Mystery kidney killer spreads fear

Experts fail to find cause of disease that affects single province

It is midmorning, and hundreds of people are squeezed under a banyan tree's shady canopy to have blood drawn by just three nurses who are working assembly-line fast. Others wait outside this dusty rural health center to get their vitals taken and give urine samples.

Most of the 1,000 villagers have come on foot and have stood for hours under the hot sun - not because they feel sick, but out of fear. They want to know if they will be the next victims of a mysterious kidney disease that has killed thousands of farmers in Sri Lanka's rice basket.