Bedford Hospital is suspending all ward visits - with immediate effect.
The decision has been taken due to what Bedfordshire Hospitals NHS Foundation Trust describes as a "rapidly increasing Covid-19" infection rate in the community.
Only in these exceptional circumstances will visitors be allowed:
If the patient is receiving end of life care or
If the patient has dementia, learning disabilities or a mental health illness and need a carer/support present
A spokesperson for Bedfordshire Hospitals NHS Foundation Trust said: "As expected at this time of year, demand for our services has increased and we are currently seeing a high number of Covid-19 positive inpatients in our hospitals. The number of Covid-19 cases across Bedfordshire and the surrounding areas is increasing, and this is being reflected in our hospitals.
"In order to help minimise the spread of infection the trust has made the difficult decision to suspend standard visiting to all adult inpatient wards with immediate effect. This does not apply to end of life patients or those patients who need a carer/support present.
"Anybody attending our hospital must observe our existing restrictions which include wearing surgical facemasks whilst on-site and attending your hospital appointment alone (excluding maternity, paediatric, those requiring carer support)."