On Wednesday, it was revealed excessive amounts of lead and nickel were found in the blood samples of patients.

More than 500 people have been hospitalised in southern India from a mysterious illness which has left health experts puzzled. The illness, reported in the city of Eluru, in the state of Andhra Pradesh, caused those affected to suddenly lose consciousness, have seizures or vomit, as well as muscle pain and in some cases, temporary memory loss. At least one person has died due to the illness. On Wednesday, Al Jazeera reported that excessive amounts of lead and nickel were found in the blood samples of patients who had fallen sick. Chief Minister YS Jagan Mohan Reddy's office said that the preliminary results from the investigation were conducted by an All India Institute of Medical Sciences (AIIMS) team. "Similarly, Indian Institute of Chemical Technology (IICT) is also running tests and the results are awaited," Reddy's office said in a statement. Local health officials are testing water, milk, vegetables and fish samples in a bid to identify a possible source of the illness, but it's still unclear where the toxins originated. Along with government teams, experts from the World Health Organisation are also on the ground where the illness was reported.