The Daily Mail says Wenger has stopped handshakes among his players and disinfected Arsenal's training ground to wipe out a virus which is spreading through the camp.
Per Mertesacker is the fourth player to be struck down recently by a coughing and sickness bug and faces a test to be fit for Saturday evening's game at West Ham.
Wenger has ordered the dressing rooms at the training ground to be washed with disinfectant. Notices have gone up reminding players how germs can be passed and he has stopped a pre-training ritual where players shake hands.
"It is a good excuse not to shake hands before the game," said Wenger. "If you shake hands the viruses go around the league."