Neutralization Testing–based Immunogenicity Analysis of Recent Prevalent Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Sublineages

Although WHO declared the end of the public health emergency for coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV-2), XBB lineages continue to evolve and emerge globally. In particular, XBB.1.5 and XBB.1.16 are raising concerns because of their high immune evasion, leading to apprehensions regarding vaccine efficacy reduction and potential reinfection. We aimed to investigate the COVID-19 outbreak in Korea and predict the likelihood of reinfection by testing neutralizing activity against live viruses from the S clade and 19 Omicron sublineages.We found a significant risk of infection with the currently prevalent XBB lineage for individuals who were either vaccinated early or infected during the initial Omicron outbreak. Vaccinated individuals were better equipped than unvaccinated individuals to produce neutralizing antibodies for other SARS-CoV-2 variants upon infection. Therefore, unvaccinated individuals do not easily develop neutralizing activity against other variants and face the highest risk of reinfection by the XBB lineage. Our study provides important information to facilitate the development of strategies for monitoring populations that would be the most susceptible to new COVID-19 outbreaks.

Characteristics of Hirayama Disease in Young South Korean Soldiers

Background@#and Purpose The purpose of this study was to describe the clinical presentation and features in electrodiagnostic and imaging investigations of young South Korean males diagnosed with Hirayama disease (HD). @*Methods@#We reviewed the electronic medical records of South Korean enlisted soldiers who were diagnosed with HD and discharged from military service during 2011–2021. We investigated the clinical characteristics and results of electrodiagnostic and magnetic resonance imaging (MRI) investigations. We analyzed laterality and identified the involved muscles using needle electromyography (EMG). Loss of lordosis, localized cervical cord atrophy, loss of attachment between the posterior dura and subjacent lamina, asymmetric flattening of the cord, crescent-shaped mass in the posterior epidural space, and noncompressive intramedullary T2-weighted high signal intensity were investigated using neutral- or flexion-position MRI. @*Results@#Forty-two male patients aged 20.2±0.8 years (mean±standard deviation) were identified. All patients complained of hand weakness, and 10 complained of hand tremor (23.8%).Four patients (9.5%) had symptoms in both upper limbs, and five (11.9%) had sensory disturbances. Needle EMG revealed that muscles in the C7–T1 myotome were commonly involved, and C5–C6 involvement of the deltoid (10.5%) and biceps brachii (12.5%) was also observed.In cervical MRI, localized cord atrophy (90.0%) was the most characteristic finding, and cord atrophy was most severe at the C5–C6 level (58.3%). @*Conclusions@#This is the first description of a large number of patients with HD in South Korea.The clinical presentation and features found in electrodiagnostic and imaging investigations will improve the understanding of HD in the young South Korean male population.

Effects of a Health Partnership Program Using Mobile Health Application for Male Workers with Cardiovascular Risk Factors in Small and Medium Enterprises: A Randomized Controlled Trial

Purpose@#This study aimed to apply a health partnership program using commercially available mobile health apps to improve cardiovascular risk factors in male employees and verify its effectiveness. @*Methods@#Using a randomized control group pretest-posttest design, male employees with cardiovascular risk factors from five small and medium-sized workplaces were randomly assigned to an experimental group (n = 32) and a control group (n = 31). The experimental group was encouraged to use three mobile health apps for 12 weeks to acquire the necessary cardiovascular disease-related information and practice strengthening training, walking, and diet management appropriate to their level. They also received feedback on their weekly activities and motivational text messages from health partners. Hypotheses were tested using the SPSS WIN 22.0. @*Results@#The experimental group showed a significant difference compared to the control group in terms of their perception of mobile health app (p < .05), self-efficacy for exercise and diet, self-management partnership, and cardiovascular disease prevention health behavior (p < .001). In particular, there were significant decreases in the body mass index, ratio, serum fasting blood sugar, total cholesterol, and triglyceride in the experimental group (p < .001); however, there was no significant difference in high-density lipoprotein-cholesterol. @*Conclusion@#Intervention using mobile apps based on partnership with health managers is effective in improving the objective cardiovascular risk index in male employees; therefore, such intervention should be continuously used as a useful lifestyle modification strategy in the workplace.

Epidemiology of Respiratory Viruses in Korean Children Before and After the COVID-19 Pandemic: A Prospective Study From National Surveillance System

Background@#The coronavirus disease 2019 (COVID-19) pandemic led to a decrease in the seasonal incidence of many respiratory viruses worldwide due to the impact of nonpharmaceutical interventions (NPIs). However, as NPI measures were relaxed, respiratory viral infections re-emerged. We aimed to characterize the epidemiology of respiratory viruses in Korean children during post-COVID-19 pandemic years compared to that before the pandemic. @*Methods@#A nationwide prospective ongoing surveillance study has been conducted for detection of respiratory viruses between January 2017 and June 2023. We included data on adenovirus (AdV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus (HMPV), human rhinovirus (HRV), influenza virus (IFV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV), which were detected in children and adolescents younger than 20 years. We analyzed the weekly detection frequency of individual viruses and the age distribution of the affected children. The study period was divided into prepandemic (2017–2019) and postpandemic (2021–2023) periods. @*Results@#A total of 19,589 and 14,068 samples were collected in the pre- and postpandemic periods, respectively. The overall detection rate of any virus throughout the study period was 63.1%, with the lowest occurring in the 2nd half of 2020 (50.6%) and the highest occurring in the 2nd half of 2021 (72.3%). Enveloped viruses (HCoV, HMPV, IFV, PIV, and RSV) almost disappeared, but nonenveloped viruses (AdV, HBoV, and HRV) were detected even during the peak of the COVID-19 pandemic. The codetection rate increased from 15.0% prepandemic to 19.1% postpandemic (P < 0.001). During the postpandemic period, a large out-of-season PIV and HMPV epidemic occurred, but the usual seasonality began to be restored in 2023.The mean age of children with each virus detected in 2023 was significantly greater than that in prepandemic years (P = 0.003 and 0.007 for AdV and HCoV, respectively; P < 0.001 for others). The mean age of children with IFV increased in 2022 (11.1 ± 5.2 years) from prepandemic years (7.9 ± 4.6 years) but decreased to 8.7 ± 4.1 years in 2023. @*Conclusion@#With the relaxation of NPI measures, several seasonal respiratory viruses cocirculated with unusual seasonal epidemic patterns and were associated with increasing age of infected children.

Risk factors for SARS-CoV-2 transmission during a movie theater outbreak in Incheon in the Republic of Korea, November 2021: a retrospective study

Objectives@#We examined factors contributing to the transmission of an acute respiratory virus within multi-use facilities, focusing on an outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a movie theater in the Republic of Korea. @*Methods@#This retrospective cohort study involved a descriptive analysis of 48 confirmed cases. Logistic regression was applied to a cohort of 80 theater attendees to identify risk factors for infection. The infection source and transmission route were determined through gene sequencing data analysis. @*Results@#Of the 48 confirmed cases, 35 were theater attendees (72.9%), 10 were family members of attendees (20.8%), 2 were friends (4.2%), and 1 was an employee (2.1%). Among the 80 individuals who attended the 3rd to 5th screenings of the day, 35 became infected, representing a 43.8% attack rate. Specifically, 28 of the 33 third-screening attendees developed confirmed SARS-CoV-2, constituting an 84.8% attack rate. Furthermore, 11 of the 12 cases epidemiologically linked to the theater outbreak were clustered monophyletically within the AY.69 lineage. At the time of the screening, 35 individuals (72.9%) had received 2 vaccine doses. However, vaccination status did not significantly influence infection risk. Multivariate analysis revealed that close contacts had a 15.9-fold higher risk of infection (95% confidence interval, 4.37–78.39) than casual contacts. @*Conclusion@#SARS-CoV-2 transmission occurred within the theater, and extended into the community, via a moviegoer who attended the 3rd screening during the viral incubation period after contracting the virus from a family member. This study emphasizes the importance of adequate ventilation in theaters.

Replication kinetics and infectivity of SARS-CoV-2 Omicron variant sublineages recovered in the Republic of Korea

Objectives@#We analyzed the correlation between the infectivity and transmissibility of the severe acute respiratory syndrome coronavirus 2 Omicron sublineages BA.1, BA. 2, BA.4, and BA.5. @*Methods@#We assessed viral replication kinetics and infectivity at the cellular level. Nasopharyngeal and oropharyngeal specimens were obtained from patients with coronavirus disease 2019, confirmed using whole-genome sequencing to be caused by the Omicron sublineages BA.1, BA.2, BA.4, or BA.5. These specimens were used to infect Vero E6 cells, derived from monkey kidneys, for the purpose of viral isolation. Viral stocks were then passaged in Vero E6 cells at a multiplicity of infection of 0.01, and culture supernatants were harvested at 12-hour intervals for 72 hours. To evaluate viral replication kinetics, we determined the cycle threshold values of the supernatants using real-time reverse transcription polymerase chain reaction and converted these values to genome copy numbers. @*Results@#The viral load was comparable between BA.2, BA.4, and BA.5, whereas BA.1 exhibited a lower value. The peak infectious load of BA.4 was approximately 3 times lower than that of BA.2 and BA.5, while the peak load of BA.2 and BA.5 was about 7 times higher than that of BA.1. Notably, BA.1 demonstrated the lowest infectivity over the entire study period. @*Conclusion@#Our results suggest that the global BA.5 wave may have been amplified by the higher viral replication and infectivity of BA.5 compared to other Omicron sublineages. These analyses could support the rapid assessment of the impact of novel variants on case incidence.

Within-Host Evolution of SARS-CoV-2in a B-Cell Depleted Patient With Successful Treatment

Prolonged viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an immunocompromised host is a challenge as the treatment and infection control for chronic coronavirus disease 2019 infection is not well established and there is a potential risk of new variants emerging. A 48-year-old woman who underwent chemotherapy, including rituximab and steroid, had reactivation of SARS-CoV-2 68 days after the virus was first detected. She successfully recovered after receiving convalescent plasma and intravenous immunoglobulin. Genomic analysis demonstrated that viruses collected from the nasopharyngeal specimens at day 0 and day 68 had 18 different nucleotide mutations, implying within-host evolution after in-depth epidemiologic investigation.

The Profile of Early Sedation Depth and Clinical Outcomes of Mechanically Ventilated Patients in Korea

Background@#Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. @*Methods@#From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation–Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. @*Results@#Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence inter val [CI], 0.55– 0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% 0.56–0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79–1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65–2.17; P = 0.582). @*Conclusion@#In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.

Prevalence of Neuromuscular Diseases in Young South Korean Males; A Korean Military Manpower Administration and Medical Command Data-Based Study

Background@#and Purpose All young males in South Korea must undergo a physical examination for their participation in military service. We aimed to determine the prevalence rate (PR) of various neuromuscular diseases in young South Korean males using the data of exempted patients and soldiers. @*Methods@#The number of males exempted based on specific items of physical examination corresponding to neuromuscular disease during 2011–2020 were obtained from the records of the Military Manpower Administration. The list of enlisted soldier patients who were discharged from military service due to neuromuscular diseases during 2011–2020 was obtained from the Armed Forces Medical Command, and their medical records were reviewed. @*Results@#The PR of neuromuscular diseases was calculated among 948 identified males: 713 exempted males and 235 soldiers. The PRs of overall hereditary neuropathies, Hirayama disease (HD), myasthenia gravis (MG), and inherited muscle diseases in South Korean males in their early 20s were 8.34 (95% confidence interval [CI], 7.39–9.30), 5.54 (95% CI, 4.76–6.32), 2.97 (95% CI, 2.40–3.55), and 10.38 (95% CI, 9.31–11.46) per 100,000 persons, respectively.Among the enlisted soldiers, hereditary neuropathy with liability to pressure palsy was the most common neuromuscular disease, with a prevalence among the enlisted soldiers of 3.11 (95% CI, 2.42–3.80) per 100,000 persons. Myotonic dystrophy was the most prevalent myopathy, followed by facioscapulohumeral muscular dystrophy. @*Conclusions@#The 10-year PRs of hereditary polyneuropathies, HD, MG, and inherited muscle diseases in young South Korean males have been reported. These data could be valuable to understanding each neuromuscular disease in the young male population of South Korea.

The Impact of Entry Restrictions on the Spread of Severe Acute Respiratory Syndrome Coronavirus Variants Between 2021 and 2022

To contain the surge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the South Korean government has implemented non-pharmacological interventions as well as border restrictions. The efficacy of entry restrictions should be evaluated to facilitate their preparation for new variants of SARS-CoV-2. This study explored the impact of border policy changes on overseas entrants and local cases of SARS-CoV-2 variants. Data from the Korea Disease Control and Prevention Agency randomly collected between April 11, 2021 and August 20, 2022 were evaluated using the Granger causality model. The results showed that the outbreak gap of delta variants between international and domestic cases was 10 weeks, while that of omicron variants was approximately 2 weeks, meaning that the quarantine policy helped contain delta variants rather than more transmissible variants. It is recommended that countries implement quarantine policies based on particular purposes accounting for the specific features of different variants to avoid potential negative impacts on the economy.

Increased viral load in patients infected with severe acute respiratory syndrome coronavirus 2 Omicron variant in the Republic of Korea

Objectives@#Coronavirus disease 2019 (COVID-19) has been declared a global pandemic owingto the rapid spread of the causative agent, severe acute respiratory syndrome coronavirus 2.Its Delta and Omicron variants are more transmissible and pathogenic than other variants.Some debates have emerged on the mechanism of variants of concern. In the COVID-19 wave that began in December 2021, the Omicron variant, first reported in South Africa, became identifiable in most cases globally. The aim of this study was to provide data to inform effective responses to the transmission of the Omicron variant. @*Methods@#The Delta variant and the spike protein D614G mutant were compared with the Omicron variant. Viral loads from 5 days after symptom onset were compared usingepidemiological data collected at the time of diagnosis. @*Results@#The Omicron variant exhibited a higher viral load than other variants, resulting in greater transmissibility within 5 days of symptom onset. @*Conclusion@#Future research should focus on vaccine efficacy against the Omicron variant and compare trends in disease severity associated with its high viral load.

Results of contact tracing for SARS-CoV-2 Omicron sub-lineages (BA.4, BA.5, BA.2.75) and the household secondary attack risk

Objectives@#This study aimed to assess the contact tracing outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sub-lineages BA.4, BA.5, and BA.2.75 within Republic of Korea, and to generate foundational data for responding to future novel variants. @*Methods@#We conducted investigations and contact tracing for 79 confirmed BA.4 cases, 396 confirmed BA.5 cases, and 152 confirmed BA.2.75 cases. These cases were identified through random sampling of both domestically confirmed and imported cases, with the goal of evaluating the pattern of occurrence and transmissibility. @*Results@#We detected 79 instances of Omicron sub-lineage BA.4 across a span of 46 days, 396 instances of Omicron sub-lineage BA.5 in 46 days, and 152 instances of Omicron sub-lineage BA.2.75 over 62 days. One patient with severe illness was confirmed among the BA.5 cases; however, there were no reports of severe illness in the confirmed BA.4 and BA.2.75 cases. The secondary attack risk among household contacts were 19.6% for BA.4, 27.8% for BA.5, and 24.3% for BA.2.75. No statistically significant difference was found between the Omicron sub-lineages. @*Conclusion@#BA.2.75 did not demonstrate a higher tendency for transmissibility, disease severity, or secondary attack risk within households when compared to BA.4 and BA.5. We will continue to monitor major SARS-CoV-2 variants, and we plan to enhance the disease control and response systems.

Factors Affecting the Quality of Life in Low-Income Older Adults with Sarcopenia:A Cross-Sectional Study

Purpose@#This study aimed to identify the factors influencing quality of life (QoL) of low-income older adults (LOAs) with sarcopenia. @*Methods@#A convenience sample of 125 older adults was recruited from Jeonbuk Province, South Korea. Data were collected using a self-report questionnaire that included nutritional status, the Depression Anxiety Stress Scale-21, and the World Health Organization Quality of Life Instrument-Older Adults Module. Additionally, grip strength and appendicular skeletal muscle mass, were evaluated, along with the short physical performance battery. @*Results@#Sarcopenia and severe sarcopenia were observed in 43.2% and 56.8% of participants, respectively. Using multiple regression analysis, depression (β = - .40, p < .001), nutritional status (β = .24, p = .003), and anxiety (β = - .15, p = .042) were identified as factors affecting the QoL of the older adults in low-income groups with sarcopenia, the explanatory power of these variables was 44%. @*Conclusion@#The results of this study can be used to develop a nursing intervention program and establish policies to improve depression, anxiety, and nutritional status to enhance QoL of LOAs with sarcopenia.

Intensive care unit nurses’ knowledge, attitudes, perceptions of a safe environment, and compliance with the use of personal protective equipment: a descriptive observational study

Purpose@#This study investigated the knowledge, attitudes, and perceptions of a safe environment, as well as self-reported and observed compliance with the use of personal protective equipment (PPE), among intensive care unit (ICU) nurses. @*Methods@#This study was conducted in October 2021 with 55 nurses working in the medical and surgical ICUs of a general hospital in Seoul. A self-reported questionnaire and an observational tool for compliance with the use of PPE were used to collect data.Result: Except for masks, the observed compliance for all other PPE types was lower than the self-reported compliance. Male nurses showed significantly higher observed compliance than female nurses. Self-reported compliance with PPE use, including “when there is a possibility of contact with objects contaminated with blood or body fluids, mucous membranes, damaged skin, or contaminated skin” (r=.23, p=.015) and “when there is a possibility of contact with blood, body fluids, secretions, or exudates” (r=.27, p=.004) showed significant correlations with knowledge of PPE. In the results for self-reported compliance with PPE use, gown use had a significant correlation with knowledge (r=.24, p<.001) and perceptions of a safe environment (r=.15, p=.016) for PPE, and gloves showed significant correlations with attitudes (r=.14, p=.024) and perceptions of a safe environment (r=.18, p=.003). @*Conclusion@#The observed compliance with PPE use tended to be lower than the self-reported compliance among ICU nurses. It is necessary to develop and apply an effective educational program that can enhance improve actual compliance with PPE use among intensive care unit nurses.

Trends in infection-related patient safety incident reporting before and during the COVID-19 pandemic in Korea

Purpose@#The purpose of this study was to analyze the trends and characteristics of infection-related patient safety incident reporting before and during the coronavirus disease 2019 (COVID-19) pandemic in Korea, and to provide basic data for preventing infection-related patient safety incidents and improving their management. @*Methods@#A cross-sectional analysis of secondary national data (Patient Safety Reporting Data) was conducted. In total, 517 infection-related patient safety incidents reported from 2018 to 2021 were analyzed. Changes in the number of reports before and during the COVID-19 pandemic and differences in variables related to infection-related patient safety incidents were analyzed using the chi-square test and independent t-test in SPSS 29.0. @*Results@#This study found that infection-related patient safety incidents decreased during the COVID-19 pandemic compared to before the pandemic. Furthermore, incident-related characteristics, such as the type of healthcare organization, severity of harm, and post-incident actions, changed during the COVID-19 pandemic. @*Conclusion@#The many changes in the infection control system and practices during the COVID-19 pandemic may have contributed to a decrease in the reporting of infection-related patient safety incidents. It is hoped that longitudinal studies on patient safety incidents related to the pandemic and analytical studies on factors influencing patient safety incidents will continue to be conducted to prevent and improve patient safety incidents.

Significant Reduction in External Ventricular Drain-Related Infections After Introducing a Novel Bundle Protocol: A Before and After Trial

Background@#External ventricular drain (EVD)-related infection (ERI) is a serious complication in neurosurgical patients. The estimated ERI rates range from 5 to 20 cases per 1,000 EVD catheter days. The pathophysiology of ERI is similar to central line-associated bloodstream infections (CLABSIs) stemming from skin-derived bacterial colonization. The use of bundle management can reduce CLABSI rates. Due to the pathogenic similarities between infections related to the two devices, we developed and evaluated the effectiveness of an ERI-bundle protocol based on CLABSI bundles. @*Methods@#From November 2016 to November 2021, we conducted a study to evaluate the effectiveness of an ERI-bundle protocol. This study adopted a before-and-after trial, comparing the ERI rates for the 2 years before and 3 years after the introduction of the newly developed ERI-bundle protocol. We also analyzed the contributing factors to ERI using logistic regression analysis. @*Results@#A total of 183 patients with 2,381 days of catheter use were analyzed. The ERI rate decreased significantly after the ERI-bundle protocol from 16.7% (14 of 84; 14.35 per 1,000 catheter days) to 4.0% (4 of 99; 3.21 per 1,000 catheter days) (P = 0.004). @*Conclusion@#Introduction of the ERI-bundle protocol was very effective in reducing ERI.

In vivo study for the hemostatic efficacy and foreign body reaction of a new powder-type polysaccharide hemostatic agent

Purpose@#Various hemostatic agents have been introduced in therapy as postoperative bleeding is a poor prognostic factor for postoperative outcomes. These products can be divided into those that directly promote the hemostatic cascade and those that physically form a barrier by absorbing blood. The latter, powder-type hemostatic agents have the advantages of being inexpensive and more absorbable with less foreign body reactions (FBRs) and are applicable to a relatively wide area. This study was conducted to verify the safety and efficacy of a newly invented polysaccharide product (OOZFIX, Theracion Biomedical), which improves blood absorption and hemostatic effects. @*Methods@#Two separate animal experiments were performed. The first evaluated FBRs histologically at 3 days, 2 weeks, and 4 weeks, after implantation of OOZFIX in rats, and the second compared hemostatic performance of OOZFIX and Arista AH (Bard) in the porcine liver punch biopsy model. @*Results@#We found minimal FBRs in the 3-day group and no reactions in both the 2-week and 4-week groups after implantation of hemostatic agents. The time to hemostasis of OOZFIX was not significantly different from that of Arista AH (median [interquartile range]: 9 [6–10] minutes vs. 8 [6–10] minutes, respectively; P = 0.522). When comparing the serial bleeding grade tendency, there was no statistical difference between OOZFIX and Arista AH (P = 0.656). @*Conclusion@#OOZFIX caused a minimal FBR that disappeared within 2 weeks in vivo, and its hemostatic performance was comparable with that of an existing agent, Arista AH. Further clinical studies are required in the future.

Aerosolized antibiotics in the treatment of hospital-acquired pneumonia/ventilator-associated pneumonia

Aerosolized antibiotics are being increasingly used to treat respiratory infections, especially those caused by drug-resistant pathogens. Their use in the treatment of hospital-acquired pneumonia and ventilator-associated pneumonia in critically ill patients is especially significant. They are also used as an efficient alternative to overcome the issues caused by systemic administration of antibiotics, including the occurrence of drug-resistant strains, drug toxicity, and insufficient drug concentration at the target site. However, the rationale for the use of aerosolized antibiotics is limited owing to their insufficient efficacy and the potential for underestimated risks of developing side effects. Despite the lack of availability of high-quality evidence, the use of aerosolized antibiotics is considered as an attractive alternative treatment approach, especially in patients with multidrug-resistant pathogens. In this review, we have discussed the effectiveness and side effects of aerosolized antibiotics as well as the latest advancements in this field and usage in the Republic of Korea.

Neonatologist-Performed Cranial Ultrasonography in the Neonatal Intensive Care Unit

Cranial ultrasound (CUS) is an initial screening imaging tool used to evaluate the neonatal brain. It is an accessible, inexpensive, and harmless technique that can be used at bedside as frequently as required. Timely focused CUS in the neonatal care unit can play a major role in the diagnosis, follow-up, and management of brain damage. Despite the increasing use of point-of-care ultrasonography by intensive care physicians, neonatologist-performed CUS remains unusual. This review aims to provide an overview of neonatal CUS to neonatologists, focusing on the optimal settings, standard planes of the brain, and main pathologies in preterm infants. Adding Doppler studies allows evaluation of the patency of intracranial arteries and veins, flow velocities, and indices. This may provide an opportunity for earlier targeted circulatory support to prevent brain injury and improve long-term neurodevelopmental outcomes.

Importation and Transmission of SARS-CoV-2 B.1.1.529 (Omicron) Variant of Concern in Korea, November 2021

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel.There may be more transmissions with this VOC in Korea than reported.