2009: A new form of Ebola virus has been detected in some Phillippine Islands pigs, raising concerns that it could mutate and put humans at-risk.
Ebola-Reston virus (REBOV) has only previously been transmitted by monkeys to humans, and through human-to-human contact. Pigs are likely to provide the point where Ebola-Reston could mutate into a virus that infects human beings through contact with them.
The discovery and related theories are featured in the journal, Science.
Researchers from the U.S. Centers for Disease Control and Prevention, stress that the virus at present appears to pose no risk to humans at this time.
Ebola-Reston virus has been detected in farm workers who tend the infected pigs, and they have as yet shown no signs of illness. Researchers said: “REBOV infection in domestic swine raises concern about the potential for emerging disease in humans and a wider range of livestock.
“There is concern that its passage through swine may allow REBOV to diverge and shift its potential for pathogenicity.”
REBOV is a filovirus, types of which usually target primates.
Foloviruses such as Ebola and Marburg are marked by haemorrhagic fevers, which cause extensive internal bleeding and can be fatal.
The latest filovirus study examined tissue samples taken from pigs from different parts of the Philippines which were experiencing severe respiratory infections.
Analysis showed that the animals were infected with widely varying strains of the virus, suggesting it may have circulated widely in pigs even before it was first discovered in monkeys exported to the US from the Philippines in 1989.
The researchers said it was possible that REBOV originally emerged in another, unknown host. Fruit-eating bats have been suggested.
Pigs are known to provide an ideal host in which viruses may mutate. Experts say that risk is heightened since pork products are a common feature of the worldwide food chain, and because pigs often come into close contact with people.
Researcher Dr. Michael McIntosh said: “We know that this family of viruses is associated with fatal illnesses in humans.”
“Even though there is no evidence at this time to suggest REBOV causes diseases in humans it does seem that it can infect humans, and be transmitted from swine to humans.
“The effect of such an infection on an immuno-compromised host – human or swine – is also an unknown factor of concern.”
The World Health Organization says that pork is safe to eat if prepared and cooked properly–washed and well-done until grey inside.