With Ebola reported to have officially entered the United States, concerns about an outbreak happening stateside are beginning to grow. This is natural but experts are quick to downplay the issue, saying the virus is infectious but not very contagious.

What does that even mean?

To understand what experts are saying, defining what infectious and contagious mean is necessary. First, what is infectious. How infectious a disease is can be determined by how much of the virus is needed for an infection to take place. A highly infectious disease will require only a small portion of a virus to get the job done. As for what is contagious, think of it as how easily an infection spreads.

Ebola is highly infectious in the sense that contact with just a few particles of the virus will be enough to get someone sick. However, it is not so contagious in that the sickness is not easy to transmit. In fact, a person infected with Ebola is not contagious until they start showing symptoms. Should symptoms not present themselves, an individual can be infected without being contagious.

There is also what is known as the "R0." This is a mathematical term used to refer to the number of people that can get sick on average from just one person who is infected. Measles, as one of the most contagious diseases ever discovered, has an R0 of 18. This means that just one sick person can get 18 more sick as well, without vaccination. Ebola, on the other hand, has an R0 of just 1.5 to 2.0.

If it's not so contagious, why the outbreak in West Africa?

Understand that conditions are different in the region compared to what is the norm in the U.S. For starters, cultural practices, like washing the dead, put people in direct contact with bodily fluids from infected individuals. How many instances are people in the U.S. exposed to blood, for instance? Not a lot.

Liberia, Guinea, and Sierra Leone also don't have enough facilities to quarantine the sick and isolate infected patients. This means more people are exposed to the virus than necessary because of lacking health care. The U.S. is more than equipped with the necessary facilities to not only isolate but provide supportive care to patients so Ebola doesn't spread.

It's good to hear Ebola won't be doing as much damage to the U.S. as it did in West Africa but this does not mean people should be less vigilant against the virus. Should anyone start developing symptoms, most especially after coming into contact with anyone from West Africa, it is important to go to the nearest hospital to be checked out.