• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.267-273
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• 2013

Multiplex RT-PCR was used to detect respiratory viruses in 5,318 clinical samples referred to the laboratory of a tertiary teaching hospital from December 2006 to November 2010. The acquired data were analyzed with respect to types, ratio, and co-infection trends of infected respiratory viruses. Trends in respiratory viral infection according to sex, age, and period of infection were also analyzed. Of the 5,318 submitted clinical samples, 3,350 (63.0%) specimens were positive for at least one respiratory virus. The infection rates were 15.8% for human rhinovirus, 14.4% for human respiratory syncytial virus A, 9.7% for human respiratory syncytial virus B, 10.1% for human adenovirus, 5.4% for influenza A virus, 1.7% for influenza B virus, 4.7% for human metapneumovirus, 2.3% for human coronavirus OC43, 1.9% for human coronavirus 229E/NL63, 3.7% for human parainfluenza virus (HPIV)-1, 1.1% for HPIV-2, and 5.3% for HPIV-3. The co-infection analysis showed 17.1% of double infections, 1.8% of triple infections. The median age of virus-positive patients was 1.3 years old, and the 91.5% of virus-positive patients were under 10 years old. Human respiratory syncytial virus was the most common virus in children < 5 years of age and the influenza A virus was most prevalent virus in children over 5 years of age. These results help in elucidating the tendency of respiratory viral infections.

• BMB Reports
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• v.44 no.4
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• pp.232-237
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• 2011

Human respiratory syncytial virus (HRSV) is a major cause of upper and lower respiratory tract illness in infants and young children worldwide. Despite its importance as a respiratory pathogen, there is currently no licensed vaccine for prophylaxis of HRSV infection. There are several hurdles complicating the development of a RSV vaccine: 1) incomplete immunity to natural RSV infection leading to frequent re-infection, 2) immature immune system and maternal antibodies of newborn infants who are the primary subject population, and 3) imbalanced Th2-biased immune responses to certain vaccine candidates leading to exacerbated pulmonary disease. After the failure of an initial trial featuring formalin-inactivated virus as a RSV vaccine, more careful and deliberate efforts have been made towards the development of safe and effective RSV vaccines without vaccine-enhanced disease. A wide array of RSV vaccine strategies is being developed, including live-attenuated viruses, protein subunit-based, and vector-based candidates. Though licensed vaccines remain to be developed, our great efforts will lead us to reach the goal of attaining safe and effective RSV vaccines in the near future.

• Clinical and Experimental Pediatrics
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• v.55 no.9
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• pp.309-315
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• 2012

Human respiratory syncytial virus (HRSV) is a major cause of severe respiratory tract illnesses in infants and young children worldwide. Despite its importance as a respiratory pathogen, there is currently no licensed vaccine for HRSV. Following failure of the initial trial of formalin-inactivated virus particle vaccine, continuous efforts have been made for the development of safe and efficacious vaccines against HRSV. However, several obstacles persist that delay the development of HRSV vaccine, such as the immature immune system of newborn infants and the possible Th2-biased immune responses leading to subsequent vaccine-enhanced diseases. Many HRSV vaccine strategies are currently being developed and evaluated, including live-attenuated viruses, subunit-based, and vector-based candidates. In this review, the current HRSV vaccines are overviewed and the safety issues regarding asthma and vaccine-induced pathology are discussed.

• Pediatric Infection and Vaccine
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• v.21 no.3
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• pp.207-213
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• 2014

Purpose: This study aimed to investigate the association between respiratory virus infection and pneumococcal colonization in children. Methods: From May 2009 to June 2010, nasopharyngeal (NP) aspirates were obtained from patients under 18 years old who visited Seoul National University Children's Hospital for respiratory symptoms. NP samples were used to detect respiratory viruses (influenza virus A and B, parainfluenza virus 1, 2 and 3, respiratory syncytial virus A and B, adenovirus, rhinovirus A/B, human metapneumovirus, human coronavirus 229E/NL63 and OC43/HKU1) by RT-PCR and pneumococcus by culture. Results: Median age of the patients was 27 months old. A total of 1,367 NP aspirates were tested for respiratory viruses and pneumococcus. Pneumococcus was isolated from 228 (16.7%) of samples and respiratory viruses were detected from 731 (53.5%). Common viruses were rhinovirus (18.4%), respiratory syncytial virus (RSV) A (10.6%), adenovirus (6.9%), influenza virus A (6.8%). Pneumococcal isolation rate was significantly higher in the cases of positive virus detection than negative detection [21.3% (156/731) vs. 11.3% (72/636), P <0.001]. For individual viruses, pneumococcal isolation rate was positively associated with detection of influenza virus A [24.7% (23/93) vs 16.1% (205/1274), P=0.001], RSV A [28.3% (41/145) vs 15.3% (187/1222), P=0.001], RSV B [31.3% (10/32) vs 16.3% (218/1335), P=0.042], rhinovirus A/B [22.6% (57/252) vs 15.3% (171/1115), P=0.010]. Conclusion: The study revealed that pneumococcal isolation from NP aspirates is related with respiratory virus detection. The result of this study could be used to investigate how respiratory viruses and pneumococcus cause clinical diseases.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.2006-2013
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• 2019

The isolation of respiratory viruses, especially from clinical specimens, often shows poor efficiency with classical cell culture methods. The lack of suitable methods to generate virus particles inhibits the development of diagnostic assays, treatments, and vaccines. We compared three inoculation methods, classical cell culture, the addition of a JAK2 inhibitor AZD1480, and centrifugation-enhanced inoculation (CEI), to replicate human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV). In addition, a combined method using AZD1480 treatment and CEI was used on throat swabs to verify that this method could increase virus isolation efficiency from human clinical specimens. Both CEI and AZD1480 treatment increased HRSV and HMPV genome replication. Also, the combined method using CEI and AZD1480 treatment enhanced virus proliferation synergistically. The combined method is particularly suited for the isolation of interferon-sensitive or slowly growing viruses from human clinical specimens.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.1
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• pp.22-27
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• 2017

The length of hospital stay (LOS) for patients with respiratory virus infections has been reported to depend the virus type and infection severity. However, the impact of co-infections remains unclear. Patients with suspected respiratory virus infections, who visited Dankook University Hospital between December 2006 and February 2014, were included to examine the relationship between co-infections and LOS. Multiplex reverse transcriptase-polymerase chain reactions were used to identify the causative viruses. LOS was analyzed with respect to sex, age, virus, and co-infection. During this period, 5,310 out of the 8,860 patients (59.9%; median age, 1.5 years) were respiratory virus-positive. In respiratory virus-positive patients with single, double, and three-or-more infections, the average LOS was 7.3, 6.7, and 6.6 days, respectively. Longer LOS was observed for older patients and those with human coronavirus OC43 infections compared with adenovirus or respiratory syncytial virus A infections. LOS differed significantly according to age, virus type, and co-infection, but not between double and three or more infections.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.114-120
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• 2014

Purpose: The objective of this study was to assess and investigate the epidemiology of pertussis in infants under 6 months of age. Methods: A prospective study was conducted between October 1, 2011 and April 30, 2013 in CHA Bundang Medical Center, Seongnam, South Korea. Polymerase chain reaction (PCR) or culture was used to detect Bordetella pertussis in nasopharyngeal aspirates from case patients who were hospitalized for acute lower respiratory tract infection (LRTI). In addition, multiplex real-time PCR assays were also performed to detect 6 etiologic viruses, including adenovirus, human metapeumo-virus, influenza virus, parainfluenza virus, respiratory syncytial virus and rhinovirus. Results: Of the 79 enrolled case patients, whose median age was 2 months of age, the most common diagnoses uncovered in this study were acute bronchiolitis (60%) and pneumonia (28%). B. pertussis infection was found in 13 cases (16%), in which 7 (53%) was coinfected with respiratory syncytial virus and 1 (7%) with influenza A virus. Of the 13 patients with B. pertussis infection, 6 (46%) were not vaccinated with the diphtheria, tetanus toxoid, and acellular pertussis vaccine, while 6 (46%) received 1 dose, and 1 (8%) received 2 doses. Conclusion: B. pertussis infection was present in 16% of under 6 month-old infants, who were hospitalized for acute LRTI. Therefore, a nationwide epidemiological surveillance of pertussis, including institutions that cater to infants under 6 months of age is necessary and needed.

• Journal of Yeungnam Medical Science
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• v.30 no.2
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• pp.95-100
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• 2013

Background: This study was performed to investigate the epidemiologic and clinical features of acute respiratory viral infection in hospitalized children. Methods: From 2010 to 2012, we tested nasopharyngeal swab specimen in 1,584 hospitalized children with multiple real-time polymerase chain reactions to identify 10 kinds of respiratory viruses (including influenza virus A, B (FluA, FluB), respiratory syncytial virus (RSV), human metapneumovirus (MPV), adenovirus (AdV), human coronavirus (CoronaV), human enterovirus (HEV), human bocavirus (HBoV), parainfluenza virus (PIV), and human rhinovirus (Rhinovirus)). We analyzed the positive rate, annual and seasonal variations, and clinical features (respiratory tract and non-respiratory tract) according to the retrospective review of medical records. Results: Respiratory viruses were detected from 678 (42.8%) of 1,584 patients. The most common detected virus was RSV (35.0%), and then AdV (19.0%), HEV (18.1%). The critical period of the respiratory viral infection was during the first 12 months of a child's life. PIV increased by 8.4%, 12.1%, and 21.1% annually. Bronchiolitis was most frequently caused by RSV, and croup was frequently caused by PIV. The most common cause of meningitis was HEV. Hepatitis-associated respiratory virus was developed 111 in 678 cases. Conclusion: Although this study was confined to a single medical center for three years, we identified the epidemiology and clinical feature of respiratory viruses in Daegu from 2010 to 2012. Future surveillance will be necessary for annual and seasonal variations.

• Clinical and Experimental Pediatrics
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• v.63 no.4
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• pp.135-140
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• 2020

Background: Breastfeeding reportedly reduces the overall frequency of infections. Respiratory syncytial virus (RSV), the most common respiratory pathogen in infants, involves recurrent wheezing and has a pathogenic mechanism related to airway structural damage. Purpose: This study aimed to investigate whether breastfeeding has a beneficial effect against RSV-induced respiratory infection compared to formula feeding among infants in Korea. Methods: We retrospectively reviewed the medical records of infants under 1 year of age who were admitted with RSV infection between January 2016 and February 2018 at the department of pediatrics of 4 hospitals. We investigated the differences in clinical parameters such as cyanosis, chest retraction, combined infection, fever duration, oxygen use, oxygen therapy duration, intensive care unit (ICU) admission, and corticosteroid treatment of exclusive breast milk feeding (BMF), artificial milk formula fed (AMF), and mixed feeding (MF) groups. Results: Among the 411 infants included in our study, 94, 161, and 156 were included in the BMF, MF, and AMF groups, respectively. The rates of oxygen therapy were significantly different among the BMF (4.3%), MF (8.1%), and AMF (13.5 %) groups (P=0.042). The odds ratios (ORs) for oxygen therapy was significantly higher in the AMF group than in the BMF group (adjusted OR, 3.807; 95% confidence interval, 1.22-11.90; P=0.021). The ICU admission rate of the BMF group (1.1%) was lower than that of the MF (3.5%) and AMF (4.5%) groups; however, the dissimilarity was not statistically significant (P=0.338). Conclusion: The severity of RSV infection requiring oxygen therapy was lower in the BMF than the AMF group. This protective role of human milk on RSV infection might decrease the need for oxygen therapy suggesting less airway damage.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.309-314
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• 2016

Korean Red Ginseng (KRG) is a heat-processed ginseng developed by the repeated steaming and air-drying of fresh ginseng. Compared with fresh ginseng, KRG has been shown to possess greater pharmacological activities and stability because of changes that occur in its chemical constituents during the steaming process. In addition to anticancer, anti-inflammatory, and immune-modulatory activities, KRG and its purified components have also been shown to possess protective effects against microbial infections. Here, we summarize the current knowledge on the properties of KRG and its components on infections with human pathogenic viruses such as respiratory syncytial virus, rhinovirus, influenza virus, human immunodeficiency virus, human herpes virus, hepatitis virus, norovirus, rotavirus, enterovirus, and coxsackievirus. Additionally, the therapeutic potential of KRG as an antiviral and vaccine adjuvant is discussed.