U.S. health officials are preparing to screen passengers flying in from Rwanda for symptoms of Marburg virus, a severe infection similar to Ebola.

“Starting mid-October, airline passengers who have been in Rwanda in the last 21 days will have their travel to the United States rerouted” to one of three airports: Chicago O’Hare, JFK in New York and Washington Dulles in suburban Virginia, the Centers for Disease Control and Prevention said in a statement Monday.

According to the statement, the passengers landing at one of those airports will need to meet with CDC staffers for temperature checks and assessments of any other visible symptoms, such as sore throat, vomiting or rashes that often appear on the torso.

People infected by the virus can start showing symptoms two to 21 days after their exposure, according to the CDC.

The screenings are set to begin the week of Oct. 14.

Marburg is a virus that causes hemorrhagic fevers and internal bleeding, much like Ebola. Like Ebola, it spreads through contact with bodily fluids, including blood and semen. There is no treatment or vaccine.

No Marburg cases have been detected in the U.S. As of Sunday, Rwandan health officials had reported 49 cases, according to the U.S. Department of Health and Human Services.

At least 12, nearly a quarter, have died. The death rate can be as high as 88%, according to the World Health Organization.

Nineteen cases have been among health care workers.

The CDC began alerting U.S. doctors about Marburg last year. The risk to the public, it said, is low.

Also Monday, the CDC issued what’s known as a level 3 travel health notice, warning people against unnecessary travel to Rwanda.

The advisory suggested that anyone who must travel to the outbreak area watch for symptoms for 21 days.

“If you develop fever, chills, headache, muscle aches, rash, chest pain, sore throat, nausea, vomiting, diarrhea, or unexplained bleeding or bruising,” the advisory said, “isolate immediately and seek medical care.”