There are fears that a virus that has killed millions of piglets in the US and sent retail pork prices to record highs could reach Europe in the coming months.

Industry sources claim little has been done to try to prevent its arrival.

Porcine Epidemic Diarrhea Virus (PEDv) has killed around seven million young pigs since first being identified in the US almost a year ago.

The virus attacks the gut of piglets, preventing them from absorbing fluids and leading to death by dehydration. Older pigs normally survive.

The virus can spread through faecal matter, and US experts say tiny amounts can infect huge numbers of animals – a tablespoon of PEDv-infected manure is enough to infect the entire 66 million-head US hog herd, they estimate.

There is also evidence that feed products may play a role, particularly those made from pig blood.

Blood products such as pig plasma are commonly used in post-weaning piglet diets around the world, including in Europe.

"We are just watching with horror how it is rampaging across America, and no-one in Europe seems to be the least bit interested," said Zoe Davies, general manager of Britain's National Pig Association.             

"Some protein-rich by-products, such as dried blood, are incorporated in feed products. This can go in the feed of other pigs, spreading the disease," said Bernard Vallat, director general of the World Organisation for Animal Health, adding thermal treatment of these products could kill the virus.

Some believe the deadly strain originated in China and has already travelled thousands of miles to North America, though how it achieved this remains unclear.

It is nearly identical to one that infected pigs in China's Anhui province, according to a report published in the American Society of Microbiology journal mBio.

"We find genetic similarities between the two, but we did not trace the virus between China and the United States," OIE's Vallat said.

Spain has the largest breeding herd in Europe, while Germany is the top pork producer.

"We are monitoring the PEDv situation in the United States and other countries with concern," said Klemens Schulz, spokesman for German pig producers' association ZDS.

"It is a little surprising that it is not much of a theme (in Europe), considering the impact it has had there."

The virus is not transmissible to humans and there are no food-safety concerns, but there could be substantial financial costs for countries where the virus strikes.

The foot-and-mouth outbreak in Ireland and Britain in 2001, for example, led to the slaughter of sheep and cattle in a bid to stop the disease spreading.

Frederic Vincent, a spokesman for the European Commission ,said there were no harmonised measures in place in the EU against the virus, adding it was discussed in a meeting with experts from member states two weeks ago.

"The Commission is following closely, together with Member States, the situation with a view to update the risk assessment," he added.

A milder strain of PEDv was identified in Europe in the early 1970s but did not lead to widespread problems and slowly disappeared from herds as immunity developed.