Yep. I was reading on Canada’s Public Health website about Ebola, and according to them, there is a possibility of infecting someone before showing symptoms, which is what one would expect with any other virus, so why would this be different?
COMMUNICABILITY: Communicable as long as blood, secretions, organs, or semen contain the virus. Ebola virus has been isolated from semen 61 days after the onset of illness, and transmission through semen has occurred 7 weeks after clinical recovery.
Yikes.
I read one reason may be that Ebola is not an airborne virus, unlike the common cold, say. In other words, what they seemed to be saying was that airborne viruses tend to be transmissible during incubation, while non-airborne viruses generally aren't. Now, why that should be the case, at the microbiological level, I have no idea... I'm not an expert. It's just something I read.
if it was only possible to infect someone AFTER showing symptoms, then almost every disease could be prevented by isolating sick people
This is HIGHLY contagious- if it was hard to catch it would not be a story.