How did Ebola travel throughout the building?

Ebola was airborne. It traveled through the air.

From the text:

"But Ebola had drifted across a room. It had moved quickly, decisively, and by an unknown route. Most likely the control monkeys inhaled it into their lungs. "It got there somehow," Nancy Jaax would say to me as she told me the story some years later. "Monkeys spit and throw stuff. And when the caretakers wash the cages down with water hoses, that can create an aerosol of droplets. It probably traveled through the air in aerosolized secretion. That was when I knew that Ebola can travel through the air."