On her third day in Liberia last July, Allison Arwady, M.P.H., M.D. ’08, HS ’12, was in the country’s Ministry of Health and Social Welfare when the building caught fire. The brother of a man who’d died of the Ebola virus, angered over what he considered the government’s lack of response to the epidemic, had set the fire.

When Arwady arrived as part of a surveillance team from the Centers for Disease Control and Prevention, the scope of the epidemic was not yet apparent to health workers, both national and international. In short order, however, they would see the number of cases rise exponentially, and greater international attention would converge on West Africa as two infected American aid workers were evacuated to a hospital in Atlanta. And calls would come from around the world for industrialized nations to do more to help stem the epidemic.

What was clear in July was that the virus had overwhelmed Liberia’s health care system. The country had two centers for Ebola patients and each had 20 beds. When Arwady left a month later, each center had 100 beds, but needed 1,000. “There is no capacity right now to put people in specialized treatment centers,” said Arwady, whose team of six soon grew to 12 CDC officers. Her role on the team was surveillance; case finding, contact tracing, and implementing effective control methods. Arwady and her colleagues also realized that local health care workers couldn’t keep up with the epidemic and the number of cases was greater than reported. A national hotline to report Ebola cases had a staff of one, with a single phone line. When the worker ran out of forms, he didn’t even have paper to take notes. Health workers lacked such basic resources as personal protection equipment, the masks and gowns needed to protect them from the bodily fluids that spread the virus. At one hospital a patient infected 21 health workers before his case was diagnosed as Ebola. Sixteen nurses, nurses aides, X–ray techs, and lab techs died. “What is this small hospital going to do now?” Arwady asked.

She also saw a shortage of physicians—one county with a population of 100,000 had only one doctor—and basic infrastructure deficits. One area’s only ambulance had a single working wheel. Many hospitals were unable to isolate Ebola victims. “There is no separation between this part of the hospital and the rest of the hospital,” she said of one hospital with a ward for Ebola patients. “There are fluids on the floor and mattresses that need to be burned, but probably won’t be.”

In a talk at internal medicine grand rounds on Sept. 18, Arwady was one of four speakers who discussed the virus, its history, and its effects. The latest outbreak, Arwady said, differs in major ways from previous eruptions. It is the first in West Africa, and it’s the largest since the Ebola virus was identified in 1976. It has affected more people than all 16 previous outbreaks combined—more than 7,000 infected and more than 3,000 dead. Whereas previous outbreaks occurred in rural areas that were easy to isolate, Ebola has spread to such cities as Liberia’s capital, Monrovia, where large segments of the city’s 1 million inhabitants live in slums with poor sanitation and inadequate access to running water.

The outbreak began in neighboring Guinea last December. A 2-year-old boy died, and his mother, grandmother, and sister died soon after. Local burial traditions, which call on family members to wash the body, are believed to be responsible for spreading the infection. From Guinea, the outbreak spread to Sierra Leone and Liberia. The World Health Organization (WHO) estimates that it will infect at least 20,000 people and will cost $1 billion to contain.

The epidemic, Arwady observed, affected virtually every aspect of life in Liberia. Schools and stores were shuttered. Soccer games were cancelled. A curfew was in effect. Airlines were curtailing flights to the country. Border crossings were closed. Hardest hit was the health care system. Staff and patients were wary of hospitals, seeing them as a place where people get Ebola and die. Not only those with Ebola were affected. “If you have a car accident, if you need a C–section, right now the health care system is not working,” Arwady said.

Her path to Liberia started after she completed her residency at Yale and signed on to a two-year training program with the CDC’s Epidemic Intelligence Service. She is based in Chicago, but earlier last summer she spent time in Saudi Arabia, investigating Middle East Respiratory Syndrome. In July the CDC emailed staff, seeking volunteers to help Liberian health workers deal with the Ebola outbreak. “It was before we realized the scale of it, and before it had reached such a high level of attention,” Arwady said.

Arwady’s interest in global health began between her first and second years of medical school, when she spent a summer in South Africa. Along with two other medical students she provided education on HIV to high school students. A few years later she had her first clinical experience in Africa when she went to Uganda as a medical student on an international rotation at Mulago Hospital in Kampala. While in Uganda, Arwady and other medical students visited Lacor Hospital in Gulu, site of an Ebola outbreak in 2000. Among the more than 200 dead were 13 workers at the hospital, including the medical director.