Mystery kidney killer spreads fear in Sri Lanka

It's midmorning and hundreds of people are squeezed under a banyan tree's shady canopy to have blood drawn by just three nurses, working assembly-line fast.
Others wait outside this dusty rural health centre to get their vitals taken and give urine samples.
Most of the 1,000 villagers have come here 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.
Many have watched neighbours and loved ones -- some only in their 30s -- quickly succumb to deaths after their kidneys gave out. In the worst-hit villages, it kills as many as 10 people every month. No one knows why.

"In some cases, you only know if a certain person died of kidney disease after the autopsy," says Kalyani Samarasinghe, 47, standing outside the health center with a handful of medical papers and a cotton ball taped to her arm. "If you get a pain in the stomach or something, then you think: Is it the kidney?"

The disease has killed up to 20,000 people over the past 20 years and sickened another 70,000 to 400,000.
It has expanded from two districts to seven in the North Central province's dry zone, where farming was transformed after the introduction of modern techniques in the 1960s and '70s.

No cases have been detected elsewhere in the country, and research has failed to determine the cause.
Some blame the water, heavy use of pesticides and fertiliser. Others wonder if it's something in the food, or whether heavy metals or toxic algae could be the source.
Villagers have been told to give up lake fish, aluminum cooking utensils and illicit home-brewed alcohol, but no one's sure if any of it helps.
Rajeeva Dassanayake, a kidney specialist at the area's largest hospital in Anuradhapura, has come to the screening to try to calm the crowd.
"You need not fear and flee from this place," he says. "There are a lot of things being said by many people. Until they have finished fighting each other and come up with an answer, we can say nothing."

Similar diseases are wiping out thousands of farmers in parts of Central America, India and Egypt.