The affected farms in three northern Philippine provinces have been quarantined and farm and slaughterhouse workers who might have been exposed all tested negative for Ebola Reston, Agriculture Secretary Arthur Yap said in a statement.

As a precaution, he said all pork exports have been suspended until further notice.

"We advise the public that it is safe to eat pork provided that the pork is was properly handled and thoroughly cooked," Health Secretary Francisco Duque said in a statement.

Lyndon Lee-Suy, a health department disease control manager, said in a telephone interview that studies show the virus is a "low level" pathogen.

"Humans can get the virus, but it does not cause illness," he said.

Ebola's three other subtypes - the Zaire, Sudan and Cote d'Ivoire strains - can cause deadly hemorrhagic fever in humans, according to the World Health Organization.

Animal authorities and local government units have been ordered to continually test pigs in their localities, and to quarantine all farms found with the virus, Yap said. Infected pigs are to be destroyed.

The government has also notified the WHO, the Food and Agriculture Organization and other international bodies about the findings, he added.