A new study estimates that people who do not exhibit any symptoms will infect about 10% of the infections. As a result of this study, you get the answer why do you need to wear a mask when going out?
Research has estimated the frequency of transmission of the coronavirus of the infected person before symptoms arise.
The corona virus (SARS-CoV-2) is a new virus, so scientists are urgently looking to understand how it works. Find out from the research to guide disease response and help authorities design interventions and preventive measures.
Scientists from the University of Texas in Austin are trying to find out how quickly viruses can spread. Their recent findings are awaiting publication in Emerging Infectious Diseases.
1. Serial time
The study involved scientists from the US, France, China and Hong Kong. They are especially interested in finding out how quickly SARS-CoV-2 can spread.
When estimating the spread rate of the virus, the researchers paid attention to two main factors:
+ Number of people infected – the number of people who can be infected from a person infected with the virus.
+ Serial time – the time from when a person develops symptoms of the disease until the second person is infected and develops symptoms.
The researchers found that the serial duration of SARS-CoV-2 was about 4 days.
They explained that the shorter the serial time, the more difficult the disease would be to control and the faster it spread.
“Ebola, with a series of weeks, is much easier to control than flu, with a series of days. Health authorities responding to Ebola have more time to identify and isolate cases before they infect others, ”explains Professor Lauren Ancel Meyers from the University of Texas at Austin. “The data shows corona virus can spread like flu. This means we need to act quickly and positively to contain this new threat. ”
2. Silent transmission
Silent transmission occurs when a person who is infected with the virus shows no symptoms but spreads the virus to others. The new study is one of the first studies on this phenomenon of SARS-CoV-2.
Scientists studied 450 case reports from 93 Chinese cities.
They have found the most compelling evidence so far that infected people can transmit the virus before symptoms begin, a scenario called symptomatic transmission.
The authors estimated that those who had not developed symptoms transmitted to about 10% of the cases in the study.
It is not known how asymptomatic or asymptomatic transmission plays a role in the corona virus pandemic. But these findings can help make better predictions about how the virus works.
3. Other questions related to COVID19
Some people infected with SARS-CoV-2 have no symptoms and it is likely that only 1-3% of people are called asymptomatic carriers.
However, in all Covid-19 cases, there is a delay between infection and the onset of symptoms, which is called the incubation period.
The time from infection to symptoms can range from 2 to 14 days.
A recent study of incubation period has concluded that the average time to develop symptoms is 5.1 days and 97.5% of people develop symptoms within 11.5 days.
Understanding the degree of virus transmission from pre-symptomatic people is important.
“This provides evidence that extensive control measures, including quarantine, quarantine, school closures, travel restrictions and the cancellation of crowded gatherings are essential. Transmission from asymptomatic people certainly makes it harder to stop the disease. ”
Prof. Lauren Ancel Meyers explains: “The authors of the study also made it clear that, as the number of people infected with the virus increases, their latest estimates may change. With a team of scientists working around the clock to understand how the virus works, we will need to wait for more data before we can draw firm conclusions about the silent transmission rate.“
As such, wearing a mask is essential to avoid contracting Covid19 from a neighbor or the opposite person if that person is infected with Covid19 (but he still has not had the expression of Covid19 because he may be in incubation period).
Therefore, you should wear a mask when going out, especially when you go to public places. Thereby, it not only helps you prevent and combat COVID19, but also helps protect your loved ones and the community against this pandemic.
As of March 19, 2020, the Vietnamese government requires all citizens to wear masks when visiting public places.
(Source: WHO and Vietnam Ministry of Health)