The highly infectious norovirus has not spread to any other hospital patients since it was first detected.
A small number of cases had been confirmed on Sarratt and Croxley wards at Watford General Hospital last month.
Spokesman for the West Herts Hospitals NHS trust, Paul Gough, said: “There have been no further reported cases of norovirus at the hospital since the previous statement released on February 25. Patients within Sarratt and Croxley wards who have been diagnosed with norovirus continue to be closely monitored.
“Subject to no further cases, these wards will be implementing restricted visiting times shortly.
“For more information, visitors should telephone the wards in advance of arrival.”