By Sarah Hannan Over 3,500 persons from four areas within the Colombo Municipal Council (CMC) administrative region are presently held in isolation zones after one or more persons were tested positive for Covid-19 from the area over the past week. The areas that are currently identified as isolated zones are located at Nakulugamuwa Street in Grandpass (280 persons), Bandaranayake Mawatha in Grandpass (about 2,000 persons out of which 1,020 were sent to quarantine centres), Torrington 60 Watta in Jawatte (343), Muhandiram E.D. Dabare Mawatha in Narahenpita (212), and Imamul Aroos Mawatha in Maradana (680). CMC Public Health Department Chief Medical Officer Dr. R.L. De S. Wijayamuni, speaking to The Morning, informed that with the requirement to obtain samples from the first contacts of the Covid-19-infected persons, the CMC has been able to successfully identify a large number of cases within the past week. “Two weeks ago, we asked the first contacts of a patient to observe home quarantine and did not take samples or send them for PCR testing. However, following the incident at Bandaranayake Mawatha in Grandpass, the method of screening changed. Now we take samples from all the first contacts of a Covid-19-infected person to prevent the virus from spreading further,” Dr. Wijayamuni explained. With aggressive testing in place, the CMC said that 150-200 samples are obtained per day and are sent for testing to the medical faculties of the University of Colombo and the University of Sri Jayewardenepura as well as the Ragama Hospital. “We conduct the sample collection in two batches – one in the morning from 9.30 a.m to 12 noon and the second from 2 p.m. to 4.30 p.m. The samples are immediately transferred to the respective medical faculty through the Epidemiology Unit and the test results are shared with the health authorities at 2 a.m.” Dr. Wijayamuni noted that the CMC has appointed a Covid-19 rapid response team which immediately takes the necessary steps to transfer the persons tested positive for Covid-19 to the nearest hospital – in this case, to the National Institute of Infectious Diseases (IDH). “We arrange an ambulance through Suwasariya Ambulance Service and once the patients are identified, our team collects the details of their first contacts and the places they visited in the recent past. Since this mechanism was in place, we were able to collect samples from the contacts who lived outside the residential area for PCR testing.” Accordingly, the 136 close contacts of the persons tested positive for Covid-19 identified from Nakulugamuwa Street in Grandpass, Torrington 60 Watte in Jawatte, Muhandiram E.D. Dabare Mawatha in Narahenpita, and Imamul Aroos Mawatha in Maradana were sent to the quarantine centre in Punani. Dr. Wijayamuni further noted that even the persons who provided essential services to these areas were required to provide samples for PCR testing, which included the grama niladhari, public health inspectors (PHIs), cleaning staff, etc. Accordingly, 162 such persons underwent the PCR test and were tested negative. Meanwhile, following the incident in the Welisara Navy Camp, all security force personnel who were deployed for duty in isolated zones, PHIs, nursing staff, and Medical Officer of Health for the area had to provide samples for testing. The test results for these individuals have been negative, but as a measure of precaution, the aforementioned groups had informed the CMC that they will be observing home quarantine for the next two weeks. The CMC has now reassigned five PHIs to assist them during this period. The CMC will be collecting random samples from adjacent areas where clusters are detected and aggressive testing will be carried out to the communities if there are positive Covid-19 cases detected, Dr. Wijayamuni reiterated.