[Q&A] Even Asymptomatic COVID-19 Patients Can Experience Aftereffects

Korea Disease Control and Prevention Agency 'Understanding COVID-19 Aftereffects'

[Asia Economy Reporter Kim Young-won] The government announced on the 10th that it will conduct a survey on post-COVID-19 symptoms targeting 10,000 citizens. Earlier, in March, the National Institute of Health Research announced that it would investigate post-COVID-19 symptoms in 1,000 confirmed cases through a network involving 14 domestic institutions. With about one-third of the population having a history of COVID-19 infection due to the Omicron surge in the first half of this year, attention is focused on post-COVID-19 symptoms.

What are post-COVID-19 symptoms?

The World Health Organization (WHO) defines post-COVID-19 symptoms as those that begin within three months of the onset of COVID-19, last for at least two months, and cannot be explained by alternative diagnoses. The detailed definitions vary slightly by country. In the United States, symptoms persisting for more than four weeks after COVID-19 infection, whether continuous, recurrent, or newly appearing, are considered post-COVID-19 symptoms.

What are the main symptoms?

Generally, over 200 diverse symptoms have been reported, including headache, decreased concentration, cognitive impairment, sleep disorders, abnormalities in smell and taste, cough, hair loss, shortness of breath, joint and muscle pain, palpitations, menstrual cycle changes, fatigue, and abdominal pain. Some cases report multi-organ symptoms affecting the heart, lungs, kidneys, skin, and brain function. Various research studies are ongoing both domestically and internationally.

How long do the symptoms last?

The duration varies by individual. According to WHO, most confirmed cases fully recover, but about 10-20% experience various symptoms in the medium to long term even after the initial infection symptoms have resolved. The duration of post-COVID-19 symptoms can differ from person to person.

Is there a possibility of transmission?

While symptoms due to post-COVID-19 conditions may persist, it is known that there is no infectiousness.

Can asymptomatic or mild COVID-19 patients also experience post-COVID-19 symptoms later?

Yes. Post-COVID-19 symptoms are presumed to be unrelated to the severity of initial infection symptoms or hospitalization status.

Can children and adolescents also experience post-COVID-19 symptoms?

Children and adolescents are reported to potentially experience post-COVID-19 symptoms similar to adults. However, most existing studies on post-COVID-19 symptoms have primarily focused on adults, so information on children and adolescents remains very limited.

In children infected with COVID-19, the COVID-19-associated multisystem inflammatory syndrome in children (MIS-C) has been reported rarely, at about 0.02?0.31%. The age range is between 3 months and 20 years, occurring 2?4 weeks after COVID-19 infection, with symptoms such as fever, gastrointestinal symptoms including abdominal pain, diarrhea, vomiting, and rash.

In Korea, since the first case in May 2020, there have been 19 cases of multisystem inflammatory syndrome among COVID-19 confirmed patients aged 0?18 years, all of whom improved and were discharged.

How can it be treated?

So far, no specific treatment has been reported. It is recommended to visit medical institutions for symptomatic treatment according to the symptoms. Symptoms tend to improve over time, and sufficient rest is necessary for relief. If there are concerns about mental health deterioration due to anxiety, depression, or stress, the National Psychological Support Center can be utilized.

Does the COVID-19 vaccine help alleviate post-COVID-19 symptoms?

More research is needed on the impact of COVID-19 vaccination on post-COVID-19 symptoms. However, COVID-19 vaccination helps form immunity against the virus, which can aid in preventing infection and severe illness.

Eight studies analyzing the effectiveness of vaccination before COVID-19 infection in the UK found that vaccinated individuals were less likely to experience post-COVID-19 symptoms compared to unvaccinated individuals.