‘India’s COVID-19 infections grossly underestimated’

[NEW YORK] India’s southern state of Karnataka alone may have had 31.5 million cases of COVID-19 or nearly 95 times greater than have been reported, says a new study that puts a question mark on the 10 million plus cases reported for the whole country so far.

Published this month in the美国医学协会杂志该研究基于数据从卡纳塔克邦20个地区的代表性样本中收集，其中有7000万印度13亿人口。

截至2月15日星期一，根据Worldometers, India had recorded 10,916,589 cases of COVID-19, second only to the US with 28,261,470 cases. Brazil came in third with 9,834,513 cases.

Anup Malani，该研究的作者和教授University of Chicago’s Law School和Pritzker School of Medicine, tellsSciDev.Net尽管官方报告表明该病毒已感染了印度一千万人，但测试率很低。“我们的研究对传播的估计更为精确COVID-19，“ 他说。

研究人员使用针对RBD Spike蛋白的测试，从卡纳塔克邦州城市和农村地区的家庭中收集了有关最近和过去CoVID-19感染的抗体的数据，并更好地识别了暴露于Covid-19病毒而不是其他冠状病毒。

Malani says a unique feature of the study is that it tested the same individuals for current infections using the RT-PCR test. “This pairing allows the study to both report current levels of immunity and forecast future immunity because most of today’s infected population will, in a few weeks, join tomorrow’s immune population,” he emphasises.

Manoj Mohanan, co-author of the study and associate professor of global health at the Sanford School of Public Policy, Duke University, North Carolina, says that 44.1 per cent of the population in Karnataka’s rural areas and 53.8 per cent in the urban areas tested positive for antibodies to COVID-19 by the end of August 2020.

The researchers found that rural areas had nearly the same level of exposure to COVID-19 as urban areas. Although城市were more densely populated, rural areas faced additional risk becausebeplay下载官网西西软件is an essential sector and exempted from lockdown restrictions.

In Karnataka, says Malani, 46 per cent of the population had COVID-19, which is 95 times the amount reported. A subsequent study in Tamil Nadu suggests that 32 per cent of the people there have had it or 36 times the official number. Both studies were done with approval or in collaboration with the state governments.

“If COVID-19 is much more widely spread, it tells us two things,” says Malani. “Assuming death statistics are correct, the infection fatality rate is lower. On the other hand, India’s efforts to control spread of the virus were less successful than many other countries. We need to investigate how India can do better in the next pandemic, especially if it is more dangerous to Indians than COVID-19.”

“We need to investigate how India can do better in the next pandemic, especially if it is more dangerous to Indians than COVID-19”

杜克大学Manoj Mohanan

马拉尼认为，在印度农村地区所见，在南亚和东南亚的其他地区可能被低估。他告诉他说：“低测试率在低收入和中等收入国家中很普遍，低测试可能是州能力低的函数。”SciDev.Net.

高阳性率下降Karnatak的农村地区a and Tamil Nadu was attributed by Malani to millions of migrants fleeing the cities for rural areas once the lockdown was lifted in May. Although cities were more densely populated, rural areas faced additional risk because agriculture was exempted from lockdown restrictions.

Neelanjan Sircar, professor of economics, Ashoka University, Sonipat, India, says the study allows comparison of rural and urban populations. “We may understand the core trade off in spread of infection between urban and rural areas in India in the following way: urban may be more susceptible to spread due to density of social contact, but they have also seen greater state intervention in stemming spread as compared to rural areas.”

Sircar补充说：“研究估计，与农村地区（44％）相比，城市地区（54％）的感染点高约10个百分点。”“这提供了证据，表明城市地区的国家控制措施并未完全减轻城市地区传播的更大风险。”

This piece was produced by SciDev.Net’s Asia & Pacific desk.