While COVID has now claimed more than 1 million lives in the United States alone, these aren’t the only fatalities caused at least in part by the virus. A small but growing number of Americans are surviving acute infections only to succumb months later to the lingering health problems caused by long COVID.
Much of the attention on long COVID has centered on the sometimes debilitating symptoms that strike people with the condition, with no formal diagnostic tests or standard treatments available, and the effect it has on quality of life. But new figures from the US Centers for Disease Control and Prevention (CDC) show that long COVID can also be deadly.
More than 5000 Americans have died from long COVID since the start of the pandemic, according to new estimates from the CDC.
This total, based on death certificate data collected by the CDC, includes a preliminary tally of 1491 long COVID deaths in 2023 in addition to 3544 fatalities previously reported from January 2020 through June 2022.
Guidance issued in 2023 on how to formally report long COVID as a cause of death on death certificates should help get a more accurate count of these fatalities going forward, said Robert Anderson, PhD, chief mortality statistician for the CDC, Atlanta, Georgia.
“We hope that the guidance will help cause of death certifiers be more aware of the impact of long COVID and more likely to report long COVID as a cause of death when appropriate,” Dr. Anderson said. “That said, we do not expect that this guidance will have a dramatic impact on the trend.”
There’s no standard definition or diagnostic test for long COVID. It’s typically diagnosed when people have symptoms at least 3 months after an acute infection that weren’t present before they got sick. As of the end of last year, about 7% of American adults had experienced long COVID at some point, the CDC estimated in September 2023.
The new death tally indicates long COVID remains a significant public health threat and is likely to grow in the years ahead, even though the pandemic may no longer be considered a global health crisis, experts said.
For example, the death certificate figures indicate:
COVID-19 was the third leading cause of American deaths in 2020 and 2021, and the fourth leading cause of death in the United States in 2023.
Nearly 1% of the more than one million deaths related to COVID-19 since the start of the pandemic have been attributed to long COVID, according to data released by the CDC.
The proportion of COVID-related deaths from long COVID peaked in June 2021 at 1.2% and again in April 2022 at 3.8%, according to the CDC. Both of these peaks coincided with periods of declining fatalities from acute infections.
“I do expect that deaths associated with long COVID will make up an increasingly larger proportion of total deaths associated with COVID-19,” said Mark Czeisler, PhD, a researcher at Harvard Medical School, Boston, Massachusetts, who has studied long COVID fatalities.
Months and even years after an acute infection, long COVID can contribute to serious and potentially life-threatening conditions that impact nearly every major system in the body, according to the CDC guidelines for identifying the condition on death certificates.
This means long COVID may often be listed as an underlying cause of death when people with this condition die of issues related to their heart, lungs, brain or kidneys, the CDC guidelines noted.
The risk for long COVID fatalities remains elevated for at least 6 months for people with milder acute infections and for at least 2 years in severe cases that require hospitalization, some previous research suggested.
As happens with other acute infections, certain people are more at risk for fatal case of long COVID. Age, race, and ethnicity have all been cited as risk factors by researchers who have been tracking the condition since the start of the pandemic.
Half of long COVID fatalities from July 2021 to June 2022 occurred in people aged 65 years and older, and another 23% were recorded among people aged 50-64 years old, according a report from CDC.
Long COVID death rates also varied by race and ethnicity, from a high of 14.1 cases per million among America Indian and Alaskan natives to a low of 1.5 cases per million among Asian people, the CDC found. Death rates per million were 6.7 for White individuals, 6.4 for Black people, and 4.7 for Hispanic people.
The disproportionate share of Black and Hispanic people who developed and died from severe acute infections may have left fewer survivors to develop long COVID, limiting long COVID fatalities among these groups, the CDC report concluded.
It’s also possible that long COVID fatalities were undercounted in these populations because they faced challenges accessing healthcare or seeing providers who could recognize the hallmark symptoms of long COVID.
It’s also difficult to distinguish between how many deaths related to the virus ultimately occur as a result of long COVID rather than acute infections. That’s because it may depend on a variety of factors, including how consistently medical examiners follow the CDC guidelines, said Ziyad Al-Aly, MD, chief of research at the Veterans Affairs, St. Louis Health Care System and a senior clinical epidemiologist at Washington University in St. Louis.
“Long COVID remains massively underdiagnosed, and death in people with long COVID is misattributed to other things,” Dr. Al-Aly said.
An accurate test for long COVID could help lead to a more accurate count of these fatalities, Dr. Czeisler said. Some preliminary research suggests that it might one day be possible to diagnose long COVID with a blood test.
“The timeline for such a test and the extent to which it would be widely applied is uncertain,” Dr. Czeisler noted, “though that would certainly be a gamechanger.”
A version of this article appeared on Medscape.com.