About one in five of the 16,000 people tested during a serological survey in Uttar Pradesh in September showed the prevalence of antibodies against the Sars-Cov-2 pathogen that causes the Covid-19 disease, the state health department said on Thursday.
“Of the total 16,000 samples, 3,536 tested positive for antibodies, which is 22.1% in terms of sero prevalence,” said additional chief secretary, health, Amit Mohan Prasad.
Samples were collected in 11 districts with the maximum Covid-19 cases on September 4, he said. From each district, 1,450 samples were collected for tests. These districts are Meerut, Lucknow, Kanpur, Varanasi, Gorakhpur, Kaushambi, Prayagraj, Moradabad, Ghaziabad, Baghpat and Agra.
The samples were sent to King George’s Medical University (KGMU), Lucknow, for testing to determine the presence of antibodies, he said.
Health experts said the sero survey indicated two things. “If 22.1% people had antibodies in September, it means the percentage will be even more than that today,” said Dr Ved Prakash, head of the department of pulmonary critical care medicine at KGMU.
Dr PK Gupta, former president of IMA, Lucknow, said, “This report is an indication of community spread in the state. Now, the state government should focus on a mass awareness campaign to break the chain of infection. People should follow the Covid-19 protocol strictly, covering their face with mask, maintaining social distancing and washing hands at regular intervals,” he said.
Dr Gupta said the state government should also increase sample tests by engaging private laboratories. The increase in sample tests would ensure that people testing positive for Covid-19 would immediately go into isolation or get admitted in hospital, he said. It would check the spread of the infection among the remaining population, he added.
Medical practitioner Dr AK Singh said data of the sero-survey implied that 50 million people out of the 230 million population of Uttar Pradesh might have been exposed to the virus and become carriers of the antibodies by September. The number of the people exposed to the virus must have multiplied by November, he added.
The state government had taken the correct decision to increase the sample tests and launch a mass awareness campaign across the state, he said.
Dr Amresh Singh, head of the microbiology department at Baba Raghav Das Medical College in Gorakhpur, said the numbers showed that even after infection, a large population may not have developed antibodies due to co-morbidity or a weak immune system. There was a need for regular follow-up to get a clear picture of the extent of infection, he said.
Antibodies are immune molecules produced by the body to fight pathogens. The presence of antibodies in the blood typically suggests that people infected with a virus would gain immunity for some period. The latest studies show that antibodies are not sustainable and begin to disappear within three to four months, Dr Singh said