Many people are still suffering from the aftereffects of COVID-19, such as coughing, breathing difficulties and fatigue, four years since the first novel coronavirus infection was confirmed in Japan in January 2020.

An estimated 10 to 20 percent of adults in Japan who have been infected have experienced “long COVID” symptoms.

Since May 2023, COVID-19 has been classified in the same category as seasonal influenza under the infectious disease prevention law.

The eased sense of urgency about COVID-19 has made it difficult for some people suffering from continuing symptoms to find relief.

A 50-year-old woman in Osaka Prefecture who contracted the virus in July 2022 is still showing symptoms a year and a half later.

She often coughs and becomes short of breath when she talks, and she continues to experience body fatigue.

She works as a temporary staff worker who mainly handles phone calls, and she sometimes finds it difficult to speak clearly.

The woman took a three-month break from work right after she became infected.

She used to work six times a week for more than eight hours a day, but she now works only three times a week for about four hours a day.

Her income has been drastically reduced.

“If you can’t work any longer, we will have to let you go,” her staffing agency told her.

She said she contacted more than 10 medical institutions about the aftereffects but was told they were not accepting new patients with long COVID.

One clinic agreed to check her condition, but the symptoms did not improve after the visit.

She was referred to another hospital in Osaka that has an outpatient service specifically for COVID aftereffects.

When she visited the hospital in December, the doctor advised her to gradually return to her normal life.

“I felt hopeful,” she said.

However, she still feels distressed by the lack of understanding shown by people at her workplace and her surroundings.

“It’s hard being seen as someone who continues to suffer from unexplained health issues,” she said. “I hope that the cause of the aftereffects will be clarified, and that society’s understanding of the health issue will improve.”

Satoshi Marumo, a doctor at the Medical Research Institute Kitano Hospital who treated the woman, said most post-COVID symptoms improve over time, but there are no established methods for diagnosis and treatment yet.

He said the main approach is symptomatic therapy to alleviate the symptoms while running tests to rule out other diseases as their cause.

“It cannot be said that there are enough medical facilities to accept these patients,” Marumo said.

AFTEREFFECT MECHANISMS

The COVID aftereffects vary, and their duration differs from person to person. The lingering symptoms could occur in anyone following infection.

More than 17 million people in Europe are believed to have experienced COVID aftereffects between 2020 and 2021.

The World Health Organization defines long COVID or Post-COVID-19 Condition as “the continuation or development of new symptoms three months after the initial infection, with these symptoms lasting for at least two months with no other explanation.”

While much remains unknown about long COVID, some aspects on how the symptoms keep occurring are becoming clearer.

Some health experts said the development of aftereffects is related to prolonged initial infections, abnormalities in the immune system and other factors.

A research team, including Akiko Iwasaki, professor of immunology at Yale University in the United States, published a study in British scientific journal Nature in September 2023, suggesting that changes had occurred in substances related to immune functions.

An analysis of blood samples from patients whose aftereffects have continued for more than a year showed the amount of cortisol, a hormone that increases under stress, was reduced by half.

Reduced cortisol can cause low blood sugar and low blood pressure, leading to poor concentration, fatigue and malaise.

The study also found an increase in B cells and T cells, types of lymphocytes responsible for immunity, and reactivation of the herpes virus in the bodies of long COVID patients.

The decrease in cortisol appears to be a contributing factor to some symptoms, indicating that the novel coronavirus and the herpes virus are lingering in the body, triggering the COVID aftereffects.

“The study showed that aftereffects are not psychological problems; it has become evident that physical changes are occurring,” Iwasaki said.

(This article was written by Mirei Jinguji and Tokiko Tsuji, senior staff writer.)