McCurdie's advice was aimed at British athletes competing in the games and was among a series of health tips being looked at by the British Olympic Association for their 550-strong team of athletes and 450 supports staff.
Others include being screened for allergies, reporting any symptoms of illness early, and having probiotic drinks containing friendly bacteria to help ward off infection.
"Almost certainly, the greatest threat to performance is illness and possibly injury. Hand hygiene is it. It is all about hand hygiene," said McCurdie.
He pointed out that the Olympic environment is a 'pretty hostile one', with athletes from the 204 competing nations sharing rooms and eating together, in dense housing. Anything from cutlery to door handles could have unwanted bugs lurking on it, the advice said.
Athletes are also to expect sleep deprivation, long hours and having to cope with living in a different place.
"At an Olympics you're normally in a bubble and there is quite a limited number of people you interact with when you are away in another country.
"In London we do not believe that is going to be the case. The variety of people the athletes and support staff are going to interact with is going to be huge."
- Daily Mail