Analysis of national surveillance of respiratory pathogens for community-acquired pneumonia in children and adolescents.

BACKGROUND: Respiratory infections among children, particularly community-acquired pneumonia (CAP), is a major disease with a high frequency among outpatient and inpatient visits. The causes of CAP vary depending on individual susceptibility, the epidemiological characteristics of the community, and the season. We performed this study to establish a nationwide surveillance network system and identify the causative agents for CAP and antibiotic resistance in Korean children with CAP. METHODS: The monitoring network was composed of 28 secondary and tertiary medical institutions. Upper and lower respiratory samples were assayed using a culture or polymerase chain reaction (PCR) from August 2018 to May 2020. RESULTS: A total of 1023 cases were registered in patients with CAP, and PCR of atypical pneumonia pathogens revealed 422 cases of M. pneumoniae (41.3%). Respiratory viruses showed a positivity rate of 65.7% by multiplex PCR test, and human rhinovirus was the most common virus, with 312 cases (30.5%). Two hundred sixty four cases (25.8%) were isolated by culture, including 131 cases of S. aureus (12.8%), 92 cases of S. pneumoniae (9%), and 20 cases of H. influenzae (2%). The cultured, isolated bacteria may be colonized pathogen. The proportion of co-detection was 49.2%. The rate of antibiotic resistance showed similar results as previous reports. CONCLUSIONS: This study will identify the pathogens that cause respiratory infections and analyze the current status of antibiotic resistance to provide scientific evidence for management policies of domestic respiratory infections. Additionally, in preparation for new epidemics, including COVID-19, monitoring respiratory infections in children and adolescents has become more important, and research on this topic should be continuously conducted in the future.

Vaccine-related Anaphylaxis Cases Confirmed by KCDC from 2001-2016.

BACKGROUND: A national immunization program (NIP) to prevent disease and reduce mortality from vaccine preventable diseases (VPD) is very important. METHODS: We analyzed only the anaphylaxis cases that occurred between 2001 and 2016 that Korea Centers for Disease Control and Prevention (KCDC) determined had a definite causal relationship with a vaccine. The clinical symptoms were assessed according to the Brighton Collaboration case definition (BCCD) level. RESULTS: During the period, there were 13 cases of vaccine-related anaphylaxis. The median age was 9 years (range, 1 month to 59 years). The incidence of anaphylaxis per million doses was 0.090 in 2005, 0.079 in 2012, 0.071 in 2013, 0.188 in 2015, and 0.036 in 2016. Of those cases, 23.1% were influenza vaccines, and 76.9% were BCCD level 2. Epinephrine was used in 46.2%. CONCLUSION: Vaccine-related anaphylaxis seems to have been very rare in the past, but health care professionals must always be aware of anaphylaxis.

Epidemiology and surveillance implications of community-acquired pneumonia in children.

Community-acquired pneumonia (CAP) is the single largest infectious cause of hospitalization and death in children worldwide. With improved immunizations, the incidence of bacterial pneumonia and the number of colonized bacteria have decreased. However, respiratory viruses are still an important cause of CAP, especially as new infectious agents such severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge. The SARS-CoV-2 virus emerged in 2019 and caused the current coronavirus disease 2019 pandemic. Therefore, it is necessary to elucidate the epidemiology and causative pathogens of CAP. Recently, the Pneumonia and Respiratory Disease Study Group, affiliated with the Korean Academy of Pediatric Allergy and Respiratory Disease, investigated the causative pathogens of respiratory infections in children hospitalized with CAP, the serotype of Streptococcus pneumoniae, and the prevalence of Mycoplasma pneumoniae with gene mutations. Antibiotic resistance and serotype test results can determine the use of empirical antibiotics. Moreover, it is possible to help develop future vaccines by comparing bacterial culture results with vaccine serotype and identifying the changes and prevalence of each serotype. Therefore, we will perform continuous national surveillance and monitor the epidemiology of respiratory pathogens in Korea and worldwide. The surveillance of these respiratory infections can play a role in monitoring the emergence of new infectious diseases such as SARS-CoV-2.

Characteristics of anaphylaxis patients who visited emergency departments in Korea: Results from a national emergency department information system.

BACKGROUND: Anaphylaxis is an allergic disease with fatal respiratory or cardiovascular symptoms that require immediate emergency treatment. We aimed to understand the characteristics and frequency of emergency department (ED) visits of patients with anaphylaxis in Korea. METHODS: Between 2007 and 2013, using data from 147 ED from the National Emergency Department Information System in Korea, we retrospectively evaluated patients with a primary diagnosis of anaphylaxis. RESULTS: During the study, a total 23,313 patients visited the ED due to anaphylaxis. The number of patients with anaphylaxis who visited the ED increased from 3.0 per 100,000 population in 2007 to 11.6 per 100,000 population in 2013 (P<0.001). Overall, the frequency of anaphylaxis emergency department visits increased by 1.24 times each year (95% CI 1.23-1.25). The risk of visiting ED due to anaphylaxis by population-based age-specific group was highest in the 60-69 years old (OR 2.30, 95% CI 1.96-2.70). Deaths from anaphylaxis increased by 1.35 times per year (95% CI 1.13-1.62). The causes of anaphylaxis were unknown (80.8%; 95% CI 80.35-81.38), drugs (8.9%; 95% CI 8.47-9.24), food (4.1%; 95% CI 3.87-4.39), bees (3.2%; 95% CI 3.02-3.48) and arthropods (2.3%; 95% CI 2.11-2.48). In 2009, drugs were the most common cause of anaphylaxis in November (35.5%), followed by food in May (15.5%) (P<0.001). Between July and September, stings from insects were the most common causes (P<0.001). By age, food was the most common cause in children aged <6 years (7.6%, <12 months; 9.0%, 1-6 years) and drugs in those aged ≥7 years. The 7-year overall mortality rate was 0.104 case per 1,000,000 population; men accounted for 77.8% of the deaths. By region, the number of cases was the highest in metropolitan areas, Gyeonggi and Seoul; however, the number of anaphylaxis cases per 100,000 population was the highest in Jeju and Gangwon. CONCLUSION: Based on ICD-10 codes, the number of ED visits due to anaphylaxis is increasing in Korea, and the incidence of anaphylaxis varies by region, season, and age.

Assessment of variables associated with prolonged admission duration in children with Mycoplasma pneumoniae pneumonia.

INTRODUCTION: Macrolide-resistant Mycoplasma pneumoniae (MRMP) has become prevalent in children. This study investigated the clinical and laboratory variables of MRMP and macrolide-sensitive M. pneumoniae (MSMP) and identified factors associated with prolonged hospital admission in children. METHODS: A prospective multicenter study was conducted in 1063 children <18 years old in July 2018-June 2020. The 454 had a positive M. pneumoniae polymerase chain reaction assay. RESULTS: Most subjects had MRMP (78.4%), and all mutated strains had the A2063G transition. We defined MRMP* (n = 285) as MRMP pneumonia requiring admission and MSMP* (n = 72) as MSMP pneumonia requiring admission. Patients with MRMP pneumonia were older, more likely to have segmental/lobar pneumonia, and had more febrile days than those with MSMP pneumonia. C-reactive protein (CRP), lactate dehydrogenase (LDH), and percentage neutrophils were more strongly associated with MRMP* than MSMP* groups. Percentage neutrophils, CRP, and alanine aminotransferase significantly changed between admission and follow-up measurements in patients with MRMP* (P < 0.05). The duration of admission positively correlated with the number of febrile days after initiation of antibiotic medication and laboratory variables (white blood cell count, CRP, and aspartate aminotransferase [AST]) (P < 0.05). Random forest analysis indicated that the number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission was over five. CONCLUSIONS: This study indicated that children with M. pneumoniae pneumonia with a higher number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission were more likely to have prolonged admission duration.

Investigation of adverse events following bacille Calmette-Guérin immunization using immunization safety surveillance system in Korea Centers for Disease Control and Prevention.

PURPOSE: The report of adverse events following immunization (AEFI) in Korea has continued since 1994, and the most frequently reported cases of AEFI of Korea Centers for Disease Control and Prevention (KCDC) is bacille Calmette-Guérin (BCG). Meanwhile, various inoculation methods and strains have been used in the past 6 years in Korea. Therefore, we investigated AEFI of BCG by strain types and inoculation methods using immunization safety surveillance of KCDC. MATERIALS AND METHODS: We reviewed BCG AEFIs registered in the KCDC from January 2013 to June 2018. RESULTS: There were 336 AEFI cases during the period, and average time interval from vaccination to symptom onset was within 2 months. AEFI proportion was 6.4 cases per 100,000 doses for BCG percutaneous Tokyo strain, 41.6 cases per 100,000 doses of BCG intradermal Danish strain, and 25.9 cases per 100,000 doses of BCG intradermal Tokyo strain. Intradermal type was more reported AEFI than percutaneous type in the same strain. The most common adverse events were local reaction like BCG lymphadenitis and severe adverse reactions such as osteomyelitis or disseminated BCG disease were 0.1 to 0.2 cases per 100,000 doses which are correlated with the range of World Health Organization published AEFI rates. CONCLUSION: The AEFI reporting rate does not equal the actual proportion of AEFI occurrence. Because AEFI monitoring is a passive surveillance system, various factors might influence the number of events reported. Nevertheless, it is important to analyze BCG AEFI by vaccine strains and inoculation method using surveillance data of KCDC.