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Four respiratory infections, including influenza (flu), novel coronavirus disease (COVID-19), respiratory syncytial virus (RSV), and human metapneumovirus (HMPV), are currently circulating simultaneously. With family members likely gathering together during the long Lunar New Year holiday, health authorities are on high alert.
With multiple types of viruses spreading, there is a possibility of being infected by another illness even after being infected with one. For high-risk groups, there is a shortage of intensive care unit beds, making this holiday the biggest challenge.
This is not the first time four respiratory infections have circulated simultaneously. Each winter, 4 to 5 respiratory diseases have typically circulated. However, this time, the spread of respiratory infections, including flu, is notably rapid and large in scale.
Lee Jae-gap, a professor of infectious diseases at Hallym University Gangnam Sacred Heart Hospital, posted on social media, "RSV was the first to spread, followed by influenza and HMPV, leaving only COVID-19. I am concerned about the possibility of a 'quadrupledemic' occurring due to four respiratory viruses spreading at once."
According to the Korea Disease Control and Prevention Agency, the number of suspected flu cases showed an increase from 7.3 per 1,000 people in the first week of December last year (Dec. 1-7) to 99.8 in the first week of January this year (Dec. 29, 2024-Jan. 4, 2025), a nearly 14-fold increase in just one month. This is the highest level since tracking began in 2016. Hospitalizations for COVID-19 have also been on the rise for the past three weeks, with 62.9% of hospitalized patients being people aged 65 and older. The RSV outbreak is also concerning. Fewer people have been infected with RSV compared to flu, and there is no vaccine currently available in the country, making it necessary to monitor the spread closely.
Respiratory infections are categorized into upper respiratory infections like acute rhinitis, acute pharyngitis, acute laryngitis, and acute pharyngolaryngitis, and lower respiratory infections such as pneumonia and bronchitis.
The most common cause of infection is viral transmission through hands. Primarily, droplets that are released when coughing or sneezing enter the respiratory system directly or come into contact with mucous membranes in the eyes, nose, or mouth, leading to infection. If a virus is present on the hands, touching the face can also result in infection.
The typical symptoms of respiratory infections include high fever, cough, sore throat, body aches, muscle pain, headache, and inflammation in the upper or lower respiratory tract, often recognized as flu symptoms. However, for infants and the elderly, who have weaker immune systems, respiratory distress and cough with yellow phlegm can lead to complications such as pneumonia and, in severe cases, death. Particularly, RSV causes most children to experience a primary infection within the first two years of life, and among them, 20-30% may progress to bronchiolitis (inflammation of the small airways in the lungs) and pneumonia.
The number of suspected flu outpatients decreased by 13.7% to 86.1 per 1,000 in the second week of January (Jan. 5-11), indicating that the peak of the outbreak may have passed, but experts emphasize that the period from Jan. 25-30 during the six-day Lunar New Year holiday will be critical.
Eom Joong-sik, a professor of infectious diseases at Gachon University Gil Medical Center, noted, "The number of suspected flu cases has passed its peak, but typically after the holiday, the number increases again, and we could see another peak in 1-2 weeks. Care during the holidays is especially important." He warned that isolating suspected patients or high-risk groups by partitioning spaces is practically impossible, stating, "Following preventive measures such as wearing masks and handwashing is a priority, and there needs to be a cultural shift to exclude those with symptoms from holiday gatherings."
Professor Eom expressed concern about the shortage of intensive care unit beds due to the increase in hospitalizations. He explained, "After respiratory viral infections, damage occurs to the respiratory mucosa, leading to bacterial infections and pneumonia. Although the number of suspected cases may have reached a peak, the number of hospitalizations will likely continue to rise for up to two weeks after the peak. Currently, a major problem is the lack of medical personnel to manage patients and the fact that there are no places available for high-risk infants or elderly patients to be hospitalized."
In response to these concerns, the Ministry of Health and Welfare announced special measures on Jan. 16 to maintain the emergency medical system during the Lunar New Year holiday. With the emergency treatment system in conflict with the medical community already lasting nearly a year, combined with the recent surge of respiratory illnesses such as flu and COVID-19, measures have been increased compared to last Chuseok (harvest festival) holiday. The Ministry has designated the two-week period from Jan. 22 to Feb. 5 as the "Lunar New Year Emergency Response Week" and plans to conduct focused inspections and support for the medical system.
The Ministry will implement robust medical support measures during the long Lunar New Year holiday, which can last up to nine days. The top priority will be to strengthen support for severe and emergency surgeries. This aims to prevent delays in severe treatment due to shortages of medical personnel or hospital beds, as well as avoid situations known as emergency room ‘bumping.’ They plan to provide a 100% increase in overnight and holiday fees for severe and emergency surgeries at 181 regional emergency medical centers and area emergency medical centers. Consequently, the fee increase will rise from the previous 200% to 300%.