Analysis of Critical COVID-19 Cases Among Children in Korea

Background@#Coronavirus disease 2019 (COVID-19) is generally asymptomatic or mild in otherwise healthy children, however, severe cases may occur. In this study, we report the clinical characteristics of children classified as critical COVID-19 in Korea to provide further insights into risk factors and management in children. @*Methods@#This study was a retrospective case series of children 97% for infant) and one was overweight (BMI 21.3). All patients had fever, six patients had dyspnea or cough and other accompanied symptoms included sore throat, headache, lethargy and myalgia. Radiologic findings showed pneumonia within 1–8 days after symptom onset. Pneumonia progressed in these children for 2–6 days and was improved within 5–32 days after diagnosis. Among the eight critical cases, remdesivir was administered in six cases.Steroids were provided for all cases. Inotropics were administered in one case. Six cases were treated with noninvasive mechanical ventilator and three required mechanical ventilator. One case required ECMO due to acute respiratory distress syndrome. All cases were admitted to the intensive care unit and admission period ranged from 9–39 days. Among all critical COVID-19 cases < 18 years of age, there were no fatal cases. @*Conclusion@#To develop appropriate policies for children in the COVID-19 pandemic, it is important to monitor and assess the clinical burden in this population.

Analysis of a COVID-19 Prescreening Process in an Outpatient Clinic at a University Hospital during the COVID-19 Pandemic

Background@#To minimize nosocomial infection against coronavirus disease 2019 (COVID-19), most hospitals conduct a prescreening process to evaluate the patient or guardian of any symptoms suggestive of COVID-19 or exposure to a COVID-19 patient at entrances of hospital buildings. In our hospital, we have implemented a two-level prescreening process in the outpatient clinic: an initial prescreening process at the entrance of the outpatient clinic (PPEO) and a second prescreening process is repeated in each department. If any symptoms or epidemiological history are identified at the second level, an emergency code is announced through the hospital's address system. The patient is then guided outside through a designated aisle. In this study, we analyze the cases missed in the PPEO that caused the emergency code to be applied. @*Methods@#All cases reported from March 2020 to April 2021 were analyzed retrospectively. We calculated the incidence of cases missed by the PPEO per 1,000 outpatients and compared the incidence between first-time hospital visitors and those visiting for the second time or more; morning and afternoon office hours; and days of the week. @*Results@#During the study period, the emergency code was applied to 449 cases missed by the PPEO. Among those cases, 20.7% were reported in otorhinolaryngology, followed by 11.6% in gastroenterology, 5.8% in urology, and 5.8% in dermatology. Fever was the most common symptom (59.9%), followed by cough (19.8%). The incidence of cases per 1,000 outpatients was significantly higher among first-time visitors than among those visiting for the second time or more (1.77 [confidence interval (CI), 1.44–2.10] vs. 0.59 [CI, 0.52–0.65], respectively) (P < 0.001). @*Conclusion@#Fever was the most common symptom missed by the PPEO, and otorhinolaryngology and gastroenterology most frequently reported missed cases. Cases missed by the PPEO were more likely to occur among first-time visitors than returning visitors. The results obtained from this study can provide insights or recommendations to other healthcare facilities in operating prescreening processes during the COVID-19 pandemic.

Immunogenicity and Safety of a Newly Developed Tetanus-Diphtheria Toxoid (Td) in Healthy Korean Adolescents: a Multi-center, Randomized, Doubleblind, Active-Controlled Phase 3 Trial

Background@#Although the combination tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) is recommended at adolescence in developed countries, the tetanus and diphtheria toxoid vaccine (Td), which is less costly, is recommended instead in some parts of the world. A new Td, BR-TD-1001, was developed by a Korean manufacturer for distribution to endemic regions and for use in the initial step of novel Tdap development. @*Methods@#This phase 3, randomized, double-blind, multi-center trial, conducted in Korea, aimed to evaluate the immunogenicity and safety of BR-TD-1001. Healthy children aged 10 to 12 years were randomized 1:1 to receive either BR-TD-1001 or the control Td (Td-pur, GlaxoSmithKline). Antibodies were measured using enzyme-linked immunosorbent assay. @*Results@#A total of 218 subjects (BR-TD-1001, n = 108; control, n = 110) were enrolled and included in the safety analysis. Vaccine-mediated antibody responses were similar in both groups. We confirmed the non-inferiority of BR-TD-1001 against the control, Td; 100% of both groups achieved seroprotection against diphtheria and tetanus. Furthermore, there was no significant difference between groups in the proportion of participants who demonstrated boost responses against diphtheria and tetanus toxoids. The incidence of solicited local and systemic adverse events (AEs), unsolicited AEs, and serious AEs did not differ significantly between groups. @*Conclusion@#The BR-TD-1001 satisfied the immunological non-inferiority criterion against diphtheria and tetanus, with a clinically acceptable safety profile.

Activities of an infection control surveillance-working group for the infection control and prevention of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic is unlikely to end soon, and hospitals face a high risk of exposure to COVID-19 and nosocomial infections. Therefore, strengthened infection control and prevention (ICP) strategies are crucial. Here, we share our experience of activities implemented by an infection control surveillance-working group (ICS-WG) and the introduction of a hospital emergency code for patients requiring screening for COVID-19, which were established at a university-affiliated hospital. This hospital applies multi-step processes to identify patients who must visit the outdoor screening clinic for COVID-19 testing, instead of entering the hospital building. However, some of these patients inevitably end up inside the hospital building. To solve this issue, we implemented a process to announce the emergency code (“code apple”) and have the medical personnel escort such patients to the outdoor screening clinic. This process was useful in protecting the hospital from unnecessary exposure to COVID-19. The ICS-WG was assigned to conduct the surveillance of ICP practices, patrol the hospital, and recommend improvements for any practices that did not adhere to the guidelines. The ICS-WG also developed a checklist as a monitoring tool for ICP practices. The checklists were distributed to the infection control coordinators who were assigned to monitor their team’s ICP practices and report to the ICS-WG. Overall, we believe that code apple and the ICS-WG are effective strategies in improving ICP practices of COVID-19 at hospitals.

A clinico-epidemiological multicenter study of herpes zoster in immunocompetent and immunocompromised hospitalized children

PURPOSE: There are limited population-based data regarding herpes zoster in children. Thus we conducted a multi-institutional epidemiological analysis of herpes zoster in children and comparative analysis according to their immune status. MATERIALS AND METHODS: The study included 126 children under the age of 18 years who were hospitalized for herpes zoster at 8 hospitals in South Korea, between July 2009 and June 2015. The subjects were divided into 2 groups according to their immune status, and medical records were reviewed. RESULTS: There were 61 cases (48.4%) in the immunocompetent group and 65 cases (51.6%) in the immunocompromised group. Median age was older in immunocompromised group (11.4 vs. 8.6) (p<0.001). The mean duration of hospitalization was longer in immunocompromised group (11.0 vs. 6.6) (p<0.001). Patients were treated with oral or intravenous antiviral agents. A total of 12 in immunocompetent group were cured only by oral acyclovir. No treatment failure was found in both groups. Six immunocompromised patients had postherpetic neuralgia and 1 case was in immunocompetent group. In immunocompetent children, herpes zoster was likely caused by early varicella infection. There was no increase in progression of severity in both groups due to appropriate treatment. CONCLUSION: Early initiation of therapy is necessary for those in immunocompromised conditions. And inactivated herpes zoster vaccination may be considered in immunocompromised adolescents in the future.

Coronary Arterial Lesions of Kawasaki Disease Observed in a Mouse Model of Sepsis: A Pilot Study and a Review of the Literature

PURPOSE: Coronary arterial lesions (CALs) were reported to have developed in children with systemic inflammatory diseases, as well as those with Kawasaki disease (KD). The purpose of this study was to confirm that the CAL development in children with KD occurs in a mouse model of sepsis presenting typical systemic inflammatory response syndrome (SIRS). METHODS: To induce the sepsis mouse model with SIRS, 6-week-old C57BL/6 mice were intraperitoneally injected with endotoxin. We compared histological findings of the major organs between the control and the sepsis groups and examined CAL in the heart of the septic mice. RESULTS: Infiltrating inflammatory cells were relatively increased in the heart, liver, and kidneys of the sepsis group, compared with those of the control group. We confirmed lymphocytic infiltration in the myocardium (myocarditis) and the pericardial soft tissue of the heart. Furthermore, coronary artery of the septic mouse was identified, but CAL was not observed. CONCLUSIONS: In this study, we failed to confirm the existence of CAL in a mouse model of sepsis. However, it is well-known that CALs are seen in many kinds of diseases that cause SIRS. Our findings suggest further investigation into the clinical significance of CAL in various systemic inflammatory diseases, including KD.

Clinical Features of Kawasaki Disease with Pyuria

PURPOSE: Clinical and laboratory features of two Kawasaki disease (KD) groups were evaluated; the patient with pyuria and those without pyuria. METHODS: From January 2015 to December 2016, the medical records of 140 (86 males and 54 females) inpatients with KD were retrospectively analyzed. RESULTS: Forty-eight KD patients (34.3%) presented with pyuria. KD patients with pyuria showed a higher level of C-reactive protein (CRP) and a higher proportion of elevated liver enzymes than those without pyuria. There were no differences in the proportions of unresponsiveness to intravenous immunoglobulin and coronary artery lesions between the two groups. Six KD patients (12.5%) with pyuria underwent a renal imaging study to rule out the possibility of a urinary tract infections. Thirty-two KD patients (66.7%) with pyuria received treatment with antibiotics in addition to the standard treatment for KD. CONCLUSIONS: KD patients with pyuria showed a higher level of CRP and elevated levels of liver enzymes than those without pyuria. These findings suggest that KD patients with pyuria have more severe systemic inflammation than those without pyuria.

A Case of Epiploic Appendagitis with Acute Gastroenteritis / 대한소아소화기영양학회지

Epiploic appendagitis is an inflammation of the epiploic appendage in which the small sacs projecting from the serosal layer of the colon are positioned longitudinally from the caecum to the rectosigmoid area. Epiploic appendagitis is rare and self-limiting; however, it can cause sudden abdominal pain in children. Epiploic appendagitis does not typically accompany other gastrointestinal diseases. Here, we report on a healthy eight-year-old girl who presented with abdominal pain, fever, vomiting, and diarrhea. Based on these symptoms, she was diagnosed with acute gastroenteritis, but epiploic appendagitis in the ascending colon was revealed in contrast computed tomography (CT). The patient was treated successfully with conservative management. CT is beneficial in diagnosis and further assessment of epiploic appendagitis. Pediatricians need to be aware of this self-limiting disease and consider it as a possible alternate diagnosis in cases of acute abdominal pain.

A Case of Pyogenic Liver Abscess Caused by Staphylococcus epidermidis in a Healthy Child / 소아감염

Staphylococcus epidermidis is a normal inhabitant of skin, throat, mouth, vagina, and urethra. It is not usually pathogenic, particularly in immunocompetent hosts. This report describes a case of a pyogenic liver abscess caused by Staphylococcus epidermidis in a healthy 12-year-old boy. He was admitted to Seoul St. Mary's Hospital with intermittent fever for 6 days. Findings on abdominal computed tomography (CT) showed a mass measuring 7.0x6.5 cm in the right hepatic lobe. Culture of the abscess resulted in growth of Staphylococcus epidermidis as a causative organism. The patient was successfully treated with intravenous administration of antibiotics and percutaneous drainage of the abscess.

Nasopharyngeal Carriage Rate and Serotypes of Streptococcus pneumoniae and Antimicrobial Susceptibility in Healthy Korean Children Younger than 5 Years Old: Focus on Influence of Pneumococcal Conjugate Vaccination

BACKGROUND: Even after pneumococcal vaccination introduction, Streptococcus pneumoniae (pneumoccocus) is still an important cause of respiratory and invasive severe infection. Pneumococcus is resided in nasal mucosa and local or systemic infection begins with the nasal mucosa damage. We studied the indirect effect of pneumococcal conjugate vaccine (PCV) on pneumococcal nasopharyngeal carriage rates, serotypes and antimicrobial susceptibility between vaccinate and non-vaccinated children. MATERIALS AND METHODS: From January 2010 to October 2010, 379 healthy children under 5 years old from three university hospitals were recruited. Fully vaccinated children over 3 time doses of PCV and children with no vaccination history of PCV were enrolled, and nasopharyngeal aspirations were obtained from these children. Serotypes using multibead serotyping assay with multiplex PCR and antimicrobial susceptibility was analyzed. Antimicrobial susceptibilities were determined by the CLIS guideline. RESULTS: Two hundred seventy six children were received pneumococcal vaccination while 103 were not. 137 pneumococci were isolated from nasopharyngeal aspiration specimens. Nasal carriage rate was significantly low in vaccinated group (P-value; 0.001). Nasopharyngeal carriage rate was 28.6% (79/276) in vaccinate group and 56.3% (58/103) in non-vaccinated group. Among those vaccinated group, 13.0% (36/276) of the serotypes were vaccine or vaccine related type with the most common type 19F. In contrast, 31.1% (32/103) of the serotypes in non vaccinated group were vaccine or vaccine related type with the most common type 6A. The resistant rate of penicillin was 90.5%. For antimicrobial susceptibility, amoxicillin and amoxicillin/clavulanate showed high susceptibility (73.0%), but 19F and 19A serotypes were all resistant against amoxicillin. CONCLUSIONS: High nasopharyngeal carriage rate in non vaccinated group corresponded to the result of past study. However, 19F and 19A still came up as problematic serotypes with a high carriage rate and antimicrobial resistance in both vaccinated and non vaccinated groups. Also, this study showed that the resistance rate of primary oral antimicrobial agents was increased in compared to past. For solving these problems, the selective antimicrobial use with establishment of high dose amoxicillin/clavulanate regimen and active PCV immunization should be needed. Furthermore, pneumococcal carriage and serotype study concerning with antimicrobial susceptibility should be conducted in the future in 10 or 13-valent PCV received children.

Regional differences in phylogenetic group of Escherichia coli strains isolated from children with urinary tract infection in Korea / 소아과

PURPOSE: We phylogenetically analyzed the Escherichia coli strains isolated from children with urinary tract infection (UTI) in 2 regions of Korea. Virulence factors (VFs) and antibiotic resistance of the strains were also determined to compare the possible differences. METHODS: A total of 138 E. coli strains were collected from the 2 regions; Gyeongin (78 strains) and Gyeongnam (60 strains). The phylogenetic groups were determined using the triplex polymerase chain reaction (PCR) method and multiplex PCRs were used to detect 7 VFs genes (fimH, papC, iutA, hlyA, sfa/focDE, afa/draBC, and kpsMT II). We also tested for antibiotic resistance. RESULTS: Phylogenetic groups, B2 (61.6%) and D (26.8%), comprised the majority of all isolated strains. Regional comparisons revealed that more B2 strains and fewer non-B2 (A+B1+D) strains were found in Gyeongnam, than in the Gyeongin region (P=0.033), and certain VFs were predominantly detected in Gyeongnam (P<0.05). Neither regional nor phylogenetic differences, in antibiotic resistance of the strains, were significant. CONCLUSION: We were able to confirm that the geographic location is an important determinant of the distribution of the phylogenetic groups and VFs among the E. coli strains that cause UTI in children.

Infant Pertussis and Household Transmission in Korea

A recent resurgence of pertussis has raised public health concerns even in developed countries with high vaccination coverage. The aim of this study was to describe the clinical characteristics of infant pertussis, and to determine the relative importance of household transmission in Korea. The multicenter study was prospectively conducted from January 2009 to September 2011. We identified the demographic and clinical data from these patients and performed the diagnostic tests for pertussis in their household contacts. Twenty-one patients with confirmed pertussis were included in the analysis. All infections occurred in infants younger than 6 months of age (mean age, 2.5 months) who had not completed the primary DTaP vaccination except for one patient. Infants without immunization history had a significant higher lymphocytosis and longer duration of hospital stay compared to those with immunization. All were diagnosed with PCR (100%), however, culture tests showed the lowest sensitivity (42.9%). Presumed source of infection in household contacts was documented in 85.7%, mainly parents (52.6%). Pertussis had a major morbidity in young infants who were not fully immunized. Household members were responsible for pertussis transmission of infants in whom a source could be identified. The control of pertussis through booster vaccination with Tdap in family who is taking care of young infants is necessary in Korea.

Immunoassay of Pertussis According to Ages / 소아감염

PURPOSE: We conducted the immunoassay of pertussis according to ages, in order to evaluate protective immunity against pertussis in Korean populations. METHODS: Healthy subjects were enrolled at four university hospitals in Korea. The subjects were grouped as seven age groups (every 10 years). Antibodies against pertussis toxin (PT) in sera were measured by enzyme linked immunosorbent assay (ELISA) kits. Geometric mean concentrations (GMC) of antibodies and the ratios of the subjects with seroprotective antibody levels were determined. The subjects with antibody titers > or =24.0 EU/mL were considered to seroprotective as the manufacturer's protocol. RESULTS: Total 1,605 subjects (age: 2 months-65 years) participated in this study, and their GMC was 56.16+/-50.54 EU/mL. Among seven age groups, age group or =11 year) showed lower levels of antibody against pertussis and lower ratio of the subjects with seroprotective antibody titers than children (age group <11 year).

Immunogenicity and safety of primary and secondary DTaP booster vaccination

Diphtheria-tetanus-acellular pertussis (DTaP) vaccination must currently be administered three times starting at 2 months of age, at intervals of two months, with the first and second boosters administered at 15 to 8 months and 4 to 6 years of age. A high rate of vaccination is maintained, but studies of the efficiency and safety of booster vaccination are lacking. This study evaluated the immunogenicity and safety of the DTaP booster vaccine. Seventy-two infants who had been vaccinated with the first booster and 78 children who had been vaccinated with the second booster were enrolled in this study. Local and systemic adverse reactions after vaccination were recorded. Sera obtained before and 1 month after booster vaccination were analyzed for antibodies to diphtheria and tetanus toxoid, and anti-pertussis toxin. Diphtheria: The GMT was increased. Tetanus: The geometric mean antibody titer (GMT) was increased. Pertussis: The GMT was increased by 13.72 times and 14.37 times after the first and the second additional vaccination, respectively. Although the seroconversion rate was low prior to the first booster, the average amount of anti-pertussis toxin antibodies before the first additional vaccination was 143.37 EU/mL, which rose to 261.88 EU/mL after the vaccination. The seroconversion rate also increased to 100%. Adverse reactions showed spontaneous resolution within a few days after vaccination. After the second additional vaccination, there was a statistically significant increase in the manifestation of myalgia compared to after the first additional vaccination. In conclusion, DTaP booster vaccination was effective in Korean children, demonstrating that modifications to the current regimen would be unnecessary.

Clinical manifestations of CNS infections caused by enterovirus type 71 / 소아과

PURPOSE: Enterovirus 71, one of the enteroviruses that are responsible for both hand-foot-and-mouth disease and herpangina, can cause neural injury. During periods of endemic spread of hand-foot-andmouth disease caused by enterovirus 71, CNS infections are also frequently diagnosed and may lead to increased complications from neural injury, as well as death. We present the results of our epidemiologic research on the clinical manifestations of children with CNS infections caused by enterovirus 71. METHODS: The study group consisted of 42 patients admitted for CNS infection by enterovirus 71 between April 2009 and October 2009 at the Department of Pediatrics of 5 major hospitals affiliated with the Catholic University of Korea. We retrospectively reviewed initial symptoms and laboratory findings on admission, the specimen from which enterovirus 71 was isolated, fever duration, admission period, treatment and progress, and complications. We compared aseptic meningitis patients with encephalitis patients. RESULTS: Of the 42 patients (23 men, 19 women), hand-foot-and-mouth disease was most prevalent (n=39), followed by herpangina (n=3), upon initial clinical diagnosis. Among the 42 patients, 15 (35.7%) were classified as severe, while 27 (64.3%) were classified as mild. Factors such as age, fever duration, presence of seizure, and use of intravenous immunoglobulin (IVIG) were statistically different between the 2 groups. CONCLUSION: Our results indicate that patients with severe infection caused by enterovirus 71 tended to be less than 3 years old, presented with at least 3 days of fever as well as seizure activity, and received IVIG treatment.

Clinical Investigation of Bacteremia in Children with Hemato-Oncologic Diseases

BACKGROUND: The purpose of this study was to determine the spectrum of locally prevalent pathogens and their susceptibility patterns responsible for bacteremia in pediatric hemato-oncologic patients for empiric antimicrobial therapy. MATERIALS AND METHODS: A one-year retrospective study of pediatric hematooncologic patients with bacteremia in Seoul St. Mary's Hospital, the Catholic University of Korea, from April 2009 to March 2010 was conducted using previous medical records. The findings were compared with our previous data obtained from 2004 to 2006. RESULTS: Sixty-five episodes of bacteremia were recorded in 41 patients. Of them, 55 (84.6%) occurred in neutropenic and 10 (15.4%) in non-neutropenic patients. Gram-positive organisms were more commonly isolated than Gram-negative organisms (56.9% vs. 41.5%) in the following order: viridans streptococci (23.1%), Klebsiella pneumoniae (21.6%), coagulase-negative staphylococci (12.3%), Staphylococcus aureus (7.7%), Enterococcus faecium (7.7%). Susceptibility rates of viridans streptococci to penicillin, cefotaxime and vancomycin were 33.3%, 60% and 100%, and those of Enterobacteriaceae to amikacin, ceftazidime, piperacillin/ tazobactam and meropenem were 94.7%, 73.7%, 78.9%, and 100%, respectively. Compared to our previous data, infection still contributed towards a major fraction of mortality and morbidity in the management of patients with cancer. No differences in mortality rate were observed between isolated organisms from bacteremia. CONCLUSIONS: Gram-positive organisms were more prevalent than Gram-negative organisms in our population. The monitoring of causative agents and antimicrobial resistance should be considered in therapeutic strategies of pediatric hemato-oncologic infection.

Macrophage Activation Syndrome as the Extreme Form of Kawasaki Disease / 소아감염

Few cases of macrophage activation syndrome (MAS) or reactive hemophagocytic lymphohistiocytosis (HLH) during the acute febrile phase of Kawasaki disease (KD) have been reported. We report on a case of a 19 month-old girl with MAS or reactive HLH during the course of KD. Despite immunoglobulin and steroid therapy, she showed persistent fever with hepatosplenomegaly and evidence of hemophagocytosis in the bone marrow. A high index of suspicion for clinical features associated with MAS is necessary for KD patients in order to provide appropriate treatment.

Two case of thanatophoric dysplasia type I / 대한주산의학회잡지

Thanatophoric dysplasia (TD) is a lethal inherited skeletal disorder characterized by extremely short limbs, narrow chest, skull deformity and underdeveloped lungs. TD is divided into two types, depending primarily upon whether the bone in the upper leg (the femur) is curved or straight. We experienced two case of TD type I that were confirmed by clinical and radiological features after birth. Unlike previously reported cases of TD in our country, the multiple anomalies of CNS, kidney and cardiovascular system were identified in one of these cases.

Predictors of Serious Bacterial and Viral Infections among Neonates with Fever

PURPOSE: The purpose of this study was to describe the epidemiologic features of febrile illnesses in newborns and to predict the risk of serious infections in this population. METHODS: A retrospective study was conducted on 123 full-term infants 38 degrees C who were hospitalized between 2000 and 2006. Neonates with prenatal risk factors, congenital anomalies, antibiotic administration prior to admission to the hospital, or suspected hospital-acquired infections were excluded. We evaluated the symptoms, physical examination findings, laboratory data, and clinical course between the high- and low-risk groups for serious infections. RESULTS: The high-risk group included 30 infants with the following diagnoses in order of frequency: aseptic meningitis, urinary tract infection, bacterial meningitis, infectious enteritis, sepsis concomitant with disseminated intravascular coagulopathy, bacteremia, pneumonia, cellulitis, and omphalitis. Leukocytosis and thrombocytopenia were statistically different between the two groups. Factors, such as moaning signs, seizures, body temperature, and pulse rate were statistically significant. CONCLUSION: Unlike previous studies, we included newborns with clinical bacterial infections and aseptic meningitis as the high-risk group. Leukocytosis, thrombocytopenia, moaning signs, seizures, and changes in vital signs were considered useful predictors for identifying febrile neonates at high-risk for serious infections in spite of a difference in the definition of serious infection.

An analysis of one-year experience of pediatric observation unit: The first report in Korea / 소아과

PURPOSE: While pediatric observation units (POU) have become a common practice in hospitals throughout developed countries, there has been no report about POUs in Korea so far. The aims of this study were to analyze our one-year's experience of the POU and to decide which disease entities are suitable for the POU. METHODS: All children admitted from March 2006 to February 2007 to the POU at the Department of Pediatrics in Our Lady of Mercy Hospital were included in this study. Data were collected from retrospective reviews of their medical records. RESULTS: There were a total of 1,076 POU admissions. Median age of patients was 2.4 years and median length of hospital stay 14.0 hours. The most common diagnoses were gastroenteritis (42.7%), pharyngotonsillitis (19.1%), bronchiolitis (7.8%), pneumonia (5.5%) and febrile seizure (5.2%). Overall, 7.5% of the POU patients required subsequent inpatient admissions due to hospital stays of longer than 48 hours. The disease entities that were most likely to require inpatient admission were pneumonia (17.0%), febrile seizure (12.5%) and asthma (11.5%). Diseases that allowed successful discharge from the POU were gastroenteritis (4.6%), upper respiratory tract infection (5.8%), such as otitis media and pharygnotonsillitis and seizure disorder (6.4%). Compared with the previous year when the POU was not in operation, there was a statistically significant reduction in the average length of hospital stays (from 4.69 to 3.75 days), as well as a rise in the bed turnover rate (from 78.8 to 98.2 patients/ bed). CONCLUSION: Our study shows that the POU is efficient for the management of children with certain acute illnesses. Based on this study, we suggest that the POU be used as a new modality which links between the outpatient, inpatient, and emergency departments in the field of pediatrics in Korea.