Haryana Health Minister Anil Vij on Monday said a sero survey is being carried out with an aim to gauge the penetration of Covid-19 and to monitor its transmission trends.Additional Chief Secretary (Health) Rajeev Arora said the findings of the study would be useful in designing and implementing appropriate containment measures in the state."A sero survey is testing of a group of individuals to monitor trends in prevalence of Covid-19 as it helps in understanding the number of people affected by the disease. The study will help us to determine the burden of Covid-19 at the community level in the state and monitor the trends of transmission of SARS-CoV-2 (COVID-19) infection," he said.As per the blueprint, the sample size has been estimated at district-level. Thus, from each district 850 participants will be covered.Arora said a stratified multistage random sampling would be done. The sample size of 850 will be divided into two parts -- rural and urban.A total of 88 samples from rural clusters and 44 samples from each urban cluster will be taken.The Health Minister said the survey has already started in Panchkula and Ambala in coordination with the Department of Community Medicine and the School of Public Health of the Post Graduate Institute of Medical Education and Research (PGIMER) in Chandigarh.The Health Department aims to complete it by the end of this month. "It is an antibody test and it will be conducted in every district on 850 persons from both urban and rural populations of respective districts. A nodal officer has been designated in every district to monitor and supervise the sero survey activity," he added."Existing and ongoing data of laboratory results will be used to calibrate the positivity rate among tests of RT-PCR in all districts for ongoing pandemic control and mitigation," added Arora.