Related: Masks are Effective at Preventing COVID-19, but Fit Matters
COVID-19 Transmission at School Appears Remarkably Low
According to CDC researchers, there is little evidence that schools contribute meaningfully to increased community COVID transmission
Closing schools could adversely affect students’ academic progress, mental health, and access to essential services. As many schools have reopened for in-person instruction in some parts of the US as well as internationally, school-related cases of COVID-19 have been reported, but there has been little evidence that schools have contributed meaningfully to increased community transmission. The preponderance of available evidence from the fall school semester has been reassuring insofar as the type of rapid spread that was frequently observed in congregate living facilities or high-density worksites has not been reported in education settings in schools.
According to the European CDC, COVID transmission in schools is relatively uncommon
The conclusion from the literature is that SARS-CoV-2 transmission in schools is relatively uncommon. Schools comprise a minority of settings for COVID-19 transmission in countries with data on suspected location infection, and countries that have comprehensive data on cases in the school setting have found very low (<1%) prevalence of SARS-CoV-2. A case-control study from the USA of 397 pediatric SARS-CoV-2 infection found that in-person school or childcare attendance in the two weeks preceding the positive test was not associated with an increased likelihood of SARS-CoV-2 infection. Investigations in Germany, France, Ireland, Australia, Singapore and the USA have found no or very low secondary attack rates within preschool, primary school, and secondary school settings. A contact tracing study from Italy identified a secondary attack rate of 0% in infant-toddler centers, 0.44% in primary schools, but a higher rate of 6.46% in secondary schools. A study of educational settings in Australia noted an overall child-to-adult attack rate of 1.0%.
No child-to-adult COVID transmission among 90,000 students over 9 weeks in NC; 32 student-to-student transmissions
From 08/15/2020–10/23/2020, 11 school districts were open for in-person instruction for all 9 weeks of the first quarter and agreed to track incidence and secondary transmission of SARS-CoV-2. RESULTS: Over 9 weeks, school districts had more than 90,000 students and staff attend school in-person; of these, there were 773 community-acquired SARS-CoV-2 infections documented. Through contact tracing, NC health department staff determined an additional 32 infections were acquired within schools. Most of these cases of secondary transmission were related to absent face coverings. No instances of child-to-adult transmission of SARS-CoV-2 were reported within schools. CONCLUSIONS: In the first 9 weeks of in-person instruction in NC schools, we found extremely limited within-school secondary transmission of SARS-CoV-2, as determined by contact tracing.
https://pediatrics.aappublications.org/content/pediatrics/early/2021/01/06/peds.2020-048090.full.pdf
According to meta-analysis, 99% of students and staff who come in contact with COVID at school avoid infection
2178 articles were retrieved and 11 studies were included. Five cohort studies reported a combined 22 student and 21 staff index cases that exposed 3345 contacts with 18 transmissions (overall infection attack rate: 0.08%). Infection attack rates for students and school staff were 0.15% and 0.70% respectively.
https://pubmed.ncbi.nlm.nih.gov/33437465/
In Norway, 99% of students who came in contact with a child testing positive for COVID in school remained COVID-free; 98% of adults did
We aimed to examine transmission of SARS-CoV-2 from confirmed pediatric COVID-19 cases in primary schools in Norway by systematically testing all contacts within the school twice during their quarantine period. Among the 234 child contacts that were tested for SARS-CoV-2, two primary cases (0.9%) and no secondary cases were identified, and among the 58 adult contacts one primary case (1.7%) and no secondary cases were detected. This prospective study shows that transmission of SARS-CoV-2 from children under 14 years of age was minimal in primary schools in Oslo and Viken, the two Norwegian counties with the highest COVID-19 incidence.
https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.26.1.2002011
In Australian school settings, 99.5% remained unaffected after contact with students testing positive for COVID
Laboratory-confirmed pediatric and adult COVID-19 cases who attended a school or early childhood education setting while considered infectious in New South Wales from Jan 25 to April 10, 2020, were investigated for onward transmission. All identified school close contacts were required to home quarantine for 14 days, and were monitored and offered SARS-CoV-2 nucleic acid testing if symptomatic. Five secondary cases (three children; two adults) were identified (attack rate 0.5%; 5/914 contacts) in three schools.
https://www.thelancet.com/journals/lanchi/article/PIIS2352-4642(20)30251-0/fulltext
96.3% of COVID cases within Wisconsin schools originated from outside school; no transmission among staff
A total of 4,876 students and 654 staff members contributed data to the study. During the 13-week study period, cases occurred in 133 students and 58 staff members. Among these 191 cases, seven (3.7%) were attributed to in-school SARS-CoV-2 transmission, and all occurred among students. No in-school transmission between separate classroom cohorts was reported. COVID-19 incidence in schools conducting in-person instruction was 37% lower than that in the surrounding community. Observed student masking compliance ranged from 92.1% to 97.4% and did not vary by student age.
https://www.cdc.gov/mmwr/volumes/70/wr/mm7004e3.htm
In Italy, 93% of COVID cases in schools do not spread beyond original student
As of 5 October 2020, a total of 1350 cases of SARS-CoV-2 infections have been registered in the Italian territory schools (involving 1059 students, 145 teachers and 146 other school members), for a total of 1212 out of 65104 (1.8%) Italian schools involved. National schools reported only 1 case of SARS-CoV-2 infection in 93% of cases.
https://www.medrxiv.org/content/10.1101/2020.10.10.20210328v1.full.pdf
Without requiring masks during Spring 2020, no COVID deaths among nearly 2 million Swedish school children; 20 ICU visits among 103k school teachers
Sweden was one of the few countries that decided to keep preschools and schools open. Here, we present data from Sweden on Covid-19 among children 1 to 16 years of age and their teachers. In Sweden, Covid-19 was prevalent in the community during the spring of 2020. Social distancing was encouraged in Sweden, but wearing face masks was not. Among the 1,951,905 children in Sweden, a total of 15 children with Covid-19 were admitted to an ICU. No child with Covid-19 died. Data from the Public Health Agency of Sweden showed that 20 schoolteachers in Sweden received intensive care for Covid-19 (20 per 103,596 schoolteachers). As compared with other occupations (excluding health care workers), this corresponded to sex- and age-adjusted relative risks of 0.43 among schoolteachers.
https://www.nejm.org/doi/10.1056/NEJMc2026670
Attending school is not associated with increased risk of COVID among children
Among 397 children and adolescents investigated, in-person school or child care attendance ≤14 days before the SARS-CoV-2 test was reported for 62% of case-patients and 68% of control participants and was not associated with a positive SARS-CoV-2 test result. Among 236 children aged ≥2 years who attended child care or school during the 2 weeks before SARS-CoV-2 testing, parents of 64% of case-patients and 76% of control participants reported that their child and all staff members wore masks inside the facility (odds ratio = 0.4). In the 2 weeks preceding SARS-CoV-2 testing, case-patients were more likely to have had close contact with a person with known COVID-19 (odds ratio = 3.2), have attended gatherings with persons outside their household, including social functions (odds ratio = 2.4) or activities with other children (odds ratio = 3.3), or have had visitors in the home (odds ratio = 1.9) than were control participants. Close contacts with persons with COVID-19 and gatherings contribute to SARS-CoV-2 infections in children and adolescents.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7745952/
Children may be 43% less likely to become infected when exposed to COVID, according to meta-analysis
A total of 32 studies comprising 41,640 children and adolescents and 268,945 adults met inclusion criteria, including 18 contact-tracing studies and 14 population screening studies. The pooled odds ratio of being an infected contact in children compared with adults was 0.56. Three school-based contact-tracing studies found minimal transmission from child
or teacher index cases. Most studies were consistent with lower seroprevalence in children compared with adults, although seroprevalence in adolescents appeared similar to adults. CONCLUSIONS AND RELEVANCE In this meta-analysis, there is preliminary evidence that children and adolescents have lower susceptibility to SARS-CoV-2, with an odds ratio
of 0.56 for being an infected contact compared with adults. There is weak evidence that children and adolescents play a lesser role than adults in transmission of SARS-CoV-2 at a population level.
https://jamanetwork.com/journals/jamapediatrics/fullarticle/2771181
Among household COVID transmission, only 3.8% originates from children; children may also be 38% less susceptible to household outbreaks
We performed a meta-analysis of the published literature on household SARS- CoV-2 transmission clusters (n=213 from 12 countries). Only 8 (3.8%) transmission clusters were identified as having a pediatric index case. Asymptomatic index cases were associated with a lower secondary attack in contacts than symptomatic index cases (estimate risk ratio 0.17). To determine the susceptibility of children to household infections the secondary attack rate in pediatric household contacts was assessed. The secondary attack rate in pediatric household contacts was lower than in adult household contacts (risk ratio, 0.62).
https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1825/6024998
COVID-19 Does Not Present a High Risk to Most Children
99.997% of children who contract COVID are expected to survive
CDC best estimate of infection fatality ratio for children aged 0-19: 0.00003
https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html
96% of symptomatic COVID cases in children are mild or moderate
27 studies (4857 patients) fulfilling the eligibility criteria were included in this systematic review, from a total of 883 records. About half of the patients had each of fever and cough, 11% had fast breathing, and 6-13% had gastrointestinal manifestations. Most of the patients had mild to moderate disease, and only 4% had a severe or critical illness. Conclusions: Even among the symptomatic COVID-19 cases, severe manifestations are seen in very few children. Though fever and respiratory symptoms are most common, many children also have gastrointestinal manifestations.
https://pubmed.ncbi.nlm.nih.gov/32583808/
Social Isolation May Have Long Term Emotional Consequences
In children, social isolation increases risk for future depression and anxiety; duration of loneliness more relevant than intensity
63 studies reported on the impact of social isolation and loneliness on the mental health of previously healthy children and adolescents (n = 51,576; mean age 15.3 years). One of these studies was a retrospective investigation after a pandemic. Social isolation and loneliness increased the risk of depression, and possibly anxiety at the time at which loneliness was measured and between 0.25 and 9 years later. Duration of loneliness was more strongly correlated with mental health symptoms than intensity of loneliness. Conclusion: Children and adolescents are probably more likely to experience high rates of depression and most likely anxiety during and after enforced isolation ends. This may increase as enforced isolation continues.
Masks are Effective at Preventing COVID-19, but Fit Matters
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