Traces of lead and nickel have been found in the blood of the people who contracted the mystery illness in Andhra Pradesh's Eluru, doctors from the All-India Institute of Medical Sciences have found. Nearly 400 people have been found ailing since December 5, more than 45 children below the age of 12 are among them. All complained of convulsions, nausea and fainting. One person, a 45-year-old, has died.