Covert coronavirus infections could be seeding new outbreaks - Nature (news)
Bron: 20-03-2020 https://www.nature.com/articles/d41586-020-00822-x(link is external)
Jane Qiu
Key message
- Covert cases could represent 18-59% of all infections.
- Viral shedding most likely present in asymptomatic or mildly symptomatic
- Patients can be highly contagious when they have mild or no symptoms.
Details
Covert cases estimate:
- A developed model using clinical data from 26,000 laboratory-confirmed cases reported to the health commission of Wuhan: estimates of 37,400 people (59%) with the virus in Wuhan whom authorities didn’t know about.
- 3,711 passengers and crew members on Diamond Princess: 18% of some 700 infected individuals never showed symptoms. This is a special population with mostly elderly people.
- 565 Japanese citizens, evacuated from Wuhan in early February, 31%, never developed symptoms.
Viral shedding:
- 9 cases in Germany: High levels of the virus in throat swabs early in illness, when symptoms were mild.
- In China: High viral loads detected in 17 people with COVID-19 soon after they became ill. Another infected individual never developed symptoms but shed a similar amount of virus.
- Patients can be highly contagious when they have mild or no symptoms.
- Underestimate of children’s susceptibility to the virus: Of 700 infected children in China 56% had mild or no symptoms.