More than six years after the tainted water tragedy in Walkerton, Ont., most residents report improvements in their health, but researchers continue to find health complications.

Seven people died and more than 2,000 became sick after deadly E. coli bacteria contaminated the town's water in May 2000.

A health study tracking the medical difficulties of the town's 4,500 residents found that 85.4 per cent of residents surveyed rated their health as good or excellent. That's an increase of two points since last year's survey.

Nearly 84 per cent report their health is stable or better than it was last year.

Dr. William Clark of London's Lawson Health Research Institute, the lead investigator on study, released the latest results at a town hall meeting Tuesday night in Walkerton.

One of the focuses this year was how children were affected by gastroenteritis, inflammation of the stomach or intestines caused by the bacteria.

Clark said he was relieved to discover that, unlike adults with severe gastroenteritis, children did not appear to have an increased risk of high blood pressure and renal structure abnormalities.

"We were concerned about the children and we've looked at them very closely," said Clark. "They do not have any increased risk so that's good news."

Earlier research suggested that those who suffered severe gastroenteritis from the water contamination were seven to eight times more likely to develop diabetes.

But Clark said the latest study, which screened for people with milder gastroenteritis, concluded that there is no correlation.

Clark also noted that many residents who suffer from high blood pressure, renal difficulties and kidney problems now have their conditions under control with the help of medication.

Early indications point to a link between the E. coli contamination and increased arthritis in the community, Clark said, but added that more studies need to be conducted before providing a definitive result.

The doctor intends to examine inflammatory bowel disease and high blood pressure in pregnancy during testing in 2007.

A team of medical doctors began studying the health of residents five years ago. A final report card on the community's health is expected to be released in 2008.

But researchers plan to continue monitoring health in the community through hospital and health records until 2030 to watch for longer-term problems.

In 2004, former Walkerton water manager Stan Koebel was sentenced to a year in jail and his brother Frank got nine months house arrest for their roles in the town's water contamination.

With files from Canadian Press