광주지역 소아에서 유행한 호흡기바이러스 역학 조사 및 human Bocavirus의 유전자형 분석에 관한 연구

Abstract

ABSTRACT

Practical Surveillance for Respiratory Viruses Prevalent in Children in Gwangju between 2005 and 2007 and Molecular characterization of human Bocavirus Isolated

This investigation was conducted as part of an epidemiological surveillance program designed to provide a genetic analysis of respiratory viral agents in samples obtained from children with acute respiratory infections in Gwangju, as well as to reveal the prevalence and genetic identities of acute viral respiratory infections currently circulating in Gwangju. For this study, 3,695 specimens obtained from patients with acute respiratory infections were collected by collaboration with pediatric hospitals in Gwangju between 2005 and 2007. Specimens were screened for8 respiratory viruses including influenza viruses (IFV), human rhinoviruses (HRV), human coronaviruses (HCoV), adenoviruses (ADV), parainfluenza viruses (PIV), human enteroviruses (HEV), respiratory synthitial viruses (RSV) and human bocaviruses (HBoV). Respiratory viruses were detecting using multiplex (RT) PCR with viral specific primers. Out of 3,695 specimens, the ratio of virus detection was 24.9% (919). Overall, HRV (35.5%) and IFV (34.9%) were the most common viruses found, followed by HBoV (14.8%), HCoV (10.6%), RSV (3.7%), ADV (3.4%), PIV (3.2%) and HEV (3.0%). In addition, multiple infections were detected in 80 patients (8.7%). When the prevalence was analyzed according to season, HBoV, IFV and HCoV showed two epidemic points, late spring and early winter. ADV, HRV, RSV PIV and HEV, however, were all found to have only one epidemic point, with RSV being most common during winter and the others being most prominent during spring. When epidemiological analysis was conducted, 59.6% of the patients was found to have been infected for less than 36 months. However, when IFV was considered, 52.9% of patients carrying the virus was between the ages of 3 and 7, with the highest occurrence being observed in children with limited past exposure and during the time period in which preschools and kindergartens were in session. Additionally, 59.1% of the patients who were found to have a viral infection were boys and 40.9% were girls (1.4:1 boys:girls). When the subtypes of the viruses were evaluated, different subtypes of IFV, HCoV, ADV and PIV were observed. Three subtypes of IFV were observed in infected patients, and these subtypes appeared to differ with the epidemic seasons, with type A viruses being predominant (A/H1N1 43.3%, A/H3N2 41.4%, Type B 15.3%). When HCoV was considered, the incidence of HCoV 229E like strain (68%) was higher than that of HCoV OC43 like strain (32%). When ADV was considered, Type 3 was predominant (76.5%) and types 1, 2, 4, and 6 occurred only occasionally. When PIV was considered, type 3 PIV was predominant (75.9%) followed by type 2 (13.8%) and type 1 (10.3%). When sequence analysis of HBoV detected in Gwangju was conducted, the strains formed a unique genetic cluster that was 99.5-100% homologous with other HBoV strains reported in Korea, regardless of their genetic components. Through this epidemiological surveillance, the respiratory viruses prevalent in children in Gwangju area were investigated, but it will be strongly recommended that nationwide policy including long term collection of data and samples, vaccine development and prevention education of the misuse of antibiotics regarding prevalent respiratory virus. It is believed that the results of this study will be of value for domestic introduction of disease prevention education programs for parents of young children and adolescents in advanced countries.