By Lina Sorg
Ebola virus disease (EVD), more commonly known as Ebola, is a severe and often deadly illness that affects humans and primates. Instances of the disease were at first limited to remote areas of Central Africa, but the most recent outbreak saw cases in urban West Africa as well. Spread and severity of an Ebola outbreak depend on the population of an affected region, the specific strain of the virus, and cultural aspects of human behavior. At the recent SIAM Conference on the Mathematics of Planet Earth (MPE16), held in Philadelphia, PA, Christina Edholm, (University of Nebraska) presented a model of Ebola that illustrates the importance of education in limiting future outbreaks.
At the disease’s onset, those affected typically only experience headache, fatigue, fever, or muscle soreness. But around the tenth or eleventh day of infection, patients develop a sudden high fever, and may begin vomiting blood or bleeding from the mouth, nose, and eyes. Excessive bruising, organ failure, and brain damage can also occur. Approximately 60 percent of cases result in death, and there is currently no vaccination.
Edholm studies cultural practices in West Africa to understand the role of education—or lack thereof—in Ebola transmission. When someone becomes sick, family members see it as their duty to care for the patient. Thus, an Ebola patient is more likely to stay at home or be treated by a community member who knows medicine rather than go to a hospital. As a result, the infected frequently infect their family members. Family members also commonly touch or kiss their deceased before burial, which is dangerous because Ebola can be transmitted even after the host has died. Healthcare settings are unfortunately often not much better-equipped, and patients are typically crammed in a small area with many exposed fluids.
After crafting the model—in collaboration with the Southern Africa Mathematical Sciences Association’s Masmau Program—Edholm conducted a parameter estimation using data from the 1976 and 1979 Ebola outbreaks in Sudan. She assumes that the population was uneducated in 1976 but educated by 1979. In 1976, 280 cases of Ebola were recorded in Sudan; only 38% of the cases originated in the community, meaning the remainder were spread in hospital settings. In 1979, only 34 cases were reported, 85% of which occurred in the community; the reduced number of cases indicates that the community was better prepared to handle an outbreak, and the low percentage of hospital cases suggests that healthcare staff was more sufficiently educated in preventative practice.
Thus far, Edholm’s parameter estimation is fitting the model well. “As healthcare starts moving towards early education efforts, and even preemptive education, we’re going to very much reduce the number of cases we’ll have overall,” she said.