Nigerian health authorities revealed last week that Nigeria, which used to be unaffected by the Ebola outbreak in three other West African countries namely Sierra Leone, Liberia and Guinea, already has its first Ebola case after an infected man boarded a plane from Liberia to Nigeria.

Patrick Sawyer, who works as a consultant for the finance ministry of Liberia, vomited on the plane and was later discovered to be positive for Ebola, a contagious and highly fatal virus that has affected thousands in what the World Health Organization (WHO) describes as the worst Ebola outbreak in history. Sawyer later died of the disease.

Although the incident has prompted tighter screening of passengers boarding airplanes in West Africa, where the disease has so far killed over 670 people since it emerged in March, it has inevitably raised concerns of the possibility that Ebola is just a plane ride away from other populated countries including the U.S and this is exacerbated by the fact that WHO has not yet imposed travel restrictions.

Sawyer's wife Decontee even said that her husband planned to visit Minnesota next month for the birthday celebration of two of his daughters. "It's a global problem because Patrick could have easily come home with Ebola, easy," Decontee Sawyer told KSTP-TV in Minnesota.

Experts, however, said that the risks of travelers getting infected by the deadly disease is considerably low as the virus requires direct contact with bodily fluids such as saliva, urine, blood and sweat. The disease does not also spread like flu that can be contracted through casual contact.

"While it's possible that someone could become infected with the Ebola virus in Africa and then get on a plane to the United States, it's very unlikely that they would be able to spread the disease to fellow passengers," said Stephan Monroe, the deputy director of the National Center for Emerging and Zoonotic Infectious Diseases of the Centers for Disease Control and Prevention (CDC).

The CDC said that patients are only contagious once the disease has progressed and the patient starts to show symptoms which include diarrhea, vomiting, fever, muscle aches and internal bleeding, which often results in massive blood loss that could lead to death in most cases.

Despite growing fears of Ebola spreading to the U.S, Monroe assured that the risk of the deadly disease spreading beyond West Africa is remote albeit he noted that the CDC still needs to be prepared for such "remote possibility."

"I want to underscore that Ebola poses little risk to the U.S. general population," Monroe said.