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. 2021 Apr 9;13(2):340-347.
doi: 10.3390/idr13020033.

Asymptomatic Cases, the Hidden Challenge in Predicting COVID-19 Caseload Increases

Brett Snider  1 , Bhumi Patel  1 , Edward McBean  1
Affiliations

Asymptomatic Cases, the Hidden Challenge in Predicting COVID-19 Caseload Increases

Brett Snider et al. Infect Dis Rep. .

Abstract

The numbers of novel coronavirus cases continue to grow at an unprecedented rate across the world. Attempts to control the growth of the virus using masks and social-distancing, and, recently, double-masking as well, continue to be difficult to maintain, in part due to the extent of asymptomatic cases. Analyses of large datasets consisting of 219,075 individual cases in Ontario, indicated that asymptomatic and pre-symptomatic cases are substantial in number. Large numbers of cases in children aged 0-9 were asymptomatic or had only one symptom (35.0% and 31.4% of total cases, respectively) and resulted in fever as the most common symptom (30.6% of total cases). COVID-19 cases in children were more likely to be milder symptomatic with cough not seen as frequently as in adults aged over 40, and past research has shown children to be index cases in familial clusters. These findings highlight the importance of targeting asymptomatic and mild infections in the continuing effort to control the spread of COVID-19. The Pearson correlation coefficient between test positivity rates and asymptomatic rates of -0.729 indicates that estimates of the asymptomatic rates should be obtained when the test positivity rates are lowest as the best approach.

Keywords: COVID-19; asymptomatic; caseloads; pre-symptomatic; transmission-risk.

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Conflict of interest statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Figures

Figure 1
Figure 1
Frequency of symptoms (cough, headache, fatigue, fever, sore throat and shortness of breath) and asymptomatic cases.
Figure 2
Figure 2
Frequency of asymptomatic cases per age group.
See this image and copyright information in PMC

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