When the Ebola Reston virus was discovered in pigs in the Philippines last year, it marked the virus's first known foray outside primates, and raised fears of a potential threat to human health.Is an Ebola-virus subtype killing pigs?REUTERS Last week, a joint mission of 22 international health and veterinary experts returned from investigating the outbreak with more questions than answers about the virus's pathology and epidemiology.The Ebola Reston virus was first discovered, in 1989, in crab-eating macaques imported to the United States from the Philippines. Since then, the virus has killed most infected monkeys, yet had no effect on the...