Four physicians and a staff of Lohagara Upazila Health Complex tested positive for coronavirus on Wednesday morning.
Civil Surgeon Dr Md Abdul Momen said they sent the samples of eight people for coronavirus test on Tuesday and five of them found positive for the virus.
Local administration put the entire upazila under lockdown to avoid further transmission of the highly contagious virus in the community, said Dr Momen.
So far, six coronavirus patients detected in the upazila.