The National Medical Center (NMC) has succeeded in analyzing the characteristics of mpox using funds from the “Support Project for Overcoming Infectious Diseases in Korea” donated by the late Samsung Group Chairman Lee Kun-hee.

The NMC said Thursday that its infectious disease research team published the results characterizing the mpox virus in Korea.

Mpox is an acute rash-like contagious disease caused by infection with monkeypox virus. Initially, it causes cold-like symptoms, such as fever, chills, headache, and respiratory symptoms, usually developing a rash on the face, hands, feet, chest, and anogenital area after one to four days.

According to World Health Organization statistics, from Jan. 1, 2022, to March 31, 2024, 95,226 cases of infection have been reported in 117 countries, resulting in 185 deaths.

The WHO has declared a Public Health Emergency of International Concern (PHEIC) from July 2022 to May 2023 to respond to the outbreak, which is having a serious impact globally, with the number of cases increasing in the United States and the emergence of a highly lethal strain in the Democratic Republic of Congo.

In Korea, the first patient was reported in June 2022 after arriving in the country from abroad, followed by a community-acquired epidemic of 151 cases in 2023, which seemed to have subsided, but four cases resurfaced in 2024.

The recent study included 18 mpox patients admitted to the National Medical Center between September 2022 and June 2023. Seventeen (94.4%) were male, with an average age of 32.5 years.

The researchers collected samples from the oropharyngeal (OP), anogenital (AL), and skin lesions (SL) of the patients and conducted virus isolation experiments, isolating three subtypes of the virus (A.2.1, B.1.1, and B.1.3).

Based on this, they comprehensively analyzed the characteristics of the virus and its clinical manifestations, including the duration of infectious virus shedding by lesion site after the onset of symptoms, gene detection patterns, and production of neutralizing antibodies in the blood.

Domestic mpox virus sheds for up to 15 days

The researchers found that the infectious virus shedding period, viral gene (DNA) detection, and neutralizing antibody cross-reactivity by strain were up to 15 days from symptom onset, and viral genes were detected even after 23 days.

There were also significant differences in neutralizing antibody cross-reactivity to viruses of different strains, suggesting that patients who have had one episode of mpox can become reinfected when exposed to a new strain of virus.

“It is important to have a research system that can quickly identify the clinical features and pathogen characteristics of a new infectious disease when it is introduced,” said Dr. Jin Beom-sik, head of the research team.

NMC President Park Jun-sun said, “We are establishing a research network with Soon Chun Hyang University Hospital Seoul and Seoul Medical Center to conduct research on mpox, including the antibody retention rate of mpox high-risk groups, natural infection with mpox, and changes in antibodies after vaccination. We expect this research will be used as evidence to guide the direction of mpox control strategies.”

The research is the first accomplishment in the research support sector of the Korea Infectious Disease Overcoming Support Program, funded by a donation from the family of the late Samsung Group Chairman Lee Kun-hee.