Twenty-Five Year Trend Change in the Etiology of Pediatric Invasive Bacterial Infections in Korea, 1996–2020

Background@#The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI). @*Methods@#A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed. @*Results@#A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (rs = −0.430, P = 0.036), H. influenzae (rs = −0.922, P 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.

Pediatric Sarcoidosis Misdiagnosed as Hepatosplenic Abscesses: A Case Report and Review

Sarcoidosis is a systemic granulomatous disorder of unknown etiology characterized by granuloma formation. Due to the limited incidence of sarcoidosis in pediatric patients, little is known about the clinical course of this disease. A combination of clinical, radiologic, and pathologic examination is necessary to exclude other differential diagnoses (i.e., infection and granulomatous inflammatory disorder) and establish a diagnosis of sarcoidosis. Here, we report a case of histologically confirmed sarcoidosis initially misdiagnosed as hepatosplenic abscesses in an 11-year-old male. Treatment with corticosteroids improved his symptoms and resolved his skin and hepatosplenic lesions. A three-year follow-up was uneventful. This study emphasizes the importance of considering sarcoidosis in children presenting with findings of multi-organ involvement in the presence of histologic evidence of granuloma.

Delayed Influenza Treatment in Children With False-Negative Rapid Antigen Test: A Retrospective Single-Center Study in Korea 2016–2019

Background@#We aimed to examine the delay in antiviral initiation in rapid antigen test (RAT) false-negative children with influenza virus infection and to explore the clinical outcomes. We additionally conducted a medical cost-benefit analysis. @*Methods@#This single-center, retrospective study included children (aged < 10 years) with influenza-like illness (ILI), hospitalized after presenting to the emergency department during three influenza seasons (2016–2019). RAT-false-negativity was defined as RAT-negative and polymerase chain reaction-positive cases. The turnaround time to antiviral treatment (TAT) was from the time when RAT was prescribed to the time when the antiviral was administered. The medical cost analysis by scenarios was also performed. @*Results@#A total of 1,430 patients were included, 7.5% were RAT-positive (n = 107) and 2.4% were RAT-false-negative (n = 20). The median TAT of RAT-false-negative patients was 52.8 hours, significantly longer than that of 4 hours in RAT-positive patients (19.2–100.1, P< 0.001). In the multivariable analysis, TAT of ≥ 24 hours was associated with a risk of severe influenza infection and the need for mechanical ventilation (odds ratio [OR], 6.8, P = 0.009 and OR, 16.2, P = 0.033, respectively). The medical cost varied from $11.7–187.3/ILI patient. @*Conclusion@#Antiviral initiation was delayed in RAT-false-negative patients. Our findings support the guideline that children with influenza, suspected of having severe or progressive infection, should be treated immediately.

Evaluation of Interferon-gamma Release Assay in Children with Confirmed Tuberculosis

Purpose@#This study aimed to evaluate the diagnostic value of the QuantiFERON-TB Gold InTube (QFT-GIT) in children with confirmed tuberculosis (TB). @*Methods@#We retrospectively reviewed the medical records of children aged ≤18 years who underwent both QFT-GIT and Mycobacterium tuberculosis culture between 2006 and 2017.Confirmed TB was defined as the presence of at least one positive specimen for M. tuberculosis on culture or a nucleic acid amplification test. @*Results@#Of the 582 patients included in the analysis, 48 were confirmed to have TB. The sensitivity and specificity of QFT-GIT for the diagnosis of confirmed TB were 85.4% and 95.5%, respectively. Among children with confirmed TB, the proportion in the immunocompromised state was higher in the QFT-GIT negative group than in the QFT-GIT positive group (50.0% vs. 5.7%, P=0.010). The median age at sampling was lower in the QFTGIT indeterminate group than in the QFT-GIT positive group (7 years vs. 17 years, P=0.008), and the proportion of immunosuppression was higher in the QFT-GIT indeterminate group than in the QFT-GIT positive group (42.9% vs. 5.7%, P=0.017). The interferon gamma response to mitogen control was significantly higher in the 10–18 years group than in the 0–9 years group (P<0.001), and was significantly higher in the immunocompetent group than in the immunocompromised group (P=0.001). @*Conclusion@#The QFT-GIT results should be interpreted carefully in immunocompromised or younger children suspected of having TB.

A case of neonatal lupus presenting with fever and skin rash in a 47-day-old girl

Neonatal lupus (NL) is a passively acquired autoimmune disease that occurs in infants born from asymptomatic mothers having anti-SSA or anti-SSB antibody. Infants with NL may show symptoms of systemic lupus erythematosus, including skin rash, congenital heart block, hepatic dysfunction, and hematological abnormalities. Mothers of the infants are asymptomatic or diagnosed with autoimmune diseases. When infants born to asymptomatic mothers who have never been diagnosed with the diseases show symptoms of NL, they may be mistaken for having infections. We report an NL case of a 47-day-old girl who presented to the emergency department with fever and skin rash.

Evaluation of Interferon-gamma Release Assay in Children with Confirmed Tuberculosis

Purpose@#This study aimed to evaluate the diagnostic value of the QuantiFERON-TB Gold InTube (QFT-GIT) in children with confirmed tuberculosis (TB). @*Methods@#We retrospectively reviewed the medical records of children aged ≤18 years who underwent both QFT-GIT and Mycobacterium tuberculosis culture between 2006 and 2017.Confirmed TB was defined as the presence of at least one positive specimen for M. tuberculosis on culture or a nucleic acid amplification test. @*Results@#Of the 582 patients included in the analysis, 48 were confirmed to have TB. The sensitivity and specificity of QFT-GIT for the diagnosis of confirmed TB were 85.4% and 95.5%, respectively. Among children with confirmed TB, the proportion in the immunocompromised state was higher in the QFT-GIT negative group than in the QFT-GIT positive group (50.0% vs. 5.7%, P=0.010). The median age at sampling was lower in the QFTGIT indeterminate group than in the QFT-GIT positive group (7 years vs. 17 years, P=0.008), and the proportion of immunosuppression was higher in the QFT-GIT indeterminate group than in the QFT-GIT positive group (42.9% vs. 5.7%, P=0.017). The interferon gamma response to mitogen control was significantly higher in the 10–18 years group than in the 0–9 years group (P<0.001), and was significantly higher in the immunocompetent group than in the immunocompromised group (P=0.001). @*Conclusion@#The QFT-GIT results should be interpreted carefully in immunocompromised or younger children suspected of having TB.

A case of neonatal lupus presenting with fever and skin rash in a 47-day-old girl

Neonatal lupus (NL) is a passively acquired autoimmune disease that occurs in infants born from asymptomatic mothers having anti-SSA or anti-SSB antibody. Infants with NL may show symptoms of systemic lupus erythematosus, including skin rash, congenital heart block, hepatic dysfunction, and hematological abnormalities. Mothers of the infants are asymptomatic or diagnosed with autoimmune diseases. When infants born to asymptomatic mothers who have never been diagnosed with the diseases show symptoms of NL, they may be mistaken for having infections. We report an NL case of a 47-day-old girl who presented to the emergency department with fever and skin rash.

Role of Biomarkers in Juvenile Idiopathic Arthritis

The aim of this review was to identify the utility of biomarkers used in the diagnosis and the monitoring and treatment of Juvenile idiopathic arthritis (JIA). JIA is a heterogeneous group of diseases characterized by arthritis of unknown etiology that lasts for at least 6 weeks, with onset before the age of 16 years. Unlike adult rheumatoid arthritis, JIA is a heterogeneous arthritis with different subtypes. The diagnosis of JIA is based on clinical evaluation and often involves ruling out other causes of arthritis.Many biomarkers have been studied or are under development to define the classifications of JIA, assess disease activity, predict disease course, treatment response, or the risk of relapse. The diagnostic and prognostic use of biomarkers in JIA could be applied differently depending on diverse subtypes or individuals. To obtain the best clinical outcomes in JIA, it is important to understand the pathophysiology of each JIA subtype and to select and use appropriate biomarkers.

Clinical Features of and Antibiotic Resistance in Recurrent Urinary Tract Infection in Children with Vesicoureteral Reflux

Purpose@#This study aimed to investigate the clinical features of recurrent urinary tract infection (UTI) in children with vesicoureteral reflux (VUR) and to compare the causative uropathogen and antibiotic susceptibility between the first and recurrent UTI episodes. @*Methods@#We retrospectively reviewed the medical records of children with VUR who had recurrent UTI. Group 1 included patients in whom the same pathogen caused the first and recurrent UTI episodes. Group 2 included patients in whom different pathogens caused the first and recurrent UTI episodes. @*Results@#During a 13-year study period (2005–2018), 77 children with VUR experienced at least one episode of UTI. Among these, 47 patients (61.0%) had recurrent UTI. Of the children with recurrent UTI, 19 (40.4%) were in group 1 and 28 (59.6%) were in group 2. Escherichia coli was the most commonly isolated uropathogen (n=37; 39.4%) in both episodes of recurrent UTIs, followed by Klebsiella pneumoniae (n=18; 19.1%), Enterococcus faecalis (n=14; 14.9%), and Enterobacter aerogenes (n=7; 7.4%). Although the difference was not significant, the rate of resistance to the antibiotics ceftazidime, piperacillin/tazobactam, and trimethoprim-sulfamethoxazole increased in patients with the second episode of E. coli recurrence in group 1, and that to cefotaxime, ceftazidime, piperacillin/tazobactam, and meropenem increased in children with the second episode of E. aerogenes recurrence in group 1. @*Conclusions@#When selecting empirical antibiotics for recurrent UTI in children with VUR, it is important to consider that the pathogen and antimicrobial susceptibility of the previous UTI are not always the same in recurrent UTIs.

Incidence and Characteristics of Clostridioides difficile Infection in Children

Purpose@#We evaluated the incidence and characteristics of Clostridioides difficile infection (CDI) in Korean children. @*Methods@#Medical records of patients aged 2–18 years and diagnosed with CDI at a tertiary hospital between 2009 and 2018 were analyzed. The patients were classified into three CDI groups: community-acquired (CA), community onset-health care facility-associated (COHCFA), and healthcare facility onset (HO). @*Results@#The incidence of CDI increased from 1.00 to 10.01 cases per 10,000 admissions from 2009 to 2018 (P<0.001). As compared to the CA group, the HO group had a higher frequency of operation and malignancy as predisposing factors (40.4% vs. 0.0%, P=0.001; and 27.7% vs. 0.0%, P=0.027, respectively), frequency and number of previous antibiotic use (97.9% vs. 31.3%, P<0.001; and 2 vs. 0, P<0.001, respectively), and median postdiagnosis hospital stay (13 vs. 5 days, P=0.008). The CO-HCFA group had a lower median age and higher frequency of malignancy than the CA group (5 vs. 13 years, P=0.012; and 30.8% vs.0.0%, P=0.030, respectively). As compared to the HO group, the CA group had a higher frequency of abdominal pain and hematochezia (56.3% vs. 10.6%, P=0.001; and 50.0% vs. 10.6%, P=0.002, respectively), inflammatory bowel disease (68.8% vs. 2.1%, P=0.001), and intravenous metronidazole treatment (37.5% vs. 2.1%,P=0.001). @*Conclusions@#With the increasing incidence of pediatric CDI, awareness regarding its epidemiology and clinical characteristics is important to manage nosocomial infections.

Incidence and Characteristics of Clostridioides difficile Infection in Children

Purpose@#We evaluated the incidence and characteristics of Clostridioides difficile infection (CDI) in Korean children. @*Methods@#Medical records of patients aged 2–18 years and diagnosed with CDI at a tertiary hospital between 2009 and 2018 were analyzed. The patients were classified into three CDI groups: community-acquired (CA), community onset-health care facility-associated (COHCFA), and healthcare facility onset (HO). @*Results@#The incidence of CDI increased from 1.00 to 10.01 cases per 10,000 admissions from 2009 to 2018 (P<0.001). As compared to the CA group, the HO group had a higher frequency of operation and malignancy as predisposing factors (40.4% vs. 0.0%, P=0.001; and 27.7% vs. 0.0%, P=0.027, respectively), frequency and number of previous antibiotic use (97.9% vs. 31.3%, P<0.001; and 2 vs. 0, P<0.001, respectively), and median postdiagnosis hospital stay (13 vs. 5 days, P=0.008). The CO-HCFA group had a lower median age and higher frequency of malignancy than the CA group (5 vs. 13 years, P=0.012; and 30.8% vs.0.0%, P=0.030, respectively). As compared to the HO group, the CA group had a higher frequency of abdominal pain and hematochezia (56.3% vs. 10.6%, P=0.001; and 50.0% vs. 10.6%, P=0.002, respectively), inflammatory bowel disease (68.8% vs. 2.1%, P=0.001), and intravenous metronidazole treatment (37.5% vs. 2.1%,P=0.001). @*Conclusions@#With the increasing incidence of pediatric CDI, awareness regarding its epidemiology and clinical characteristics is important to manage nosocomial infections.

The First Case Series of Cryopyrin-Associated Periodic Syndrome in Korea

Cryopyrin-associated periodic syndrome (CAPS) is a hereditary autoinflammatory syndrome caused by mutations in NLRP3 (encoding cryopyrin), which presents with fever, fatigue and arthralgia. Thus far, however there have been no reports of CAPS in Korea. Herein, we report 3 cases of CAPS for the first time in Korea. The first case, a 28-year-old man with recurrent urticaria, arthralgia and fever induced by cold, all of which were observed in his father, showed elevated erythrocyte sedimentation rate and C-reactive protein. He exhibited a p.Gly303Asp variant of the NLPR3 gene. The second case, a 2-year-old girl who had recurrent urticaria, arthritis and oral and genital ulcers, was positive for HLA B51 and a p.Glu569Lys mutation in exon 3 of the NLRP3 gene. Administration of anakinra greatly improved her symptoms. The third case, a 4-year-old boy who presented with recurrent urticaria, arthralgia, and fever, exhibited a p.Val72Met mutation in exon 1 of the NLRP3 gene. Administration of tocilizumab improved all of his symptoms. This small case series suggests that clinicians consider CAPS and conduct genetic studies when arthralgia and fever are accompanied by urticaria in Korea.

Characterization of Oropharyngeal Carriage Isolates of Neisseria meningitidis in Healthy Korean Adolescents in 2015

The meningococcus carriage rate is age-dependent, with a high prevalence in adolescents and young adults. This cross-sectional study aimed to estimate the oropharyngeal carriage rate of meningococcus among healthy Korean adolescents and its relationship with several population characteristics. The survey was conducted from April to May 2015 among 1,460 first-year high-school students in 9 high schools located in Gyeonggi province, Korea. Each student answered a short questionnaire assessing risk factors for carriage, and posterior pharyngeal wall swab samples were obtained. These samples were cultured on meningococcus-selective media, with colonies resembling meningococci identified using the Vitek® MS system (bioMérieux, Marcy l'Etoile, France). All isolates were characterized by molecular serogrouping and multilocus sequence typing (MLST). Meningococci were identified from 3.4% (49/1,460) swabs. Current smokers had significantly higher carriage rates than non-smokers (8.2% vs. 2.9%, P = 0.002), and boys had significantly higher carriage rates than girls (4.4% vs. 1.6%, P = 0.004). Serogroup B was the most common serogroup, followed by serogroup C, then 29E and Y. Twenty-seven different sequence types (STs) were identified; the most common were ST-3091, ST-11278, and ST-44. These belonged to clonal complexes (CCs) 269, 32, and 41/44, respectively, known as the hypervirulent clones. Evaluating meningococcal carriage is important to understand the epidemiology of meningococcal disease; however, little data exist in Korea. Similar to western countries, meningococcal serogroup B has emerged in Korea, and hypervirulent clones were identified. It is necessary to monitor the genetic and serologic characteristics of circulating meningococci and to assess the potential strain coverage of meningococcal vaccines.

Vitamin D and Risk of Respiratory Tract Infections in Children: A Systematic Review and Meta-analysis of Randomized Controlled Trials

PURPOSE: Recent observational studies have found that vitamin D deficiency is associated with respiratory tract infections. However, randomized controlled trials (RCTs) regarding the efficacy of vitamin D in childhood respiratory tract infection (RTI) have yield inconsistent results. We performed a systematic review and meta-analysis to evaluate the association between vitamin D supplementation and the risk of RTI. METHODS: A comprehensive search was conducted using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trial. Randomized controlled trials of vitamin D supplementation for prevention of RTI in children were included for the analysis. Cochrane Collaboration's tool for assessing the risk of bias was used to assess the quality of the studies. Pooled risk ratios with 95% confidence intervals (CIs) were meta-analyzed using Review Manager 5.3. RESULTS: A total of seven RCTs were included in the meta-analysis. According to a random-effects model, the risk ratio for vitamin D supplementation was 0.82 (95% CI: 0.69-0.98) and I2=62% for heterogeneity. On subgroup analysis, heterogeneity decreased in the subgroup with follow-up less than 1 year, participants ≥5 years of age, patients subgroup, and subgroup with dosing daily. Funnel plot showed that there might be publication bias in the field. CONCLUSIONS: The present meta-analysis supports a beneficial effect of vitamin D supplementation for the prevention of RTI in children. However, the result should be interpreted with caution due to limitations including a small number of available RCTs, heterogeneity among the studies, and potential publication bias.

Vaccine Evaluation Studies Performed in Korea from 2000 to 2014

PURPOSE: Vaccine evaluation studies were initiated from 2000 by the Ministry of Food and Drug Safety to produce proper data about the safety and immunogenicity of vaccines. The purpose of this study was to review studies and reports on evaluation of vaccine such as immunogenicity, efficacy, effectiveness, safety and other related topics in order to find and analyze the data on the usefulness of each vaccine. METHODS: From 2000 to 2014, the project "The vaccine evaluation" had been performed by several researchers, and studies and reports of vaccine evaluation. We reviewed the results and outcomes of studies regarding the evaluation of vaccine's usefulness and analyzed the possibilities of applying these data for establishing vaccine policies. For each vaccine, data analysis and organization were done according to evaluation fields. RESULTS: A total of 83 studies were performed on vaccines from 2000 to 2014. For each vaccine, 8 studies were performed on BCG, 14 on DTaP/Td, 1 on poliovirus, 5 on Hib, 3 on pneumococcus, 11 on influenza, 3 on hepatitis A, 11 on MMR, 11 on varicella, and 16 on Japanese encephalitis. All studies were analyzed by the following evaluation area, such as safety, immunogenicity, seroprevalence, persistence of immunity, efficacy, effectiveness, vaccine evaluation methods, quality control product for vaccine, and others. CONCLUSIONS: Vaccine evaluation studies performed in Korea may be useful as references for establishing vaccination strategy and policy and could be used as baseline data for future studies on vaccine evaluation, vaccine policy establishment, and public/expert vaccine education in Korea.

Reappraisal of the Immunogenicity and Safety of Three Hepatitis A Vaccines in Adolescents

Although the overall incidence of hepatitis A in Korea has been decreasing, adolescents remain highly vulnerable to its outbreaks. This study was conducted to compare the immunogenicity and safety of three hepatitis A vaccines in Korean adolescents. Healthy anti-hepatitis A virus seronegative subjects aged 13 to 19 yr were randomized in three equal groups to receive two doses of Avaxim(TM), Epaxal(R), or Havrix(R), 6 to 12 months apart. Seroconversion rates one month after the first dose were 98%, 95%, and 93% for Avaxim(TM), Epaxal(R), and Havrix(R), respectively. Seroconversion rates reached 100% for all vaccine groups one month after the second dose. Anti-HAV geometric mean concentrations (GMCs) were 7,207.7 mIU/mL (95% CI, 6023.1-8684.7), 1,750.5 mIU/mL (95% CI, 1362.9-2248.3), and 1,953.5 mIU/mL (95% CI, 1459.4-2614.7) after two doses of Avaxim(TM), Epaxal(R), and Havrix(R) respectively. Avaxim(TM) was significantly more immunogenic than Epaxal(R) and Havrix(R), whereas there were no significant differences in antibody responses between Epaxal(R) and Havrix(R). Local and systemic solicited adverse events (AEs) were mostly of mild-to-moderate intensity and resolved within 5 days. No serious AEs were reported. In conclusion, all three vaccines are highly immunogenic and well-tolerated in Korean adolescents. (Clinical Trial Registry NCT00483470)

A Case of Lung Involvement Associated with Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) can develop extra-articular manifestations, including growth retardation, osteopenia and chronic uveitis. However, pleuropulmonary involvement is rare. Approximately 40% of patients with JIA have abnormal pulmonary function tests without pulmonary symptoms, with the commonest abnormality in carbon monoxide diffusing capacity, but clinically evident pulmonary parenchymal disease in JIA is extremely uncommon. We describe a 15-year-old male with JIA who presented with dyspnea due to interstitial lung disease.

Enhanced detection and serotyping of Streptococcus pneumoniae using multiplex polymerase chain reaction / 소아과

PURPOSE: Methods for quick and reliable detection of Streptococcus pneumoniae are needed for the diagnosis of pneumococcal disease and vaccine studies. This study aimed to show that sequential multiplex polymerase chain reaction (PCR) is more efficient than conventional culture in achieving S. pneumoniae-positive results. METHODS: Nasopharyngeal (NP) secretions were obtained from 842 pediatric patients admitted with lower respiratory infections at Severance Children's Hospital in Korea between March 2009 and June 2010. For identification and serotype determination of pneumococci from the NP secretions, the secretions were evaluated via multiplex PCR technique with 35 serotype-specific primers arranged in 8 multiplex PCR sets and conventional bacteriological culture technique. RESULTS: Among the results for 793 samples that underwent both bacterial culture and PCR analysis for pneumococcal detection, 153 (19.3%) results obtained by PCR and 81 (10.2%) results obtained by conventional culture technique were positive for S. pneumoniae. The predominant serotypes observed, in order of decreasing frequency, were 19A (23%), 6A/B (16%), 19F (11%), 15B/C (5%), 15A (5%), and 11A (4%); further, 26% of the isolates were non-typeable. CONCLUSION: As opposed to conventional bacteriological tests, PCR analysis can accurately and rapidly identify pneumococcal serotypes.

A Nationwide Survey on the Child Day Care and Common Infectious Diseases / 소아감염

PURPOSE: As the number of children who attend child care centers has increased, concerns has increased about the effect of child day care on childhood illness. This study was conducted to examine the relationship between experience in child care and common infectious diseases in children under 5 years of age. METHODS: Data were collected by surveying 1,000 respondents with children under age 5 through online interviews using a structured questionnaire. The contents of the survey were composed of demographic characteristics, child care facilities usage, experience in infectious diseases, and immunization status. RESULTS: Among the 1,000 children <5 years of age, 78.5% attended a child care facility. Rates of common communicable illnesses were higher in children in child care than for children reared exclusively at home. The predominant communicable diseases which the respondents' children experienced, in order of decreasing frequency, were gastroenteritis (47.1%), otitis media (41.8%) and pneumonia (19.1%). The immunization rate of vaccines that are not included the national immunization program (NIP) (Haemophilus influenzae type b vaccine - 76.6%, hepatitis A vaccine - 63.3%, pneumococcal vaccine - 59.4%, rotavirus vaccine - 43.1%) was lower than that of the NIP vaccines (90.4%). CONCLUSION: Children in child care experience more bouts of common infectious disease, so nationwide policies to prevent or to control the spread of infectious agents in a child-care should be available and appropriate immunization should be emphasized as the most effective method for the control of infectious disease for children.

Phylogenetic Analysis of Human Bocavirus in Hospitalized Children with Acute Respiratory Tract Infection in Korea / 소아감염

PURPOSE: Human bocavirus (hBoV), a recently discovered virus, has been detected in children with respiratory tract infections worldwide. The aim of this study was to analyze the frequency and molecular phylogeny of hBoV in the respiratory samples of children with acute respiratory tract infections in 2010. METHODS: Nasopharyngeal samples were collected from 953 children with lower respiratory tract infections at Severance children's hospital in Korea from January 2010 to December 2010. We applied the multiplex PCR technique for the identification of 12 respiratory viruses from the samples. Among the total specimens, hBoV positive samples were subjected to phylogenetic analysis by sequencing a fragment of the VP1/VP2 gene junction. RESULTS: hBoV was detected in 141 (14.8%) among 953 patients. The 61.7% of hBoV-positive samples were found to co-exist with other respiratory viruses. The results of phylogenetic analysis showed that all 141 hBoV-positive isolates were identified as hBoV 1, revealing a high similarity among the isolates (>98%). CONCLUSION: hBoV 1 with minimal sequence variations circulated in children with acute respiratory infections during 2010. More research is needed to determine the clinical severity and outcomes of the minimal sequence variations.