Asymptomatic Transmission of COVID-19 Accounts for 59% of Coronavirus Infections
Health Editor’s Note: When at least 59% of those who have no symptoms of coronavirus it is impossible to know (without some sort of test which most of us do not receive) who is infected. Thus, properly wearing the masks, physically distancing, avoiding any group, staying home if you are sick, washing your hands all the time, never touching your face, nose, eyes, or mouth without first thoroughly washing your hands, staying home unless you have a necessity to go out, are all essential to our lives. Get the vaccine when it is offered to you and be sure to take the second vaccine when it is due. Be proactive and contact your local health department in your country to find out what the exact process is for receiving vaccinations.
It will take many more weeks before we will start seeing some protection by the vaccination process. Sluggishness (very irritating) of getting those vaccines given is harmful to the ‘getting rid of this COVID-19 pandemic,’ but with each person who is vaccinated and with each time you keep yourself safe, you can make a dent in the pandemic and we can persevere and survive to live the days we are supposed to have….Carol
IMPORTANCE Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiology of coronavirus disease 2019 (COVID-19), is readily transmitted person to person. Optimal control of COVID-19 depends on directing resources and health messaging to mitigation efforts that are most likely to prevent transmission, but the relative importance of such measures has been disputed.
OBJECTIVE To assess the proportion of SARS-CoV-2 transmissions in the community that likely occur from persons without symptoms.
RESULTS The baseline assumptions for the model were that peak infectiousness occurred at the median of symptom onset and that 30% of individuals with infection never develop symptoms and are 75% as infectious as those who do develop symptoms. Combined, these baseline assumptions imply that persons with infection who never develop symptoms may account for approximately 24% of all transmission. In this base case, 59% of all transmission came from asymptomatic transmission, comprising 35% from presymptomatic individuals and 24% from individuals who never develop symptoms. Under a broad range of values for each of these assumptions, at least 50% of new SARSCoV-2 infections was estimated to have originated from exposure to individuals with infection but
CONCLUSIONS AND RELEVANCE In this decision analytical model of multiple scenarios of proportions of asymptomatic individuals with COVID-19 and infectious periods, transmission from asymptomatic individuals was estimated to account for more than half of all transmissions. In addition to identification and isolation of persons with symptomatic COVID-19, effective control of spread will require reducing the risk of transmission from people with infection who do not have
symptoms. 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.
JAMA Network Open. 2021;4(1):e2035057. doi:10.1001/jamanetworkopen.2020.35057
Carol graduated from Riverside White Cross School of Nursing in Columbus, Ohio and received her diploma as a registered nurse. She attended Bowling Green State University where she received a Bachelor of Arts Degree in History and Literature. She attended the University of Toledo, College of Nursing, and received a Master’s of Nursing Science Degree as an Educator.
She has traveled extensively, is a photographer, and writes on medical issues. Carol has three children RJ, Katherine, and Stephen – one daughter-in-law; Katie – two granddaughters; Isabella Marianna and Zoe Olivia – and one grandson, Alexander Paul. She also shares her life with her husband Gordon Duff, many cats, and two rescues.