The USDA's Plum Island Animal Disease Laboratory has isolated an atypical porcine reproductive and respiratory syndrome virus from swine samples 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 isolated PCV-2 and an atypical PRRS virus with 98 percent 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.
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 in 1976. Human pathogenic strains can result in fatality rates of 50 to 90 percent.
The Reston-Ebola strain is different from 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 and Uganda strains. Also, the Reston strain has not caused illness in humans who come in contact with infected animals.
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.
Source: World Organization for Animal Health