Background: Human adenovirus type 7 (HAdV7) is globally attracting great concern as its high morbidity and severity in respiratory diseases, especially in Asia.
Objective: To investigate the clinical and epidemiologic characteristics of HAdV7 infection outbreak in East China.
Methods: The clinical samples were collected from the patients of an ARD outbreak in East Chinafor the detection of causative pathogens by multiplex PCR. The molecular type of human adenovirus isolates were identified by sequencing and homologous comparison based on their hexon genes. The spatiotemporal dynamics of global HAdV7 was investigated using the phylogenetic and phylogeographic analyses. Total 67 referenced HAdV7 hexon sequences (>800 bp) from GenBank were selected for constructing the maximum likelihood tree by MEGA 5.1.0, grouped according to the tree topology for the further migration analysis by PAUP* 4.0 and MigraPhyla 1.0 b to understand the transmission patterns of HAdV7 in global epidemics.
Results: The results showed HAdV7 as the causative pathogen in this outbreak, and the outbreak strains had the hexon sequences highly identical with the isolates in Shaanxi (2012). The origin of HAdV7 was inferred as California, meanwhile a total of 21 migration routes were acquired. HAdV7 in this outbreak was statistically proven dispersed from Shaanxi province (2012).
Conclusions: The analyses of epidemiology and transmission pattern of HAdV7 would not only enrich the molecular biological basic database but also provide theoretical basis for HAdV7 prevention and control strategy.
Keywords: Human adenovirus type 7; clinical characteristics; epidemiology; phylogeny; phylogeography.