The world has become more vulnerable to outbreaks of disease caused by contaminated food because of growing global trade, the World Health Organization (WHO) said Thursday.

Investigating these outbreaks has also become more difficult because food can contain ingredients from around the world and is transported through a complex global supply chain, top WHO officials said.

"Outbreaks of food-borne disease have become an especially large menace in a world bound together by huge volumes of international trade and travel," said WHO director-general Margaret Chan at a conference in Singapore on improving preparedness against global health threats.

"Problems nowadays can arise from any link or kink in a convoluted food chain," Chan said.