IDSA outlines four-tiered approach for COVID-19 testing
The Infectious Diseases Society of America has released recommendations for health care professionals to use in prioritizing testing for COVID-19 during the ongoing shortage of accessible tests.
The IDSA testing recommendations, which were announced Thursday, use a four-tiered approach that is based on patient characteristics and risk levels.
The first tier includes:
- Critically ill patients in ICU-level care who have unexplained symptoms of viral pneumonia or respiratory failure regardless of travel history or close contact with patients who have suspected or confirmed COVID-19 infection;
- Individuals (including health care workers) with a fever or respiratory symptoms and either one of the following scenarios: close contact with a patient who has a laboratory-confirmed case of COVID-19 within 14 days of symptom onset, including all patients in a long-term care facility who have a laboratory-confirmed case of COVID-19 or recent travel (within 14 days of symptom onset) to areas with high community transmission; and
- Patients with fever or respiratory symptoms and either one of the following scenarios: being immunosuppressed (including patients with HIV) or elderly or having underlying chronic conditions or being an individual critical to the pandemic response, including health care workers, public health officials and other essential leaders.
Tier two includes hospitalized patients who are not in the ICU and long-term care residents with an unexplained fever and symptoms of a lower respiratory tract infection. IDSA recommends considering the number of confirmed COVID-19 cases in the community in their explanation of tier two: “As testing becomes more widely available, routine testing of hospitalized patients may be important for infection prevention and management at discharge.”
Tier three includes individuals in outpatient settings who are eligible for influenza testing, such as those with select comorbid conditions like diabetes, chronic obstructive pulmonary disease and congestive heart failure. Tier three also includes patients who are older than 50 years and immunocompromised hosts.
In outlining their criteria for tier three, IDSA notes that, given the limited data on the subject, “testing of pregnant women and symptomatic children with similar risk factors for complications is encouraged.” They also recommend that the number of confirmed cases of COVID-19 in the community should be taken into account.
The final tier includes individuals in communities being monitored by public health and/or infectious disease authorities.
According to IDSA, these recommendations will be revised as testing becomes more widespread and new information become available.
“Overall, current prevalence of COVID-19 disease in the United States remains low,” the release from IDSA notes. “Thus, in interpretation of diagnostic test results, clinicians should consider that, when disease prevalence is low, false-positive results of testing are increased. Typically, false-positive rates of testing are increased when disease prevalence is below 15%-20%. If [a] false positive is suspected, test should be repeated (with a new specimen if possible) or a test using a second assay that targets a different gene should be performed.” – by Caitlyn Stulpin
IDSA. COVID-19 prioritization of diagnostic testing. https://www.idsociety.org/globalassets/idsa/public-health/covid-19-prioritization-of-dx-testing.pdf. Accessed March 19, 2020.