Minimizing Outbreaks of Covid-19 during School Openings

By: Supriya Sehgal

School openings in the fall have raised many questions children’s role in spreading disease during this pandemic.  Parents are concerned about risks of children getting infected and the risk of infected children transmitting Covid-19 to adults in the home as well as teachers and other school faculty.

Initial data of children infected with Covid-19 appeared to show that children who are infected do not get sick.  However, it has since been shown that 1/3 children who are infected with Covid-19 admitted to hospitals transfer to the intensive care unit.  New data from a small study in the UK suggests that children who are infected with Covid-19 have a higher risk of subsequently developing type 1 diabetes.  

There is also conflicting data as to whether children transmit disease to adults and contribute to community spread.  Some studies have suggested that children are not significant spreaders of Covid-19.  However, other studies refute this. A model based on epidemiologic data from China suggests that children are half as likely to spread Covid-19 as adults. 

Also, we are not testing enough kids to know who is actually infected, since kids are less likely to have symptoms when infected with Covid-19.  As a result of this, we may not have sufficient epidemiologic data to determine whether children are significant contributors to community transmission. 

Amid this debate, schools are opening all over the world. Clearly, measures must be in place to ensure prevention of outbreaks and potential spread of disease in the community.

It is critically important to make sure that disease is controlled in the community.  If cases are rising in the community, it will be difficult to open schools as this will potentially increase the risk of outbreaks in our educational institutions. We must be certain that disease is controlled prior to opening schools.

In the community, the Rt – that is, the number of secondary cases per infected case – must be less than 1.

This indicates that the number of infected cases is declining in the population.  This decline must be sustained for at least 2 weeks.

Rt represents only one of the parameters that identify community spread.  Decline from peak numbers of cases should also be observed.  There should be a greater than 50 percent decline in cases from peak seen over three weeks of both probable and confirmed cases. It is critical that decline is seen over a sustained period of time, not just a few days.

The incidence of disease should also be low.  Less than 5 percent of tested samples should be positive in order for schools to open.  This must be based on an adequate testing sample size where a minimum of 1/1000 people in the community are tested per week. Hospitalizations must decline over 2 weeks and deaths must decline over 3 weeks as well.  If cases are rising in any of these parameters or the incidence of disease is higher than 5 percent, it will be difficult to prevent outbreaks in schools.

The local health systems must also be able to cope with potential surges should schools open.  This includes having isolation beds in hospitals and an ability to handle at least a 20 percent increase in the number of Covid-19 cases.  

There must also be extensive contact tracing in the community. Positive cases must be identified quickly and included in epidemiologic data within 24 hours.  Delays in testing and reporting positive cases will inevitably result in spread of disease. 

Even with all these measures in place, there is always a risk of an outbreak, particularly when considering that the highest Ro reported in medical literature has been 5.7.  For comparison, the Ro for SARS was thought to be between 2 and 5.  

School buildings also need to be revised to accommodate outbreaks.  School and school bus ventilation systems need to be inspected, updated, and possibly replaced.  The virus has a component that is aerosolized, so it is critical that proper ventilation is in place to help prevent transmission of disease.  

School layouts must be modified as well.  Desks need to be a minimum of 6 feet apart, although, with the virus being partially aerosolized and able to travel up to 26 feet, this does not guarantee prevention of spread of disease.  Buses should also have distanced seating arrangements.  Alternate day school attendance and schedules will help promote social distancing in schools.

Physical barriers must also be in place between seating areas to help prevent transmission of virus in case someone coughs or sneezes. 

These barriers must also be promoted during recess and mealtimes to help prevent spread of disease.  Universal masking must be in place to help prevent transmission as well.

These are just a few of the measures that must be in place for schools to open safely.  A community effort is required to ensure that this is done in a way to prevent outbreaks in schools.   However, Covid-19 is partially aerosolized, and even if all of these measures are in place, there is no guarantee that schools will be free from outbreaks.