COVID-19: 3 Steps for Reopening Schools
Schools can reopen successfully by addressing COVID-19 health issues in a scientific and pragmatic way. Effective communication of protective measures, health metrics and safety related information is key to addressing employee, student and parent apprehension. With proper procedures and good data, stakeholders can make informed decisions about the risk involved in returning to school as “normal.”
In this article I will outline 3 steps that can be put into place for employee and student personal protection, for sanitization and disinfection and for scientific testing that can be conducted to document the results of protective measures.
Before I get into the three steps to take for reopening schools, let’s review the current understanding about how the virus is transmitted. According to the CDC, the SARS-CoV-2 virus is most likely spread by aerosol transmission. Aerosols are water droplets, mucus proteins and other biological materials that are less than five micrometers (<5 µm) in size (a µm is 1/1,000 of a millimeter). The virus particle itself is only about 0.1 µm in size but is almost always bonded to an aerosol.
These types of aerosols are generated through normal breathing, talking, singing, sneezing, coughing or by flushing a toilet. Aerosols can be airborne, can be deposited on surfaces and can be re-aerosolized if disturbed or as moisture evaporates. If aerosols contain the virus in sufficient quantity, a susceptible person could inhale them and become infected.
Spread of the SARS-CoV-2 virus has proven difficult to control because it is often spread by asymptomatic and pre-symptomatic individuals. Pre-symptomatic individuals may be contagious up to four days before the onset of symptoms. The SARS-CoV-2 virus is most contagious before symptoms begin and at the early onset of symptoms.
To reopen successfully, appropriate protective measures need to be put into place to make classrooms and living spaces as safe as possible. The key to successful reopening is to create a plan that includes procedures to:
- Reduce the chance of virus transmission / limit potential exposure
- Implement disinfection procedures
- Conduct testing to confirm COVID-19 protective measures are effective
1. Reduce the chance of virus transmission / limit potential exposure
Since people become infected with the virus by inhaling aerosols, the initial step is to reduce the generation and spread of aerosols. In this case the (most current) CDC recommendations are:
- Wear a mask.
- Maintain a 6 ft social distance.
- Erect dividers and partitions.
- Encourage employees and visitors to stay at home if they are experiencing any of the following symptoms: a new cough, fever, chills, shortness of breath, sudden loss of taste or smell, or diarrhea.
- Follow isolation or quarantine guidelines if employees are sick or have been in close contact with someone who has symptoms or tested positive for COVID-19.
- Encourage vaccination when eligible.
2. COVID-19 disinfection and sanitization procedures
CDC testing has shown viruses can live on surfaces for hours or in some cases days. Viruses can be transferred by touch or by re-aerosolization. Rigorous disinfection and sanitization procedures must be followed to mitigate the spread of virus from surfaces. Special focus should include disinfection of common touch surfaces such as door handles, railings, elevator buttons, keyboards, light switches, toilets, faucets, sinks, counter tops, touch screens, TV remotes, etc. These surfaces should be sanitized using an EPA approved disinfectant proven to kill the SARS-CoV-2 virus.
Since aerosols are continuously moving and being deposited and re-deposited on surfaces, it is important to perform regular sanitization. Disinfection of plexiglass dividers and partitions should be included in the cleaning regimen. Reference the CDC guidance for cleaning and disinfecting for more information about these procedures.
3. COVID-19 testing to confirm protective measures are effective
Testing for the presence of SARS-CoV-2 can be used to initiate immediate sanitization and other measures to protect the health and safety of employees, students and their environment. Specific COVID-19 sampling and RT-PCR testing procedures provide a unique opportunity to assess the need for cleaning and to document whether the cleaning has been performed adequately. Testing is also relevant for suppliers to document that no infection has been left after delivery, repair or maintenance of equipment. It enables the administration to test, determine, monitor and strengthen the effectiveness of implemented sanitation measures.
Accurate sampling and testing for the presence of virus particles is crucial to assess the risk of potential exposure and transmission. This risk can be assessed by testing commonly touched surfaces, the air the occupants are breathing and the PPE they are wearing. Below is a list of the types of COVID-19 tests that can be conducted in schools and on college campuses:
Testing of Common Touch Surfaces
Thorough cleaning is important to avoid further spread of COVID-19. Confirmation of sanitization is accomplished by conducting a RT-PCR test for the detection of Coronaviruses and SARS-CoV-2 on surface swabs. This test provides the opportunity to determine the presence of the COVID-19 virus on solid surfaces. Documentation of negative virus presence is key to attaining employee, student and parent confidence.
HVAC Sampling
Indoor air can be re-conditioned and circulated multiple times. Swab testing of return air plenums and filters is conducted to determine if an HVAC system is circulating the SARS-CoV-2 virus. This type of testing is key to assessing the need for more extensive disinfection.
Indoor Air Monitoring
Indoor air testing provides a unique opportunity to evaluate indoor spaces for the presence of the SARS-COV-2 virus in the air. The potential use of the test spans from offices and classrooms to residences, cafeterias, gymnasiums, auditoriums and other indoor environments. For buildings that are used by the same group of people, the test may provide relevant information to detect or prevent infections or outbreaks. In other settings with changing occupancy the overall air quality and general risk of potential exposure can be assessed.
High traffic or large gathering areas such as cafeterias, auditoriums and gymnasiums may benefit from aerosol testing for COVID-19 to re-assure customers and audiences. Aerosol testing does not address transmission caused by direct contact or when in close proximity to an infected individual. It does, however, enable us to address aerosol transmission and air quality as it relates to SARS-CoV-2.
Bulk Face Mask Testing.
Face masks accumulate nasal secretions and virus has been detected on the inner surface of non-medical masks worn by infected individuals. Masks can be tested for the presence of SARS-CoV-2. Bulk testing of disposable face masks following a day of use may eliminate the need for invasive nasal swab testing of individuals. Up to five (5) face masks can be composited and analyzed. If a composite group of masks test negative, then individual tests can be avoided. While this type of test is no replacement for clinical tests, the detection of COVID-19 virus on worn masks represents a non-invasive, additional tool for SARS-CoV-2 environmental testing.
This type of test can be particularly useful to monitor the virus presence in work groups, living groups and sports teams. Results can be available in as few as 24 hours.
Wastewater Testing
Infected people have been shown to shed the virus when they use the restroom. Wastewater testing is used to determine if building occupants are shedding the COVID-19 virus. This type of testing is effective for buildings with up to 1,000 occupants. Automated composite 24-hr samplers are used to collect weekly or twice weekly samples. By utilizing quick turnaround services, it is possible to ascertain virus detection three to four days in advance of symptoms. Positive results indicate the need for more testing to identify current symptomatic or asymptomatic cases among occupants and take appropriate action.
Key Points
Students, teachers and employees can return to school. But for now, we have to take appropriate protective measures including:
- Establish and document procedures to reduce the number of aerosols that are spread by potentially affected people.
- Develop a sanitization process and use EPA certified products proven to kill the virus on contact.
Conduct RT-PCR testing to verify disinfection processes, validate indoor air quality and give Students, employees and parents confidence in the protective measures that have been put in place.
