Summary of Recent Updates (July 1, 2022):
- Updated to reflect emerging data about early reinfection with Omicron variants at several points in the text.
- Clarified wording about home testing.
- Changed green and yellow category names in algorithms to enhance clarity about exposure and evidence of infection.
Testing for infection with SARS-CoV-2, the virus that causes COVID-19, can inform individual patient care and decision making for parents and families. In addition, population-level testing helps determine what interventions may need to be put in place to control the spread of disease within a community. This guidance is intended to assist pediatricians in understanding indications for SARS-CoV-2 testing as well as test selection and interpretation. The document also provides algorithms for common testing scenarios and information about practical considerations for in-office testing for SARS-CoV-2. No guidance can cover all clinical scenarios, and information regarding SARS-CoV-2/COVID-19 is evolving rapidly. In addition, the spectrum of clinical disease and epidemiology of transmission may differ between SARS-CoV-2 variants in circulation in specific geographic regions. Links to guidelines and research from the Centers for Disease Control and Prevention (CDC) and other organizations are provided for additional information to help guide decision making.
When should patients be tested for COVID-19?
The 3 common reasons and optimal timing for COVD-19 testing are as follows:
- Patients who have symptoms consistent with COVID-19 should be tested immediately.
- Patients who are asymptomatic but have had close contact with an individual who has confirmed or probable COVID-19 should be tested at least 5 days after last exposure; however, these patients should be tested immediately if they develop symptoms consistent with COVID-19.
- Patients who are required to obtain screening tests based on local public health authorities, school districts or other local organizations should be tested as recommended. Vaccination status may affect decisions about the need for screening tests.
See AAP Newborn Guidance for additional information about testing newborn infants.
Does the community prevalence of COVID-19 or other respiratory infections influence testing decisions?
Testing for SARS-CoV-2 infection should be guided by clinician judgment in accordance with the prevalence of COVID-19 in a given community. Decisions regarding testing for other pathogens should be informed by local epidemiology, including current levels of community transmission. Diagnosis of some other infections that share symptoms with SARS-CoV-2 (ie, influenza) may be clinically actionable, and coinfections may occur. Children with influenza documented by testing may be treated with an influenza antiviral, with more rapid resolution of symptoms possible, allowing for earlier return to school, per AAP policy. Clinicians should consider local seasonal influenza activity when deciding whether to test patients for influenza. Tests for many common causes of upper and lower respiratory tract symptoms, such as rhinovirus, are not routinely available.
Should vaccination status impact decisions about COVID-19 testing?
Vaccination status of the patient should not guide decisions about testing in the setting of compatible symptoms. This is particularly true for variant strains of SARS-CoV-2 such as Omicron, BA.2 and subsequent variants, for which vaccines are very protective against severe illness, hospitalization and death but less protective against infection and mild illness. However, vaccination status may affect decisions about the need for screening tests.
Does recent SARS-CoV-2 infection impact decisions about COVID-19 testing?
Children who have had laboratory-confirmed SARS-CoV-2 infections in the prior 3 months may continue to have positive test results even in the absence of current infection. In particular, small amounts of viral genetic material may remain detectible for several months after infection. Nucleic acid amplification tests (NAATs – see Test Selection and Interpretation section below), including polymerase chain reaction (PCR) tests, may remain positive during that time despite clinical recovery and lack of contagiousness. Antigen tests remain positive for shorter lengths of time. Decisions about testing symptomatic children with prior confirmed infections in the past 3 months should take into account the possibility of false-positive results, particularly for PCR tests and other NAATs. However, emerging data suggest that reinfections within the 3-month window are more frequent with recent SARS-CoV-2 variants (including Omicron and related strains) and may occur at higher rates in young, unvaccinated individuals. In a child with known exposure and compatible symptoms, there may be situations in which it is reasonable to retest within the 3-month window. If testing is performed within that window, antigen testing is generally preferable to NAATs because of the potential for false-positive NAAT results attributable to prior infection.
What are the symptoms of COVID-19? Are symptoms different with recent SARS-CoV-2 variants?
Common symptoms of COVID-19 include: fever or chills, cough, congestion or runny nose, loss of taste or smell, shortness of breath or difficulty breathing, body aches, fatigue, headache, sore throat and gastrointestinal symptoms (nausea, vomiting or diarrhea). The decision to test does not differ by the age of the child, although some symptoms such as body aches, shortness of breath and loss of taste/smell are more prevalent in young adults than in school-aged children or infants, and symptoms from nonverbal infants may be more difficult to assess than in older children. Different variants of SARS-CoV-2 may produce a different constellation of symptoms, including asymptomatic infection. In adults, recently prevalent strains, including Omicron, BA.2 and others, generally appear to cause milder disease compared with earlier SARS-CoV-2 variants. However, there was a marked increase in pediatric hospitalizations in the United States attributable to infection with the Omicron variant. Unvaccinated children were at substantially higher risk for hospitalization than those who had been vaccinated against SARS-CoV-2. Recent variants also appear to be associated with laryngotracheobronchitis (croup) to a greater extent than earlier SARS-CoV-2 variants.
What constitutes close contact for children and adolescents?
Determining whether a patient has had a close contact depends on whether exposure occurred in a K-12 school setting:
- Close contact refers to a distance of less than 6 feet for a cumulative total of at least 15 minutes over a 24-hour period from a person with laboratory-confirmed or probable SARS-CoV-2 infection.
- Close contact in K-12 schools – see CDC guidance for details.
Do asymptomatic close contacts require testing?
Asymptomatic patients who meet the definition of close contact should be tested for SARS-CoV-2 infection 5 days after the most recent contact with the confirmed/probable case. Potential exceptions include:
- Asymptomatic children who have had laboratory-confirmed SARS-CoV-2 infections in the prior 90 days may be considered for exemption from testing after close contact exposures, although emerging data suggest that early reinfection may occur, particularly in unvaccinated children.
- If the exposure is to a close contact of an individual with confirmed/probable SARS-CoV-2 infection and not the infected person themselves, unless the close contact is also a confirmed/probable case.
School-based “test-to-stay” protocols are now endorsed by the CDC and combine frequent testing and contact tracing to allow asymptomatic children who are not up to date on COVID-19 vaccine to remain in school following a close-contact exposure.
In what other situations might testing be required?
Specific situations in which screening testing may be used include:
- School Attendance: The CDC and AAP strongly support efforts to provide safe, in-person instruction in K-12 schools. Depending on levels of community transmission, screening (ie, testing of groups of asymptomatic individuals without known SARS-CoV-2 exposure) may be useful for early identification and isolation of SARS-CoV-2 cases, identification of additional potentially exposed individuals through contact tracing and detection of clusters of cases. The CDC offers guidance on Screening Testing for COVID-19 Prevention in K-12 Schools.
- Extracurricular Activities and Workplace Screening:
- Preparticipation screening of children may be performed prior to higher-risk extracurricular activities (ie, intermediate- or high-risk sports, or high-risk extracurriculars such as those that involve increased exhalation such as singing, shouting, band or other exercise), particularly for activities conducted indoors. Specific CDC recommendations regarding such screening are available.
- Screening in these situations depends on the specific activities, physical spacing and the levels of community transmission.
- Adolescents who are employed may be subject to screening testing as a condition of employment. Such policies are instituted by employers, subject to local public health guidance and applicable laws.
- Travel (detailed information is available at the CDC website related to domestic travel and international travel).
- Health Care Settings: Many hospitals recommend that children receive testing for active SARS-CoV-2 infection prior to outpatient procedures such as elective surgery and for all children admitted to a hospital for any reason. These decisions should be made on the basis of local recommendations and institutional policies. Parents or other caregivers of children may be subject to public health requirements and hospital-based or other health care-based screening policies as well.
Test Selection and Interpretation
Which test should I use for my patients?
For patients who have symptoms consistent with COVID-19, either NAATs, which include PCR tests, or antigen tests can be used. A positive result on either test indicates SARS-CoV-2 infection. If the patient has a negative antigen test, the pediatrician should consider either a NAAT test within 48 hours or serial antigen tests every 3 to 7 days for 10 days as an alternative. See Test Selection and Interpretation and Algorithm 1 below for additional information.
For patients who are asymptomatic but have close contact with an individual with suspected or confirmed COVID-19, either a NAAT or antigen test may be used. See Test Selection and Interpretation and Algorithm 2 below for additional information.
Should I provide COVID-19 tests in my office? What should I consider when making this decision?
See Practical Considerations for In-Office Testing for additional information.
Are oral samples more sensitive than nasal samples when testing for the Omicron variant of SARS-CoV-2?
As of now, no at-home antigen tests have been authorized by the FDA for use with oral samples, and there are no robust data suggesting that oral samples should be preferred over nasal samples for any SARS-CoV-2 variant.
How should I interpret home test results?
Home tests may be challenging to interpret because of the inability to verify the adequacy of the sample collection or that the testing procedures were performed correctly. Generally, because of the high specificity of these tests, any positive result should result in home isolation. If the pretest probability is low (ie, low community prevalence, no symptoms or exposures), confirmation of a positive home test with a NAAT such as a PCR test should be considered.
Can at-home antigen tests be used in children younger than 2 years?
As of now, no at-home antigen tests have been authorized by the FDA for use in children younger than 2 years.
The algorithms below are intended to provide guidance for common clinical situations. Please see CDC testing guidance including the Guidance for Antigen Testing for SARS-CoV-2 for Healthcare Providers Testing Individuals in the Community for further details. In each algorithm, a pathway is provided depending on whether the initial testing is performed with a PCR test or an antigen test. Non-PCR NAATs have not been included because of limited availability and limited performance data in children. Until more pediatric data are available, we suggest considering results of non-PCR NAATs such as LAMP and NEAR assays as comparable to antigen testing rather than PCR. This guidance may change in the future as more data become available.
Table 2 provides an interpretation to the color-coded outcomes in testing of symptomatic and asymptomatic children as noted in the following algorithms. These algorithms assign patients to one of three categories based on a combination of pretest probability (including both clinical presentation and exposures) and testing results:
Table 2. Definitions of Algorithm-Assigned Infection Risk Categories
Algorithm A. Patients with symptoms consistent with COVID-19
- Patients who have symptoms consistent with COVID-19 should be tested without delay. Given the ongoing spread of SARS-CoV-2 throughout the United States, a positive test (PCR or antigen) in a symptomatic patient should be taken as evidence of SARS-CoV-2 infection.
- A symptomatic patient with a negative PCR test (performed either as an initial test or as follow-up to a negative antigen test) who has a known close contact exposure to an individual with confirmed or probable SARS-CoV-2 infection in the past 10 days falls into the “Exposed and no current evidence of SARS-CoV-2” category. These patients may have symptoms from another viral infection while still potentially in the incubation period with SARS-CoV-2 and may, therefore, require continued quarantine/isolation.
- A symptomatic patient with a negative PCR test (performed either as an initial test or as follow-up to a negative antigen test) and without a known exposure to an individual with confirmed or probable SARS-CoV-2 infection in the past 10 days can be considered “Not exposed and no current evidence of SARS-CoV-2” but should still isolate until symptom resolution.
- Serial antigen testing may be considered for symptomatic individuals who have a negative initial antigen test. Current CDC guidance allows for repeated antigen testing every 3 to 7 days for 10 days as an alternative to confirmatory NAAT in this situation.
Algorithm B. Patients who have close contact with individuals with confirmed or probable SARS-CoV-2 infection
- Asymptomatic patients with close contact exposure to an individual with confirmed or probable SARS-CoV-2 infection in the past 10 days should be tested for SARS-CoV-2 infection and may require quarantine, as outlined in the CDC guidance on quarantine and isolation. Note that the definition of close contact may differ for students in classroom settings in K-12 schools. CDC guidance generally recommends delaying testing until day 5 after exposure in asymptomatic individuals, regardless of vaccination status.
- Exposed and asymptomatic children who are not up to date on COVID-19 vaccine and have not had a positive SARS-CoV-2 test in the past 90 days generally require quarantine per CDC guidance. An exception to this situation is that some school systems have instituted “test-to-stay” protocols, which have been evaluated in several studies in US schools and are endorsed by the CDC. The specific details of test-to-stay protocols may vary across sites. In general, asymptomatic children who are not up to date on COVID-19 vaccine may be eligible for test-to-stay if both the child who tested positive for SARS-CoV-2 and the close contact were properly masked at the time of the contact. Under test-to-stay, the close contact may continue to participate in in-person learning after exposure and must have repeated testing over the next 7 days. Test-to-stay is only applicable to school-based contacts and not to contacts in other settings (such as home), which may be associated with higher intensity contact and increased risk of spread. Testing frequency can vary (for example, from twice in the 7-day period to daily). More frequent testing can more quickly identify students who become infected with SARS-CoV-2 and need to isolate. Students who participate in test-to-stay should consistently and correctly wear masks while in school and should stay home and isolate if they develop symptoms or test positive for SARS-CoV-2. Schools that are considering implementing test-to-stay must have robust contact tracing in place and access to testing resources (for example, testing supplies and personnel to conduct testing, or access to an existing community testing site), among other layered prevention strategies. Because close contacts who are up to date on COVID-19 vaccine are not required to quarantine following exposure (see next bullet point), they would not be included in test-to-stay. Some states and local jurisdictions offer publicly available plans and protocols that describe how they conduct test-to-stay. Their plans may include eligibility criteria for and duration of in-school monitoring, testing type, how often to test, and other relevant considerations. Contact your state or local health department or visit their website to learn more about whether test-to-stay is being implemented in your area.
- If an exposed and asymptomatic child is up to date on COVID-19 vaccination or has had a positive SARS-CoV-2 test in the past 90 days and has close contact with an individual with confirmed SARS-CoV-2 infection, the child does not need to quarantine per CDC guidance. However, the child should wear a well-fitting mask in all public indoor settings and at home for 10 days. However, emerging data suggest that reinfections within 90 days are more frequent with recent SARS-CoV-2 variants (including Omicron and related strains) and may occur at higher rates in young, unvaccinated individuals. If suspicion of reinfection is high, it is reasonable for the child to quarantine even within the 90-day period.
Algorithm C. Screening testing in asymptomatic individuals without known SARS-CoV-2 exposures
- Depending on local community levels of transmission, screening testing algorithms may be used as part of layered prevention strategies in schools and other settings. Screening applies to children who do not have symptoms consistent with COVID-19 and who do not have a known close contact exposure to an individual with confirmed or probable SARS-CoV-2 infection in the past 10days.
- Note: in the setting of high levels of local transmission, a positive rapid screening antigen test (Table 1) may be considered sufficient to make a diagnosis of SARS-CoV-2 infection, even in the absence of PCR confirmation.
- Many schools are using new testing platforms to balance test accuracy with cost and logistical barriers to use. For example, pooled PCR testing followed by individual testing of samples from positive pools can decrease cost, although turnaround time may be increased.
Interim Guidance Disclaimer: The COVID-19 clinical interim guidance provided here has been updated based on current evidence and information available at the time of publishing. Guidance will be regularly reviewed with regards to the evolving nature of the pandemic and emerging evidence. All interim guidance will be presumed to expire on December 31, 2022 unless otherwise specified.
American Academy of Pediatrics