Scientists believe up to 1 in 4 coronavirus carriers could be asymptomatic

Much of the world is currently in lockdown and social distancing has become an all too familiar term in our vocabulary. There’s a reason why.

Robert Redfield, the director of the Centres for Disease Control and Prevention, confirmed that 25 percent of coronavirus infected individuals don’t present any symptoms or fall ill but can still transmit the virus to others.


Leading health professionals confirm that asymptomatic carriers of coronavirus may be the cause of the pandemic’s fast spread across the globe.

Speaking to NPR, Redfield described that they had “pretty much confirmed” that “a significant number of individuals that are infected actually remain asymptomatic,” arguing that these cases are most likely contributing to the virus’ rapid global spread.

Back in February, a study of evacuees from Wuhan found that 30.8 percent of people who tested positive showed no symptoms. The first case of asymptomatic transmission was confirmed back in February also, where a 20-year-old woman from Wuhan passed the virus onto five other family members, but never became physically sick herself.

Accord to Redfield, people who have contracted the virus are at their most infectious 48 hours before symptoms appear. This is referred to as presymptomatic transmission. Research from Singapore has found that from a sample of 157 local cases, 10 involved presymptomatic transmission, with scientists concluding that exposure to the virus occured within Redfield’s 48-hour time frame.

It is important to keep in mind, however, that the average symptom onset takes five days post-infection. 

Research published in The Lancet and paediatric infectious diseases expert John Williams have confirmed that children have a much higher risk of being asymptomatic carriers. The Lancet reports that out of a study of 36 children who tested positive for coronavirus, half had “mild disease with no presenting symptoms.”

There are suggestions that wearing face masks may assist in reducing presymptomatic transmission, however, the most effective methods are maintaining a 1.5m distance from others, avoiding touching the face, staying home, and practising good hygiene.

While this information is daunting and this period is challenging for everyone, it’s important to stay calm, positive, and safe. This is all temporary, and our scientists and health-care workers are working their hardest to combat this pandemic. Being responsible is the best thing we can all do right now. So maybe think twice before you go for a cheeky hang at your mate’s place this week. Wash your hands, don’t touch your face, and please dear god just stay at home.