UNT medical geographer is mapping diseases

Joseph Oppong, professor of geography and associate dean for research and professional development in the Toulouse Graduate School. (Photo by Ahna Hubnick)When Mali became the sixth West African nation to have a confirmed case of Ebola after a 2-year-old girl was diagnosed in late October, it proved what Joseph Oppong, professor of geography, has long claimed about infectious diseases.

"Diseases do not respect political boundaries, and they travel internationally without visas," he says.

The girl's father contracted Ebola in neighboring Guinea, which is believed to be where the Ebola outbreak started last March. He later died, becoming one of more than 4,800 people killed by the virus in West Africa. The girl and her grandmother then traveled to Mali and the girl was taken to a hospital, where a test confirmed that she had Ebola. She later died as well.

Disease data is vital

Oppong has been tracking the spread of diseases since becoming a UNT faculty member in 1992. He gathers data and programs it into a geographical information system, which produces an electronic geographic map on an outbreak. He uses data from repositories from the Centers for Disease Control and Prevention, the World Health Organization and the Texas Department of State Health Services, among others. The database information includes:

  • characteristics of a disease
  • the locations where patients were identified
  • the date of the diagnoses
  • how many people from each location were diagnosed
  • economic indicators
  • health care policies and practices
  • population information according to location, such as ZIP codes

Oppong also considers information about opportunities for those infected to spread the disease.

"A disease outbreak anywhere on the surface of the Earth puts every person at risk. If you know where a disease is most likely to have a severe impact, people in the affected area can be provided with health information and vaccinations or quarantined, if necessary," he says.

Culture is key factor for Ebola spread in Africa

The Ebola outbreak in West Africa, he says, is primarily tied to cultural practices in Sierra Leone, Guinea and Liberia -- the three nations with the most identified cases of Ebola and the most deaths from the disease. Instead of being taken to hospitals, those affected with Ebola are more likely to be cared for hands-on at home by family members and friends, who do not use gloves or other proper protection and are likely to further spread the virus or become infected themselves, Oppong says. After a death, family members are likely to personally prepare the bodies for burial by bathing and clothing them, and mourners may touch a dying or dead person.

Hospitals in West Africa often lack basic supplies and are understaffed, leading to distrust by families and friends of those who are ill. Oppong points out that in both Sierra Leone and Liberia, recent civil wars have decimated the health care system and led to general distrust in government.

Geography a contributing factor

He says geography is also a key reason why the virus has spread in West Africa. Guéckédou, the city in Guinea where the virus was first identified last March, is on the southern border and close to both Liberia and Sierra Leone.

"The borders of the three countries almost intersect right there. If a death occurs in Guéckédou, family members from neighboring countries come to the funeral and carry the disease with them to those other countries," Oppong says.

West Africans have found it easy to travel from one nation to another in recent years because of improved transportation. Roads have been built flowing in and out of Guéckédou, and people routinely use buses over long distances.

"All of these factors become the perfect recipe for disaster," Oppong says.

Oppong says that if the Ebola outbreak had started in a rural community far from a city, it would have been easier to impose a quarantine and contain the virus. In large cities, he says, "it becomes much, much more difficult to control."

Oppong has also studied the spread of Buruli ulcer in Benin and Ghana, Africa; Severe Acute Respiratory Syndrome (SARS) in Asia; H5N1, or the avian flu, in Asia and Europe and tuberculosis in Ghana and among homeless populations in Texas.

Development of Ebola medicine not likely soon

He points out that although many of these diseases were first identified decades ago -- including Ebola -- developing medications and vaccines for them have not been priorities in the medical profession.

"Ebola is not a sexy disease. It is not a disease that affects the rich, developed world. It affects a small number of people so it is not in the interest of big pharmaceutical companies to invest a lot of money in research on Ebola," he says.

Helping the poorer nations where diseases are first identified is the best way for the U.S. and other developed nations to avoid outbreaks within their own borders, Oppong says. If outbreaks are identified early, guidelines could be put in place to stem the spread of the diseases, he says.