The second round of serosurvey to assess the prevalence of Covid-19 in the state began from January 25.
The survey would help trace people who had the infection before and in those people in whom SARS-CoV-2 is still active.
All 30 districts of the state, including eight zones of BBMP (East, West, South, Bommanahalli, Dasarahalli, Mahadevapura, RR Nagar and Yelahanka) are included in the survey, which is 38 units in all.
While the sample size of the survey is estimated to be 1,050 per unit, the total sample size required for all the units is 39,900. The sampled population includes all adults aged 18 and above. However, some are ineligible to provide samples. They include Covid positive cases, participants in the first round of the survey and those
The study will be conducted in 290 health centres and select population settings.
The low-risk group would include pregnant women presenting at ANC clinics and attendees of patients coming to OPD clinics.
Moderate risk group involves bus conductors, auto drivers, vegetable market vendors, besides healthcare workers like doctors, opticians, laboratory technicians and radiographers.
The moderate risk category also includes hospital attendants, veterinarians, medical practitioners, ambulance staff, paramedics, ANMs, ASHA workers, nurses, pharmacists, hospitals receptionists, pourakarmikas/waste collectors, apart from those congregating at markets, malls, retail stores, bus stops, railway stations and hotel staff.
Samples will also be taken from people having the highest risk of contracting Covid like senior citizens and persons with comorbid conditions.
The data collection will be done through an app specifically made for the study. It will be mapped to the samples using the ICMR Specimen Referral Forms for Covid-19.
Rapid Antigen Test (RAT) will not be conducted for the second round of the serosurvey. Participants in all three risk categories will undergo an RT-PCR test for the diagnosis of acute infection and antibody tests for assessing immunity.
One sample of a nasopharyngeal swab and oropharyngeal swab will be collected. Venous blood collected from the participants will be transported to identified IgG ELISA testing labs.
Five adjacent districts have been mapped to nine ICMR labs (NIMHANS, BMCRI- Bengaluru, NIV-Bengaluru, MMCRI–Mysuru, KIMS-Hubballi, GIMS-Kalaburagi, HIMS- Hassan, VIMS-Ballari and SIMS-Shivamogga) for ELISA testing.
Analysis of the second round of serosurvey data will be useful for local decision-making at the district level to mount the necessary public health response.