COVID-19 Can Kill Months After Infection

April 23, 2021 — Long-haul COVID-19 patients face many health threats — including a higher chance of dying — up to 6 months after they catch the virus, according to a massive study published in the journal Nature.

A second study, released by the CDC on Friday, also found lingering symptoms months later among COVID-19 patients who originally had mild symptoms.

For the Nature study, researchers examined more than 87,000 COVID-19 patients and nearly 5 million control patients in a federal database. They found COVID-19 patients had a 59% higher risk of death up to 6 months after infection, compared to non-infected people.

Those findings translate into about eight extra deaths per 1,000 patients over 6 months, because many deaths caused by long-term COVID complications are not recorded as COVID-19 deaths, the researchers said. Among patients who were hospitalized and died after more than 30 days, there were 29 excess deaths per 1,000 patients over 6 months.

“As far as total pandemic death toll, these numbers suggest that the deaths we’re counting due to the immediate viral infection are only the tip of the iceberg,” Ziyad Al-Aly, MD, the senior author of the study and a director of the Clinical Epidemiology Center at the Veterans Affairs St. Louis Health Care System, said in a news release from the University of Washington Medical School in St. Louis.

Johns Hopkins University says more than 3 million people worldwide and about 570,000 people in the United States have died of coronavirus-related reasons.

Long-haul COVID patients also had a much higher chance of getting sick, and not just in the respiratory system, according to the study.

The patients had a high rate of stroke and other nervous system ailments; mental health problems such as depression; the onset of diabetes; heart disease and other coronary problems; diarrhea and digestive disorders; kidney disease; blood clots; joint pain; hair loss; and general fatigue.

Patients often had clusters of these ailments. And the more severe the case of COVID-19, the higher the chance of long-term health problems, the study said.

Researchers based their study on health care databases of the U.S. Department of Veterans Affairs. Besides the 87,000 COVID patients, the database included about 5 million patients who didn’t catch COVID. The veterans in the study were about 88% men, but the large sample size included 8,880 women with confirmed cases, the news release said.

Al-Aly, an assistant professor at Washington University Medical School, said the study shows that long-haul COVID-19 could be “America’s next big health crisis.”

“Our study demonstrates that up to 6 months after diagnosis, the risk of death following even a mild case of COVID-19 is not trivial and increases with disease severity,” he said. “Given that more than 30 million Americans have been infected with this virus, and given that the burden of long COVID-19 is substantial, the lingering effects of this disease will reverberate for many years and even decades.”

Meanwhile, the CDC on Friday released a new study of people who had milder cases of COVID-19. It found that almost two-thirds of them returned to the doctor within 6 months of their initial infections with new symptoms. 

The study validates the accounts of many COVID-19 long haulers who say they are still sick months later though their initial infections were mild.

More than 3,100 cases were reviewed for the study.  None of the patients had been hospitalized for their initial infections. The study found that nearly 70%, or 2,100 people, with mild infections treated by the Kaiser Permanente health system in Georgia returned to the doctor 1 to 6 months after that initial diagnosis, and nearly 40% needed to see a specialist.

Compared to people who didn’t return to the doctor after recovering from their initial infections, the long haulers were more likely to be African American, women, and people over the age of 50.  About 10% of them were given a second diagnosis of an active COVID infection.

“Health care providers used the diagnosis of active infection to indicate that the effects of COVID-19 were affecting medical care at the time of the visit,” study author Alfonso Hernandez-Romieu, MD, said in an email. “Therefore it cannot be determined whether patients might have been experiencing symptoms of reinfection with SARS-CoV-2, rather than ongoing COVID-19 symptoms,” said Hernandez-Romieu, who is part of the clinical team at CDC studying the long-term complications of COVID-19.

Pulmonologists, cardiologists, neurologists, and mental health professionals were some of the most frequently consulted specialties.

The study authors say doctors should be aware that patients coming to them might have new symptoms related to a past COVID diagnosis.