Long COVID-19 has caused or at least contributed to the deaths of more than 3,500 Americans, according to new research released early Wednesday by the Centers for Disease Control and Prevention’s (CDC) National Center for Health Statistics. 

Researchers analyzed the text of death certificates from Jan. 1, 2020, through June 30, 2022, and found 3,544 deaths mentioning key terms such as “chronic COVID,” “long COVID,” “long haul COVID,” or “long hauler COVID.”

Those deaths represent just 0.3 percent of the more than 1 million people who have died from COVID-19 in the U.S., but the report is part of the growing recognition of the severity of long COVID, a condition that remains poorly understood.

Long COVID occurs when patients who are no longer infected with the coronavirus still have symptoms after recovery. In some cases, these symptoms can persist for months or even years. Some of the most debilitating problems include brain fog, heart issues and extreme fatigue.

But until recently, there was no specific diagnostic code or universal definition of what long COVID is. There was no diagnostic code for long COVID in the U.S. until October 2021.

A death can only be attributed to long COVID if a patient was diagnosed with it.

The researchers found the highest number of deaths with long COVID occurred this February. The percentage of COVID-19 deaths with long COVID peaked in June 2021, which coincided with periods of declining numbers of COVID-19 deaths. 

The vast majority of deaths — 78.5 percent — were among white Americans, the researchers found. Non-Hispanic Black people accounted for 10 percent of deaths, followed by Hispanic people at 7.8 percent. Those numbers are notable because both Hispanics and Black people accounted for much higher rates of overall COVID-19 deaths than white Americans.

These differences may be due to higher mortality among non-Hispanic Black and Hispanic populations, resulting in fewer COVID-19 survivors left to experience long COVID conditions, the report said.

Low rates of long COVID among non-Hispanic Black and Hispanic people may also be due to poor access to health care and appropriate diagnosis and reporting of post-COVID-19 conditions in these population, according to the researchers. 

Men accounted for a slightly larger percentage of long COVID deaths, at 51.5 percent, than women, 48.5 percent.

People between ages 75 and 84 accounted for nearly 29 percent of long COVID deaths, followed closely by those aged 85 and older and then those aged 65 to 74.