The dark side of southeast Asia's street food

From steaming hot bowls of pho bo in Hanoi to spicy roti canai in KL and freshly-grilled sate in Jakarta, it's a sheer delight eating your way around the street food of Southeast Asia.

But street food can often deliver a few nasty surprises to the digestive system, especially for us lily-livered expatriates. (Many locals have immunity to the most commonplace bacteria and parasites but poor food hygiene can still be a serious problem, especially for children).

So I was disturbed, if not surprised, to see a report on the VietnamNet news website that over 70 percent of the restaurants and food stalls in Ho Chi Minh City are serving raw vegetables infested with parasites such as worms.

Researchers from Pham Ngoc Thach Medical University took samples of vegetables from 50 restaurants and 50 street stalls and found that 72 percent were contaminated.

Hygiene at street stalls, which lack running water and fridges, was much worse, according to the report. The samples taken from street stalls were 2.4 times more likely to be infested than those from restaurants.

It's almost enough to put you off your dinner. But I'm hungry and there's a cheap and tasty warung down the road that serves great lamb sate.