent strain, was still capable of spreading rapidly if it got a foothold.
The director said: “We first detected the outbreak in a large care home in Bridlington on Monday, April 5.
“It’s now under control and we’ve got regular testing in place for residents and staff and we’ve worked closely with national and local infection control specialists.
“We’re still testing daily but we’ve only picked up a couple more staff cases recently.
“That outbreak skewed all the rest of our figures.
“Residents and staff have been vaccinated and that reduces their risk of catching coronavirus by around 80 % with the first dose, so it was partly bad luck.
“But it doesn’t mean they won’t catch it, that’s why you need two doses and it takes a few weeks to embed in the body.
“The way you control it is through social distancing, mask wearing and other measures, but this wasn’t a community outbreak it was just in this one home.
“It’s a demonstration of how quickly coronavirus can still spread once it gets into an environment like that.”
Mr Kingdom said the outbreak and the fact that 94,000 people in the East Riding are yet to be vaccinated showed the importance of following rules despite restrictions easing.
The director said: “At the moment it’s so far so good since restrictions eased, but I’m not sure we’ve seen the full impact yet.
“Council environmental health officers have been inspecting venues and their safety precautions seem to be working well, we’ve only had a few complaints.
“If everyone continues to do the good work then I’m hopeful, it’s just about basic responsibility.
“People normally drink to let their inhibitions go, they want to sing and to hug each other, I’d just ask them to hold off for a little longer.
“Remember when you’re sat in a beer garden there will be people there who are out for the first time, we’ve got a lot of people still nervous about going out, some haven’t left their homes for months.”