How high is the infection rate and death rate of the new crown? The study combines data from 45 countries and regions to obtain results-IT and Health-cnBeta.COM

In the penultimate month of 2020, the cumulative number of confirmed cases of new coronary pneumonia worldwide exceeded 47 million. As the Northern Hemisphere enters fall and winter, the epidemic in some countries and regions has worsened again.How high is the level of transmission of the new coronavirus and the severity of the infection? Today, the leading academic journal “Nature” published an online research article in the form of “Quick Article Preview”.Scientists from the University of Cambridge in the United Kingdom and the Pasteur Institute in France combined epidemiological data from 45 countries and regions to make calculations.

The researchers noted that the inconsistency of the existing data makes it difficult to estimate the scale of the new coronavirus epidemic and the severity of the infection. The number of deaths is often used as a key indicator to assess the transmission rate and severity of infections, but due to the large differences in death rates among the elderly reported by countries, simply comparing the total number of deaths can give a wrong understanding of the basic level of transmission of the new coronavirus.

Another indicator is the seroprevalence rate, that is, how many people have developed antibodies against the new coronavirus through serological surveys. Antibodies indicate whether a person has been infected with the new coronavirus in a given period, so it can indicate the infection rate of the entire population. But this type of data is affected by the detection capabilities.

In this study, in order to more accurately assess the transmission rate and mortality trends of new coronavirus infections, the research team used a combination of new official coronary pneumonia death data from 45 countries and 22 serology national. Based on the results of the survey, a model framework was established.

“Our model shows that among people under the age of 65, the mortality rate of the new crown by age is very constant in all countries and regions, and can be used as a reliable indicator of the number of infections in the entire population. In the event that most infections go undetected, “This is very important.” Said lead study author Professor Megan O’Driscoll.

Using only death data for the age group under 65, the model estimates that as of September 1 of this year, in these countries and regions evaluated, an average of 5% of the population was infected with the new corona virus. The results of the model also indicated that in some South American countries, higher transmission may have occurred.

The researchers estimated from infection to death (IFR), the proportion of people who could die from the virus. In different countries / regions, the proportion of deaths caused by the new crown in the age group of 5-9 years is always the lowest. For every 5 years of age, the death rate from infection increases by 0.59%.

The model estimates the death rate from COVID-19 in 45 countries and regions, including China (Image source: Reference[1]; Click to enlarge the image)

According to IFR, the researchers calculated the expected number of deaths for people 65 and older and compared the estimated number with the reported number of deaths in this age group, and found differences in the numbers between countries. For example, in the UK, Canada, Sweden and other countries, the reported number of deaths from the new crown of people over 65 is higher than expected due to multiple outbreaks in nursing homes. In contrast, some countries in South America and Asia reported significantly fewer deaths over 65 years than expected. The author looked at a possible explanation that the number of deaths from new coronary pneumonia in the elderly was not reported.

In the abstract of the article, the researchers said that monitoring the level of transmission of the new coronavirus and the severity of the infection is an important means of guiding the response to this epidemic. This model framework can help various countries and regions assess the progress of the new corona epidemic. We also hope that this information will help countries and regions of the world to prevent and control the epidemic, and get the world back on track as soon as possible.