Background: Immunocompromised children are a high-risk group for severe coronavirus disease 2019 (COVID-19). A nationwide study in Korea found that the average COVID-19 vaccination rate in high-risk children was higher than in the general pediatric population, whereas vaccination rates in pediatric cancer patients were lower. Materials and Methods: Surveys on COVID-19 vaccination among pediatric cancer patients and parents were conducted during the pandemic (July 1, 2022-July 31, 2022) and post-pandemic (December 26, 2023-January 5, 2024) periods. Vaccination rates of patients and their parents were compared with general population data. Factors associated with the vaccination status of patients were identified. Parental reasons for not vaccinating their children were also assessed. Results: In the first survey of 111 patients, the two-dose COVID-19 vaccination rate was 28.8%, lower than the rate in the general pediatric population, 40.7% (P=0.028). The two-dose vaccination rates for fathers (90.1%) and mothers (85.6%) were also lower than those of the general adult population (96.4%) (P<0.001). In the second survey of 26 patients, two patients received seasonal COVID-19 vaccination (7.7%). Among patients aged 12-19 years from the first survey, those in the younger age group, hematopoietic cell transplantation recipients, or those with parental under-vaccination status were more likely to be unvaccinated. Parental concerns about vaccine adverse reactions were a primary factor in their decision not to vaccinate their children. Conclusion: Considering the negative attitude toward the COVID-19 vaccine among parents of children with cancer, the government and healthcare professionals should endeavor to increase parental trust in this novel vaccine platform.
BACKGROUND:Pasteurella multocida is an important zoonotic pathogen that causes soft-tissue infections in humans; however, recent antimicrobial susceptibility data in Korea remain limited. MATERIALS AND METHODS:A total of 70 clinical P. multocida isolates collected at a nationwide commercial laboratory in Korea between November 2022 and July 2025 were analyzed. Antimicrobial susceptibility testing was performed using the disk diffusion method on Mueller-Hinton agar supplemented with 5% sheep blood. Five clinically relevant antimicrobial agents were tested: penicillin, amoxicillin-clavulanic acid (AMC), levofloxacin, tetracycline, and trimethoprim-sulfamethoxazole (TMP-SMX). For isolates classified as penicillin non-susceptible by disk diffusion, minimum inhibitory concentration (MIC) testing was performed using E-test and β-lactamase production was assessed using a phenotypic method. RESULTS:All tested isolates were susceptible to tetracycline and TMP-SMX by disk diffusion. Susceptibility rates by disk diffusion were 97.1% for AMC, 91.4% for levofloxacin, and 85.7% for penicillin. All 10 isolates initially classified as penicillin non-susceptible by disk diffusion were confirmed to be susceptible to penicillin by MIC testing and were β-lactamase negative. The 2 isolates classified as non-susceptible to AMC by disk diffusion were also β-lactamase negative and susceptible to penicillin by MIC testing. CONCLUSION:No β-lactam resistance was identified among the 70 clinical P. multocida isolates analyzed. These findings support current recommendations that β-lactams and other first-line agents remain active against P. multocida isolates in Korea.
BACKGROUND:Clostridium ramosum is an opportunistic anaerobic gut commensal associated with invasive infections in immunocompromised adults. However, sepsis caused by C. ramosum in newborn infants, especially in preterm infants, is extremely scarce. MATERIALS AND METHODS:A retrospective case series of ten preterm infants with C. ramosum sepsis who were admitted to a neonatal intensive care unit since birth between 2022 and 2024. Clinical data including epidemiologic and demographic characteristics, management, and outcomes were collected. A literature review was also performed on published cases from 2010 to 2025. RESULTS:All infants were preterm with multiple comorbidities, the median gestational age was 32⁺³ weeks. No significant temporal clustering was observed. Common presentations were feeding intolerance and bloody stool, with 80% of cases having necrotizing enterocolitis (NEC). Laboratory findings showed elevated inflammatory markers. All infants received meropenem-based therapy, and 40% of cases required surgical intervention. No acute infection-related mortality occurred. Literature review of adult cases (n=30) showed a direct mortality of 36.7%, often associated with unresolved infection sources and severe sepsis. CONCLUSION:C. ramosum can cause severe sepsis in preterm infants, often associated with NEC. Early recognition, appropriate antimicrobial therapy based on susceptibility testing (e.g., a carbapenem), and prompt surgical intervention when indicated are crucial for favorable outcomes.
Infective endocarditis (IE) is uncommon in children, particularly in those without congenital heart disease or indwelling catheters. We describe an adolescent patient without prior history of cardiac disease or previously diagnosed predisposing conditions who developed Streptococcus sanguinis endocarditis of the native mitral valve. Despite appropriate antibiotic therapy, the clinical course was complicated by acute mitral regurgitation and heart failure requiring valve replacement. This report highlights the diagnostic and therapeutic challenges of pediatric IE in the absence of traditional risk factors and emphasizes the importance of early clinical suspicion, pathogen-directed antimicrobial therapy, and timely surgical intervention.
We investigated the distribution of human adenovirus (HAdV) types and their associated clinical features during the post-coronavirus diseases 2019 period among Korean children. After their near absence in 2020-2021, HAdV-1 and HAdV-2 began circulating in early 2022, followed by a large HAdV-3-driven outbreak between June and September 2023. Children aged 2-5 years (43.0%) were the most affected, and 33.1% presented with lower respiratory tract infections, including pneumonia (25.4%). Overall, 12.4% of the patients required oxygen therapy, including 3.5% who required intensive care. These findings highlight the post-pandemic resurgence of HAdV infections in Korea, contributing to increased healthcare demands among children.
Background: Tuberculosis (TB) remains the leading cause of death among people living with human immunodeficiency virus (PLHIV). Latent tuberculosis infection (LTBI) poses a serious challenge because immune suppression substantially increases the risk of progression to active disease. In Mongolia, where TB incidence is high, little is known about LTBI prevalence and risk factors among PLHIV. This study aimed to estimate the prevalence of LTBI and identify risk factors for LTBI in Mongolia. Materials and Methods: A retrospective cohort study was conducted using secondary data from the AIDS/STI Surveillance and Research Department of the National Centre for Communicable Diseases between September 2023 and January 2024. A total of 196 PLHIV without active TB were screened using the QuantiFERON-TB Gold Plus test. Sociodemographic and clinical variables were analyzed with chi-square tests and multivariable logistic regression. Results: The prevalence of LTBI was 39.3% (77/196). Interruption of antiretroviral therapy was significantly associated with (odds ratio, 27.7; 95% confidence interval, 3.04-252.2). The history of TB contact was also associated with high risk (P=0.047). Viral load level and duration of HIV infection were not significantly associated with LTBI. Conclusion: These findings indicate that LTBI prevalence among PLHIV in Mongolia is high, comparable to other high-burden settings. Ensuring continuous ART use, implementing systematic LTBI screening, and expanding preventive therapy are critical to reduce progression to active TB and to strengthen TB/HIV control efforts.
Orientia tsutsugamushi causes scrub typhus (tsutsugamushi disease), an acute febrile disease. The infection has been effectively treated with antibiotics since chloramphenicol was introduced. However, occasional reports of treatment failures or delayed responses occur in scrub typhus, and their underlying causes remain poorly understood. This narrative review assesses whether antibiotic antagonism between β-lactam and anti-rickettsial antibiotics delays the resolution of scrub typhus. To address this, we reviewed historical changes in antibiotic use, pitfalls in interpreting study results, in vitro antagonism data, and relevant clinical reports. In subtropical regions, doxycycline and ceftriaxone are frequently used concurrently for the empirical treatment of severe acute undifferentiated fever, targeting scrub typhus and typhoid fever. However, an in vitro study demonstrated that cefotaxime reduces the effects of anti-rickettsial antibiotics, including doxycycline, by at least 25%. This potential antibiotic antagonism may delay fever resolution by 1-5 days, a minor difference often difficult to detect in individual patients. Even when detected, it is frequently misinterpreted as antibiotic resistance or attributed to severe disease or atypical clinical manifestations. Furthermore, this phenomenon may contribute to mortality in cases with life-threatening complications.
We aimed to characterize human immunodeficiency virus (HIV) drug-resistance mutations among patients in Korea HIV/acquired immunodeficiency syndrome (AIDS) Cohort. Among 1,579 surveyed between December 2006 and December 2020, 148 had resistance mutations (64 ART-naïve and 84 ART-experienced). The most common mutations in ART-naïve patients were related to non-nucleoside reverse transcriptase inhibitors (V179F/D/E/L; 50.0%), whereas those in ART-experienced were M184V/I (73.8%), conferring resistance to nucleotide reverse transcriptase inhibitors. Multivariate logistic regression identified poor compliance (adjusted odds ratio [aOR], 18.780; 95% confidence interval [CI], 1.883-187.300; P=0.012) and viral load ≥1-100,000 copies/mL at ART initiation (aOR, 3.117; 95% CI, 1.160-8.374; P=0.024) as being associated with resistance mutations.
BACKGROUND:Colistin is a last-resort antibiotic for treating carbapenem-resistant Klebsiella pneumoniae (CRKP). The emergence of colistin resistance threatens public health by further limiting therapeutic options. This study aimed to molecularly characterize colistin resistance in 17 CRKP isolates obtained from seven hospitals in lower Southern Thailand between March and August 2019. MATERIALS AND METHODS:Antimicrobial susceptibility testing was performed using broth microdilution, and whole-genome sequencing was employed to identify acquired antimicrobial resistance genes, mutations associated with colistin resistance, virulence-associated genes (VAGs), and plasmid replicons. RESULTS:All isolates were multidrug-resistant but remained susceptible to amikacin and, in 80% of cases, tigecycline. Multilocus sequence typing revealed 6 distinct sequence types with ST16 predominating. Average nucleotide identity and core genome single-nucleotide polymorphism analysis suggested clonal relatedness. While no mcr gene was detected, mutations were identified in genes implicated in lipid A modification, including mgrB, lpxM, arnB, arnT, and eptA. Several isolates harbored VAGs encoding for yersiniabactin and aerobactin siderophore. CONCLUSION:Our findings highlight the convergence of resistance and virulence in clonally related CRKP strains, emphasizing the need for continued genomic surveillance and antimicrobial stewardship.
BACKGROUND:Healthcare-associated infections (HAIs) pose a significant threat to patient safety, particularly for vulnerable populations such as critically ill patients, the elderly, and individuals with multiple comorbidities. Hospital surfaces often act as reservoirs for pathogens, including multidrug-resistant strains, yet conventional disinfectants frequently lack sustained activity. We evaluated the real-world effectiveness of a novel disinfectant wipe combining low-concentration didecyldimethylammonium chloride (DDAC) and organosilane quaternary ammonium compound (Si-QAC) for its immediate and persistent antimicrobial properties across multiple hospitals. MATERIALS AND METHODS:A multi-center, paired-design study was conducted at five university-affiliated hospitals between March and April 2025. Eight high-touch surfaces were categorized into dry zones (e.g., bed rails, nurse station desks) and wet zones (e.g., ward sinks, toilet lids). We compared the disinfection effectiveness of DDAC+Si-QAC wipes (experimental group) against each hospital's standard disinfection protocol (control group). Microbial samples were collected at baseline and at 1, 6, and 24 hours post-disinfection. Effectiveness was measured by the change in microbial load (Δ colony-forming unit/mL) from baseline. RESULTS:A total of 640 specimens were analyzed from 160 surfaces. To ensure rigorous analysis, pairs containing "zero-point" baseline surfaces were excluded, resulting in 39 pairs (78 surfaces) for final evaluation. The experimental group showed significant reductions from baseline at 1, 6, and 24 hours (P<0.001), whereas the control group failed to exhibit significant changes. In comparative analysis, the experimental group demonstrated superior effectiveness over the control group at 1 hour (P=0.041) and 6 hours (P=0.042). Although the difference at 24 hours (P=0.276) was not statistically significant, the experimental group maintained a lower median microbial load. Sub-group analysis revealed that the experimental group's potency was most pronounced in wet zones at 1 hour (P=0.004), where the bioburden was highest. CONCLUSION:The DDAC+Si-QAC wipe provides superior and sustained antimicrobial activity compared to standard hospital protocols, particularly in challenging high-bioburden wet environments. While the statistical advantage diminished at 24 hours, the persistent coating effect of Si-QAC offers a robust alternative to conventional point-in-time disinfection. Integrating these wipes into routine environmental management may help prevent the formation of microbial reservoirs and contribute to reducing HAIs.
BACKGROUND:Several studies have demonstrated the real-world efficacy and tolerability of dolutegravir/lamivudine (DTG/3TC). However, data from Asian countries-particularly regarding long-term use-remain limited. MATERIALS AND METHODS:We conducted a retrospective cohort study of adult people living with human immunodeficiency viruses (PLWH) who were treated with DTG/3TC at a tertiary hospital in Korea. Individuals with a 36-month observation period from the initiation of DTG/3TC were included in the study, as well as those who switched to other regimens during follow-up were also analysed. Both treatment-naive individuals and those who switched to DTG/3TC from other regimens were included. Baseline characteristics, DTG/3TC maintenance rates, effectiveness, and changes in metabolic parameters over 36 months were evaluated. RESULTS:Between July 2020 and April 2024, 305 PLWH received DTG/3TC, of whom 134 had an observation period of 36 months or longer. Most PLWH were male (94.0%), with a median age was 45.5 years. No participant switched from DTG/3TC to other regimens during the 36-month follow-up period. In the treatment-naïve group, HIV RNA levels remained <50 copies/mL from 6 to 36 months after starting DTG/3TC treatment. In the switching group, 99.2% maintained <50 copies/mL at 36 months. Among the treatment-naïve individuals, the CD4+ T cell count increased from a median of 494 cells/μL at baseline to 795 cells/μL at 36 months. During the 36-month follow-up, no significant changes were observed in lipid profiles or body weights in either the treatment-naïve or switching groups, apart from an increase in high-density lipoprotein cholesterol in the switching group. CONCLUSION:DTG/3TC demonstrated sustained viral suppression and maintained CD4 count, with no significant adverse effects on lipid profiles or body weight.
We describe a rare case of neonatal varicella from sequential household transmission of varicella-zoster virus. A vaccinated sibling developed herpes zoster before delivery, followed by maternal varicella and neonatal infection at 20 days of life. The infant showed generalized vesiculopustular eruptions with mild respiratory symptoms. Polymerase chain reaction confirmed infection presumed to be caused by the vaccine strain because the sibling had no history of natural varicella and there were no other exposure sources. Intravenous acyclovir was administered with good response. The patient recovered fully. This case reminds clinicians to consider vaccine-strain transmission in families with a non-immune mother.
Streptococcus gallolyticus subsp. pasteurianus is a rare pathogen causing bacteremia and meningitis in neonates and infants. We present a case of septic shock with cardiac arrest due to S. gallolyticus subsp. pasteurianus infection in a previously healthy infant and review of the literature. Although S. gallolyticus subsp. pasteurianus infections are typically considered to follow a mild clinical course in infants, this case highlights the potential for aggressive progression even in the absence of comorbidities. Evidence points that infants without apparent perinatal insults or immune dysfunction are susceptible. Therefore, clinical awareness is crucial for early diagnosis and prompt treatment.
