Scientists are adding new answers daily to the question of how novel coronavirus spreads. US CDC website says that the virus is 'thought' to spread mainly from person-to-person, in close contact with one another (within about 6 feet) and also when respiratory droplets produced from an infected person's cough or sneeze land in the mouths, noses or eyes of uninfected people. CDC also says, "some spread might be possible before people show symptoms."
Such "asymptomatic" spreading of the virus can't be identified without COVID-19 test. But, testing would only be done if there are symptoms. This is the paradox. A virus that spreads in the shadows. CDC website says that asymptomatic spreading "is not thought to be the main way the virus spreads."
At a press briefing at the White House(US) on Saturday, Dr. Deborah Birx, the admin's coronavirus response coordinator said that they were trying to understand those under the 20 without significant symptoms. "Are they a group that are potentially asymptomatic and spreading the virus," she questioned and said that one has to understand how many people are asymptomatic and are transmitting it.
Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota said in a statement to CNN that asymptomatic transmission likely plays an important role in spreading novel coronavirus.
Microsoft founder and philanthropist Bill Gates wrote in an article, "There is also strong evidence that it can be transmitted by people who are just mildly ill or even presymptomatic. That means COVID-19 will be much harder to contain than the Middle East respiratory syndrome or severe acute respiratory syndrome (SARS), which were spread much less efficiently and only by symptomatic people."
Dr. Sandra Ciesek, director of the Institute of Medical Virology in Frankfurt, Germany had tested 7 positive cases of COVID-19 among 24 passengers who had just flown in from Israel on Tuesday, March 10. But four of them had no symptoms and Ciesek noted that viral load from the sample of asymptomatic patients were higher than the ones who had symptoms, as reported by CNN. A higher load means that one is more likely to spread the virus to other people.
In another paper, Ciesek and colleagues concluded after a study done on evacuating 126 people who came from Wuhan to Frankfurt, "a symptom-based screening process was ineffective in detecting SARS-CoV-2 [novel coronavirus] infection in 2 persons who later were found to have evidence of SARS-CoV-2 in a throat swab. We discovered that shedding of potentially infectious virus may occur in persons who have no fever and no signs or only minor signs of infection."
The AFP report on Elizabeth Schneider(37), living in Seattle didn't have the most common symptoms like a cough or shortness of breath but had been tested positive for novel coronavirus. The test result came as a "pleasant surprise" only after she recovered from "flu like symptoms." People like Elizabeth could spread the virus until tested for one.
People who are ill can obviously be identified and isolated resulting in controlling an outbreak, which is not the entire case. Dozens of studies on the subject have been published. However, it remains a questionable thing that officials are so sure that asymptomatic spread is not a major driver of COVID-19.