Sero positivity rate increased in non-slum areas, says study The third sero survey conducted within Mumbai has shown the presence of antibodies in 36.30% samples out of the total 10,197. The survey’s results show the sero positivity rate has increased in non-slum areas compared with slum areas. “Around 35.02% of the total male samples have shown sero positivity, while it was 37.12% in the total female samples,” an official said. The sero survey in slum areas has shown the sero positivity at 41.6%, which has come down from 57% in July 2020 and 45% in August 2020. In non-slum areas, the sero positivity was registered in 28.5% samples, which increased from 16% in July 2020 and 18% in August 2020.