tech2 News StaffJan 13, 2021 10:01:29 IST
A model developed by researchers at the USCenters for Disease Control and Prevention shows that people who don't show symptoms for Covid-19 are responsible for over half of all the cases of SARS-CoV-2 transmission.The data, collected from multiple Chinese studies, was used to determine the proportion of presymptomatic people (who shed virus before developing symptoms), asymptomatic and symptomatic people exist in the population.Thefindings from the model were published on 7 Jan in the journal JAMA Network Open. The model reiterates what earlier studies havefound, indicating that asymptomatic individualsare contributing to the rapidtransmission of Covid-19.
According to therecentmodel, 59 percent of all transmissions of the novel coronavirusstarts withasymptomatic individuals, of which 35 percent of new casesbeginwithpresymptomatic people, who infect others beforeany symptoms of Covid-19 appear.
"30 percent of individuals with infection never develop symptoms and are 75 percent as infectious as those who do develop symptoms," the authors wrote in the study."These findings suggest that measures such as wearing masks, hand hygiene, social distancing, and strategic testing of people who are not ill will be foundational to slowing the spread of Covid-19 until safe and effective vaccines are available and widely used," they added.
Airlines are trying to convince a frightened public that measures like mandatory face masks and hospital-grade air filters make sitting in a plane safer than many other indoor settings during the coronavirus pandemic, but it isnt working. AP
Asymptomatic transmission has been the subject of studies from early daysof the Covid-19 pandemic. A study published on 12 March in peer-reviewed medical journalEurosurveillance, found that 17.9 percent of the 3,711 passengers and crew members aboard the Diamond Princess cruise ship thesite of a majorCovid-19 superspreader event were asymptomatic. Even if the symptomatic caseswere isolated quarantined till they recovered or tested negative for the coronavirus "a vast outbreak"would haveunfolded anyway, the study concluded.
'Silent transmission' was the word usedin a6 July study in Proceedings of the National Academy of Sciences, referring tothe phenomena of Covid-19 infections by asymptomatic and presymptomatic individuals.TherecentCDCanalysis adds to mounting evidence that testing andisolating symptomatic Covid-19 patients alone won't curbthespreadof SARS-CoV-2 in the community.