A fifth of the total number of residents in Greater Chennai Corporation’s areas have been exposed to Covid-19, a serological survey has fou...
A fifth of the total number of residents in Greater Chennai Corporation’s areas have been exposed to Covid-19, a serological survey has found, reported PTI.
Serology tests “look for antibodies in blood”, according to the US’ Centers for Disease Control and Prevention. “If antibodies are found, that means there has been a previous infection,” it says. “However, there is a chance a positive result means that you have antibodies from an infection with a virus from the same family of viruses (called coronaviruses), such as the one that causes the common cold.”
Serological surveys show the number of people that may have been infected with the coronavirus in an area. However, they do not show how many are immune to the virus. It is still unclear how long antibodies last in infected persons and how many antibodies are required to protect a person from reinfection.
“Overall, one-fifth of the population in Chennai was exposed to SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) infection,” the preliminary report said. Blood samples were collected from 12,405 individuals from 51 wards in all the 15 zones of the Corporation. The samples were collated between July 18 and July 28 and were tested by August 6 for IgG antibodies (start appearing...
