On a day Mumbai and Maharashtrarecorded first coronavirus-linked death, the Brihanmumbai Municipal Corporation (BMC) said on Tuesday that only one person tested positive for the infection out of 131 samples examined at the civic-run Kasturba Hospital here.A 49-year-old man from N-ward of the city was admitted to Kasturba Hospital on March 16 and he tested positive on Tuesday, the BMC said in a release.Daksha Shah, deputy director of the corporation's health department, said the man had traveled to the United States and returned to Mumbai on March 7, 2020."Four (of his) high-risk contacts were tracked and advised admission (to hospital quarantine). Seven low-risk contacts were tracked and advised home isolation for 14 days," said Shah.So far 15 persons have tested positive for the coronavirus in Mumbai, including eight who hail not from the city but from peripheral areas. It also includes the 64-year- old man who died at Kasturba Hospital on Tuesday."This patient had a chronic history of high blood pressure, pneumonia and inflammation of heart muscles, and increased heart rate led to death," said the BMC release.This patient had returned to Mumbai from Dubai on March 5 and admitted to a private hospital on March 8 before being shifted to Kasturba Hospital on March 13 on being tested positive.A senior official said over 80 staff from the private hospital had come in contact with him, and hence samples were taken from all these persons."All of them tested negative for coronavirus, but as a precautionary measure all 80-82 staffers have been kept under 14-day isolation at the hospital," said the official.A new isolation facility with 20-bed capacity at Jogeshwari HBT Trauma Care Hospital is being put to use, the BMC release added.So far the civic body was admitting suspected coronavirus patients to Chinchpokali-based Kasturba Hospital, which has an isolation ward of 100 beds.A total of 82 patients were admitted to isolation facilities at Kasturba Hospital and HBT Trauma Care Hospital on March 17, Shah said.