key: cord-0956139-34i6r0au
authors: Thampi, Nisha; Sander, Beate; Science, Michelle
title: Preventing the introduction of SARS-CoV-2 into school settings
date: 2021-01-04
journal: CMAJ
DOI: 10.1503/cmaj.202568
sha: 7badda17368a04bb7d4f2503c6cdb74ee8d36ea4
doc_id: 956139
cord_uid: 34i6r0au

nan

.7% of children who tested positive. 1 This frequency is comparable to findings in a cohort of children of health care workers in the United Kingdom, but lower than the 20% reported in a hospital-based pediatric cohort in Massachusetts. [3] [4] [5] King and colleagues suggest that screening questionnaires should perhaps include only symptoms associated with positive test results, but they acknowledge the infrequency with which these symptoms occur, relative to upper respiratory tract symptoms and fever. Although the authors calculated positive likelihood ratios for the presence of each symptom in their analysis, this approach links the symptom to the infection but does not show whether the symptom occurred in isolation of other symptoms (e.g., Does isolated rhinorrhea, with or without an exposure history, predict SARS-CoV-2 infection?) or whether a child with rhinorrhea is likely to test positive for SARS-CoV-2. Given that symptoms such as headaches and rhinorrhea are common among school-aged children even in the absence of an infection, it would be important to determine the positive predictive value of these symptoms for COVID-19, particularly as isolated symptoms. 

• Children with severe acute respiratory syndome coronavirus 2 (SARS-CoV-2) infection are most likely to be asymptomatic, or to present with mild to moderate symptoms.

• Some symptoms, such as cough, rhinorrhea and fever, can be indistinguishable from those associated with other viral respiratory illnesses.

• Anosmia/ageusia has been shown to be strongly associated with a positive test for SARS-CoV-2 infection, but the true predictive value of many symptoms remains unknown.

• Since no symptom screening strategy will prevent every child with SARS-CoV-2 infection from entering school, additional schoolbased health and safety measures -including physical distancing, hand hygiene, masking, improved ventilation and outdoor learning opportunities -must continue to play a prominent role in preventing the spread of infection in this setting. For which symptoms, then, should children be screened before entering school? There are trade-offs between taking a broad versus narrow approach to symptom screening. Attempting to identify all students who may have symptomatic SARS-CoV-2 before entering the school environment would also result in the exclusion of many students with symptoms potentially unrelated to, yet indistinguishable from, COVID-19. Furthermore, the requirement for testing and isolation based on screening for a broad range of symptoms may rapidly overwhelm testing capacity and decrease the willingness of children and parents to report symptoms. Conversely, targeting specific but infrequent symptoms may result in children with unrecognized COVID-19 entering the school environment.

Given the high proportion of children with SARS-CoV-2 who remain asymptomatic, it is unlikely that any symptom screening strategy will prevent every child with SARS-CoV-2 infection from entering school. Therefore, school-based health and safety meas ures beyond screening -including physical distancing, hand hygiene, masking, improved ventilation and outdoor learning opportunities -play an essential role in preventing the spread of infection in this setting. [6] [7] [8] It is important to gather information on secondary transmission within schools to evaluate these health and safety measures and adjust as necessary.

In addition to robust public health measures in testing, contact tracing and isolation of cases and their exposed contacts, noninvasive and rapid test result turnaround could help to identify children with mild or asymptomatic infections, and could result in greater compliance with testing and isolation recommendations. Network epidemiology, accompanied by phylogenetic analyses of case clusters, could be additional tools to understand SARS-CoV-2 transmission among children and their households, and the conditions under which transmission occurs (i.e., the duration, frequency and intensity of exposures), particularly among those who are asymptomatic carriers. 9 Although children have been shown to have higher viral loads early in the course of illness, it would be important to correlate these laboratory findings with the risk of transmission over the course of illness, and against the effect of mitigation measures across age groups (preschool, elementary and high school). 4, 10 The clinical presentation of pediatric SARS-CoV-2 infection is often indistinguishable from other respiratory viral infections, yet the implications for school attendance are far greater. To better direct finite resources to public health and school-based measures, it is critical that transmission risks be understood and mitigated as much as possible, weighed against the known benefits of in-person learning. 11 

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Systematic review and meta-analysis of smell and taste disorders in COVID-19

Pediatric severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): clinical presentation, infectivity, and immune responses

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This article was solicited and has not been peer reviewed. Contributors: All authors contributed to the conception and design of the work, drafted the manuscript, revised it critically for important intellectual content, gave final approval of the version to be published and agreed to be accountable for all aspects of the work.

This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY-NC-ND 4.0) licence, which permits use, distribution and reproduction in any medium, provided that the original publication is properly cited, the use is non-commercial (i.e. research or educational use), and no modifications or adaptations are made. See: https://creativecommons.org/licenses/by-nc-nd/4.0/ Correspondence to: Nisha Thampi, nthampi@cheo.on.ca