A sero survey is aimed at monitoring trends in prevalence and transmission of a disease, which can help design and implement appropriate containment measures.
The state’s third sero survey will cover those above the age of six years. Blood samples of 3ml will be taken from people in various categories — fully vaccinated, non-vaccinated, vaccinated with first doses, recovered from Covid as well as those not infected. All samples will be sent for analysis to the district lab in Panchkula.
In the first sero survey, 18,700 samples — 850 from each district — were collected while the second survey gathered 15,840 samples, or 720 from each district. This time, the scale is much bigger, with the sample count almost double as that of the first. A health official said the aim is to analyse more data.
The sample size in the districts will also vary this time. At 3,000, Gurugram will account for the highest number of samples. Out of these, 1,800 will be adults, 900 will be between the ages of 10 and 17 while 300 will be aged between 6 and 9.
Gurugram chief medical officer Virender Yadav said 75 clusters — 45 rural and 30 urban — have been identified for the study. Each day, 25 clusters will be covered. Each cluster will be divided into four quadrants, each of which will comprise 10 households. Six adults, three adolescents (aged 10 to 17 years) and one child (aged 6 to 9 years) will be selected from houses till the sample size of 10 is reached.
A total of 40 individuals in each village or ward will be enrolled for the survey, the CMO added. Health teams comprising 12 supervisors will record the information of selected individuals, including name, age, gender, vaccination status, and whether they have had Covid or if they suffered from any comorbidities, on a mobile app.
Gurugram will be followed by Nuh (2,700 samples), Ambala (2,400), Karnal (2,200), Panipat (2,000), Bhiwani (1,800), Kurukshetra (1,720), Sonepat (1,680), Fatehabad (1,600), Jind (1,600) , Jhajjar (1,600), Rohtak (1,600), Panchkula (1,520), Rewari (1,400), Yamunanagar (1,480), Kaithal (1,480), Faridabad (1,320), Hisar (1,320), Charkhi Dadri (1,080), Mahendergarh (1,200) ), Sirsa (1,000) and Palwal (800).