Bacteria can easily be passed by hand
A Londonderry priest has given parishioners the choice of whether or not to shake hands with others at Mass.
The parish priest in Ballymagroarty has said he has had a letter from a Mass-goer worried that the traditional "sign of peace" could spread germs.
Father Patrick O'Kane suggested that if people are concerned they should just nod and smile at their neighbour.
"Personally I think these fears are misguided but that does not make them any less real," he said.
"The option we have introduced allows people to nod and smile, rather than shake hands, so people will not feel rejected by not having their gesture recognised."
Fr O'Kane said he thought the concern was "media-driven and has no medical basis because we can't live in a germ-free world".
"The new option is just to cater for a very small minority."
The parish priest said it was a matter of choice.
However, many parishioners said they had no problem with shaking the hands of those beside them.
But some said people had "a right to opt out".
Angela Thompson from the Foyle Health Trust said as long as people washed their hands regularly and thoroughly there was little risk of spreading germs.
"People should be worried about spreading germs," she said.
"The best way we can avoid them is to wash our hands correctly, using soap and water and drying your hands very well afterwards, using a paper towel or else a cotton towel."
Sinn Fein Councillor Billy Page said he was there when the move was was announced and said there was "a sense of dismay and utter disgust" over it.
"I have never seen anyone refusing to shake hands with anyone else," he said.
"I am sure the church gets all types of crank letters. Do they have to take them all as gospel?"