| Incomplete symptom reporting or restrictive symptom assessment |
Diamond Princess cruise ship
11
- Sakurai A
- Sasaki T
- Kato S
- et al.
Natural history of asymptomatic SARS-CoV-2 infection.
|
311 (44%) of 712 individuals |
>14 days |
Cough, dyspnoea, chest pain, sore throat, nasal discharge |
Symptoms prospectively assessed |
Skilled nursing facility in the USA
12
- Patel MC
- Chaisson LH
- Borgetti S
- et al.
Asymptomatic SARS-CoV-2 infection and COVID-19 mortality during an outbreak investigation in a skilled nursing facility.
|
13 (39%) of 33 individuals |
30 days |
Typical (fever, cough, shortness of breath, hypoxia) and atypical (sore throat, nasal congestion, diarrhoea, decreased appetite, chills, myalgias, headaches, new onset confusion) symptoms |
Authors note that memory impairment might have resulted in an overestimation of the asymptomatic rate |
Call centre in South Korea
9
- Shin Young P
- Young-Man K
- Seonju Y
- et al.
Coronavirus disease outbreak in call center, South Korea.
|
4 (4%) of 97 individuals |
14 days |
Not defined |
Face-to-face interviews for symptom assessment |
Vo, Italy
13
- Lavezzo E
- Franchin E
- Ciavarella C
- et al.
Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo’.
|
34 (42%) of 81 individuals |
12 days |
Fever or cough or at least two of the following symptoms: sore throat, headache, diarrhoea, vomit, asthenia, muscle pain, joint pain, loss of taste or smell, or shortness of breath |
Mix of prospective and retrospective symptom assessment |
Pregnant women presenting for delivery in New York City, NY, USA
14
- Sutton D
- Fuchs K
- D’Alton M
- Goffman D
Universal screening for SARS-CoV-2 in women admitted for delivery.
|
26 (79%) of 33 individuals |
Variable, median follow-up 2 days |
Fever or other symptoms of COVID-19 |
Symptom screen on admission; unclear how symptoms were assessed during follow-up period |
| Cross-sectional studies or inadequate follow-up |
Homeless shelters in Boston, MA, USA
15
- Baggett TP
- Keyes H
- Sporn N
- Gaeta JM
Prevalence of SARS-CoV-2 infection in residents of a large homeless shelter in Boston.
|
129 (88%) of 147 individuals |
None |
Cough, shortness of breath, other symptoms optional |
Single timepoint symptom screen |
Iceland
16
- Gudbjartsson DF
- Helgason A
- Jonsson H
- et al.
Spread of SARS-CoV-2 in the Icelandic population.
|
525 (43%) of 1221 individuals |
None |
“cough, fever, aches, and shortness of breath” |
Single timepoint symptom screen |
Nursing home in the USA
17
- Arons MM
- Hatfield KM
- Reddy SC
- et al.
Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility.
|
3 (6%) of 48 individuals |
7-day prospective follow-up |
Comprehensive |
Nurse-administered symptom assessments on days 1 and 7 |
Antarctic-bound cruise ship
10
COVID-19: in the footsteps of Ernest Shackleton.
|
104 (81%) of 128 individuals |
None |
Not described |
Mechanism of symptom assessment not clear |
Long-term care facilities in the USA
18
High proportion of asymptomatic SARS-CoV-2 infections in 9 long-term care facilities, Pasadena, California, USA, April 2020.
|
257 (41%) of 631 individuals |
14 days before testing |
Comprehensive |
Symptom assessments by case reports |
USS Theodore Roosevelt aircraft carrier
19
- Payne DC
- Smith-Jeffcoat SE
- Nowak G
- et al.
SARS-CoV-2 infections and serologic responses from a sample of US Navy Service Members—USS Theodore Roosevelt, April 2020.
|
44 (18%) of 238 individuals |
Not well defined |
Comprehensive |
Convenience sample; retrospective symptom assessment |
| Serological study |
Spain
20
- Pollán M
- Pérez-Gómez B
- Pastor-Barriuso R
- et al.
Prevalence of SARS-CoV-2 in Spain (ENE-COVID): a nationwide, population-based seroepidemiological study.
|
680 (29%) of 2390 participants (of 51 958 participants screened with immunoassay) |
Single timepoint but serological survey |
Fever, chills, severe tiredness, sore throat, cough, shortness of breath, headache, anosmia or ageusia |
Antibody responses of asymptomatic individuals with SARS-CoV-2 infection currently poorly defined |
