Covid-19 discriminates against those who it sickens and kills. The disease discriminates both by ethnicity and by pre-existing disease. The two are likely to be synonymous given what we know about the social determinants of health. A newly released report by the CDC summarizes the stark differences in how SARS-CoV-2 infection impacts different populations.
Risk of illness and death by pre-existing condition:
The report reveals that of those with pre-existing conditions at the time of infection 45.4% percent were hospitalized and 19.5% died, as compared to 7.6% of those who were healthy who were hospitalized and 1.6% who died. To my knowledge this is an unprecedented difference for an infectious disease. Heart disease, diabetes, and lung disease are the primary illnesses that predispose a patient to death following infection.
The most common underlying conditions reported in people with Covid-19 were:
Heart Disease 32%
Lung Disease 18%
Other preexisting conditions included liver disease, kidney disease, neurodevelopmental or intellectual disability, and immunocompromised conditions.
This reflects similar global findings published in the Lancet, which suggests that those with chronic kidney disease, diabetes, cardiovascular disease, and chronic respiratory disease are most at risk. Globally, about one in five individuals worldwide could be at increased risk of severe Covid-19, should they become infected, due to these underlying health conditions.
Risk of illness and death by ethnicity:
The report also reveals a profound difference in the impact of Covid-19 by ethnicity.
Once infected, ethnic minorities have on average about twice the chance of becoming seriously ill and dying as compared to non-Hispanic whites.
Hispanics, who make up 18% of the population, account for 33% of those who become seriously ill or die from Covid-19.
Blacks, who make up 13% of the population, account for 22% of the seriously ill or dead.
And Native Americans and Alaskan Natives make up 1.7% of the population yet account for 2.6% of the seriously ill or dead.
As dramatic as these differences are, they explain only part of the total picture. The incidence of infection also differs according to ethnicity. In some communities, the infection of black and Hispanic populations is four to five times greater than those of non-Hispanic whites. The incidence of infection is also very high in Native American peoples.
The report also addresses the question of asymptomatic transmission—the fraction of infections that can be attributed to people who did not know they were infected at the time. The CDC estimates that asymptotic transmission may account for 41% of all infections.
My first conclusion: People with these underlying health conditions and their families should be especially careful to avoid exposure. Schools and workplaces should provide exceptional protection for those who identify themselves as especially at risk.
My second conclusion: The differences in illness and death can be directly attributed to social determinants of health. The difference in the underlying health of people of differing ethnicities in the United States corresponds closely to differences in the outcomes of Covid-19 infection.
Health outcomes in the United States fall well below those of all other high income and OECD nations. The disparities in health revealed by Covid-19 are well known to all of us in the health industry and are a cause of great suffering. They are also one of the reasons the cost of healthcare in the United States is almost twice that of other nations. Health disparities are also one of the reasons we lead the world in Covid deaths.
My third conclusion: The high proportion of infection attributable to asymptomatic carriers reinforces he need for continued personal precautions. On average, slightly more than 20,000 people in the United States are discovered to be newly infected by SARS-CoV-2 each day, a number that has been near constant since April 1. If people are infectious on average for ten days that translates to a prevalence of 200,000 infectious people on any given day.
The safest assumption, and the one I make, is that everyone I meet may be infected. Until the infection is dramatically reduced, I urge all to wear masks in public, follow social distancing guidelines, and to adhere to all other recommended precautions.