Covid-19: Pune study shows seroprevalence of antibodies in 51.5% samples

Pune's first sero survey has found that 51.5 per cent of the 1644 respondents from five highly- affected wards in the city have seroprevalence of antibodies against SARS-CoV-2, the virus which causes Covid-19 infection.

A serological survey is done to detect the presence of specific antibodies, and is used to assess the prevalence of a disease in the population.

Data from the Pune sero survey was released on Monday. The survey had 1,664 respondents (all above 18 years) from the city's five wards whose population is 366,000.

The survey was conducted by the Indian Institute of Science Education and Research (IISER) in collaboration with Pune Municipal Corporation, Savitribai Phule Pune University, Translational Health Science and Technology Institute at Faridabad, and Christian Medical College, Vellore.

Pune divisional commissioner Saurabh Rao said the survey was not comprehensive and two more sero surveys will be conducted with a larger sample size.

Dr Aurnab Ghose, associate professor, IISER, said 52.8 per cent men and 50.1 per cent women were found to have seroprevalence of antibodies.

The survey found that people living in huts and tenements had higher sero-positivity than those residing in apartments and bungalows, he said.

He said blood samples were collected from 1,664 people who were either asymptomatic or symptomatic but undetected (not tested) from areas like Yerwada, Kasba Peth, Rasta Peth, Lohiya Nagar (Kasewadi) and Navipeth (Parvati) which are high-incidence wards of the Pune Municipal Corporation.

Blood samples were collected between July 20 and August 5.

The survey also indicated a higher prevalence of sero-positivity in users of shared toilets (62.3 per cent) compared to users of independent toilets (45.3 per cent).

"We found the presence of IgG antibodies against SARS-CoV-2. This indicates past infection but does not necessarily suggest immunity from subsequent infection," he said.

Pune district reported 1,829 new coronavirus cases on Monday, taking the tally to 1,27,026. The death toll reached 3,104 with the death of 82 more patients.