To halt a yellow fever epidemic in central Sudan's Kordofan province, medical teams from Doctors Without Borders/Médecins Sans Frontières (MSF), working with Sudanese health officials, led a mass vaccination campaign in Abu Gebeiha and Rashad, two of the province's largest towns.

In this province of 1.7 million people, MSF teams are tasked with vaccinating the inhabitants of two large cities, Abu Gebeiha and Rashad, as well as the populations in the surrounding villages. Photo © MSF

The teams faced the following challenge: to provide yellow fever vaccinations to 200,000 people in a desert region over a two week period, using a vaccine that must be kept cold.

The first cases of yellow fever in Kordofan, a province of 1.7 million people, were recorded in September, but the epidemic was not confirmed until late October. Once administrative formalities and negotiations on how MSF would conduct its activities were completed in early December, twenty three international MSF aid workers set out to vaccinate the population of Abu Gebeiha and Rashad, two large urban centers in the east of South Kordofan, as well as the residents of neighboring towns with more than 3,000 people. Teams from the Sudanese Ministry of Health focused on small towns and rural villages outside the cities, as well as on other locations throughout the province.

No treatment for yellow fever exists

Because there is no specific treatment for yellow fever, a highly contagious viral illness, treating symptoms is the only option. Even those whose symptoms are treated remain in grave danger as nearly 25% die. To prevent the disease from spreading, the vaccination campaign targeted practically everyone: adults as well as children over nine months old. The vaccine provides immunity for 10 years.

"Organizing such a large-scale campaign in a very short time is a real challenge," said Coralie Léchelle, of MSF's emergency department, who recently returned from Kordofan. "After the discussions with the Ministry of Health to set out each party's responsibilities, the major difficulty was organizing the cold chain so that we could transport the vaccine doses."

To bring a mass vaccination campaign to this desert region, a cold chain must be established. Photo © MSF

The vaccine must be kept between 35°-46° Fahrenheit at all times in order to maintain its effectiveness. In the desert, that means 1,300 pounds of ice," said logistician Fleury Girard. "Ice that has to be produced, packaged and transported every day."

Heavy mobilization of material and staff

Organizing the vaccination teams also proved to be a major logistical undertaking.

"For the city of Abu Gebeiha, with a population of 40,000, and for the surrounding towns, we set up three two-person teams composed of a logistician and a nurse," Girard said. "Each pair supervised four vaccination teams, made up of two vaccinators, four people who prepared the vaccines, two counters and two people responsible for registration. To give you an idea of the resources mobilized, each pair had seven cars — including three pick-ups to deliver the supplies — for a total of more than 50 cars during the entire campaign."

Another challenge involved gathering data about the population.

"The existing statistics are not always reliable," Léchelle said. "The village populations are sometimes under- or over-estimated. And that's not counting nomads who travel through the area, as well as those people who, for fear of getting sick, sometimes walk for days to be vaccinated. For the campaign to be effective, nearly everyone over 9 months must be vaccinated."

Vaccination coverage difficult to estimate

The nomadic population must sometimes travel for days to be vaccinated. Photo © MSF

The teams also treated 583 people already infected with yellow fever. Nearly a quarter of these patients died, while those who survived will have lifetime immunity against the disease.

"Kordofan province is huge and our data are not sufficiently reliable," Léchelle said. "It is likely that certain cases, and even deaths, could not be reported."

"During the first few days, each vaccinator immunized 1,200 people per day," Girard said. "Later, between 100 and 200 people were immunized per vaccinator, in an effort to catch up with people who could not get there during the major vaccination days."

In all, nearly 200,000 people were vaccinated in fewer than two weeks, with the campaign ending Sunday, December 18.