In recent days there has been a flood of reports suggesting, if not always saying quite directly, that many more young people (<50 or <60) are getting sick and even severely ill than we were expecting based on data out of China from earlier in the year. As best I can tell (and I'm looking very carefully at the available data) this is not true. Many young and middle aged people are getting sick. But not at rates that are beyond what we should expect or out of line with data out of China or other parts of the world that are running ahead of us in the pandemic.
(As we discussed on February 28th – which seems like a lifetime ago – numeracy is both the hardest thing to hold on to in a situation like this and critical to making good decisions both personally and as a society.)
The simplest way to put this is that many people have taken the relatively low incidence of severe illness and death in people under 65 to mean something more like if you’re young and healthy you don’t get that sick. Obviously those are two very different things.
One of the iconic stories of this unfolding tragedy is that of Li Wenliang, a doctor from Wuhan who was one of the first to raise the alarm about the disease in late December. He was detained by police on January 3rd for “spreading false rumors” and forced to sign a document admitting to breaking the law. He later contracted the disease and died on February 6th. He was 34 years old.
There is a separate debate about why doctors and medical professionals appear to be particularly susceptible to severe disease. This may be a phantom of limited data. But it has been speculated by disease experts that the intensity of their exposure may result in more severe disease. Setting that debate aside, Dr. Li’s fate stands in for a simple point: apparently young, healthy people can and do die from COVID-19.
The CDC just released this report on COVID-19 disease incidence and outcomes in the United States between February 12th and March 16th. The authors make clear that in the rush of recent events there is a lot of data that has yet to be compiled on the 4,226 cases studied. Let me quote their caveats: “This report describes the current epidemiology of
COVID-19 in the United States, using preliminary data. The findings in this report are subject to at least five limitations. First, data were missing for key variables of interest. Data on age and outcomes, including hospitalization, ICU admission,
and death, were missing for 9%–53% of cases, which likely resulted in an underestimation of these outcomes. Second, further time for follow-up is needed to ascertain outcomes
among active cases. Third, the initial approach to testing was to identify patients among those with travel histories or persons with more severe disease, and these data might overestimate the prevalence of severe disease. Fourth, data on other risk
factors, including serious underlying health conditions that could increase risk for complications and severe illness, were unavailable at the time of this analysis. Finally, limited testing to date underscores the importance of ongoing surveillance of
COVID-19 cases. Additional investigation will increase the understanding about persons who are at risk for severe illness and death from COVID-19 and inform clinical guidance and community-based mitigation measures.”
Here is the chart for absolute numbers of hospitalizations, ICU admissions and deaths.
And here is a chart showing estimates of the percentages of these outcomes by age group. Note the incompleteness of the data has required them to do upper and lower bound estimates in each case.
Big picture. These numbers are fairly similar to those from the outbreak in Wuhan. Mortality and severe disease are heavily concentrated among those over 65 and especially over 85. But from young adulthood on up people do get very ill; a significant percentage are hospitalized, some in critical condition and some die. As you can see from these numbers, if you are a healthy 45 year old, your chances of dying from COVID-19 are quite low, less than 1%. But your chances of requiring hospitalization are quite real and your chance of requiring admission to an ICU are still non-trivial.
The one saving grace to these numbers – particularly for those of us who are parents of young children – is that under the age of 20 people really do seem largely immune from bad COVID-19 outcomes. No, it’s not absolute. But it appears to be close. The initial outbreak in China recorded zero deaths in people 0-9 and one fatality in those between 10 and 19. This is out of roughly 70,000 cases for the outbreak as a whole. As you can see from this CDC data, they estimate the percentage of ICU admissions or death for those under twenty years of age to be zero and a very small number (no more than 2.5%) even requiring hospitalization.
One final point. Bear in mind that this new CDC data – at least as I am able to understand it – is for confirmed cases. They are taking the number of confirmed cases and using statistical models to estimate outcome percentages since they don’t have all the data for those cases. But this is still for confirmed cases, which all assume are only a subset, quite possibly a very small subset, of the actual number of infections in the United States. Many of those are milder or even asymptomatic.