Underlying Health Conditions Linked to Greatest Risk of Severe COVID-19 Infection

A report from the CDC’s COVID-19 Response Team includes preliminary data on patients with the highest risk of severe infection.

Initial reports from China and Italy led US health officials to suggest the patients at the greatest risk of severe infection from novel coronavirus 2019 disease (COVID-19) are older and/or have underlying health conditions.

However, confirmatory data from the United States—now the country with the highest number of confirmed COVID-19 cases—has been unavailable until now.

The US Centers for Disease Control and Prevention’s (CDC) COVID-19 Response Team have published preliminary data on the prevalence of particular underlying health conditions in the Morbidity and Mortality Weekly Report. The report shows that US data are consistent with other countries and patients with underlying health conditions are at higher risk of becoming critically ill.

The COVID-19 Response Team highlight data from confirmed cases that were reported to the CDC from all 50 states between February 12th and March 28th. Cases were excluded if individuals were repatriated from Wuhan, China or the Diamond Princess cruise ship.

Cases were reported to CDC with a standardized case report form which requires giving “yes, no, or unknown” answers concerning various underlying health conditions. Conditions and risk factors included chronic lung disease, diabetes, cardiovascular disease, chronic liver disease, neurodevelopmental disability, pregnancy, current and former smoker status, as well as chronic renal disease.

Percentages of hospitalization with and without ICU admission were estimated for people aged 19 years or older with and without underlying health conditions. To account for missing data in preliminary reporting, ranges were estimated based on known cases.

As of March 28th, US states and territories had reported 122,653 COVID-19 cases to CDC, with data available on underlying health conditions and other risk factors for severe illness available in 7162 (5.8%) cases.

Among the 7162 cases, 2692 (37.6%) of patients had 1 or more underlying health condition or risk factor.

Among 457 COVID-19 patients who required intensive care unit admission, 358 (78%) had an underlying health condition or risk factor.

In addition, 732 of 1037 cases that led to hospitalization without intensive care unit admission involved underlying health conditions.

“The most commonly reported conditions were diabetes mellitus, chronic lung disease, and cardiovascular disease. These preliminary findings suggest that in the United States, persons with underlying health conditions or other recognized risk factors for severe outcomes from respiratory infections appear to be at a higher risk for severe disease from COVID-19 than are persons without these conditions,” the authors wrote.

Given the increased risk of severe infection for those with an underlying health condition, the COVID-19 Response Team suggests these individuals must be cautious despite community measures such as social distancing and increased handwashing.

When social distancing measures are relaxed, those with underlying health conditions may still have to be particularly careful. This has been the case in severe flu seasons in years past, but with COVID-19, extra and extended precaution for at-risk groups may be necessary.