Rapid antigen testing reveals 90% of Covid-positive patients as asymptomatic

After testing 6,000 people at Covid care centres (CCC) with rapid antigen kits, the Brihanmumbai Municipal Corporation (BMC) has found that of the 600 people who

After testing 6,000 people at Covid care centres (CCC) with rapid antigen kits, the Brihanmumbai Municipal Corporation (BMC) has found that of the 600 people who tested positive for Sars-Cov-2, the virus that causes Covid-19, close to 90% were asymptomatic, making them silent carriers of the infection.

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The 6,000 people tested had earlier been identified as high-risk contacts and were brought to CCCs. They were primarily from parts of north Mumbai like Andheri, Goregaon, Malad, Kandivli, Borivli, and Dahisar,

“We have found that 10% of those who tested positive are symptomatic and they are getting treated at CCC in their respective civic wards,” said Suresh Kakani, additional commissioner, BMC.

The civic body started testing high-risk contacts and suspected patients with rapid antigen kits, which, unlike the reverse transcription-polymerase chain reaction (RT-PCR) test, that takes almost eight hours to provide results, gives reports within 30 minutes.

According to ICMR protocol, every positive report from the testing group will be treated as a ‘true positive’, while negative samples will have to be mandatorily re-tested by the RT-PCR process.

BMC’s findings have led organisations like Jan Aarogya Abhiyan (JAA) to reiterate their claim that the civic body should have been using the kit much earlier, to control the spread of the virus. Dr Abhijit More, co-convenor, JAA, said, “This is the reason why we have been demanding for more number of Covid-19 tests which could have helped us in faster diagnosis and to control its spread.”

Dr Ravikant Singh, a health activist said that the antigen test should have been used while sending migrants back to their home states. “These kits give results in 30 minutes. So, before allowing migrants to board the trains, the government should have tested them and quarantined the infected ones. This could have stopped the spread of the virus to other parts of the state,” he said.

On July 2, BMC procured 1 lakh rapid testing kits from South Korean firm SD Biosensors – the only company approved by the Indian Council of Medical Research (ICMR) to supply the kits.

Dr Sanjay Pattiwar, a public health expert, said, “Asymptomatic patients are silent carriers of the virus. Though their chances of spreading the infection are less, they are still infectious. So, in a pandemic, identifying such patients is essential, to break the chain of reaction. Thus, the civic body should have started with the rapid antigen tests earlier.”

Sero survey completed, second comparative survey to be conducted in Aug

After much delay due to the ongoing monsoon, Brihanmumbai Municipal Corporation (BMC) has finally concluded the national serological survey by collecting 10,000 samples on Thursday. Next month again, the corporation will run a consecutive survey of the same wards for a comparative study.

The survey is being conducted by BMC, along with NITI-Aayog, and Tata Institute of Fundamental Research.

“Data collection was completed on Thursday. On Friday, we retook samples of some individuals due to technical errors,” said Suresh Kakani, additional commissioner, BMC. “A comparative study with a month’s gap will help us to know how many are exposed to the virus and its pattern of infection.”

On June 29, the civic body under the direction of Indian Council of Medical Research (ICMR), started taking blood samples in Tilaknagar, Chembur, Matunga, Sion, Wadala, Dahisar, and Mandapeshwar. In a serological survey, a group of individuals undergoes blood tests to detect the presence of IgG antibodies that the body produces against the novel coronavirus. The tests aim to identify individuals who were previously infected with the virus and have now recovered.