As of June 7, India had 28.9 million new crown diagnoses, nearly 350000 deaths, ranking third in the world after the United States and Brazil. According to the report of the Ministry of health of India on June 5, more than 120000 new crown cases were newly diagnosed on that day, which is the lowest level of newly diagnosed cases in a single day in recent two months.

In such a big environment, New Delhi, the capital, and other regions announced further easing of epidemic control measures.

According to people's net, New Delhi's chief minister, alwend kejerival, said at an online press conference Friday that the market and shopping malls will be reopened and will be opened in turn by single and double number of door brands; The New Delhi Metro will resume operations with a limited number of people.

Meanwhile, the New York Times article questioned India's undervaluation of the real new crown death toll, raising further concerns about the Indian epidemic. The article conservatively estimates that 400 million people in India are infected with the new crown and the death toll is 600000. At the worst, the death toll is estimated at 4.2 million.

The article was accused by Indian officials of "unfounded".

Three large-scale serum surveys in India predict that it is true

The number of infections is 13.5-28.5 times that reported by the government

The new crown has been popular so far, and the global discussion on the real death toll has never stopped. A report released in May by the World Health Organization estimates that the number of deaths in the world due to new crown may be 2-3 times higher than reported.

The New York Times believes that India lacks good data records and extensive testing, making it difficult to understand the number of real infections. For technical, cultural and logistical reasons, India is more likely to have confirmed cases and deaths underestimated.

Kayoko shioda, an epidemiologist from Emory University, told the New York Times that hospitals in India are overcrowded, and many new crown patients died at home but were not included in official statistics, especially in rural areas. The laboratory that can confirm the cause of death also operates overload.

The new crown caused a large number of deaths in rural India by the media.

India today reported on June 7 that, according to a new statistical report released by a New Delhi based NGO, the center for science and environment (CSE), 52 percent of new crown deaths and 53 per cent of new cases in India occurred in six rural areas in May.

The report said COVID-19 has hit India more than the city.

To get more reliable estimates, the New York Times used three national serum surveys from May 20 to January last year, covering about 30000 Indians each time.

The survey aims to understand the positive rate of COVID-19 sera antibody.

Almost every person infected with COVID-19 produces antibodies, leaving traces of infection. The New York Times believes that it is a good way to estimate the infection rate of the whole population by calculating the seropositive rate.

The results showed that the number of new crown infections in India was 28.5, 13.5 and 26.1 times higher than the official report.

Three serum survey results in India, source: New York Times, same as below

Based on this estimate, the New York Times presents three hypotheses based on the official May 24 submission data of India:

1. conservative version:

If the real number of infections is 15 times or higher than the official report, with a mortality rate of 0.15 per cent, India expects at least 400million people to be infected and 600000 deaths.

2. more likely version:

If the real number of infections is 20 times or higher than the official report, with a mortality rate of 0.3 per cent, India expects at least 539million people to be infected and 1.6 million die.

3. worse version:

If the real number of infections is 26 times or higher than the official report, and the mortality rate is 0.6 percent, India expects at least 77million people to be infected and 4.2 million die.

Dan Weinberger, an associate professor of epidemiology at Yale University School of public health, believes that even large-scale serological surveys have limitations. India has a large population base and a significant population diversity, so that no serological survey can cover all areas. But the survey provides a new idea and limits for calculating real death figures.

In addition to three nationwide serum surveys, Indian researchers conducted 61 local level serum surveys. The results showed that the positive rate of serum in different regions and population was very different.

The higher the color, the higher the positive rate of the 61 local level serum in India

"If the positive rate of serum is true, will there be a new outbreak in India," a high praise comment later in the New York Times article said? Can high serum positive rates not significantly inhibit the second wave of the epidemic in India? Is the high serum positive rate exactly mean that the mortality rate is low in the population, and what are the possible explanation factors Official data tend to lag, at least weeks behind. It's a complex subject that requires some context, and I think this article can provide more. To avoid our complacency, please note that in April alone, 1100 people died in New York state alone. "

Indian officials refuted the report as "unfounded"

According to the Indian New Delhi television station (NDTV) on May 27, LAV Agarwal, Joint Secretary of the Ministry of health, said the New York Times report was groundless and absolutely wrong“ From the very beginning, we have tried to report all confirmed and deaths openly and transparently, and there is no possibility of concealment. It is also important to understand the path of virus transmission and act. "

Vinod Kumar Paul, head of the COVID-19 special task force in India, said the New York Times said the death toll of India's new crown was severely underestimated and concealed. There was no evidence to support it. The estimate is distorted, Vinod Kumar Paul said.

Paul said the number of infections could be many times as many times as the number of positive people tested, but it was impossible for the deaths to be.

"There may be delays in reporting deaths, but no state or central government will conceal it," he said. If I measure New York in the same way, it's 50000 people who die, and they report 16000, so this is a distorted approach.

Our death toll accounts for 0.05 percent of the number of people infected, but the American newspaper says it is 0.3 percent, and why does it account for 0.3 percent of the number of people infected? There is no basis at all. Five people (journalists) gathered, called each other, and then said the number. That's how the report is done. "

Paul also noted that mortality tracking systems have been established in India, and that the calculation of deaths will be more accurate and will not have major problems.

Why is it so difficult to count real data?

Since the new crown epidemic, the number of confirmed diagnosis and death reported by all countries has attracted widespread attention. People judge the governance ability of governments by ranking and comparing data.

Last August, a scientific Bulletin released by WHO on COVID-19's fatality rate said that the new crown mortality rate is indeed an important indicator. It helps us understand the severity of the disease, identify high-risk groups, and assess the quality of health care.

Mortality includes two dimensions:

One is the infection mortality ratio (IFR), which is used to estimate the proportion of all infected people.

The second is case mortality ratio (CFR), which is used to estimate the proportion of deaths in confirmed cases.

But unfortunately, we will never get an absolutely accurate data.

In order to accurately measure IFR, we must know the complete information on the number of infections and deaths of the disease, the WHO briefing said. In the early stages of the pandemic, most countries found the number of confirmed and dead based on monitoring systems, which in fact estimated CFR. So the estimates for CFR vary significantly across countries - from less than 0.1% to more than 25%.

As early as April last year, the BBC discussed why the new crown mortality rate in different countries is so different.

The article points out that different countries have different definitions of mortality, some are based on IFR and others are CFR. Secondly, the range of the population will affect the final results. Experts believe that the lack of a wide range of nucleic acid / antibody testing capabilities in most countries is the main cause of mortality differences among countries. In addition, is the cause of death really caused by the new crown? Or is it caused by other basic diseases or complications? What if the patient didn't have a test, he died? It takes time to judge the cause of death, and the calculation methods of different countries are different. The patient conceals the condition and samples the different age groups, also affects the calculation of mortality.

The World Health Organization believes that the real level of infection in the new crown is largely underestimated, and a considerable proportion of infected people are not tested. Patients with light illness usually do not visit medical institutions, people in remote areas are unable to access detection services, cases are misdiagnosed as influenza or other diseases with similar clinical manifestations.

In addition, the differences in politics, population and medical service system will also affect the final mortality statistics and reports.

Under the influence of many complex factors, the existing estimation is only for reference. How to deal with the epidemic more effectively is perhaps the higher priority problem.