Understanding the nuances of screening and testing criteria.
During a novel outbreak, there are several critical aspects of containment and mitigation. Some of the most important involve the ability to identify those at risk for infection and thus test for the disease. For the novel outbreak of COVID-19, the guidance on how to evaluate and report persons under investigation (PUI) has been an evolving target.
Initially focused on travel to Wuhan, China and the presence of symptoms, guidance was expanded to include travel to Iran, Italy, Japan, and South Korea in late February. Moreover, those changes included exposure to a laboratory-confirmed case or those patients requiring hospitalization for a severe acute respiratory illness with no known etiology. The expansion of these criteria for PUI to help guide evaluation and testing was issued on February 28th. While focused on symptoms, this guidance opened up testing capabilities to those without a known exposure or relevant travel history.
On March 4th, though, the US Centers for Disease Control and Prevention (CDC) updated this further — expanding recommendations to a larger group of symptomatic patients. Since the clinical presentation of COVID-19 can be quite broad (fever, cough, etc.) and it is currently respiratory virus season, it can be difficult to gauge those patients requiring adequate isolation and testing.
This becomes even more challenging as community transmission continues and dependence on travel screening wanes. The CDC now states that with expanded diagnostic testing capabilities, “Clinicians should use their judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested. Decisions on which patients receive testing should be based on the local epidemiology of COVID-19, as well as the clinical course of illness. Most patients with confirmed COVID-19 have developed fever1 and/or symptoms of acute respiratory illness (eg, cough, difficulty breathing). Clinicians are strongly encouraged to test for other causes of respiratory illness, including infections such as influenza.”
Those epidemiological factors to consider include close contact with a laboratory-confirmed case within 14 days of symptom onset or travel to an affected geographical area within 14 days of symptom onset. Those affected geographical areas include the most hard-hit countries, like China, South Korea, Italy, Iran, and Japan.
While the expansion of PUI guidance is helpful in that it means a wider net to identify cases, it also will help, hopefully, lessen the burden on public health agencies as a gateway for testing determination.
Coordination with infection prevention and public health is still important though, but as testing capabilities increase, so will frontline capacity to rapidly identify patients. One of the most vital things though, in this expansion of PUI guidance is to ensure those patients being tested but not requiring hospitalization, self-isolate at home and stay in communication with local public health authorities.
Ensuring those patients stay home while sick and during the testing phase, is an important part of infection prevention and outbreak mitigation. As the COVID-19 outbreak evolves and likely grows with enhanced surveillance capabilities, it is vital we have adequate healthcare screening for potential patients and reinforce our infection prevention measures. Ensuring we stay vigilant with the i3 approach (identify, isolate, and inform) will be critical during this outbreak.