by Felice J. Freyer

In response to the West African outbreak of the deadly Ebola virus, some Boston hospitals are instructing clinical staff to ask patients as soon as they arrive about their travel histories, and reminding doctors and nurses of the symptoms.

But hospital officials say they would be ready to quickly identify the illness and prevent its spread if an infected patient showed up, using protocols and equipment already in place.

The question of whether a traveler could bring the illness to the United States took on new urgency after a Liberian infected with Ebola flew to Nigeria and died there Friday.

The federal Centers for Disease Control and Prevention, in an alert sent to health care facilities Monday, said that Ebola “poses little risk to the US general population at this time” but urged health workers to be alert for signs and symptoms in people who recently traveled to Africa.

The disease, which kills up to 90 percent of its victims, has never been seen in a human on this continent. Boston physicians interviewed Tuesday said they considered it unlikely that a person with Ebola would arrive here — but still within the realm of possibility.

“I think we would be naive to think it’s not possible,” said Dr. Nahid Bhadelia, associate hospital epidemiologist at Boston Medical Center.

“It’s such a small world now,” said Dr. Deborah Yokoe, medical director of infection control and hospital epidemiologist at Brigham and Women’s Hospital. “We want to be prepared even though the likelihood is small.”

All hospitals have protocols in place for dealing with dangerous and unusual infectious diseases. Typically, a patient with suspected Ebola would be put in an isolation room and staff would wear gowns, gloves, goggles, and masks.

Dr. Shira Doron, associate epidemiologist at Tufts Medical Center, said that normally a patient’s travel history might not come up until the person has already interacted with doctors and other staff.

“Given the increase in the number of cases of Ebola and the recent importation to Nigeria, we are taking it even more seriously right now,” she said. “We’re developing a plan to more aggressively screen patients who present to our hospital, our emergency room and our clinics, for travel history.”

Massachusetts General Hospital is directing emergency room doctors to ask about travel history, a spokesman said; other hospitals said it was already standard practice.

As of a week ago, the latest outbreak in Africa had infected more than 1,000 people and claimed 672 lives in Guinea, Liberia, and Sierra Leone. Two US health care workers in Monrovia, Liberia, have become infected.

is a frightening illness because it dispatches its victims so quickly and violently. Within two to 21 days of exposure to the virus, an infected person rapidly comes down with symptoms that include fever, headache, weakness, vomiting, and diarrhea. Some will bleed inside and outside the body. Blood pressure plummets, and within a few days the organs fail. There is no treatment to attack the virus, but hospital care can sometimes keep a person alive until the infection clears.

Ebola, however, has features that make it less of a threat in the developed world, doctors say. Unlike other worrisome infections, such as measles, Ebola does not spread through the air. To become infected, one must come in direct contact with a sick person’s bodily fluids, such as blood, urine, saliva, sweat, semen, and breast milk.

Transmitting Ebola “requires pretty close contact with bodily fluids,” Bhadelia said. That’s why, even if a case appeared in the United States, it is unlikely to spread far thanks to good infection-control practices. “The virus is pretty easily killed with soap and water and heat and alcohol,” Bhadelia said.

In Africa, a lack of protective equipment such as gowns and goggles, and traditional practices of washing the bodies of the deceased, have contributed to Ebola’s spread, she said.

Ebola has not spread as widely as some other illnesses because patients are not infectious until they have symptoms, and the symptoms are so severe that most victims do not travel, said Doron, of Tufts.

Boston doctors are contributing to efforts to cope with the illness in Africa. Bhadelia, who is also director of infection control at Boston University’s National Emerging Infectious Diseases Laboratory, plans to travel to Sierra Leone with the World Health Organization to consult on infection control and clinical care.

The Harvard Humanitarian Initiative also plans to send a physician to manage the health care program of the International Rescue Committee, said Dr. Michael J. Van Rooyen, director of the Division of International Health and Humanitarian Programs at the Brigham. Van Rooyen is also advising Samaritans’ Purse, an international relief organization working with Ebola patients.