Molecular epidemiology of rabies in Shandong province, 2010–2015

ObjectiveTo understand the genetic, evolution and spread characteristics of rabies virus in Shandong province.

MethodsThe dog brain samples and human liquid samples (saliva, serum et al), collected during 2010–2015, were detected by using DFA or RT-PCR. The N gene of the rabies virus strains isolated from the positive samples were sequenced, and the results were used for phylogenetic analysis.

ResultsAmong the 70 dog brain samples, 11 were positive; and among 21 human liquid samples, 2 were positive. The N genes (1 353 bp) were sequenced for all the rabies virus strains isolated from 13 positive samples and the phylogenetic tree was constructed based on the 26 N genes of Shandong strains and the reference strains in 7 lineages in China, which indicated that nearly 90% of the rabies strains from Shandong (collected during 2006–2015) belonged to China Ⅰ lineage, while the remaining 3 strains (collected during 2006–2008) belonged to China Ⅱ lineage. The rabies strains isolated from eastern and western Shandong were less diverse and shared similarity, but the strains isolated from Tai’an showed high diversity.

ConclusionThe rabies strains isolated in Shandong province belonged to China Ⅰ and China Ⅱ lineages, and the spread of China Ⅰ lineage was responsible for the rabies incidence in Shandong in recent years.