An outbreak of Porcine Epidemic Diarrhea virus appears to have spread on Waianae pig farms.
The state Department of Agriculture detected the virus at four additional farms in Waianae, according to a news release Tuesday.
No pigs, however, appeared to be sick.
On Nov. 20 the department’s Animal Disease Control Branch issued a quarantine order restricting the movement of pigs on Oahu after an outbreak of the virus occurred on a farm in Waianae Valley.
The virus can cause significant illness in swine and high mortality in piglets but does not pose a risk to humans or pets. It is not considered a food safety concern.
The farm affected by the November outbreak appears to have recovered, with remaining swine showing no signs of illness.
The quarantine order is still in effect, restricting the movement of pigs on Oahu. Under the order, no swine may be moved east past Nanakuli from Makaha, Waianae and Nanakuli Valley without a permit issued by state veterinarians. It also restricts transporting swine to the neighbor islands from Oahu.
The swine virus is common in parts of Asia and Europe. It was first detected in the U.S. in May 2013. To date, 32 states have reported the virus, and it’s estimated to have killed up to 8 million young pigs. The Agriculture Department said the virus found in Waianae is a less virulent strain of the disease.
Veterinarians are continuing to look into how the virus arrived on Oahu.
In July the Agriculture Department stiffened pig import requirements to help prevent the entry of pigs infected with the virus into Hawaii.
There are about 230 pig farms in the state, 70 of which are on Oahu.
Swine farmers who have questions about the disease may contact the Animal Disease Control Branch on Oahu at 483-7106.
For more information, go to the Agriculture Department’s website at hdoa.hawaii.gov/ai/ldc.