Explore the vast range of titles available.

In 2015, a large outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection occurred following a single patient exposure in an emergency room at the Samsung Medical Center, a tertiary-care hospital in Seoul, South Korea. We aimed to investigate the epidemiology of MERS-CoV outbreak in our hospital. We identified all patients and health-care workers who had been in the emergency room with the index case between May 27 and May 29, 2015. Patients were categorised on the basis of their exposure in the emergency room: in the same zone as the index case (group A), in different zones except for overlap at the registration area or the radiology suite (group B), and in different zones (group C). We documented cases of MERS-CoV infection, confirmed by real-time PCR testing of sputum samples. We analysed attack rates, incubation periods of the virus, and risk factors for transmission. 675 patients and 218 health-care workers were identified as contacts. MERS-CoV infection was confirmed in 82 individuals (33 patients, eight health-care workers, and 41 visitors). The attack rate was highest in group A (20% [23/117] vs 5% [3/58] in group B vs 1% [4/500] in group C; p<0·0001), and was 2% (5/218) in health-care workers. After excluding nine cases (because of inability to determine the date of symptom onset in six cases and lack of data from three visitors), the median incubation period was 7 days (range 2–17, IQR 5–10). The median incubation period was significantly shorter in group A than in group C (5 days [IQR 4–8] vs 11 days [6–12]; p<0·0001). There were no confirmed cases in patients and visitors who visited the emergency room on May 29 and who were exposed only to potentially contaminated environment without direct contact with the index case. The main risk factor for transmission of MERS-CoV was the location of exposure. Our results showed increased transmission potential of MERS-CoV from a single patient in an overcrowded emergency room and provide compelling evidence that health-care facilities worldwide need to be prepared for emerging infectious diseases. None.

In the Republic of Korea (ROK), social distancing and public behavior changes mitigated COVID-19 spread. However, a second wave of the epidemic is expected in the fall if neither vaccine nor antiviral drugs become available. This study investigated the impact of non-pharmaceutical measures on short- and long-term outbreak dynamics. A mathematical model based on Susceptible-Exposed-Infectious-Recovered model is developed considering isolated and behavior-changed groups. Using the least-squares fitting method, transmission and behavior change rates were estimated using cases reported from February 16 to April 20, 2020. The estimated transmission rate of COVID-19 was 4·6180 and behavior change rate was 2·6044. The model predicted the number of new cases to continuously decrease, with less than one case expected after May 6, 2020. Concurrently, a 25% reduction in behavioral changes during the outbreak would increase the case count by 60,000, resulting in 4,000 cases at maximum, exceeding the medical system's capacity. As behavioral restrictions are eased, local transmission will likely increase, with forecasted second wave peak in October 2020. Social distancing and public behavior changes have curbed the spread of COVID-19 in the ROK. Mathematical modeling demonstrates the importance of these measures in reducing and delaying outbreaks. Nevertheless, non-pharmaceutical interventions cannot eliminate the disease. In the future, vaccines and antiviral treatments combined with social distancing and public behavior changes will be paramount to ending COVID-19 epidemic.

Background: Influenza causes substantial morbidity in young children, particularly those aged 6–35 months. In this age group, optimisation of vaccine dose regimens remains important to ensure adequate immunogenicity while maintaining acceptable safety. This study evaluated the immunogenicity and safety of a full 0.5 mL dose of quadrivalent inactivated influenza vaccine (NBP607-QIV) in young children. Methods: This Phase 3, randomised, double-blind, active-controlled, multicentre study was conducted in Korea, Thailand, and Malaysia. Healthy children aged 6–35 months were randomised 2:1 to receive NBP607-QIV (0.5 mL) or control vaccine (0.25 mL). Immunogenicity was assessed using the haemagglutination inhibition assay. Primary endpoints were non-inferiority of NBP607-QIV versus Agrippal for seroconversion rate (SCR) and adjusted post-vaccination geometric mean titre (GMT) ratio against three shared strains. Immunogenicity against the additional B/Yamagata strain was evaluated according to Committee for Medicinal Products for Human Use (CHMP) criteria. Safety was assessed based on adverse events. Results: A total of 676 participants were randomised, and 675 were included in the safety set. Non-inferiority of NBP607-QIV versus control vaccine was demonstrated for SCR for all shared strains and for the adjusted GMT ratio for A/H1N1 and B/Victoria, but not for A/H3N2. Immunogenicity against the B/Yamagata strain met CHMP criteria for SCR and geometric mean ratio (GMR). Immunogenicity was consistent across prespecified subgroups, and the incidence of adverse events was comparable between groups, with no clinically meaningful safety concerns. Conclusions: NBP607-QIV administered at a 0.5 mL dose demonstrated acceptable immunogenicity and a safety profile comparable to that of a licensed trivalent influenza vaccine in children aged 6–35 months, supporting its use in this paediatric population.

We introduce SCITO-seq2, an enhanced successor to SCITO-seq that integrates probe-based RNA detection with the established ultra-high-throughput protein profiling. SCITO-seq2 achieves robust quantification of transcripts and surface proteins across more than 100,000 cells, with a shared pool barcoding strategy ensuring precise matching of molecular profiles within multiplexed droplets. SCITO-seq2 is compatible with cell hashing technology, allowing efficient sample multiplexing. We demonstrate its utility in autoimmune diseases, including childhood systemic lupus erythematosus and CTLA4 haploinsufficiency with autoimmune infiltration, enabling the detection of minor immune clusters and disease-specific protein signatures. This platform establishes a scalable, streamlined, and cost-effective next-generation single-cell multi-omics workflow.

Mycoplasma pneumoniae is the leading cause of community-acquired pneumonia in children. With increasing macrolide resistance, the use of second-line antibiotics such as tetracyclines and quinolones is also increasing. Clinical data were collected from 13 institutions between September 2023 and February 2024. MPP was defined as the detection of M. pneumoniae via polymerase chain reaction or serological tests and radiologic evidence of pneumonic infiltration. Among the 389 children with MPP included in the analysis, 89.1% were macrolide resistant (MR). The treatment groups were as follows: spontaneous resolution (SR, 21.9%), macrolide alone (ML, 18.0%), macrolide with other treatments (ML-O, 38.0%), and second-line antibiotics and/or steroids (2nd-A/S, 22.1%). The median fever duration was 5 days for the SR group, 7 days for both the ML and 2nd-A/S groups, and 8 days for the ML-O group. The ML-O group had significantly greater hospitalization rates (93.9% vs. 81.4–84.7%, P  = 0.023) and longer hospital stays (5.0 days vs. 3.0–4.0 days, P  < 0.001). The median times to defervescence from the initiation of macrolide and second-line treatments were 2–3 days and 0–2 days, respectively. In conclusion, despite high MR rates, macrolide monotherapy remains effective in many patients, even those with macrolide-resistant M. pneumoniae .

Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality post cord blood transplantation (CBT). It has been suggested that the graft-versus-host disease (GVHD) and immunosuppressants have an impact on CMV infection. This study evaluated the incidence, outcomes, and risk factors of CMV infection, while focusing on GVHD and the use of immunosuppressants, in 103 children who had received CBT. Among the patients, 92.2% were positive for CMV serology, while CMV antigenemia was observed in 68.9% and CMV disease developed in 26.2%. CMV enterocolitis was the most common, followed by retinitis and pneumonia. Patients with positive CMV serology and grade II to IV GVHD were independently associated with CMV antigenemia. Recurrent CMV antigenemia was observed significantly more frequently in patients with extensive chronic GVHD. Patients with CMV disease showed significantly worse overall survival, relapse-free survival, and non-relapse mortality than those without CMV disease. In conclusion, CMV infection is common post-CBT in countries with a high rate of CMV seropositivity in the general population and is related to worse outcomes. GVHD severity is associated with the development and recurrence of CMV infection. Thus, efforts need to be made to prevent CMV infection in children post-CBT.

Background and objectives: The objective of this study was to investigate the clinical significance of isolates from blood stream infection known to be blood culture contaminants in pediatric patients. Materials and Methods: Microbiological reports and medical records of all blood culture tests issued from 2002 to 2012 (n = 76,331) were retrospectively reviewed. Evaluation for potential contaminants were done by reviewing medical records of patients with the following isolates: coagulase-negative Staphylococcus, viridans group Streptococcus, Bacillus, Corynebacterium, Micrococcus, Aerococcus, and Proprionibacterium species. Repeated cultures with same isolates were considered as a single case. Cases were evaluated for their status as a pathogen. Results: Coagulase-negative Staphylococcus had clinical significance in 23.8% of all cases. Its rate of being a true pathogen was particularly high in patients with malignancy (43.7%). Viridans group Streptococcus showed clinical significance in 46.2% of all cases. Its rate of being a true pathogen was similar regardless of the underlying morbidity of the patient. The rate of being a true pathogens for remaining isolates was 27.7% for Bacillus and 19.0% for Corynebacterium species. Conclusions: Coagulase-negative Staphylococcus and viridans group Streptococcus isolates showed high probability of being true pathogens in the pediatric population, especially in patients with underlying malignancy.

Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) is a negative immune regulator on the surface of T cells. In humans, heterozygous germline mutations in can cause an immune dysregulation syndrome. The phenotype comprises a broad spectrum of autoinflammatory, autoimmune, and immunodeficient features. An increased frequency of malignancies in primary immunodeficiencies is known, but their incidence in CTLA-4 insufficiency is unknown. Clinical manifestations and details of the clinical history were assessed in a worldwide cohort of 184 mutation carriers. Whenever a malignancy was reported, a malignancy-specific questionnaire was filled. Among the 184 mutation carriers, 131 were considered affected, indicating a penetrance of 71.2%. We documented 17 malignancies, which amounts to a cancer prevalence of 12.9% in affected mutation carriers. There were ten lymphomas, five gastric cancers, one multiple myeloma, and one metastatic melanoma. Seven lymphomas and three gastric cancers were EBV-associated. Our findings demonstrate an elevated cancer risk for patients with CTLA-4 insufficiency. As more than half of the cancers were EBV-associated, the failure to control oncogenic viruses seems to be part of the CTLA-4-insufficient phenotype. Hence, lymphoproliferation and EBV viral load in blood should be carefully monitored, especially when immunosuppressing affected mutation carriers.

Background. Respiratory syncytial virus (RSV) lower respiratory tract disease (LRD) is a life-threatening complication in hematopoietic cell transplant (HCT) recipients. Lymphopenia has been associated with an increased risk of progression from upper respiratory tract infection (URI) to LRD. Methods. This study retrospectively analyzed the significance of lymphocyte engraftment dynamics, lung function, smoking history, corticosteroids, antiviral treatment, viral subtypes, and RSV-specific neutralizing antibodies for the progression to LRD in 181 HCT recipients with RSV URI. Results. In multivariable models, smoking history, conditioning with high-dose total body irradiation, and an absolute lymphocyte count (ALC) ≤100/mm³ at the time of URI onset were significantly associated with disease progression. No progression occurred in patients with ALCs of >1000/mm³ at URI onset. Lymphocyte engraftment dynamics were similar in progressors and nonprogressors. Pre- and posttransplant donor and posttransplant recipient RSV subtype-specific neutralizing antibody levels, RSV viral subtypes, and corticosteroids also were not significantly associated with LRD progression. Conclusions. Host and transplant related factors appear to determine the risk of progression to LRD more than viral factors. Dysfunctional cell-mediated immunity appears to be important in the pathogenesis of progressive RSV disease after HCT. A characterization of RSV-specific T-cell immunity is warranted.

ObjectiveThere is an urgent public need to readdress the school closure strategies. We aimed to describe the epidemiology of COVID-19 in schools and school-aged children to understand their roles in transmitting SARS-CoV-2 in Korea.DesignRetrospective cohort study.SettingAll schools in KoreaPatientsAll school-aged children in Korea.InterventionsNone (observational study).Main outcome measuresIncidence rate, proportion of affected schools.ResultsBetween February and December 2020, the incidence rate was lower among school-aged children (63.2–79.8 per 100 000) compared with adults aged 19 and above (130.4 per 100 000). Household was the main route of transmission (62.3%), followed by community (21.3%) and school clusters (7.9%). Among the schools in Korea, 52% of secondary schools had COVID-19 cases, followed by 39% of primary schools and 3% of kindergartens.ConclusionsWe found that schools and school-aged children aged 7–18 years were not the main drivers of COVID-19 transmission. The major sources of transmission were households.