Screening K-12 Students for Symptoms of COVID-19: Limitations and Considerations

This document provides guidance to K-12 schools on COVID-19 symptom screening as part of a school reopening process. The guidance detailed here is intended only for students in K-12 school settings. The number of reported children with SARS-CoV-2 (the virus that causes COVID-19) infection who experience symptoms, the types of symptoms they experience, and the severity of those symptoms differs from adults. Additionally, the consequences of excluding students from essential educational and developmental experiences differ from excluding individuals from other settings. Therefore, the considerations described here are different than those for other settings and populations. For guidance related to screening of teachers and staff, please refer to CDC’s Interim Guidance for Businesses and Employers Responding to Coronavirus Disease 2019 and the “Prevent Transmission Among Employees” section of CDC’s Resuming Business Toolkitpdf icon.

We learn more about COVID-19 every day, and as more information becomes available, CDC will continue to update and share information. As our knowledge and understanding of COVID-19 evolves, this guidance may change. However, based on the best available evidence at this time:

• CDC does not currently recommend universal symptom screenings (screening all students grades K-12) be conducted by schools.
• Parents or caregivers should be strongly encouraged to monitor their children for signs of infectious illness every day.
• Students who are sick should not attend school in-person.

COVID-19 is a newly identified disease caused by the virus, SARS-CoV-2. Scientists are still learning about how it spreads, how it impacts children, and what role children may play in its spread. Limited data about COVID-19 in children suggest that children are less likely to get COVID-19 than adults, and if they do contract COVID-19, they generally have less serious illness than adults. While uncommon, deaths and rare illness such as multisystem inflammatory syndrome in children (MIS-C) may still occur.

People with COVID-19 have had a wide range of reported symptoms – ranging from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to SARS-CoV-2. Symptoms can include:

• Fever or chills
• Cough
• Shortness of breath or difficulty breathing
• Fatigue
• Muscle or body aches
• Headache
• New loss of taste or smell
• Sore throat
• Congestion or runny nose
• Nausea or vomiting
• Diarrhea

This list does not include all possible symptoms and children and youth with SARS-CoV-2 infection may experience any, all, or none of these symptoms. (See Symptoms of Coronavirus for more information).

Given the wide range of symptoms and the fact that some people with SARS-CoV-2 infection (the virus that causes COVID-19) are asymptomatic, there are limitations to symptom screening conducted by schools for the identification of COVID-19.

Limitations of Symptom Screenings as Part of a School Reopening Strategy

• Symptom screenings will fail to identify some students who have SARS-CoV-2 infection. Symptom screenings are not helpful in identifying individuals with SARS-CoV-2 infection who are asymptomatic or pre-symptomatic (they have not developed signs or symptoms yet but will later). Others may have symptoms that are so mild, they may not notice them. In fact, children are more likely than adults to be asymptomatic or to have only mild symptoms. ^{[1], [2], [3]} The exact percentage of children with SARS-COV-2 infection who are asymptomatic is still unknown, but recent large studies have suggested around 16% of children with SARS-CoV-2 infection do not develop symptoms. ^[4] This means that even when schools have symptom screenings in place, some students with SARS-CoV-2 infection, who can potentially transmit the virus to others, will not be identified.

• Symptom screenings will identify only that a person may have an illness, not that the illness is COVID-19. Many of the symptoms of COVID-19 are also common in other childhood illnesses like the common cold, the flu, or seasonal allergies. The table below illustrates some of the overlap between the symptoms of COVID-19 and other common illnesses.

• Table. Many symptoms of COVID-19 are also present in common illnesses

  Symptoms of COVID-19	Strep Throat	Common Cold	Flu	Asthma	Seasonal Allergies
  Fever or chills	X		X
  Cough		X	X	X	X
  Sore throat	X	X	X		X
  Shortness of breath or difficulty breathing				X
  Fatigue		X	X	X	X
  Nausea or Vomiting	X		X
  Diarrhea	X		X
  Congestion or Runny Nose		X	X		X
  Muscle or body aches	X	X	X

• Note: The table above does not include all COVID-19 symptoms
• Available for Downloadpdf icon

The overlap between COVID-19 symptoms with other common illnesses means that many people with symptoms of COVID-19 may actually be ill with something else. This is even more likely in young children, who typically have multiple viral illnesses each year. For example, it is common for young children to have up to eight respiratory illnesses or “colds” every year. ^[1]Although COVID-19 and illnesses like colds or the flu have similar symptoms, they are different disease processes.

Some studies have tried to identify which symptoms may best predict whether an individual has COVID-19, although these studies have primarily focused on those over 18-years-old. ^{[6], [7], [8], [9]} In children, fever has been the most frequently reported symptom. However, fever is common in many other illnesses, and temperatures can be taken improperly and falsely interpreted as fever. Additionally, there is no symptom or set of symptoms that only occurs in children diagnosed with COVID-19.

Additionally, students with chronic conditions like asthma or allergies may have symptoms like cough or nasal congestion without having any infection at all. As a result, symptom screenings have the potential to exclude some students from school repeatedly even though they do not have COVID-19 or any contagious illness. This in turn may worsen disparities in students who already miss school frequently because of chronic medical conditions.

Students who are sick with contagious illnesses should not attend school, but most illnesses do not require the same level or length of isolation that COVID-19 does. Excluding students from school for longer than what is called for in existing school policies (e.g., fever free without medication for 24-hours) based on COVID-19 symptoms alone risks repeated, long-term unnecessary student absence.

Symptom screenings alone are inadequate to reduce SARS-CoV-2 transmission because of the limitations mentioned. Even when symptom screenings are implemented, other mitigation strategies (such as promoting healthy behaviors, maintaining healthy environments, maintaining healthy operations, and preparing for when someone gets sick) are still needed to help protect students, teachers, and staff from COVID-19.

The exact level of effectiveness of symptom screening in schools is not known at this time. While screening may reduce some SARS-COV-2 transmission in schools, transmission may still occur because of asymptomatic, pre-symptomatic, and mildly symptomatic students. Additionally, because symptom screenings will likely identify individuals who have symptoms that are unrelated to COVID-19 and, at times, unrelated to any infectious illness, students may be inappropriately excluded from school, which may cause unintended harm. It is because of these limitations that CDC does not currently recommend that universal symptom screenings be conducted at schools.

Considerations If Symptom Screenings Are Used in School Settings

For schools that choose to implement on-site symptom screenings, CDC offers the following considerations:

• Consider the scientific evidence outlined above and weigh the risks and benefits to students, staff, and the larger community.
• Consider how school policies regarding symptom screenings can balance the resources required and feasibility of implementation and the risk of transmission in schools.
• Consider ways to reduce the likelihood of excluding students who do not have COVID-19 from essential instructional and critical developmental experiences.
• Before sharing personally identifiable information on students concerning COVID-19, consider Federal, state, and local requirements, including provisions in the Family Educational Rights and Privacy Act (FERPA). 

Some of the factors schools may weigh include:

Uses of symptom screening

Schools should also understand what symptoms screening does and does not do. When implemented, the purpose of symptom screening is to identify individuals who may have COVID-19 and exclude those individuals from a setting to reduce the risk of transmission to others. Symptom screening does not assess whether it is safe for an individual student to attend school or whether a student has an increased risk for severe illness if they develop COVID-19. Symptom screenings also do not provide enough information to diagnose someone with COVID-19.

There is not a single symptom that is uniquely predictive of a COVID-19 diagnosis. A COVID-19 viral test is needed to confirm if someone has a current infection. Schools may already have illness management criteria in place for school admittance; this is an opportunity to review that criteria and consider recommending stricter adherence to their existing illness management criteria.

Although CDC does not currently recommend conducting universal symptom screening at school, students should not attend school when they are sick. Home symptom screenings rely on students and their parents, guardians, or caregivers initially identifying when the student may have signs and symptoms of illness and to take action (such as staying home). This process can also be followed by school staff by monitoring children for overt symptoms of any infectious illness that may develop during the school day and helping the student and family take needed actions.

It is essential for schools to reinforce to students, parents or caregivers, and staff the importance of students staying home when sick until at least 24 hours after they no longer have a fever (temperature of 100.4 or higher) or signs of a fever (chills, feeling very warm, flushed appearance, or sweating) without the use of fever-reducing medicine (e.g., Tylenol). Policies that encourage and support staying home when sick will help prevent the transmission of SARS-CoV-2 (and other illnesses including flu) and help keep schools open.

Symptom screening at home can be helpful to determine if a student:

1. currently has an infectious illness that could impair their ability to learn, or
2. is at risk of transmitting an infectious illness to other students or to school staff.

What content should schools include in a home screening process for parents or caregivers?

Schools that elect to encourage parents, guardians, or caregivers to conduct daily home screenings should ask parents to report their answers on two topics: Symptoms and Close Contact/Potential Exposure (see below). Parents, guardians, and caregivers can self-report the answers to these questions through existing school health portals or school communication platforms in the morning before the student leaves for school. Schools can use the template below to share with parents and aid in daily reporting.

Daily Home Screening for Students

Parents: Please complete this short check each morning and report your child’s information [INSERT YOUR SCHOOL REPORTING INSTRUCTIONS] in the morning before your child leaves for school.

Return-to-School Policies

If the student/parent/caregiver answers YES to any question in Section 1 but NO to any questions in Section 2, the student would be excused from school in accordance with existing school illness management policy (e.g., until symptom-free for 24 hours without fever reducing medications).

If the student or parent or caregiver answers YES to any question in Section 1 and YES to any question in Section 2, the student should be referred for evaluation by their healthcare provider and possible testing. CDC strongly encourages local health departments to work with local school systems to develop a strategy to refer symptomatic individuals to an appropriate healthcare provider or testing site. State, Tribal, territorial, and local health officials and/or healthcare providers will determine when viral testing for SARS-CoV-2 is appropriate. Schools should not require testing results as a part of return to school policies. Students who have received a negative test result should be allowed to return to school once their symptoms have otherwise improved in accordance with existing school illness management policies.

Students diagnosed with COVID-19 or who answer YES to any question in Section 1 and YES to any question in Section 2 without negative test results should stay home, isolate themselves from others, monitor their health, and follow directions from their state or local health department. Students and their families should be advised that the local health department may contact the family for contact tracing. If contacted, families should notify the contract tracer that the student attended school.

Students diagnosed with COVID-19 or who answer YES to any component of Section 1 AND YES to any component of Section 2 without negative test results should be permitted to return to school should be in line with current CDC recommendations in “When Can I Be Around Others”. A negative test or doctor’s note should not be required for return. Questions regarding return to school should be jointly decided in consultation with parents or caregivers, school personnel, and the student’s healthcare provider.

Students who are excluded from school should be afforded the opportunity, as soon as feasible when they are well enough to participate in classwork, to make up any missed classwork without penalty in order to reduce mental or physical anxieties about missed academic opportunities.

School Isolation Protocols

Some students may develop symptoms of infectious illness while at school. Schools should take action to isolate students who develop these symptoms from other students and staff.

• Students with any of the symptoms in Section 1 should follow their school’s current illness management policy to minimize transmission to others, to optimize learning opportunities, and to allow for these symptoms to resolve (at least 24 hours without fever reducing medications or in accordance with existing school illness policy).

• Students who develop any of the symptoms in Section 1 while at school should be placed in an isolation area separate from staff and other students:
  • School staff (e.g., workers, teacher aides, school health staff) who interact with a student who becomes ill while at school should use Standard and Transmission-Based Precautions when caring for sick people.
  • Students who are sick should go home or to a healthcare facility depending on how severe their symptoms are, and follow CDC guidance for caring for oneself and others who are sick.

• Students identified at school who develop any of the symptoms in Section 1 AND answer YES to any of the questions in Section 2 should be placed in an isolation area separate from staff and other students (e.g., a nurse’s office) and then sent home or to a healthcare facility if symptoms indicate a need for further evaluation:
  • If a school needs to call an ambulance or bring a student to the hospital, they should first alert the healthcare staff that the student may have been exposed to someone with COVID-19.
  • After the student is placed in an isolation area, school staff who work in the isolation area should follow CDC’s Considerations for Cleaning and Disinfecting your Building or Facility.
  • Note: In developing plans for placing students with symptoms in an isolation area, schools should be mindful of appropriate safeguards to ensure that students are isolated in a non-threatening manner, within the line of sight of adults, and for very short periods of time.

References

[1] Davies, N.G., Klepac, P., Liu, Y. et al. Age-dependent effects in the transmission and control of COVID-19 epidemics. Nat Med (2020). https://doi.org/10.1038/s41591-020-0962-9

[2] Assaker, Rita, Anne-Emmanuelle Colas, Florence Julien-Marsollier, Béatrice Bruneau, Lucile Marsac, Bruno Greff, Nathalie Tri, Charlotte Fait, Christopher Brasher, and Souhayl Dahmani. “Presenting symptoms of COVID-19 in children: a meta-analysis of published studies.” BJA: British Journal of Anaesthesia (2020). https://www.sciencedirect.com/science/article/pii/S0007091220304086?via%3Dihub

[3] Dong, Yuanyuan, Xi Mo, Yabin Hu, Xin Qi, Fan Jiang, Zhongyi Jiang, and Shilu Tong. “Epidemiology of COVID-19 among children in China.” Pediatrics 145, no. 6 (2020). https://pediatrics.aappublications.org/content/145/6/e20200702

[4] Assaker, Rita, et al. “Presenting symptoms of COVID-19 in children: a meta-analysis of published studies.” BJA: British Journal of Anaesthesia (2020).

[5] Goldmann DA. Epidemiology and Prevention of Pediatric Viral Respiratory Infections in Health-Care Institutions. Emerg Infect Dis. 2001;7(2):249-253. https://dx.doi.org/10.3201/eid0702.700249

[6] Roland, Lauren T., Jose G. Gurrola, Patricia A. Loftus, Steven W. Cheung, and Jolie L. Chang. “Smell and taste symptom‐based predictive model for COVID‐19 diagnosis.” In International Forum of Allergy & Rhinology. 2020.

[7] Clemency, Brian M., Renoj Varughese, Danielle K. Scheafer, Brian Ludwig, Jacob V. Welch, Robert F. McCormack, Changxing Ma, Nan Nan, Theresa Giambra, and Thomas Raab. “Symptom Criteria for COVID‐19 Testing of Heath Care Workers.” Academic Emergency Medicine 27, no. 6 (2020): 469-474.

[8] Stokes EK, Zambrano LD, Anderson KN, et al. Coronavirus Disease 2019 Case Surveillance — United States, January 22–May 30, 2020. MMWR Morb Mortal Wkly Rep 2020;69:759–765. DOI: http://dx.doi.org/10.15585/mmwr.mm6924e2external iconexternal icon.

[9] Assaker, Rita, et al. “Presenting symptoms of COVID-19 in children: a meta-analysis of published studies.” BJA: British Journal of Anaesthesia (2020).