Heavy rains, impassable roads and an unusual increase in the number of cases have all confronted the Sudan team.

The kala azar treatment centre in Um El Kher, in Gedaref province in northern Sudan, has become almost completely isolated due to the exceptional rains in the past weeks that have caused extensive flooding. Not only is the rainy season exceptionally heavy, but also the number of kala azar patients has been unusually high this year for the season. At the start of the rainy season - which runs from May to October - 80 to 100 patients usually remain in the hospital.

This year more than 220 people are still there, together with 80 non-kala azar patients. In a normal rainy season, transport from Gedaref city to Um El Kher is done almost exclusively by tractor, and takes 16 hours instead of the three hours in the dry season.

Vehicles have to pass through black cotton soil, a heavy clay soil that makes it difficult even for 4x4 vehicles. Now floods have also hit the region. Two weeks ago, the last transport by road made it to Um el Kher, and it took 3.5 days to complete the journey. The conditions were so bad that the trailer had to be left behind.

Last week, a helicopter was sent to Um El Kher to evacuate a national staff doctor who had fallen ill. The helicopter brought in new supplies, the medical co-ordinator and four expat doctors. In spite of all the exceptional conditions, the team has managed to continue the project successfully. The cure rate is over 90 percent. Kala azar is deadly when not treated.