Insight Regarding Testing Criteria for COVID-19 in the US

The outbreak of the novel coronavirus, SARS-CoV-2, which causes COVID-19, has been testing international public health and health care efforts since earlier this year. Over 76,000 cases of COVID-19 have been identified, and with cruise ships as the latest environment with clusters of cases, attention to this outbreak has only grown.

In the United States, there have been 14 confirmed cases, 12 of which are linked to travel. There have also been 36 cases linked to individuals repatriated from the Diamond Princess ship. There are also 3 cases from individuals repatriated from China, bringing the count to 53 cases in the United States.

However, for many working in health care and public health, there have been many persons evaluated for the disease through emergency departments, urgent cares, and medical offices. The US Centers for Disease Control and Prevention (CDC) has guidelines including criteria for testing individuals who may have COVID-19. For public health and health care workers alike it can be helpful to understand general trends and overall data on individuals requiring testing.

In the latest issue of the CDC’s Morbidity and Mortality Weekly Report (MMWR), a research team provided insights regarding individuals who meet criteria for testing. As of January 31^st, the CDC had responded to medical inquiries for 650 people who were felt to be at risk for the disease.

Following the criteria listed for patients under investigation (PUI), 210 were symptomatic and therefore tested for the disease. Of this group, 70% (148) had travel-related risk while 20% (42) had close contact with an ill laboratory-confirmed cases of COVID-19. Eighteen people from this group (9%) had both travel and contact-related risks that put them into the category for testing. Of those tested, 11 (5%) had a laboratory-confirmed case of COVID-19. Nine of these cases had traveled to Wuhan City and 2 did not have relevant travel history but did have close contact with laboratory-confirmed cases. All of the individuals who tested positive for the diseases had symptoms.

Testing was recommended for the 256 people across 34 jurisdictions and was ultimately completed for 210 people. In cases where patients were not tested, alternative diagnoses or symptom resolution occurred.

The report notes that “Among inquiries resulting in testing, 6 (3%) persons were identified through airport screening, 178 (85%) in a health care setting, and 26 (12%) through contact tracing. Among 178 persons identified in a health care setting, the type of setting was reported for 125 (70%), including 79 (63%) who were evaluated at an emergency department or hospital, 22 (18%) at a student clinic, and 24 (19%) in other outpatient care settings.”

Of those tested, 55% were male and the median age was 29 years. Interestingly 8% of tested individuals (17) were health care workers. Regarding symptoms, the study team found that 68% of individuals had a subjective fever and 90% had a cough or shortness of breath. Thirty people tested positive for another respiratory illness, including influenza. Twenty percent were hospitalized and 2% were admitted to intensive care units, with 1 dying at the time of notification.

Overall, these findings shed light on the volume of inquiries the CDC was fielding during this time frame, as well as the epidemiological risk factors. Since 20% of those patients who met testing criteria did not have recent travel to China, detecting close contact with confirmed or suspected cases, is critical.

This is an important point that should reinforce patient screening efforts that clinicians are asking suspected case patients about travel history as well as exposure to symptomatic people with a suspected or confirmed case of COVID-19. Future analyses of those patients under investigations will be important to help guide additional communication and screening efforts.