No confirmed novel coronaviruscase has been reported so far in Chhattisgarh with samples of 31 persons testing negative, a health official said.Till now 31 persons from various districts were tested for possible exposure to the virus but none of them was found to have contracted infection, he said.Another ten samples were sent to the All India Institute of Medical Sciences (AIIMS) Raipur on Saturday, he added.Earlier the samples were being sent to Pune and Nagpur for examination but from March 5 the facility was made available at AIIMS Raipur, he said.The persons whose swab and blood samples were taken for testing have been placed under home isolation for 28 days as a precautionary measure, he said.The state health department, meanwhile, sent a letter to all government and private hospitals on Saturday, asking them to collect samples of people who have symptoms of the virus infection and send them to the AIIMS here for testing.All government district hospitals have already set up isolation wards.Health department secretary Niharika Barik on Saturday issued an advisory to secretaries of all departments and district collectors take steps to educate people about precautions to be taken to prevent coronavirus infection.