Human displacement and the accompanying decline in sanitation is often a recipe for a disease outbreak, and the latest fighting in the eastern Democratic Republic of Congo is no different. The crowding and lack of safe drinking water in refugee camps could spark a cholera outbreak there, where 250,000 people are now refugees, health authorities say.

There have been at least 1,000 cases of the diarrheal disease in the region since the beginning of October, and more could occur if sanitation isn’t improved in the camps, the Associated Press is reporting today. Aid groups have diagnosed at least 90 cholera cases around the provincial capital of Goma since Friday, according to the AP. But almost a million people in the eastern DRC are at risk for water-borne diseases, the World Health Organization (WHO) said last week.

There were 13,430 cases of cholera in the country in 2005.

Some 6,311 people worldwide died of cholera in 2006, when there were nearly 237,000 cases — a 79 percent increase over the previous year, according to WHO, which blamed increasing numbers of people living in unsanitary conditions for the rise in cases. The disease can cause deadly dehydration and shock if it isn’t treated with fluids and salts.

Though poor sanitation is often the spark that lights the infectious disease fire, shifting weather patterns can also play a role. Back in 2002, scientists found that the occurrence of the El Nino Southern Oscillation — shifts in the tropical Pacific Ocean atmosphere that raise water temperatures and cause both drought and increased rainfall — accounted for 70 percent of the variation of cholera epidemics in Bangladesh. Seasonal weather patterns also affect the composition of the cholera bacteria, Vibrio cholerae, and therefore outbreaks of the disease, University of Maryland researchers reported then.

Cholera vaccines offer only short-term protection. Japanese scientists hope that rice genetically modified to make cholera toxin will offer longer term immunity.

Boy waits in line for aid in Democratic Republic of Congo/UNHCR, P. Taggart