"The rainy season is coming so it is a race against time to build enough latrines to avoid serious outbreaks of disease," Daniel Augstburger, senior emergency officer for the UN Office for Humanitarian Affairs told IRIN on Wednesday.
Of the 12 major sites for the displaced, the worst is Habile next to the town of Koukou where there are only 100 latrines for 25,000 displaced people.
"We need 700 more latrines to meet the standard of one latrine for every 30 people, otherwise we expect a disaster. The problem is basically funding. We are still waiting on donors to come good," Augstburger said.
Dysentery has already broken out in the Habile site. Hepatitis E has broken out in two other camps.
Some of the displaced sites have better sanitation than others, but none of them are yet adequate.
Medicins Sans Frontier (MSF) said it was concerned about sanitation in its site in Dogdore on the boerder with Sudan."We have everything else under control," said Chantal Gamba, MSFs' medical coordinator in Chad. "But at this time with the rainy about to start we are all worried that poor sanitation could bring cholera and other epidemics."
The current health services in many sites would be overwhelmed the moment there were an epidemic, health workers said.
In Gos Beida, a recent MSF survey found 19.5 percent of the displaced population were severely or moderately malnourished thus more susceptible to disease.
Relief workers have also identified pockets of malnutrition at various other sites such as at Ade where MSF recently opened a therapeutic feeding centre.
"The nutrition cluster of NGOs have done their assessments but using various methods and we still need to identify the causes of malnutrition, whether it's lack of food or poor eating habits or water born disease that deplete people's nutrients," Augstburger said.
Only three NGOs have health clinics for displaced populations, one for each of the main sites.
The only hospital for all the 100,000 displaced is in the main town of Goz Beida and it has just two doctors. Many smaller sites of displaced people have no health services at all.