* Flu virus prompts 20 countries to limit pork, meat imports
* Russia, China, Switzerland, Thailand, others impose bans
* Affects Mexico, U.S., New Zealand, Canada, Central America
* EU, South Korea, Japan, Kosovo tighten checks, avoid bans

GENEVA, May 4 (Reuters) – Twenty countries worldwide have banned imports of pork and other meat in response to a flu virus that has infected both people and swine, according to documents from the World Health Organisation.

While the new H1N1 strain is not food-borne, fears that it may spread through animal products have prompted restrictions on live pigs, pork, cattle, poultry, livestock, feed and animal semen from countries with reported infections, according to the documents obtained by Reuters on Monday.

The countries that have imposed bans include Russia, China, Switzerland, Croatia, Indonesia, Thailand and Ecuador. Most affect products from Mexico and the United States and some block imports from Canada, New Zealand, Spain, France, Israel, Costa Rica, El Salvador, Colombia, Cuba, Nicaragua, Panama, Honduras, Guatemala and the Dominican Republic.
The three countries most affected by the bans announced to date — Mexico, the United States and Canada — are among the world’s top pork exporters, along with the European Union, Brazil, Chile, China and Hong Kong.