40% of cases are asymptomatic

The Kovid-19 The asymptomatic form can also be takenAcute form Can be fatal according to those affected. Cases that do not have a confirmed symptom, i.e. those that do not develop any symptoms, are not a burden to hospitals, They can transmit coronavirus Without knowing. Evaluating the proportion of asymptomatic cases in infected people is valuable epidemiological data.

Many estimates of asymptomatic cases have been made through studies based on previously published scientific literature for meta-analyzes and statistical analyzes. Most recently published Jama Network On December 14, 2021, scientists from the Beijing School of Public Health included 94 different studies written in Chinese and English, counting over 29 million people in total. They estimate that 40.5% of confirmed Kovid-19 cases are asymptomatic.

40.5% of confirmed Kovid-19 cases are asymptomatic

In which Meta-analysis, Scientists have included patients who are truly asymptomatic and in the pre-symptomatic stage, i.e. those who do not show symptoms during screening then develop them later. The percentage of asymptomatic cases was calculated for two large cohorts: persons to be tested and persons with a confirmed infection.

For the first ensemble, 94 studies were examined for 11,516 asymptomatic 29,776,306 million individuals. Taken together, the percentage of asymptomatic individuals in the screening population is 0.25%.

The analysis on the confirmed cases of Kovid-19 was conducted on a small sample: 77 studies for 19,884 Kovid-19 cases, including 11,069 asymptomatic forms. Overall, the percentage of cumulative asymptomatic form in cases Kovid-19 confirmed Is 40.5%.

Limited statistical data

Depending on the sub-population being considered, the percentage will vary. For example, 3.69% of those over 60 who have been screened have asymptomatic; 60.21% of children under the age of 20 with certified Kovid-19 are asymptomatic.

Like all meta-analyzes, these analyzes are purely statistical and do not necessarily generalize to the general population. In this case, the researchers observed that each study looked at specific populations such as caregivers or seniors and calculated the asymptomatic share according to different criteria.

Kovid-19: 17 to 25% are asymptomatic individuals

Article published by Julian Hernandez on October 5, 2020

Recent meta-analysis responds somewhat more accurately to the question of the number of asymptomatic individuals and their role in virus transmission.

From the beginning Pandemic, This is the question that haunts scientists. How many asymptomatic people are there and what is their role in virus transmission. Recent meta-analysis Published in PLoS Beauty And conducted by researchers at the Swiss Institute of Social and Preventive Medicine, which answers this question somewhat more accurately.

17 to 25% of asymptomatic individuals

The researchers searched for a variety Database Scientists with information answering their question published between March 25 and June 10. Studies of individuals diagnosed with SARS-CoV-2 RT-PCR It records follow-up and symptomatic status at the beginning and end of follow-up studies or Modification Are included. A total of 94 studies were finally selected as they met the inclusion criteria.

The proportion of people infected with SARS-CoV-2 and the total number of those who remain asymptomatic throughout the infection is 17 to 25%. Based on these results, the course of the disease of the future case is between 3 and 67%. To replace the specific bias of the various studies, the scientists carried out other analyzes taking into account only seven studies related to the population. Here, we look at the proportion of asymptomatic individuals ranging from 26 to 37% and the estimated efficiency between 24 and 38%.

Limited transmission capacity

However, in line with this data, it appears Pollution People without symptoms are vulnerable. The authors noted a 75% (with a very wide confidence interval, between -90 and + 27%) reduced infection risk after consultation with the asymptomatic person, compared with the asymptomatic person. In modeling studies, presymptomatic individuals are more likely Is contagious. Although this study has several limitations, the design of the included studies is not designed to estimate the ratio of asymptomatic infections with SARS-CoV-2 and there is a risk of selection bias. Similarly, the researchers did not take into account the possibility of false negatives, which underestimated the proportion of asymptomatic individuals.