Tips on food:

Eating food contaminated with bugs leads to more than half a billion cases of illness a year, the World Health Organization warns.

It says this "global threat" contributed to 351,000 deaths in 2010.

Unsafe foods, for example under cooked meat, can cause 200 problems - from diarrhoea to cancer.

But changes in food production mean there are more opportunities for meals to harbour harmful bugs or chemicals, experts say.

A local food problem can quickly turn into an international emergency
Culinary caution

Unsafe foodstuffs can contain many types of harmful bacteria, viruses, parasites or chemicals.

Examples include under cooked meat, fruits and vegetables contaminated with faeces and shellfish containing marine toxins.

But the WHO says investigating these outbreaks has become increasingly challenging as single plates of food often have ingredients from many countries.

In its first WHO report on this issue, its director-general Dr Margaret Chan warns: "A local food problem can quickly turn into an international emergency.

"Food production has been industrialized, and its trade and distribution have been globalized.

"These changes introduce multiple opportunities for food to become contaminated with harmful bacteria, viruses, parasites or chemicals."

The analysis, which pulls together scientific literature from across the globe, shows:

Most deaths are caused by pathogens such as salmonella, E. coli and norovirus
The majority of lives lost are in Africa and South East Asia
40% of the deaths are among the under-5s, the most vulnerable group
Raw hazards

Experts say illnesses caused by food also carry major economic risks.

They estimate the E. coli outbreak in Germany in 2011 cost about US$1.3bn (£876m) in losses for farmers and industries.

WHO leaders are calling on governments to urgently strengthen food safety systems.

On April 7, the WHO launches its food safety campaign, From Farm to Plate.

It aims to prompt the public and governments to consider where individual ingredients in meals come from and question whether these are properly and safely handled at every stage.

Shellfish

How to be food-safe:

Wash hands, surfaces and equipment before preparing food
Separate raw and cooked food - use separate utensils for handling raw foods
Safe temperatures - do not keep cooked food at room temperature for more than two hours. Keep food piping hot (above 60 C) before serving
Use safe water to wash raw fruit and vegetables
Source: WHO