To halt a yellow fever epidemic in central Sudan's Kordofan province, Médecins Sans Frontières (MSF) medical teams, working with health officials, led a mass vaccination campaign in Abu Gebeiha and Rashad, two of the province's large towns.

The MSF team in Kordofan faced the following challenge: to vaccinate 200,000 people against yellow fever in two weeks, working in a desert region, using vaccines that must be maintained at between one and seven degrees celcius.

In this central Sudan province, the first cases of yellow fever were recorded in September, but the epidemic was not confirmed until late October. In early December, once the administrative formalities and negotiations on how MSF would conduct our activities were completed, 23 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.

The Sudanese Health Ministry's teams focused on the small towns around these two cities and on the rural villages, as well as on the other towns and villages in this province of 1.7 million residents.

Treatment

No specific treatment exists against yellow fever, a highly contagious viral illness. Treating symptoms is the only option. But even with appropriate treatment, the risk of death remains high, and nearly 25 percent of people who acquire the virus die from it. The vaccine provides immunity for 10 years. To prevent the disease from spreading after the epidemic began in Kordofan required a massive vaccination campaign targeting everyone - adults and children over nine months old.

"Organizing such a large-scale campaign in a very short time is a real challenge," says Coralie Léchelle, of MSF's emergency department, who 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."

Even in the desert, to maintain its effectiveness, the vaccine must be kept at temperatures between one and seven degrees celcius.

"That means 1,300 pounds of ice - which has to be produced, packaged and transported every day!" says logistician Fleury Girard.

Mobilizing 50 Cars, 600kgs of ice and over 120 people

Organizing the vaccination teams is also 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," Fleury says. "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 to the towns and villages covered in the campaign), for a total of more than 50 cars for the entire campaign."

Another challenge for a campaign of this breadth involves gathering population data.

"The statistics are not always reliable," Coralie says. "The village populations are sometimes under- or over-estimated. If the campaign is to be effective, the entire population over the age of nine months must be vaccinated, which is a real logistical headache for the teams! And that's not counting the nomads who travel through this area, as well as those people who, for fear of getting sick, sometimes walk for days to be vaccinated."

Vaccination coverage difficult to estimate

The teams also treated 583 patients. Because no specific treatment for yellow fever is available, nearly 25 percent of them died. Those who survived will have lifetime immunity against the disease.

"Kordofan province is huge and our data is not sufficiently reliable," Coralie says. "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," Fleury says. "Over the following days, 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 total, nearly 200,000 people were vaccinated in fewer than two weeks and the campaign ended on Sunday, December 18.