Nine patients have either 'definitely' or 'probably' caught Covid-19 in hospitals operated by the East and North Hertfordshire NHS Trust since May, it has been revealed.

Hospitals the trust operates include the Lister in Stevenage, Hertford County Hospital and QEII hospitals in Welwyn, as well as the Mount Vernon Cancer Centre in north west London - which many cancer patients in and around Hitchin are referred to.

Data reported to a meeting of the East and North Hertfordshire NHS Trust earlier this month shows that since May 14, there have been nine cases that were found to be 'probable' - or 'definite'.

Patients are deemed to have 'definitely' acquired Covid-19 in hospital if they test positive for the virus 15 days or more after admission - they are deemed to have 'probably' done so if the test is positive after eight days in hospital.

On Monday, it was revealed that the under-pressure trust has nearly 500 patients who have been forced to wait more than a year for medical treatment - including at the Lister Hospital.

Commenting on the data following the meeting the trust's chief nurse Rachael Corser said: "This new global health pandemic meant the NHS has faced an unprecedented health challenge, but we have very established and highly effective mechanisms for infection prevention and control, that clinicians are well trained in to care for unwell patients.

"We continue to follow all government infection prevention guidance, and have appropriate COVID-19 testing systems in place.

"It is important that patients follow the national guidance too and that we all remain vigilant – please wear a face covering if you are asked to come into the hospital, and wash your hands regularly."

The latest of these patients tested positive on July 24 – eight or more days after their admission.

Surveillance of 'nosocomial' Covid-19 infection – that's Covid 19 infection that starts in a hospital – has been mandatory since May 14. The last recorded 'definite healthcare associated' case was recorded by the trust on May 19.

The data also records a further 46 'community onset' or 'indeterminate' Covid cases in the hospital - these are patients who tested positive for Covid within two days or within seven days of admission.

According to the report to the board, the trust continues to conduct internal reviews into 'probable' and 'definite' healthcare associated cases. "to identify any lapses and or/learning".

Meanwhile in his own report to the board, chief executive Nick Carter referred to work undertaken by the hospital in recent months, caring for around 6000 patients who could have had Covid.

But he said this had now been replaced with the 'greater challenge' or restarting services.

He said: "The initial intensity of Covid related activity required the trust to extensively and rapidly rearrange services, to care for approximately 6000 patients who potentially had Covid.

"This has now been replaced with a different, but in many respects greater challenge.

"The trust is now restarting services in accordance with the requirements set out by Sir Simon Stevens, but doing so in the context of the need to maintain enhanced infection control procedures in accordance with national guidance."

In other news, it has emerged Covid is set to cost Herts County Council more than £70m.