Ebola's course of infection lasts around 37 days according to Dr. Duncan and Dr. Scott. This includes a 10 day incubation period followed by a 22 day infectious period whereby the person could be infectious but not exhibit symptoms. In the last five days the most gruesome symptoms appear in people. The 37-day estimate fits nicely with the 40-day quarantines carried out in Europe during the Black Death. Quarantine efforts in Europe were successful according to the two doctors. Sanctioning off infected families effectively "stopped the spread [of disease]." The 40-day period would have allowed for Ebola to run its course, eliminating the possibility of seemingly healthy people from infecting others during the initial 32-day period. Rats, on the other hand, would have ignored the quarantines. Thus, quarantines of plague victims could not have been as successful as an Ebola quarantine since rats are independent creatures; rats would have still been able to infect people despite a quarantine.
we're just being paranoid... the experts say this isn't so...