Covid-19: Sero study shows nearly half of Pune city is infected

A serological study shows extensive spread of SARS Cov-2 infection ranging from 36.1% to 65.4% in some areas of Pune city across all types of dwelling. This is the first serological surveillance study done in Pune and comes after similar studies in Delhi and Mumbai. Epidemiological and serological surveillance of Covid-19 in Pune city in five high-incidence sub-wards showed a prevalence of 51.5%.

Scientists and epidemiologists from Savitribai Phule Pune University, Indian Institute of Science Education and Research Pune; Translational Health Science and Technology Institute and Christian Medical College, Vellore conducted the study to estimate the prevalence of Covid-19 in the Pune Municipal Corporation (PMC) limits with funding support from the Persistent Foundation.

Prevalence was 65% in Lohiya Nagar-Kasewadi, 56.7% in Navi-Peth Parvati, 56.6% in Yerwada, 45.7% in Rasta Peth-Raviwar Peth and 36.1% in Kasba Peth-Somwar Peth. This was based on 1,664 samples collected and processed by the team. Blood samples were collected from July 20 to August 5 and processed to detect the presence of IgG antibodies. The study indicates that there has been an extensive spread of infection in the five subwards.

Seropositivity of 43.9% was observed among people residing in bungalows, while it was 56-62% among those who live in tenement or hutment dwellings. People who live in apartments have somewhat lower prevalence (33%). The prevalence is 45.3% among the people who have access to independent toilets as against 62.2% among those who share toilets. There was no difference between men (52.8%) and women (50.1%), while people of older age (above 66) have a lower prevalence (39.8%).

Data scientists, Sahil Deo, said if we take this at face value it means the worst is behind us and it is good news. This means that the most vulnerable population already had COVID-19 so the pressure on the health infrastructure should not be a concern. There will be no shortage of health infrastructure after this. Deo reckons Pune city has peaked but the concern now is the spread to the rural areas of Pune district and the Pimpri Chinchwad Municipal Corporation areas which has seen a spike in the last couple of weeks.

The Pune study randomly selected these five areas based taking into consideration the number of confirmed cases in the administrative zones of the PMC as on July 1, 2020. The principal investigators were Aarti Nagarkar (SPPU, Pune), Aurnab Ghose (IISER Pune) with co-investigators: Abhay Kudale (SPPU, Pune), LS Shashidhara (Ashoka University, on lien from IISER Pune), Susmita Chaudhuri and Guruprasad Medigeshi (THSTI, Faridabad). Jacob John (CMC, Vellore), Gagandeep Kang (CMC, Vellore and formerly at THSTI, Faridabad), Vineeta Bal (IISER Pune) and Satyajit Rath (formerly at NII, New Delhi) were advisors.