Epidemiology of acute respiratory infections in children in Guangzhou: a three-year study.

Acute Respiratory Infections (ARI) are some of the most common human diseases worldwide. However, they have a complex and diverse etiology, and the characteristics of the pathogens involved in respiratory infections in developing countries are not well understood. In this work, we analyzed the characteristics of 17 common respiratory pathogens in children (≤14 years old) with ARI in Guangzhou, southern China over a 3-year period using real-time polymerase chain reaction. Pathogens were identified in 2361/4242 (55.7%) patients, and the positivity rate varied seasonally. Ten of the 17 pathogens investigated showed positivity rates of more than 5%. The most frequently detected pathogens were respiratory syncytial virus (768/2361, 32.5%), influenza A virus (428/2361, 18.1%), enterovirus (138/2361, 13.3%), Mycoplasma pneumoniae (267/2361, 11.3%) and adenovirus (213/2361, 9.0%). Co-pathogens were common and found in 503 of 2361 (21.3%) positive samples. When ranked according to frequency of occurrence, the pattern of co-pathogens was similar to that of the primary pathogens, with the exception of human bocavirus, human coronavirus and human metapneumovirus. Significant differences were found in age prevalence in 10 of the 17 pathogens (p≤0.009): four basic patterns were observed, A: detection rates increased with age, B: detection rates declined with age, C: the detection rate showed distinct peaks or D: numbers of patients were too low to detect a trend or showed no significant difference among age groups (p>0.05). These data will be useful for planning vaccine research and control strategies and for studies predicting pathogen prevalence.

[The modified restriction of amino acids of HVR1, HVR2, HVR5, HVR7 in human adenovirus serotype 3 hexon].

The limitation of traditional Ad vectors result in wide application of capsid-incorporation of antigens into adenovirus capsid proteins, but usually it can't rescue virus successfully when we engineered the hypervariable regions (HVRs) of hexon in adenovirus serotype 3(Ad3) vector. So we deleted or retained some amino acids in HVR1, HVR2, HVR5, HVR7 predicted by bioinformatics, constructed recombinant Ad3 vector pBRAddeltaE3GFP-mHexon, and transfected it into AD293 cell to confirm the influence on the virus rescue. These data of amino acids that can be deleted or retained in the HVRs of Ad3 vector should provide operating foundation for antigen capsid-incorporation strategy in human adenovirus serotype 3, and also lay the groundwork for application of expressing foreign antigens in the hexon of human adenovirus serotype 3 as a platform of multivalent vaccine vectors.