Clinical characteristics of hospitalized cases of severe acute respiratory infection with laboratory-confirmed influenza and the risk factors analysis of influenza infection for children under 15 years old in ten provinces in China during 2009-2014
Peng Z.,U.S. Center for Disease Control and Prevention |
Xu J.,Heilongjiang Provincial CDC |
Yu Z.,Zhejiang Provincial CDC |
Sun Q.,Hunan Provincial CDC |
And 20 more authors.
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi | Year: 2015
OBJECTIVE: To identify clinical characteristics of hospitalized laboratory-confirmed influenza cases of children under 15 years old, and their risk factors of influenza infection.METHODS: Analyzing the reports of hospitalized laboratory-confirmed influenza cases of children under 15 years old who were detected by the sentinel surveillance systems in 10 provinces from December 2009 to June 2014. Such data as their demographic, medical history, clinical symptoms and signs, treatment and outcome were collected using questionnaires, with their clinical characteristics and their risk factors of influenza infection described.RESULTS: Of the 2 937 severe acute respiratory infection inpatients, 190 (6.5%) were laboratory-confirmed influenza cases. 123 (64.7%) of such confirmed cases were male, and 139 (73.2%) were children under 5 years old, with age median of 3.0 years (IQR: 1.0-5.0 years). 20 (10.5%) of them had at least one chronic medical condition, mostly chronic cardiovascular disease (3.2%), immunosuppressive disease (3.2%), and cancer/tumor (2.6%). Most common clinical symptoms of the cases were fever (92.6%) and cough (88.8%), of which abnormal pulmonary auscultation (51.1%) and abnormal chest X-ray performance (36.1%) were the most common clinical signs. 29 cases (15.8%) had complications, of which pneumonia (15.3%) was most common. 16 cases (8.6%) used antiviral drugs, and 4 cases (2.2%) were admitted into ICU. Risk factor analysis suggested that age < 6 months (OR = 0.406, 95% CI: 0.203-0.815) was a protective factor against influenza infection; and age 5-9 years old (OR = 2.535, 95% CI: 1.059-6.066) was a risk factor for influenza infection.CONCLUSION: Hospitalized laboratory-confirmed influenza cases were found mostly in children under 5 years old. Risk exposure for influenza infection varied among age groups.
Qiaoli Z.,Dongguan Municipal CDC |
Jianfeng H.,Guangdong Provincial CDC |
De W.,Guangdong Provincial CDC |
Zijun W.,China CDC |
And 12 more authors.
PLoS ONE | Year: 2012
Background: This study was conducted to identify epidemiological characteristics of the first documented CHIK fever outbreak in China and evaluate the effect of the preventive measures taken. Methodology/Principal Findings: From September 1 to October 29, 2010, China's first documented outbreak of CHIK fever occurred in the Xincun community of Wanjiang District of Dongguan city, Guangdong province; 253 case-patients were recorded, of which 129 were laboratory confirmed, with an attack rate of 1%. Before September 18th the number of CHIK fever cases remained relatively low in the Xincun community; from September 19th onwards, the number of cases increased drastically, with an outbreak peak on October 4th. Cases were distributed across nine small village groups in the Xincun community, with an attack rate of 0-12% at the village level. The household attack rates ranged between 20% and 100%. No significant difference was found in the attack rate between males and females. There was a significant difference in the attack rate in different age groups (chi-square = 18.35, p = 0.005); highest in patients aged 60 years or older and the lowest in patients aged under 10. The major clinical characteristics of patients are fever (100%), joint pain (79%) and rash (54%). Phylogenetic analysis of the E1 gene on the five earliest confirmed cases showed that the strains of CHIKV isolated from their sera were highly homologous (up to 99%) with isogeneic strains isolated in Thailand in 2009. After control measures were taken, including killing adult mosquitoes and cleaning breeding habitats of Aedes mosquitoes, the Breteau index and Mosq-ovitrap index decreased rapidly, and the outbreak ended on October 29. Conclusion/Significance: The infection source of the outbreak was imported. Cases showed obvious temporal, spatial, and population aggregation during the outbreak. Comprehensive control measures based on reducing the density of Aedes mosquitoes were effective in controlling the epidemic. © 2012 Qiaoli et al.