The second round of sero-prevalence survey began in the national capital on Saturday, with the five-day exercise set to cover all districts and various demographic segments.
The exercise is being undertaken for a comprehensive assessment of the COVID-19 situation in Delhi.
The survey has begun and samples will be collected from four districts, including North Delhi and Northwest Delhi, to start with on Saturday.
A senior government official said 15,000 samples would be collected from August 1 to 5 as part of the exercise, spanning different areas and age groups. Representative samples will be taken from all the 11 districts.
A sero-prevalence survey involves testing the blood serum of individuals to check for the prevalence of antibodies against infection.
Delhi Health Minister Satyendar Jain on July 22 had announced that after analysing the results of the last survey, it was decided that more such exercises would be undertaken every month to formulate better policies for tackling the COVID-19 situation in the city.
The last sero-prevalence survey was conducted by the Delhi government in association with the National Centre for Disease Control (NCDC) from June 27 to July 10. The second round would follow the same protocol as that was for the last survey, officials said.
The Delhi health department has prepared a detailed plan under which every district medical officer has been asked to conduct the survey in their respective jurisdictions, they said.
All CDMOs have been tasked with carrying out the survey in their districts. Random people will be tested for antibodies.
The last sero-prevalance survey had found that around 23 per cent of the people surveyed had been exposed to the novel coronavirus, the central government had said.
The previous study had tested 21,387 samples.
The Delhi government had decided to conduct more monthly sero surveys to find a greater percentage of such people who had got infected and recovered so as to formulate better policies for tackling COVID-19, Mr Jain had said.