Mumbai: The Brihanmumbai Municipal Corporation (BMC) has decided to conduct sero-surveillance in three wards of the city to get a clearer picture of the extent of spread of the coronavirus infection and,in turn, help in drawing up further strategies to defeat the virus. For this, the BMC, in partnership with NITI-Aayog, Tata Institute of Fundamental Research (TIFR) Mumbai and other institutions, will undertake sero-survey in MWest, F-North and R-North wards, which contribute 10.23 per cent of COVID-19 cases in the city.
F-North covers Matunga, Sion and Wadala, areas that used to be COVID-19 hotspots. M-West includes Chembur and Tilak Nagar. Dahisar and Mandapeshwar fall under R-North, which currently has the highest daily growth rate. Sero-surveillance is done through a blood testto get an estimate of antibody levels against vaccine preventable diseases. For this, 10,000 samples will be collected randomly from slum and non-slum areas from participants above 12 years of age. The teams will visit households and collect basic demographic information, contact history and details of comorbidities.
“We are launching a serosurvey and antigen tests under the Universal Testing Initiative. This will not only provide information about new coronavirus patients, but will also give information about how far the coronavirus infection has spread,” said Suresh Kakani, Additional Municipal Commissioner, BMC (Health). He added that the Indian Council of Medical Research (ICMR) had urged all states to take up independent serosurveys in the community to understand the spread of the disease. Moreover, the main objective of sero-surveillance is to estimate and monitor the trend of sero-prevalence for COVID-19 infection.
It will determine the social and demographic risk factors for COVID-19 infection and help in understanding the geographical spread of the infection in the general population. “The survey is done by collection of blood samples from individuals in randomly selected households. The presence of antibodies inthe blood is a sign of exposure to the virus.Itis done after taking patients’ consent and their detailed history,” Kakani said.
Besides this, the BMC has also decided to conduct antigen tests for frontline workers athospitals and quarantine centres and symptomatic patients from containment zones. Dr Shashank Joshi, part of the state’s COVID-19 Task Force said it was a great move by the BMC to screen many patients at a time and find out the status of the COVID-19 virus in hotspots of the city. “The surveillance can give an idea of the spread of COVID-19 in the general population and immunity againstit andhelp authorities strengthencontact-tracing and containment strategies,” he said.
Dr Rahul Pandit, Director-Intensive Care, Fortis Hospital, who is also a member of state government-appointed COVID19 Task Force, said a serological survey includes IgG Enzyme Linked Immunosorbent Assay (ELISA) test. It estimates the proportion of the population exposed to Sars-Cov-2 infection.“The IgG test is not useful for detecting acute infections, but it indicates episodes of infections that have happened in the past. The test is approved by ICMR for its high sensitivity and specificity,” he said.