Six people have tested positive for coronavirus and a further 13 are waiting their results following an illegal house party.
The indoor gathering, which took place in Swansea, South Wales, on April 10, was investigated by council environmental health workers following the close timing of four positive Covid-19 cases – two men and two women – which had raised suspicions.
Efforts by Swansea Test Trace Protect contact tracers to find out more were thwarted by some revellers who claimed they were not in the city at the time and that the party actually took place elsewhere.
The occupiers of the house where the gathering took place also denied at first that it had happened.
Swansea Council environmental health officials, in partnership with South Wales Police, then investigated and were able to uncover evidence enabling tracers to get on with the vital job of tracking attendees and their contacts.
Swansea Bay University Health Board’s director of public health, Dr Keith Reid, said: “The misleading information provided by some people in this case had a detrimental effect on both the speed of the investigation, and the tracers’ ability to identify exact routes of transmission and protect the public.
“This caused the potential for further spread within the community and placed the wider community at risk.
“We’re currently aware of six positive cases, and at least 13 contacts with connections to the gathering at the Swansea address. We are continuing to monitor the situation for further cases.”
Public health officials are now urging people to behave responsibly and not organise or attend large gatherings indoors or outdoors, and to cooperate fully if contact tracers get in touch.
Dr Reid added: “We know that the vast majority of people respect the rules. They understand they are there to safeguard public health, and do their best to abide by them.
“I sincerely thank them for their responsible attitude, and for the sacrifices they have made over the past year to ensure we all get back to normal as quickly as we can.
“But the behaviour demonstrated by the individuals in this case is extremely disappointing. Not only did their decision to hold a party put others at risk, but they made matters worse by then misleading contact tracers.
“That it needed a concerted investigation by officials to get to the bottom of it is shocking.”
Although infection rates in Swansea are improving overall, the city remains top of the league table in Wales for confirmed cases.
Dr Reid added: “We haven’t beaten coronavirus yet, and we can’t afford to take unnecessary risks.
“Covid loves familiarity and spreads much more easily indoors. It is very important that people continue to follow the rules, and remember to still wash their hands, wear face coverings in indoor public places and keep two-metres distance from people they don’t live with.”