Tens of thousands of people have already swarmed to a refugee camp in South Sudan and a new wave will soon begin the trek from the Nuba Mountains.
Humanitarian workers warn the influx could become a catastrophe.
As many as 15 000 more refugees could stream across the border from Sudan by the end of the year, straining a camp that has been hit by malaria and diarrhoea with many people arriving malnourished, said the UN refugee agency, UNHCR.
"We are already stretched to the breaking point here, and any surge or increase in the population will make it nearly impossible to cope with the situation," UNHCR's Kathryn Mahoney told the Associated Press.
Yida sits near the northern tip of South Sudan's Unity State near the border with Sudan. It is a remote region in one of the world's least developed countries. Recent rains have made roads impassable, and the World Food Program has been forced to drop food from the sky to meet the camps' needs. For the past week, large Ilyushin jets have screamed over the camp, dropping 64 metric tons each day from a height of 200 metres. The cheers of refugees – and some aid workers – watching the spectacle accompany each drop.
The population of Yida rose since February from 17 000 to 65 000 by September. From mid-June through mid-July, around 1 000 new arrivals came each day, along with a rash of death and disease that one Médecins Sans Frontières official described as "five weeks of hell".
According to MSF, around two people per every 10 000 in the camp were dying each day, double what the organisation considers the emergency threshold. Around 25% of those admitted to the MSF hospital in Yida were dying. Many were acutely malnourished, and the rains brought malaria and diarrhoea.
"In June, July it was so [bad]," recalled MSF emergency coordinator Foura Sassou Madi.
Three refugee camps in neighbouring Upper Nile state, South Sudan, recently declared an outbreak of Hepatitis E which has already killed 16 people. Doctors are now watching closely for any signs of it in Yida. Madi says they are also watching for any signs of cholera.
An influx of refugees is also expected at the four camps in Upper Nile State's Maban county. The refugees there have fled a similar war in Sudan's Blue Nile. There are now more than 110 000 refugees in the Maban camps.
"Aside perhaps from the Syrian crisis there is no other that matches the compelling realities that we have seen since April, May," said UNHCR's Africa director George Okoth-Obbo at a recent briefing in South Sudan's capital, Juba.
UNHCR says it needs $183-million to manage the humanitarian needs at the camps. So far only around 40% has been delivered. According to Okoth-Obbo, they need at least $20-million more by the end of the year just to maintain their current operations. – Sapa-AP