PRRS & Ebola Virus Reported in Philippine Pigs

December 15, 2008 — 

The USDA's Plum Island Animal Disease Laboratory has isolated an atypical PRRS virus from swine samples submitted from the Philippines.

The samples were collected from pigs from four farms north of Manila. The pigs exhibited clinical signs similar to those observed in cases of Porcine High Fever Disease in China and Vietnam. Researchers at Plum Island isolated PCV-2 and an atypical PRRS virus with 98% homology to the virus isolated from samples obtained from the outbreak in Vietnam. The PRRS virus is considered the most likely cause of the clinical signs observed.

Interestingly, the Plum Island researchers also isolated the Reston-Ebola virus from 6 of the 28 swine samples tested. This marks the first time the Ebola virus has been isolated from swine.

The Ebola virus belongs to the Filoviridae family to which humans and other primates are susceptible. It was first reported in the Ebola River Valley in the Democratic Republic of the Congo (formerly Zaire) in 1976. Human pathogenic strains can result in fatality rates of 50-90%.

The Reston-Ebola strain is different from the other Ebola subtypes, which are all potentially fatal to humans. The Reston-Ebola strain is of Asian origin and can be aerosol transmitted unlike the Zaire, Ivory Coast, Sudan and Uganda strains. Also, the Reston strain has not caused illness in humans who come in contact with infected animals. Serum samples from people exposed to the sick pigs in the Philippines have been tested and were all negative for Reston-Ebola antibodies. It is unknown if this virus is pathogenic in swine.

This particular strain was discovered in the Philippines in 1989 among crab-eating monkeys being exported by the Laguna-based Ferlite Farms to the Hazleton Laboratories in Reston, Virginia. A number of workers at the Reston lab were exposed to the virus and exhibited a normal immune response but no clinical symptoms were observed.

Sources:
World Organization for Animal Health (OIE), December 10, 2008

The United Nations' Food and Agriculture Organization (FAO)