The current outbreak of Ebola in West Africa is now the largest in history, but how likely is it to spread to the United States or other countries around the world? “It’s the same species of Ebola that has caused some of the larger and more prominent outbreaks in central Africa,” said Thomas Geisbert, a virologist at UTMB. This species is called Zaire Ebola virus. “It’s a slightly different strain, but I haven’t seen any data suggesting that it’s more transmissible,” Geisbert said. Still, only a small dose of the virus is required to cause infection, Geisbert said. The news also appears in Yahoo! News and LiveScience.