How contagious is Ebola? And how worried should you be about the current outbreak?

Global Health How contagious is Ebola? And how worried should you be about the current outbreak? May 20, 202610:58 AM ET By  Gabrielle Emanuel The number of Ebola cases has been growing – and growing by a lot — each day since the World Health Organization declared a public health emergency on Saturday. The latest toll? More than 600 suspected cases and 139 suspected-Ebola deaths. Loading... The vast majority of the cases are in a province in northeastern Democratic Republic of Congo — a remote place struggling after decades of bloody conflict. There are also two cases in Uganda's capital. The World Health Organization has identified the strain of Ebola as a rare one and says the outbreak could have started months before it was detected. "This is an example of a perfect storm," says Dr. Abraar Karan, an infectious disease physician and faculty at Stanford University. Since it's been more than a decade since the large West Africa Ebola outbreak, here is what you need to know about this virus and what's on the minds of infectious disease experts as they look at the current outbreak. Where and how do Ebola outbreaks start? Geographically, this is easy to answer: Ebola outbreaks have almost always started in either east and west Africa. By far, the Democratic Republic of the Congo has detected the most outbreaks. This is its 17th since 1976. Sponsor Message Exactly how humans pick up the virus remains a question mark. "We don't know for sure where it comes from but we have suspicions," says Karan, whose team has been studying Ebola and related viruses in Kenya for several years. The leading guess, he says, is that people get Ebola from eating bat meat or being exposed to bat guano – or excrement. This could happen when miners go into caves. "A number of animals have also tested positive for antibodies, so certain types of deer called duiker that eat meat have been implicated. Non-human primates have shown antibodies," he says. What tends to happen is that one person...