Going to America? You will need to acquaint yourself with some facts about the US government’s announcement Wednesday that it will begin Ebola screening at five major airports:

— WHO will be subject to screening: Travellers from the Ebola-affected nations of Guinea, Liberia and Sierra Leone, even if they’ve been already screened upon departure.

— WHAT will happen: They’ll be escorted by Customs and Border Protection agents to an area within the airport set aside for screening.

Dressing up for Ebola in Germany

Trained staff will look for signs of illness, take temperatures, ask questions and issue reminders to watch out for symptoms.

If a traveller has fever symptoms, or discloses possible exposure to Ebola, he or she will be evaluated by a Centers for Disease Control (CDC) quarantine officer who will take a fresh temperature reading and conduct an assessment.

If need be, the traveller will be referred to the appropriate public health authority.

Travellers without symptoms or known exposure to Ebola will be asked to self-monitor their health, keep a daily temperature log, and contact public health authorities if they fall ill.

— WHEN: Screening will begin Saturday at New York’s John F. Kennedy (JFK) International Airport, and sometime next week at the four other airports.

— WHERE: JFK and Newark airports in New York, Chicago’s O’Hare, Washington’s Dulles and Atlanta international airport in Georgia. Together, all five account for 94 percent of all travellers coming into the United States from Guinea, Liberia and Sierra Leone.

— WHY: Public health authorities are increasingly worried that the Ebola epidemic in West Africa will cross oceans and continents, particularly after Wednesday’s death in Texas of the first Ebola patient outside Africa.

“Entry screening is part of a layered process that includes exit screening and standard public health practices such as patient isolation and contact tracing in countries with Ebola outbreaks,” the CDC and Department of Homeland Security said.

“Successful containment of the recent Ebola outbreaks in Nigeria and the Democratic Republic of Congo demonstrate the effectiveness of this approach,” they added in a joint statement.

Statistically, travel between the United States and Africa is relatively small. In the first six months of this year, Americans welcomed 214,000 visitors from all Africa — compared to 4.5 million from Asia.