United Lincolnshire Hospital Trust’s Chief Operating Officer Simon Evans broke the news during a meeting of Lincolnshire County Council’s health scrutiny committee.
Bosses were updating councillors on the trust’s efforts to tackle coronavirus.
At the beginning of the meeting there were two confirmed cases reported at the trust, however, while responding to questions Mr Evans said: “Since Mark gave his update this morning we now have another positive case in Lincoln hospital.”
Deputy Chief Executive Mark Brassington told councillors that there had been just 14 days during the pandemic that the trust has had zero patients.
The trust is currently at level three alert status, however, is expecting to go back up to level four “fairly soon”.
“Whilst numbers might be low, we still have things in place to to enable us to deal with COVID patients,” he said.
“As with the national picture, numbers are increasing and we’re seeing a rise of people coming into hospital with query-Covid symptoms.
“While we remain low level, it’s a precarious situation and we expect that number to rise in the coming weeks.”
Councillors were also given updates on efforts to tackle backlogs – including nearly 700 operations now carried out at the Grantham COVID-free site and some diagnostic procedures exceeding 200% of pre-COVID levels.
Mr Evans confirmed the Grantham COVID-free site had not seen any coronavirus patients, and has not seen any transmission between patients and staff.
Bosses said there were currently no major issues with getting test results back for patients or staff at the trust.