[Sportschosun Jang Jong-ho] The incidence of invasive group A streptococcal infections in children, which had dropped sharply during the COVID-19 pandemic, has risen quickly again after the easing of public health measures and has rebounded to pre-pandemic levels. The first domestic case of the globally spreading M1UK lineage has also been identified, strengthening calls for a national surveillance system that tracks both severe infections and changes in bacterial strains.
A domestic multicenter research team led by Lee Hyun-joo and Kim Ye-kyung of the Division of Pediatric Infectious Diseases at Seoul National University Bundang Hospital analyzed 454 patients with invasive group A streptococcal infections at 23 university hospitals nationwide from 2015 to 2024. The findings, based on a policy project commissioned by the KDCA, were published in the international journal The Lancet Regional Health: Western Pacific. It is the largest domestic multicenter study to comprehensively examine 10 years of incidence trends, clinical characteristics, and major genotype distribution in invasive group A streptococcal infections in Korea.
Group A streptococcus is a bacterium that mainly infects the respiratory tract or skin and soft tissues. It can cause pharyngitis with swelling and fever, scarlet fever, and skin infections.
The concern is invasive group A streptococcal infection, which has a high fatality rate. Although it is relatively rare, it refers to cases in which the bacteria do not remain confined to the respiratory tract or skin and instead invade the blood, joint fluid, cerebrospinal fluid, and other parts of the body. It can rapidly worsen into sepsis or necrotizing fasciitis, or lead to toxic shock syndrome, a deadly complication in which blood pressure drops and multiple organs are damaged at the same time.
According to the research team, the most notable change over the past decade was the rebound in incidence among children and adolescents after the pandemic. Among all pediatric inpatients, the incidence of invasive group A streptococcal infection fell by about 90 percent, from 9.34 cases per 100,000 people before COVID-19 to 0.95 during the pandemic control period from 2020 to 2022. It then rose again to 10.45 in 2023 and 2024. Among adults, the rate fell from 6.57 to 1.83 over the same period, then increased only to 2.47.
For older adults, the burden was greater in severity than in frequency. The mortality rate among those aged 65 and older was 26.5 percent, far above the overall mortality rate of 15.5 percent and the pediatric mortality rate of 10.5 percent. One in five invasive cases, or 19.6 percent, progressed to toxic shock syndrome, and the mortality rate in those cases was 52.8 percent.
The study also reported the first domestic case of the M1UK lineage, which has been spreading overseas. The team explained that this "shows the need for a national surveillance system that tracks not only the number of invasive group A streptococcal infection cases, but also disease severity and genetic changes in the strains." In other words, a more robust monitoring system is needed to detect early warning signs of rising infections in specific age groups or regions, as well as the introduction and spread of new lineages such as M1UK.
As the first author, Kim Ye-kyung of the Division of Pediatric Infectious Diseases at Seoul National University Bundang Hospital said, "It is meaningful that this is the first nationwide analysis in Korea of the 10-year incidence pattern and clinical characteristics of invasive group A streptococcal infection." She added, "In particular, since cases among pediatric patients have increased sharply after the pandemic and the M1UK lineage has also been identified in Korea, continuous monitoring of future changes in outbreak patterns is necessary."
Senior author Lee Hyun-joo of the same division said, "Group A streptococcus is a bacterium people commonly encounter, so awareness tends to be low. But when it appears in invasive form, even previously healthy people can deteriorate rapidly in a very short time." She added, "We need discussions on building a more proactive surveillance system, including designating invasive group A streptococcal infection as a notifiable infectious disease."
Jang Jong-ho, bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
