4 Nov Episode 81 Children and schools

Wed, 11/04/2020 - 18:53
  1. Ref Ch 1:  Primary and secondary school closure (March-May) in the different states of US: was associated  with  a significant decline in both incidence of COVID-19 (adjusted relative change per week, −62%) and mortality (adjusted relative change per week, −58%).   States that closed schools earlier, when cumulative incidence of COVID-19 was low, had the largest relative reduction in incidence and mortality. However, it remains possible that some of the reduction may have been related to other concurrent nonpharmaceutical interventions (NPI) . To counter this bias, the authors adjusted for other NPI and test rates.


  1. Ref Ch 2: Trends of infections in US children March-Sept: Since March, 277,285 COVID-19 cases in children have been reported. COVID-19 incidence among adolescents aged 12–17 years was approximately twice that in children aged 5–11 years.  As can be seen in Fig 1, there was a rising trend in cases/100,000 from March to June and a stabilization during July-Aug-early Sept.  During summer, the percentage of positive tests also declined.   


  1. Ref Ch 3A An encouraging MMR on 4 youth summer camps in Maine with 1,022 participants showed that stringent NPI were successful at preventing COVID outbreaks.  These measures included precamp quarantine, pre- and post-arrival testing and symptom screening, cohorting, and physical distancing between cohorts. In addition, camps required use of face coverings, enhanced hygiene measures, enhanced cleaning and disinfecting, maximal outdoor programming, and early and rapid identification of infection and isolation. Under these stringent conditions, no new cases were observed in the camps.


Clearly, this is a much more reassuring report than the previous one about a camp in Georgia, where no such stringent NPI were taken and the attack rate was 44 % in total,  with a clear inverse relation to age: highest rates in the youngest participants! (Ref Ch 3B)   


  1. Ref Ch 4  Analysis of school outbreaks in Germany Feb- end Aug: Fig shows 48 outbreaks, except in weeks 13-19 (school closures)
  • Most outbreaks had few cases, more among older age groups.
  • Some outbreaks linked to households, most limited to the same grade.
  • After reopening: still new outbreaks, despite the low-incidence in the community  and enhanced NPI implemented.
  • Nevertheless NPI may have reduced the number of outbreaks and the cases per outbreak.
  • Most cases asymptomatic especially in younger age groups.
  • Some evidence of onwards transmission within classes, but limited.

Their conclusion: Only few and mostly small COVID-19 school outbreaks had been reported in Germany overall, suggesting that, the containment measures are sufficient to reduce

spillover into the community.

To avoid detrimental effects on children, school closures should be applied only cautiously and in combination with other control measures.


  1. Ref Ch 5: French Guidelines for schools: 
  • First a critical update on the role of children in transmission:
    • Children, and especially those under 10 years of age, do not contribute significantly to the dynamics of the SARS-CoV-2 epidemic:

The secondary attack rate from children is very low, and clusters initiated by a pediatric case are rare

    • A child exposed to an infectious case is less likely to become infected than an adult.
    • Infected children are more likely to be asymptomatic
    • The educational and social benefits provided by school far outweigh the risks of a possible SARS-CoV-2 contamination in school and day care centers (DCC)


  • Then clear guidelines and flow charts on how to make diagnostic decisions  and organize the school environment. 



  1. Two short editorials in Science support school re-openings, because children are not the drivers of the epidemic and the harm of school closure is considered disproportionate to the risk? But both papers formulate clear advice on how to mitigate the risk and give also a warning “there is no room for complacency”.  In addition, given schools “bridge” households, this could create a pool of ongoing viral circulation responsible for introductions of virus to the pupils’ homes and beyond.”.(Ref Ch 6B)