A suspected case of polio reported in Darbhanga district of Bihar has tested negative for the wild virus it was announced Thursday. The ERC Mumbai laboratory where the samples were being investigated confirmed the case as negative this (Thursday) evening said a statement issued by Unicef India. The union health ministry in a statement issued early Thursday had said the case was suspected to be of wild poliovirus type 3 (WPV3).As a measure of abundant precaution the ministry has initiated rolling out an immunization drive in 28 districts of Bihar early next week. Bihar has not had any case of WPV3