Med tanke på hur viruset smittar är det inte svårt att förstå att asymptomatisk smitta har funnits ovanlig.
Den som inte har några symptom hostar och nyser inte lika mycket som den som har symptom.
https://www.folkhalsomyndigheten.se/smittskydd-beredskap/utbrott/aktuella-utbrott/covid-19/fragor-och-svar/
"Smittspridning
Hur smittar covid-19?Coronaviruset (SARS-CoV-2) som orsakar sjukdomen covid-19 smittar i första hand mellan människor genom så kallad droppsmitta. Det vill säga att smitta överförs till slemhinna i ögon, näsa eller mun från droppar som sprids i luften när en sjuk person hostar eller nyser.
Läs mer om hur coronaviruset smittar.
Kan man bli smittad av en person som har covid-19 men som inte har några symtom?Utifrån den erfarenhet som finns just nu, av covid-19 och andra liknande sjukdomar, är bedömningen att smittspridningen från personer utan symtom står för en mycket begränsad andel.
Läs mer om smitta utan symptom."
Hur kan då en asymptomatisk smitta? Tja, genom saliv, snor i sängen där personen sover, genom ställen personer tar på om denne har pillat i sitt saliv och snor och inte tvättat händerna. Eller genom kyssar?
https://www.healthline.com/health-news/even-asymptomatic-people-can-spread-covid-19-within-a-room#Keeping-the-people-around-you-safe
"Zong and his team took samples from the patients’ surroundings, as well as the air, in six negative pressure rooms.
These rooms were occupied by 13 COVID-19 patients, including 2 asymptomatic ones."
"Of the 112 surface samples taken, 44 (39.3 percent) were found to be positive for the SARS-CoV-2 virus.
In addition, the rooms of the patients with symptoms ranging from none to mild were “extensively contaminated,” according to Zong and his team.
In the room of one patient in particular who was asymptomatic, positive samples were found in four locations, including the patient’s bed rail, bedsheets, and pillow, and the room’s air exhaust outlet.
The virus wasn’t detected in any of the air samples, however."
"Brian Labus, PhD, MPH, an assistant professor in the School of Public Health at the University of Nevada, Las Vegas, said that we currently know that asymptomatic and presymptomatic people can spread the virus.
Asymptomatic people test positive for the virus without ever showing any symptoms.
Presymptomatic people will eventually develop symptoms, but aren’t showing them yet.
Labus noted that up to half of people who contract the virus may be asymptomatic carriers of the disease.
However, we still don’t have a good understanding of how infectious people are if they’re not showing symptoms, he said.
This makes mask mandates an important part of preventing its spread, in his opinion.
“If everyone is wearing a mask, that decreases the chance that an asymptomatic person can spread it to someone else,” said Labus."