The dreaded Ebola virus has spread from the jungle into major cities in West Africa, and at least one American congressman believes it’s time to ban citizens of the three hardest-hit countries, as well as foreigners who recently visited them, from entering the U.S.

Rep. Alan Grayson, D-Fla., requested the travel ban in a Tuesday letter to Department of Homeland Security Secretary Jeh Johnson and Secretary of State John Kerry.

Citizens of Guinea, Liberia and Sierra Leone should be barred from entry, Grayson wrote, as should any foreign national who visited one of the countries 90 days before their intended visit to the U.S. He wants the proposed ban to remain in effect for the duration of the outbreak and to be expanded to any other country where Ebola takes hold.

“I urge you to consider the enhanced danger Ebola now presents to the American public, and therefore request that appropriate travel restrictions be implemented immediately,” he wrote.

Ebola has an incubation period of up to three weeks, according to the Centers for Disease Control and Prevention, and kills up to 90 percent of people infected. Most victims contract the virus by touching the bodily secretions or corpses of infected people, or from contaminated needles.

CDC officials said Monday it’s unlikely the virus will spread to the U.S., but that American doctors should be on the lookout. Stephan Monroe, deputy director of the CDC's National Center for Emerging and Zoonotic Infectious Diseases, compared spread of the virus to a forest fire.

“Outbreaks can be reseeded, much like a forest fire with sparks,” he told reporters on a conference call, NBC News reports.

Liberian-born U.S. citizen Patrick Sawyer was quarantined in Lagos, Nigeria, and died Friday after becoming ill with Ebola. His widow said he was en route to the United States, meaning he might have become “patient zero” for a North American outbreak.



“I don't want any other families to go through this. Ebola has to stop,” Decontee Sawyer told the Pioneer Press. "Patrick was coming here [to Minnesota]. What if he still wasn't displaying symptoms yet and came? He could have brought Ebola here."

Grayson wrote that the Sawyer case was "particularly troubling."

In addition to Sawyer, two American medical personnel caring for the sick became infected this month and are currently quarantined in Africa. Dr. Kent Brantly's wife and two children returned from Liberia days before he became sick and were interviewed by Texas health professionals. They are not being isolated from the public because they likely did not come in contact with an infected person, CBS News reports.

Ebola epidemics historically burn out because of the high mortality rate. The current outbreak began in February in a remote corner of Guinea and is the first to strike West Africa. Unlike previous episodes in central Africa, this outbreak has spread to major urban centers. Its fatality rate also appears lower.

According to World Health Organization data released Monday, through July 23 there were 1,201 suspected cases of Ebola – and 672 deaths – in Guinea, Liberia and Sierra Leone. Of the suspected cases, 814 were confirmed as Ebola.

Ebola outbreaks are deemed over after two consecutive 21-day periods pass without a new case. The current outbreak is the largest in history.

Spokespeople for the Department of State and the Department of Homeland Security did not immediately respond to requests for comment on the proposed travel ban.