[Sportschosun Jang Jong-ho, Reporter] As influenza activity has surpassed the epidemic threshold and shows signs of an earlier-than-usual seasonal outbreak, hospitalizations for COVID-19 have also continued to rise, raising concerns about a “twindemic” in which the two infectious diseases spread simultaneously. According to the Korea Disease Control and Prevention Agency (KDCA), the influenza-like illness rate in the fourth week of August rose sharply to 13.3 cases per 1,000 outpatients, up from 9.2 the previous week and more than double the 6.4 cases recorded during the same period last year. The virus is spreading mainly among elementary school students aged 7 to 12 following the start of the school term, while the number of COVID-19 patients hospitalized at general hospitals has more than doubled in four weeks.
Influenza is an acute respiratory illness caused by influenza viruses. Infection can be fatal for older adults, children, and people with underlying conditions, and may lead to complications such as pneumonia, making it important not to overlook the early symptoms.
Park Wan-beom, a professor of infectious diseases at Seoul National University Hospital, said, “We have seen a noticeable increase recently in outpatients complaining of fever and cough.” He emphasized, “To prevent influenza and respond quickly when symptoms are suspected, it is essential to accurately distinguish it from the common cold and COVID-19 and to undergo testing and vaccination in a timely manner.”
◇Sudden high fever and muscle aches may indicate influenza; COVID-19 may involve loss of smell or taste
Influenza differs from the common cold from the outset because the causative pathogens are different. While a cold usually begins gradually with a runny nose, sneezing, and a mild fever of 38°C or lower, influenza is characterized by the sudden onset of high fever, headache, chills, muscle aches, and general weakness. COVID-19, meanwhile, may resemble a cold but can also cause loss of smell or taste and, as it progresses, difficulty breathing. These features can help distinguish among the three illnesses.
◇Seek medical care if these symptoms occur
Medical attention should be sought without delay if a high fever lasts for three to four days or longer, does not come down even after taking fever-reducing medication, or is accompanied by severe respiratory symptoms such as difficulty breathing, chest pain, or cyanosis, in which the lips turn blue. In children, caregivers should closely watch for signs of dehydration, including lethargy or reduced responsiveness, refusal to drink fluids, and decreased urination. If symptoms improve and then suddenly worsen again, a secondary infection such as bacterial pneumonia should be suspected. People at high risk of complications—including adults aged 65 or older, those with chronic illnesses, pregnant women, and infants under 2—should seek medical care early even if their symptoms are mild. Avoiding work or school and getting tested when fever or respiratory symptoms are present can also help reduce the spread of infection.
◇If left untreated, influenza can lead to pneumonia or encephalitis; children should be monitored for Reye syndrome
Untreated influenza can lead to serious complications. The most serious is pneumonia, which may be caused directly by the virus or develop through a secondary bacterial infection. Other possible complications include myositis, myocarditis, pericarditis, and neurological complications such as encephalitis.
Children in particular may develop Reye syndrome as their influenza symptoms begin to improve. They may suddenly vomit, become agitated, or develop severe brain-related symptoms such as seizures. Because the condition is known to be associated with aspirin use, aspirin must never be given to children with fever or cold symptoms of unknown cause.
◇Get tested early; the golden window for antiviral treatment is within 48 hours
If influenza is suspected, a specimen should be collected when symptoms begin, or no later than four to five days afterward for adults, to maximize testing accuracy. Rapid antigen tests can produce results in about 15 minutes, but their sensitivity may decline during an outbreak. If the result is negative despite clear symptoms, it is safer to confirm it with a molecular test, such as the more accurate real-time RT-PCR test, which takes at least six hours.
Antiviral medications used for treatment, including Tamiflu, peramivir, and baloxavir, are most effective when administered within 48 hours of symptom onset. However, people at high risk of complications should begin antiviral treatment even if more than 48 hours have passed.
◇Seasonal vaccination begins in stages on September 21; follow personal prevention measures such as masking and hand hygiene
The national influenza vaccination program for this season will begin in stages by age group and eligibility category on September 21, with coverage expanded to include children up to age 14. Vaccination for adults aged 65 and older will begin in mid-October, and COVID-19 vaccination can be administered at the same time during this period.
Professor Park Wan-beom advised, “Because it is difficult to distinguish influenza, COVID-19, and the common cold perfectly based on symptoms alone, the most accurate approach is to get tested immediately when infection is suspected.” He added, “High-risk groups, including older adults and people with underlying conditions, should not delay vaccination and should strictly follow basic prevention measures such as wearing masks and practicing hand hygiene.”
Jang Jong-ho, Reporter bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
