Study the two Canada Health versions for yourself....
Wayback Machine:
https://web.archive.org/web/20140807031435/http://phac-aspc.gc.ca/lab-bio/res/psds-ftss/ebola-eng.php
Govt Canada Health today:
http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/ebola-eng.php
“INFECTIOUS DOSE: 1 - 10 aerosolized organisms are sufficient to cause infection in humans (21).”