Dulles International Airport, destination for about 22 percent of the people who fly to the U.S. from Ebola-stricken nations, will begin advanced screening of international passengers for the virus by the middle of next week.

Almost 10,000 international passengers land at Dulles each day, but only a fraction of that number will have to undergo the additional scrutiny.

In addition to the routine of entry — checking passports and visas, examining luggage — people arriving from the three West African countries hard-hit by the illness also will have their temperature taken.

Fever is a warning sign of the onset of Ebola, as the body elevates its temperature in an effort to fight the virus.

But fever also is a common symptom of colds and the flu, stomach bugs and infections of the ear, lungs, throat, bladder and kidneys. And some vaccinations — notably the flu vaccine, which is being widely administered at this time of year — can cause bouts of fever.

Passengers from Guinea, Liberia and Sierra Leone who arrive with a fever at Dulles and four other big international airports in the United States will be singled out for special attention.

An estimated 36,000 people flew from the three countries in the past two months, with about 9,000 of them bound for the United States, U.S. officials said. That’s an average of about 150 per day.

U.S. Customs and Border Protection (CBP) says that 94 percent of the passengers who arrive from those three nations fly into one of the five U.S. airports.

Many of them — 43 percent — use New York’s John F. Kennedy International Airport, where the advanced screening is scheduled to begin this weekend. The next highest number — 22 percent — land at Dulles.

By rough estimates, the Dulles passengers number fewer than 1,000 a month.

The U.S. Centers for Disease Control and Prevention has been working with African authorities since August to screen passengers boarding flights in the capitals of the three afflicted countries — Conakry, Guinea; Freetown, Sierra Leone; and Monrovia, Liberia. There are no direct U.S. flights from the three countries. The majority of African passengers bound for the United States fly through hub cities in Europe.

Any passenger who arrives at Dulles exhibiting symptoms that could be Ebola will be moved immediately to an isolation room staffed by CDC personnel.

Passengers from any one of the three countries who do not show symptoms will be taken to a separate baggage inspection area.

The passengers will be instructed to complete a medical questionnaire that asks whether they have been in contact with Ebola victims. Then they will be taken by a medical professional to an enclosed area where their temperature will be taken with a handle-grip, non-contact thermometer.

Confident they will be able to intercept Ebola victims at JFK, Dulles and three other gateway airports — Chicago’s O’Hare International, Atlanta’s Hartsfield-Jackson International and Newark Liberty International — federal authorities said CBP personnel would continue their vigilance for Ebola at all other international airports.

Countering images of workers wearing hazmat gear while treating Ebola patients, airlines and the federal agencies dealing with the virus have underscored that passengers are extremely unlikely to contract the illness simply because another passenger is showing symptoms.

The virus is not airborne, which means that to convey Ebola requires close physical contact with a victim. Bodily fluids — saliva, sweat, blood, breast milk, ears, vomit, urine or semen — from an infected person must make contact with a healthy person’s broken skin, eyes, nose, mouth or genitalia.