COVID-19 Testing in Nursing Homes: Are You Doing All Four Kinds?

While the SARS-CoV-2 transmission rate remains too high, the United States has experienced a downward trend of new COVID-19 cases since Aug. 25—a reduction that has been largely mirrored in new COVID-19 cases among nursing home residents and staff.

However, as previous cycles of the pandemic have shown, postacute-care providers shouldn’t breathe easy. A fall/winter surge that could bring significant outbreaks among nursing home residents and staff remains a possibility due to still-low vaccination rates in many communities, more indoor activities and holiday visits, and the potential spread of variants that are more infectious than the Delta variant.

Testing for SARS-CoV-2 infection is one of the key tools that nursing homes and other postacute care providers have to prevent and contain fast-moving outbreaks of COVID-19. The recommendations for when and how to test from the Centers for Disease Control and Prevention (CDC) and the Centers for Medicare & Medicaid Services (CMS) vary based on symptoms, exposure, vaccination status, time since any previous infection, and the purpose of the testing. Note: The terms SARS-CoV-2 infection and COVID-19 infection are used interchangeably in this article.

The following summary of four different testing scenarios for nursing home residents and staff is based on these resources:

• A presentation from Sophia Chiu, MD, MPH, chief medical officer for the Falls Hazard Evaluation Program at the CDC’s National Institute for Occupational Safety and Health (NIOSH) and a member of the CDC COVID-19 Response Team, at the Aug. 31 Summer 2021 Occupational Safety and Health Administration (OSHA) Healthcare Symposium;
• The Sept. 10 revision of the CMS Quality, Safety, and Oversight memo QSO-30-28-NH; and
• The Sept. 10 update to the Interim Infection Prevention and Control Recommendations to Prevent SARS-CoV-2 Spread in Nursing Homes and other CDC COVID-19 guidance.

Scenario 1: Symptomatic testing of residents and staff

“All residents and staff with signs or symptoms of COVID-19—regardless of vaccination status—should receive a viral test immediately,” says Chiu. “This includes residents and staff who are fully vaccinated, who are unvaccinated, or who had a SARS-CoV-2 infection in the last 90 days.”

The CDC considers people to be fully vaccinated “more than two weeks after receipt of the second dose in a two-dose series, or two or more weeks after receipt of a single-dose vaccine,” explains Chiu.

Next steps to take with symptomatic, tested staff are as follows:

• Restrict any staff with COVID-19 signs or symptoms from the facility while awaiting test results.

• If the staff member tests positive, follow the CDC guidance Interim Guidance for Managing Healthcare Personnel With SARS-CoV-2 Infection or Exposure to SARS-CoV-2.

• If the staff member with signs or symptoms does not test positive, respond based on the type of viral test used:

• • Point-of-care antigen tests: “Confirmatory testing [with a nucleic acid amplification test (NAAT)] is recommended in a symptomatic person with a negative antigen test,” says Chiu. For more information, see SARS-CoV-2 Antigen Testing in Long Term Care Facilities: Considerations for Use in Nursing Homes and Other Long-Term Care Facilities.
  • Laboratory-based NAATs aka reverse transcription polymerase chain reaction (RT-PCR) tests: Symptomatic staff who test negative either with an initial NAAT or a confirmatory NAAT should return to work in accordance with facility policy.

Next steps to take with symptomatic, tested residents are as follows:

• Place the resident on transmission-based precautions per the CDC guidance Interim Infection Prevention and Control Recommendations to Prevent SARS-CoV-2 Spread in Nursing Homes while awaiting test results.

• Take appropriate actions based on whether the test is positive or negative. Again, if a symptomatic resident tests negative with an antigen test, the CDC recommends confirmatory testing with a NAAT.

Scenario 2: Non-outbreak testing of “higher-risk exposures” and “close contacts”

Known or suspected COVID-19 exposures can occur when a nursing home is not in outbreak or outbreak investigation status. For example, exposures may come from a visitor, while a resident is on a leave of absence, or when a staff member is caring for a resident who is on the COVID-19 unit or on transmission-based precautions.

While all symptomatic residents and staff should be tested immediately, the CDC also recommends that asymptomatic residents who have had a “close contact” and asymptomatic staff who have had a “higher-level exposure” also be tested. The CMS memo QSO-30-28-NH defines these two terms under F-tag 886 (COVID-19 Testing—Residents and Staff):

This testing scenario includes staff and residents who are fully vaccinated and those who are unvaccinated, but not those who have had SARS-CoV-2 infection in the last 90 days. Testing should be done immediately (but not earlier than two days after the exposure) and, if negative, five to seven days after the exposure.

Higher-risk exposures for staff depend on two factors: the type of exposure and the personal protective equipment (PPE) that is worn, says Chiu. “So, the meaning of higher-risk exposure depends on the context of the healthcare setting encounter.” For example, a higher-risk exposure could include a staff member who has a prolonged close contact with a patient, visitor, or coworker with confirmed SARS-CoV-2 infection while they were not wearing eye protection and the infected person was not wearing source control, such as a cloth mask or face mask.

This testing scenario includes staff and residents who are fully vaccinated and those who are unvaccinated, but not those who have had SARS-CoV-2 infection in the last 90 days. Testing should be done immediately (but not earlier than two days after the exposure) and, if negative, five to seven days after the exposure.

As to the exemption for people who recently had COVID-19, reinfection appears to be uncommon during the initial 90 days, points out Chiu. “In adults who recovered from SARS-CoV-2 infection, positive NAAT results without new symptoms during the 90 days after initial onset more likely represent persistent shedding of viral RNA than reinfection.

This is the reasoning behind not testing asymptomatic people who have recovered in the 90 days after symptom onset. It is not related to differences in natural immunity vs. vaccine-induced immunity, but rather the ability to tell the difference between whether it is persistent viral shedding or new reinfection.”

Note: The CDC acknowledges that there could be clinical scenarios where testing is warranted for residents or staff earlier than three months after initial infection. For example, this could include people who are immunocompromised due to organ transplantation or chemotherapy, people whose initial positive result for COVID-19 is suspected of being a false positive, or people who are exposed to a novel variant. For additional information, see Interim Guidance for Managing Healthcare Personnel With SARS-CoV-2 Infection or Exposure to SARS-CoV-2 and Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic.

Scenario 3: Outbreak investigation testing of residents and staff

The following test-confirmed scenarios should trigger an outbreak investigation:

• Any new COVID-19 infection in any staff, or

• Any new nursing home-onset COVID-19 infection in a resident. The term “nursing home-onset” refers to infection that originated in the nursing home, says Chiu. “It doesn’t refer to residents who were known to have COVID-19 on admission to the facility and who were placed into appropriate transmission-based precautions to prevent transmission to others in the facility. It also doesn’t include residents who were placed into transmission-based precautions on admission and developed infection within 14 days after admission.”

The identification of a single case of COVID-19 in either other of these circumstances should result in immediate testing, says Chiu. “Fully vaccinated and unvaccinated people would be involved in this type of testing …, but not asymptomatic people who had a SARS-CoV-2 infection in the last 90 days.”

As of Sept. 10, CMS allows providers to employ two testing options for outbreak investigations:

* A contact tracing approach that targets staff with higher-risk exposures and residents with close contacts. If the facility is able to identify higher-risk exposures and close contacts with COVID-19 via contact tracing when there is a newly identified staff member with COVID-19 or a new nursing home-onset SARS-CoV-2 infection in a resident, “test all staff, vaccinated and unvaccinated, that had a higher-risk exposure with a COVID-19 positive individual” and “test all residents, vaccinated and unvaccinated, that had close contact with a COVID-19 positive individual,” says CMS in QSO-30-28-NH. The CDC guidance Interim Infection Prevention and Control Recommendations to Prevent SARS-CoV-2 Spread in Nursing Homes provides information on contact tracing.

* A broad-based approach using either facility-wide or group-level testing. If the facility is unable to identify close contacts with COVID-19 via contact tracing when there is a newly identified staff member with COVID-19 or a new nursing home-onset SARS-CoV-2 infection in a resident, “test all staff, vaccinated and unvaccinated, facility-wide or at a group level if staff are assigned to a specific location where the new case occurred (e.g., unit, floor, or other specific area(s) of the facility)” and “test all residents, vaccinated and unvaccinated, facility-wide or at a group level (e.g., unit, floor, or other specific area(s) of the facility),” says CMS.

In an outbreak investigation using a broad-based approach, immediate testing that identifies additional positives should be followed by serial viral testing (antigen or NAAT) “every three to seven days until no new cases are identified for 14 days,” says Chiu. If all tests are negative, providers should test again five to seven days later, according to the Interim Infection Prevention and Control Recommendations to Prevent SARS-CoV-2 Spread in Nursing Homes.

“If the facility has the ability to identify close contacts of the individual with COVID-19, they could choose to conduct focused testing based on known close contacts. If a facility does not have the expertise, resources, or ability to identify all close contacts, they should instead investigate the outbreak at a facility-wide or group-level (e.g., unit, floor, or other specific area(s) of the facility),” says CMS. “Broader approaches might also be required if the facility is directed to do so by the jurisdiction’s public health authority, or in situations where all potential contacts are unable to be identified, are too numerous to manage, or when contact tracing fails to halt transmission.”

Note: For the two types of outbreak testing discussed in scenario 3, the charts in memo QSO-30-28-NH recommend that providers “test all staff, vaccinated and unvaccinated” and “test all residents, vaccinated and unvaccinated,” which is slightly different than the above charts. However, CMS makes its outbreak testing guidance consistent with CDC guidance (and the above charts) to not test asymptomatic people who have had SARS-CoV-2 infection in the last 90 days by stating the following in the Other Testing Considerations section of the memo:

“Although exceptions exist, generally staff and residents who have recovered from COVID-19 and are asymptomatic do not need to be retested for COVID-19 within three months after symptom onset. Until more is known, testing should be encouraged again (e.g., in response to an exposure) three months after the date of symptom onset with the prior infection.”

Scenario 4: Routine (i.e., non-outbreak) serial screening testing of unvaccinated staff

Nursing homes must conduct routine testing of unvaccinated staff. “Serial testing of healthcare personnel with no symptoms and no known exposures—what is known as screening testing—can identify individuals with SARS-CoV-2 infection to allow for measures to prevent transmission,” explains Chiu.

“Modeling studies have shown that controlling an outbreak depends largely on the frequency of testing, the speed of the reporting, and the use of interventions to stop the outbreak. Outbreak control is only marginally improved by the sensitivity of the test. Another study has shown that serial repeated antigen testing every three days or twice a week will almost always identify SARS-CoV-2 during the early stages of infection and does significantly reduce transmission.”

As of Sept. 10, staff should monitor their community transmission level every other week using the Integrated County View at the CDC COVID-19 Data Tracker, says CMS in QSO-30-28-NH. Note: Get help finding community transmission levels here.

Screening testing of unvaccinated staff should be performed based on the previous week’s community transmission level at the minimum frequency identified in the following chart. If the level of community transmission increases to a higher level, testing staff at that higher-level frequency should begin immediately. However, if the level of community transmission decreases to a lower level, that lower transmission level needs to remain in place for at least two weeks before the facility reduces testing frequency.

Routine Testing Intervals by County COVID-19 Level of Community Transmission

+Vaccinated staff do not need to be routinely tested.
*This frequency presumes availability of Point of Care testing on-site at the nursing home or where off-site testing turnaround time is < 48 hours.

“Healthcare personnel who are fully vaccinated or who had SARS-CoV-2 infection in the last 90 days can be exempt from screening testing,” notes Chiu. In addition, routine testing of asymptomatic residents is not recommended if there is no outbreak investigation. However, providers may test asymptomatic residents “who leave the facility frequently, such as for dialysis or chemotherapy,” says CMS.

Caralyn Davis

Caralyn Davis is a freelance writer specializing in the post-acute care sector. Email her at: caralynd@outlook.com.