Epidemiology of human adenovirus and molecular characterization of human adenovirus 55 in China, 2009-2012.
BACKGROUND
Human adenovirus 55 (HAdV-55) has caused recent outbreaks of acute respiratory disease (ARD) among adults and military trainees. The active surveillance for HAdV infections was sparse in China, and current knowledge on the HAdV-type distributions and its molecular evolution is lacking.


OBJECTIVE
To acquire better understanding on the prevalence and molecular evolution of HAdV-55 strains in China, for an informed strategy for disease control and prevention.
Nasopharyngeal aspirates were collected from hospitalized children with ARTI in Chongqing during 2009-2012. The genotype of HAdV isolates were determined by sequencing the partial hexon and fiber genes. Whole genome sequences of HAdV-55 were obtained for molecular evolution analysis.


RESULTS
About 191 (8·55%) HAdV were detected in 2234 children, including 92 (48·2%) with HAdV-7, 72 (37·7%) with HAdV-3, 6 (3·1%) with HAdV-55, 5 (2·6%) with HAdV-5, 4 (2·1%) with HAdV-1, 1 (0·5%) with HAdV-2, and 11(5·8%) with untyped HAdV. Four of these children developed pneumonia, two of whom were diagnosed with severe pneumonia and/or encephalopathy. HAdV-55 isolates clustered with HAdV-11 sequences based on the hexon gene and clustered with HAdV-14 sequences based on the fiber gene and the whole genome. The overall evolutionary rates of hexon gene, fiber gene, and whole genome of HAdV-55 were estimated at 6·2 × 10(-5) s/s/y, 8·0 × 10(-5 ) s/s/y, and 1·7 × 10(-5) s/s/y, respectively.


CONCLUSIONS
This study suggested HAdV-55 as an emerging infectious disease pathogen has conserved genetic structure and is closely related to each other. Further molecular investigation based on HAdV-55 of wider origin might facilitate understanding its diversity, dissemination, and transmission in China.
School of Public Health, Peking University, Beijing, China.
Qing-Bin
QB
Lu
Yi-Gang
YG
Tong
Ying
Y
Wo
Hong-Yu
HY
Wang
En-Mei
EM
Liu
Gregory C
GC
Gray
Wei
W
Liu
Wu-Chun
WC
Cao
D000258:Adenovirus Infections, Human / Q000453:epidemiology* / Q000821:virology*; D000260:Adenoviruses, Human / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005260:Female; D016679:Genome, Viral; D006801:Humans; D007223:Infant; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny
Acute respiratory disease; China; children; human adenovirus