ABSTRACT
Objective@#To investigate the epidemiological characteristics and causes of an outbreak of respiratory infection in schools.@*Methods@#Epidemiological investigation was carried out on respiratory infection cases in schools. Pharyngeal swab samples of children were collected for respiratory tract virus nucleic acid detection, and hexon genes were amplified. Positive PCR result were sequenced.@*Results@#All cases were in school, involving 2 classes, 12 cases in class 2 (3) and 13 cases in class 3 (4), all on the west side of the 2nd and 3rd floors of teaching building 2. From September 3 to September 12, a total of 25 cases were involved, with the onset peak on the 10th and 11th. The clinical features were fever, cough, sore throat and aching limbs, etc. The onset was aggregated, the course of the disease was about 5 d, the prognosis was good, and there were no deaths. There are 13 males and 12 females. The males to females ratio is 1.08∶1. The age distribution is 7-9 years, with an average of 8.6 years. The result of fluorescence quantitative PCR were negative for influenza A/B virus and positive for adenovirus. The products of positive samples after PCR amplification were sequenced as AdV-3 and AdV-4.@*Conclusions@#The combined result of epidemiological investigation and laboratory tests demonstrated that this epidemic of school respiratory tract infection is an upper respiratory tract infection caused by adenovirus B3 and E4 mixed infection.
ABSTRACT
Objective To investigate the epidemiology of respiratory viruses in children from Wuxi area.Methods A total of 2 747 cases of children diagnosed with acute respiratory infection in Wuxi during 2011 —2014 were collected.Reverse transcription-polymerase chain reaction was used to detect nine kinds of respiratory viruses,including influenza virus A (Flu A),influenza virus B (Flu B),parainfluenza virus (PIV)Ⅰ-Ⅳ,adenovirus (ADV),respiratory sycytial virus (RSV),human metaneumovirus (hMPV), human bocavirus (HBov),human coronaviruses (hCov)and human rhinovirus (HRV).The categorical data were compared using chi square test.Results A total of 856 among the 2 747 samples were tested positive for respiratory virus nucleic acid,with the positive rate of 31 .16%.The viral distribution was uneven in different seasons,and the infection peaked in winter and spring.The virus detection rate was highest in age 1 to 2 year group (up to 40.18%),and followed by age 6 to 12 year group (32.63%).Flu A virus was the most frequently detected virus,accounting for 7.54% (207/2 747);followed by PIV, accounting for 6.95 % (191/2 747);and Flu B accounted for 4.22%(116/2 747).There were 84 cases of mixed infection of two or more kinds of respiratory viruses,with positive rate of 3.06% (84/2 747 ). Conclusions Our study suggests that Flu A is the most common pathogen in children with acute respiratory infections in Wuxi area during 2011 —2014;virus detection rate is highest in age 1 to 2 year group;and parainfluenza virus is almost detected throughout the year,while the rest of respiratory viruses are commonly seen in winter and spring.