NEW DELHI – Indian health officials have found traces of nickel and lead in a few blood samples taken from hundreds of patients who have been hospitalized by a mysterious illness in a southern state, officials said.The Andhra Pradesh state government said in a statement Tuesday night that investigations by experts from the All India Institute of Medical Sciences has not be able to ascertain the possible source of excessive nickel and lead particulate matter in the patients’ blood.Reports from other tests by experts at the Indian Institute of Chemical Technology, including toxicology reports and blood cultures, are being awaited, the statement said.Health officials and experts are still baffled by how the heavy metals got into the patients'.