Coronavirus spreads quickly and sometimes before people have symptoms, study finds.

The latest research confirms fears that the Coronavirus spreads quickly because people are often not sick.

A new study published this week looks into how the Covid-19 virus spreads, science daily reported.

We wanted to share this and how you can use this information to understand what is going on.

According to researchers at The University of Texas at Austin, the Covid-19 can spread quickly between chains of people.

They found that time between cases in a chain of transmission is less than a week. They also found that more than 10% of patients are infected by somebody who has the virus but does not yet have symptoms.

The paper published this week in the journal Emerging Infectious Diseases, a team of scientists from the US, France and China calculated the serial interval of the virus.

The scientists look at the time it takes for symptoms to appear in two people with the virus: the person who infects another, and the infected second person.

Researchers found that the average serial interval for the novel coronavirus in China was approximately four days. This also is among the first studies to estimate the rate of asymptomatic transmission- that is from a person who has no symptoms.

The speed of an epidemic depends on two things — how many people each case infects and how long it takes for infection between people to spread.

The first quantity is called the reproduction number; the second is the serial interval.

The problem with COVID-19 is that the virus has a short serial interval. This explains why the virus is spreading so quickly and could be difficult to stop, the researchers said.

“Ebola, with a serial interval of several weeks, is much easier to contain than influenza, with a serial interval of only a few days. Public health responders to Ebola outbreaks have much more time to identify and isolate cases before they infect others,” said Lauren Ancel Meyers, a professor of integrative biology at UT Austin.

“The data suggest that this coronavirus may spread like the flu. That means we need to move quickly and aggressively to curb the emerging threat.”

Meyers and her team examined more than 450 infection case reports from 93 cities in China and found the strongest evidence yet that people without symptoms must be transmitting the virus, known as pre-symptomatic transmission.

According to the paper, more than 1 in 10 infections were from people who had the virus but did not feel sick.

The new evidence is scary, as it confirms the fear that many people carry Covid-19 and pass it onto many people without any indication they are sick at all.

“This provides evidence that extensive control measures including isolation, quarantine, school closures, travel restrictions and cancellation of mass gatherings may be warranted,” Meyers said. “Asymptomatic transmission definitely makes containment more difficult.”

Infection case reports are based on people’s memories of where they went and whom they had contact with. If health officials move quickly to isolate patients, that may also skew the data.

“Our findings are corroborated by instances of silent transmission and rising case counts in hundreds of cities worldwide,” Meyers said. “This tells us that COVID-19 outbreaks can be elusive and require extreme measures.”

Zhanwei Du of The University of Texas at Austin, Lin Wang of the Institut Pasteur in Paris, Xiaoke Xu of Dalian Minzu University, Ye Wu of Beijing Normal University and Benjamin J. Cowling of Hong Kong University also contributed to the research. Lauren Ancel Meyers holds the Denton A. Cooley Centennial Professorship in Zoology at The University of Texas at Austin.

The research was funded by the U.S. National Institutes of Health and the National Natural Science Foundation of China.