A new study says that 86 percent of people infected with COVID-19 are walking around undetected. The researchers called them "stealth" cases. Six of every seven cases – meaning 86 percent— were not reported in China before travel restrictions were imposed, posing tremendous danger spreading the virus, it said.

GeekWire reported that co-author Jeffrey Shaman of Columbia University Mailman School said "It's the undocumented infections which are driving the spread of the outbreak," said, according to. The researchers used computer modeled tracking of infections before and after the travel ban in Wuhan of China, the place where the outbreak started. The study was published on Monday in the journal Science.

Coronavirus
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Stealth cases

Further the study highlights that undocumented infections with no or mild symptoms – stealth cases as the researchers termed them -- acted on the two thirds of reported patients, said many reports on such 'spreading in the shadows'.

At a press briefing in the White House(US) on Saturday, Dr. Deborah Birx, the US coronavirus response coordinator questioned whether they are "a group that are potentially asymptomatic and spreading the virus," and explained that one has to understand how many people are asymptomatic and are transmitting it. The present study possibly answers her question.

WHO had cleared its stand in February while acknowledging the asymptomatic spreading, that they don't play a major role in the transmission of the outbreak.

Another report added Shaman saying, "The majority of these infections are mild, with few symptoms at all, people may not recognize it, or they think they have a cold." These stealth cases would continue to spread, and is a challenge to contain the outbreak.

"It will continue to present a major challenge to the containment of this outbreak going forward," Shaman said, adding that it underscores the importance of restrictions on movement in hard-hit regions.

The confirmed cases of COVID-19 across the world stands at 198,155 as of Wednesday noon and caused more than 7,950 deaths, with 81,950 recoveries.