Eighteen cases of Covid-19 were recorded in Premiership Rugby's latest round of tests conducted on Monday.
The figure is down one on the 19 cases from a week earlier, with 13 players and five staff members from nine different clubs testing positive.
Northampton's derby with Leicester was called off last week after a number of Saints players tested positive.
All clubs are now taking a two-week break after European fixtures were suspended earlier this week.
French clubs were told not to compete by their government after tighter lockdown measures came into force in the UK because of a new, more contagious strain of the virus.
The next scheduled Premiership fixture is leaders Bristol against Bath on Friday, 29 January.