Serious Disease Observed in All Adult Age Groups


By: Kyle Freese, PhD, MPH

Daily summary 3/19/2020

The first, preliminary evidence from the Centers for Disease Control and Prevention (CDC) regarding serious disease from COVID-19 by age group in the U.S. was published online yesterday. Overall, the authors reported similar findings to those from China, with the addition that even young and middle-age adults (ages 20-44 years) experienced severe disease resulting in hospitalization. The figure to the right shows the number of 1) hospitalizations, 2) ICU admissions, and 3) deaths among select age groups. There were several limitations to the study, most notably were the amount of missing data (prevented the authors from providing point estimates), no data on underlying health conditions, and more broadly, testing is still not as widespread as needed.

The take-away from this report is that, though the risk of death from COVID-19 appears to follow similar trends as China, serious illness requiring hospitalization can occur in nearly any adult age group. As such, everyone should continue to practice social distancing to help prevent the spread of the virus.

In other news, Italy experienced another surge in new cases. According to the World Health Organization (WHO), there were 7,700 new confirmed cases throughout the country, compared with 3,400 three days ago and 3,200 two days ago. This is concerning for two reasons: 1) the peak of this wave of the epidemic appears to be high and 2) we should expect the number of deaths to continue to increase given this metric lags behind the identification of new cases.

Finally, China reached the important milestone of no, new local cases. This is encouraging because it might show how aggressive isolation measures can help slow the spread of the virus. Conversely, the milestone took over 10 weeks to reach; we should be cognizant that countries, such as the U.S. whose outbreak began later, could experience a prolonged epidemic, particularly if public health interventions are not successful.

Professional advice remains the same: wash your hands frequently, avoid crowds, practice social distancing, stay home if you are sick, and stay aware of any development of new sickness.

Stay safe and healthy and remember to be kind to one another.

Why “flatten the [epidemic] curve”?

Nearly all discussion surrounding the concept of “flattening the curve” has been focused on not overwhelming the healthcare system in the event of an outbreak. While this has important, direct effects, our efforts to slow the spread of the virus have other, indirect and long-term benefits.

Flattening the curve buys us time. Buys us time to conduct more basic, clinical, and epidemiologic research. Buys us time to develop an effective vaccine. Buys us time so people can recover so there are fewer infectious individuals in the community. By practicing social distancing, we are all contributing to these community goals on an individual level. Think of the sacrifices you make today as an investment for the future with an enormous return.

Our domestic and global economies rely on healthy workers to maintain the functioning of supply chains and healthy consumers to keep the wheels churning. Flattening the curve decreases the stress placed on the system that occurs with an exponential rise in cases. More crucial jobs remain filled, supply/ demand balance is maintained, and consumers and investors have more confidence in the health of the market. Decreasing uncertainty and volatility through our individual actions with the goal of flattening the curve will have huge, reverberating impacts at a societal level.

Below are the epidemic curves for select, high-income countries (Italy, Spain, France, Germany, the U.S., and the U.K.). We have a great opportunity in the U.S. to mitigate the spread of SARS-CoV-2 and have a responsibility to place our long-term health over our short-term comfort.


Severe outcomes among patients with coronavirus disease 2019 (COVID-19) – U.S., February 12-Mar 16, 2020. MMWR Morb Mortal Wkly Rep. ePub: 18 March 2020. DOI: http://dx/

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For additional references, resources, or questions, please email Dr. Kyle Freese at