Australia's swimming coach Leigh Nugent says hygiene at the Commonwealth Games Village in Delhi is a bigger concern for him than the terror threats to the October 3 to 14 event.
"You can go to a Western-style country and still get sick, but on the subcontinent they have bugs we have no resistance to," Nugent was quoted as saying by 'The Daily Telegraph'.
"Things like vomiting and diarrhoea can run rampant through a team, wreaking havoc on months of preparation and destroying medal chances.
"So you have to be extra vigilant and make sure you have as many preventative measures in place as you can."
Nugent said all the Australian swimmers have been given hand-sanitising gel, probiotics to boost immunity and long-sleeved shirts, long trousers and bug repellent plus mosquito zappers to guard against diseases such as dengue and malaria.
"And even when you're having a shower, you should keep your mouth closed," Nugent said.
"We're living in the village with probably 7000 or 8000 other people and not everyone has good hygiene, and you don't know who's touched the door in front of you," he said.
"Touching things, you can pick up bugs that you're not used to in our normal environment and next thing you're sick and out of action. All of these bugs are invisible, so you have to be ultra-careful."
Nugent said the swimmers have already instructed about personal hygiene during the October 3 to 14 event.
"They're well educated in it, but it needs to be habitual," Nugent said.
"When we're in our strategy camp in Kuala Lumpur we'll be really ramming that message home hard and prompting our athletes and our staff so that they stay fit and healthy.
"It's easy to forget, but you really can't afford to forget in this environment," he added.