Hyderabad, June 1 : Authorities have decided to conduct Covid-19 test on all 280 post-graduate medicos of the Osmania Medical College (OMC) in Hyderabad after three more medicos tested positive on Monday. The fresh cases pushed the total number of medicos testing positive to seven. OMC officials said that samples from all the PG medicos residing in the hostels on the college campus will be collected and sent for testing. They said in view of the three more positive cases, they did not want to take chances and hence decided to screen all the medicos. The college authorities hope to complete the testing in two days. The two hostels have turned into containment zones. Personnel from the Health Department and Greater Hyderabad Municipal Corporation (GHMC) swung into action to take up disinfection of hostels. A woman gynaecology PG medico was infected while discharging duties at the Government Maternity Hospital in Petlaburj and other medicos were suspected to have picked up the virus from her. Her roommate was among those tested positive. All the seven medicos have been admitted to King Koti and Gandhi Hospital for treatment. Medicos suspect that the virus might have spread in the hostels as they had been interacting with each other while preparing for PG examinations scheduled from June 28. The Telangana Junior Doctors' Association (TJUDA) has demanded that the examinations be postponed. /IANS