As many as 40-45% of the COVID positive cases may be asymptomatic finds researchers at the Scripps Research Translational Institute in La Jolla, California, according to their recent study published in the journal Annals of Internal Medicine.
The authors stated that the likelihood of about 45% getting asymptomatically infected with SARS-CoV-2 virus might reveal a greater potential than previously estimated to spread silently and deeply through human populations.
Recently, WHO also published a summary on the transmission of COVID19 studying symptomatic, pre-symptomatic and asymptomatic transmission. The study estimated that up to 40% of the COVID infections could be transmitted by people who have the virus but no symptoms (asymptomatic patients).
The Scripps study analysed a wide range data of asymptomatic individuals from over 16 cohorts between 19 April to 26 May including city residents, health care workers, homeless refugees, obstetric patients, nursing home members, aircraft crew, passengers on cruise ships, and inmates in correctional facilities. The study noted a varying rate of asymptomatic or presymptomatic cases in each cohort.
It is difficult to tell the difference between people who are presymptomatic and will later go on to develop symptoms of COVID-19 and those who will remain asymptomatic.
“The simple solution to this conundrum is longitudinal testing — that is, repeated observations of the individual over time,” the authors said.