• IMMUNE NETWORK
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• 제14권3호
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• pp.128-137
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• 2014

Respiratory viruses can induce acute respiratory disease. Clinical symptoms and manifestations are dependent on interactions between the virus and host immune system. Dendritic cells (DCs), along with alveolar macrophages, constitute the first line of sentinel cells in the innate immune response against respiratory viral infection. DCs play an essential role in regulating the immune response by bridging innate and adaptive immunity. In the steady state, lung DCs can be subdivided into $CD103^+$ conventional DCs (cDCs), $CD11b^+$ cDCs, and plasmacytoid DCs (pDCs). In the inflammatory state, like a respiratory viral infection, monocyte-derived DCs (moDCs) are recruited to the lung. In inflammatory lung, discrimination between moDCs and $CD11b^+$ DCs in the inflamed lung has been a critical challenge in understanding their role in the antiviral response. In particular, $CD103^+$ cDCs migrate from the intraepithelial base to the draining mediastinal lymph nodes to primarily induce the $CD8^+$ T cell response against the invading virus. Lymphoid $CD8{\alpha}^+$ cDCs, which have a developmental relationship with $CD103^+$ cDCs, also play an important role in viral antigen presentation. Moreover, pDCs have been reported to promote an antiviral response by inducing type I interferon production rather than adaptive immunity. However, the role of these cells in respiratory infections remains unclear. These different DC subsets have functional specialization against respiratory viral infection. Under certain viral infection, contextually controlling the balance of these specialized DC subsets is important for an effective immune response and maintenance of homeostasis.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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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.

• Tuberculosis and Respiratory Diseases
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• 제82권4호
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• pp.328-334
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• 2019

Background: Although the frequency of respiratory viral infection in patients with pulmonary acute respiratory distress syndrome (ARDS) is not uncommon, clinical significance of the condition remains to be further elucidated. The purpose of this study was to compare characteristics and outcomes of patients with pulmonary ARDS infected with influenza and other respiratory viruses. Methods: Clinical data of patients with pulmonary ARDS infected with respiratory viruses January 2014-June 2018 were reviewed. Respiratory viral infection was identified by multiplex reverse transcription-polymerase chain reaction (RT-PCR). Results: Among 126 patients who underwent multiplex RT-PCR, respiratory viral infection was identified in 46% (58/126): 28 patients with influenza and 30 patients with other respiratory viruses. There was no significant difference in baseline and clinical characteristics between patients with influenza and those with other respiratory viruses. The use of extracorporeal membrane oxygenation (ECMO) was more frequent in patients with influenza than in those with other respiratory viruses (32.1% vs 3.3%, p=0.006). Co-bacterial pathogens were more frequently isolated from respiratory samples of patients with pulmonary ARDS infected with influenza virus than those with other respiratory viruses. (53.6% vs 26.7%, p=0.036). There were no significant differences regarding clinical outcomes. In multivariate analysis, acute physiology and chronic health evaluation II was associated with 30-mortality (odds ratio, 1.158; 95% confidence interval, 1.022-1.312; p=0.022). Conclusion: Respiratory viral infection was not uncommon in patients with pulmonary ARDS. Influenza virus was most commonly identified and was associated with more co-bacterial infection and ECMO therapy.

• Clinical and Experimental Pediatrics
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• 제57권1호
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• pp.29-34
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• 2014

Purpose: In this study, we aimed to investigate the prevalence of year-round respiratory viral infection in children with lower respiratory tract infection (LRTI) and the relationship between respiratory viral infection and allergen sensitization in exacerbating asthma. Methods: We investigated the sources for acute LRTIs in children admitted to our hospital from May 2010 to April 2011. The 6 most common respiratory viruses were isolated from nasopharyngeal aspirate using multiplex reverse transcription-polymerase chain reaction in 309 children; respiratory syncytial virus (RSV), adenovirus (AV), parainfluenza virus (PIV), influenza virus (IFV), human metapneumovirus (hMPV), rhinovirus (RV). Atopic sensitization was defined if more than 1 serum specific Immunoglobulin E level measured using UniCAP (Pharmacia) was over 0.35 IU/mL. Results: RSV was the most common pathogen of bronchiolitis in hospitalized children through the year. RV or IFV infection was more prevalent in asthma exacerbations compared to other LRTIs. AV and hMPV were more likely to cause pneumonia. RV and IFV were associated with asthma exacerbations in children with atopic sensitization, but not in nonatopic children. Conclusion: RV and IFV are associated with hospitalization for asthma exacerbation in children with atopic sensitization.

• Journal of Yeungnam Medical Science
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• 제34권2호
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• pp.182-190
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• 2017

Background: Respiratory viruses play a significant role in the etiology of acute respiratory infections and exacerbation of chronic respiratory illnesses. This study was conducted to identify the epidemiological and clinical characteristics of children with acute viral lower respiratory infections. Methods: This study investigated 1,168 children diagnosed with acute viral lower respiratory tract infections (RTIs) between January 2012 and December 2014. Specimens of respiratory viruses were collected using a nasopharyngeal swab and analyzed by reverse transcriptase polymerase chain reaction. We retrospectively reviewed the medical records and analyzed the clinical features of children hospitalized for acute lower respiratory infections. Results: Respiratory syncytial virus (RSV), the main cause of infection in children aged <5 years, was the most commonly detected pathogen in children with bronchiolitis and pneumonia, and resulted in high proportions of children requiring oxygen treatment and intensive care unit admission. Rhinovirus was preceded by RSV as the second most common cause of bronchiolitis and pneumonia, and was detected most frequently in the children aged ${\geq}6$ years. In addition, asthma was predominantly caused by rhinovirus in children aged ${\geq}6$ years, whereas croup was mostly caused by parainfluenza virus in those aged <5 years. Rhinovirus infection (p<0.001) and history of asthma (p=0.049) were identified as significant risk factors for readmission within a month. Conclusion: We identified the epidemiological and clinical characteristics of respiratory viruses in children with acute lower respiratory infections during the last 3 years. Our findings may provide useful clinical insight to comprehend the acute viral lower RTIs in children.

• Clinical and Experimental Pediatrics
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• 제59권11호
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• pp.432-439
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• 2016

Asthma is recognized as a complex disease resulting from interactions between multiple genetic and environmental factors. Accumulating evidence suggests that respiratory viral infections in early life constitute a major environmental risk factor for the development of childhood asthma. Respiratory viral infections have also been recognized as the most common cause of asthma exacerbation. The advent of molecular diagnostics to detect respiratory viruses has provided new insights into the role of human rhinovirus (HRV) infections in the pathogenesis of asthma. However, it is still unclear whether HRV infections cause asthma or if wheezing with HRV infection is simply a predictor of childhood asthma. Recent clinical and experimental studies have identified plausible pathways by which HRV infection could cause asthma, particularly in a susceptible host, and exacerbate disease. Airway epithelial cells, the primary site of infection and replication of HRV, play a key role in these processes. Details regarding the role of genetic factors, including ORMDL3, are beginning to emerge. This review discusses recent clinical and experimental evidence for the role of HRV infection in the development and exacerbation of childhood asthma and the potential underlying mechanisms that have been proposed.

• Journal of Microbiology and Biotechnology
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• 제28권3호
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• pp.465-472
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• 2018

Our aim was to determine the detection rate of respiratory viruses (RVs) in feces of patients with acute viral respiratory infection (AVRI) and the detection rate of diarrheal viruses (DVs) in nasopharyngeal samples from patients with acute viral gastroenteritis. The relationships between the presence of fecal RVs or nasopharyngeal DVs and their impacts on the clinical severity were also investigated. A total of 144 fecal specimens were collected from AVRI patients and 95 nasopharyngeal specimens were collected from acute viral gastroenteritis patients. Clinical characteristics and laboratory profiles were compared between subgroups on the basis of the presence or absence of virus in the specimens. The detection rate of RVs in feces was 17.4% (25/144), whereas the detection rate for viruses identical to the respiratory pathogen was 10.4% (identical group, 15/144). Within the identical group, adenovirus (86.7%, 13/15) was most commonly found. Patients in the identical group showed statistically higher values for C-reactive protein, mean age, increased frequency of vomiting, and decreased frequency of chest film involvement and cough (p < 0.05). The detection rate of nasopharyngeal DVs among acute viral gastroenteritis patients was 19.0% (18/95), and in the identical group it was 15.8% (15/95). Norovirus group II and enteric adenovirus were the major pathogens detected in the identical group. There were no significant differences in clinical characteristics and laboratory profiles between the subgroups. In conclusion, the major pathogens of fecal RV and nasopharyngeal DV were adenovirus and norovirus group II, respectively. However, their relationship with the clinical symptoms or disease severity is unclear.

• Pediatric Infection and Vaccine
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• 제10권1호
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• pp.87-94
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• 2003

목 적 : 호흡기 바이러스는 인간에게 가장 전염성이 강한 병원체의 하나로 급성 호흡기 감염 특히 하기도 감염증은 소아에서의 유병률과 사망률의 주요 원인이 되고 있다. 저자들은 하기도 감염증에 이환된 환아들을 대상으로 influenza A, B virus, adenovirus, enterovirus의 감염 연령 분포와 계절적 유행 양상, 바이러스별 임상 양상을 알기 위하여 이 연구를 시작하였다. 방 법 : 2002년 1월부터 2002년 12월까지 부산 메리놀병원에 입원하거나 외래 방문한 하기도 감염증 소아들을 대상으로 인후 가검물, 콧물, 타액 분비물 등을 채취하여 바이러스를 동정하였고, 검사를 시행한 568명 중 바이러스가 동정된 54명을 대상으로 호발 연령, 유행 시기, 임상 증상을 후향적으로 조사하였다. 결 과 : 1) 대상 환아의 연령 분포는 2개월부터 14세 사이였고, 남녀비는 1.8 : 1이었다. 3~6세가 29.6%로 가장 많았고, 2~3세 사이가 14.8%, 12세 이상이 13% 순이었다. 2) 동정된 바이러스는 influenza A virus가 59.3%로 가장 많았고, enterovirus가 33.3%, adenovirus 5.6%, influenza B virus 1.9%였고, parainfluenza virus와 RSV는 동정되지 않았다. 3) 임상 양상은 폐렴이 51.9%로 가장 많았고, 기관지염이 31.5%, 크루프 9.3%, 모세기관지염 7.4%의 순이었다. 4) 호흡기 바이러스는 각각의 유행 시기가 있어, influenza A virus는 3~5월, 11월에 2차례의 유행이 있어 주로 겨울에 유행하는 양상을 보였으며, influenza B virus는 3월에, adenovirus는 3월과 7월에, enterovirus는 3~7월에 유행하여 주로 봄부터 여름까지 유행하는 양상을 보였다. 결 론 : 2002년 부산 지역 호흡기 바이러스 감염의 주된 원인은 influenza virus였다. 이러한 결과는 influenza virus의 유행을 보여주는 것으로 이에 대한 지속적인 감시와 예방, 조기 진단과 치료가 필요하다고 하겠다.

• 한국미생물·생명공학회지
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• 제49권2호
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• pp.249-254
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• 2021

The study of the impact of weather on viral respiratory infections enables the assignment of causality to disease outbreaks caused by climatic factors. A better understanding of the seasonal distribution of viruses may facilitate the development of potential treatment approaches and effective preventive strategies for respiratory viral infections. We analyzed the incidence of human mastadenovirus infection using real-time reverse transcription polymerase chain reaction in 9,010 test samples obtained from Cheonan, South Korea, and simultaneously collected the weather data from January 1, 2012, to December 31, 2018. We used the data collected on the infection frequency to detect seasonal patterns of human mastadenovirus prevalence, which were directly compared with local weather data obtained over the same period. Descriptive statistical analysis, frequency analysis, t-test, and binomial logistic regression analysis were performed to examine the relationship between weather, particulate matter, and human mastadenovirus infections. Patients under 10 years of age showed the highest mastadenovirus infection rates (89.78%) at an average monthly temperature of 18.2℃. Moreover, we observed a negative correlation between human mastadenovirus infection and temperature, wind chill, and air pressure. The obtained results indicate that climatic factors affect the rate of human mastadenovirus infection. Therefore, it may be possible to predict the instance when preventive strategies would yield the most effective results.

• Pediatric Infection and Vaccine
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• 제25권1호
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• pp.8-16
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• 2018

목적: 본 연구는 바이러스성 크루프로 입원하는 환아의 임상적 및 역학적 특성을 분석하여 원인 바이러스 감염에 따른 중증도를 평가하고자 하였다. 방법: 2013년 5월부터 2016년 12월까지 원주세브란스기독병원 소아청소년과에 바이러스성 크루프로 입원한 10세 이하 환아 중 비강인두도말 검체 채취 및 다중 역전사중합효소연쇄반응 검사를 하여 호흡기 바이러스가 검출된 302명을 대상으로 의무기록을 후향적으로 검토하였다. 바이러스성 크루프의 중 증도를 평가하기 위하여 Westley의 점수제를 사용하였다. 결과: 전체 302명 중 중증 바이러스성 크루프로 입원한 환아는 149명(49.3%)이었으며, 이 중 남아가 88명, 여아가 61명으로 남녀 비는 1.44:1이었다. Parainfluenza virus가 110예(48.7%)로 거의 절반에 가까운 빈도를 보였으며, 이후로 influenza virus (15.5%), human rhinovirus (11.9%), respiratory syncytial virus (10.2%) 순이었다. 중증 바이러스성 크루프와 원인 바이러스와의 연관성에 대한 분석에서는 parainfluenza virus 2형에서만 위험도가 의미 있게 높은 것으로 나타났다. Parainfluenza virus 2형은 연령에 따라서는 발병 빈도에 차이가 없었으나 여름, 가을에 상대적으로 더 높은 감염 빈도를 보였다. 결론: 본 연구에서 중증 바이러스성 크루프와 연관이 있었던 바이러스는 parainfluenza virus 2형이 유일하였다. 추후 전향적, 다기관 연구 및 추가적인 변수들을 복합적으로 고려하여 원인 바이러스 감염에 따른 중증도를 재확인하고, 원인 바이러스에 대한 지역별, 시기별, 연령별 분석이 필요하다.