Every body fluid you can think of. Sweat. Spit. Urine. Feces. All of these exit the bodies of the victims in copious amounts and all of these have copious amounts of the virus. Cough or spray aerosols the virus over a relatively large area. Being in a car with someone who is sick has already spread the disease and killed others.
In developed countries, Ebola would be less transmissible because of less crowding, much greater sanitation as a matter of routine, and the availability of modern medical care.
You would think. Except for subways, Walmarts, restaurants, malls, trains, airplanes, schools, immigrants living stacked on one another to save money, etc. etc. If anything it's just as crowded in most of our major cities as it is in Africa.
Finally, in the developed countries, isolation measures would prevent the hospitals from being centers of Ebola infection as they commonly are in Africa.
People routinely get "hospital" diseases such as mrsa. That can't even be eradicated. Unless ALL medical personnel are willing to suit up every time they see a patient with the sniffles, runny nose, fever or diarrhea this disease will spread just as surely as it is in Africa.
In the US and other developed countries, there are well-established public health measures to identify, isolate, and treat dangerous infectious disease cases and contacts. This would probably suffice for even Ebola, but, if not, the menace of a general outbreak would swiftly lead to stronger measures such as the cancellation of public events and suspension of non-essential work, shopping, and travel.
An outbreak of Ebola in a developed country would lead to face masks, gloves, and the general spraying of disinfectant becoming routine in public places. In contrast, in Africa, poverty, corruption, theft, and the shambolic nature of its societies commonly make it impossible for even medical personnel who treat Ebola to have the benefit of containment garments and disinfectants.
In a developed country that suffered an Ebola outbreak, medical care for the disease would improve rapidly, with new treatments and vaccines fast tracked into use. The result would almost certainly be the rapid and permanent containment of any such Ebola outbreak, just as bird flu and SARS were contained despite the dire predictions that attached to them.
In sum, Ebola is cause for concern and excitement in the US and other developed countries but is extremely unlikely to generate more than a relatively small number of cases.