Hui Zhang1, Houqiang Luo1, Mujeeb Ur Rehman1, Fazul Nabi1, Kun Li1, Yanfang Lan1, Shucheng Huang1, Lihong Zhang1, Khalid Mehmood2, Muhammad Shahzad2, Jiakui Li3. 1. College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. 2. College of Veterinary Medicine, Huazhong Agricultural University, Wuhan; China; College of Veterinary and AnimalSciences, Islamia University of Bahawalpur, Pakistan. 3. College of Veterinary Medicine, Huazhong Agricultural University, Wuhan; Laboratory of Detection and Monitoring of Highland Animal Disease, Tibet Agriculture and Animal Husbandry College, Linzhi, China.
Abstract
BACKGROUND & OBJECTIVES: Culex tritaeniorhynchus is the primary vector of Japanese encephalitis virus (JEV) which is a major threat to animals and humans health. This virus has been reported earlier from low altitude regions of Tibet, in mosquitoes, Tibetan pigs and local Tibetans, but no reports are available for the probable propagation of JE to high altitude regions (3100 m) of Tibet. This study aimed to find the evidence of JEV in Cx. tritaeniorhynchus and pigs from high altitude regions of Tibet, China. METHODS: In total, 102 porcine serum samples and eight pools of Cx. tritaeniorhynchus were subjected to real-time PCR (RT-PCR) for the amplification of a fragment (~ 420 bp) of the NS1 gene. The resultant amplicons of the genes were subsequently analyzed and sequenced. RESULTS: Overall seroprevalence of JE in Tibetan pigs was 6.86%, while five pools of Cx. tritaeniorhynchus were found positive for JEV. Results showed genotype III as the most prevalent (100%) among JEV positive isolates. Furthermore, phylogenetic analysis of the JEV positive strains showed 98.8-99% similarity to four reference strains from China (JEV-Hubei, Whe, HYZ and CQ11-66). INTERPRETATION & CONCLUSION: The present study revealed that JEV has extended its geographic range to high altitude regions of Tibet. The factors like increased tourism and transportation might play key role in the transmission of JE that comprises a potential health risk for humans and animals.
BACKGROUND & OBJECTIVES:Culex tritaeniorhynchus is the primary vector of Japanese encephalitis virus (JEV) which is a major threat to animals and humans health. This virus has been reported earlier from low altitude regions of Tibet, in mosquitoes, Tibetan pigs and local Tibetans, but no reports are available for the probable propagation of JE to high altitude regions (3100 m) of Tibet. This study aimed to find the evidence of JEV in Cx. tritaeniorhynchus and pigs from high altitude regions of Tibet, China. METHODS: In total, 102 porcine serum samples and eight pools of Cx. tritaeniorhynchus were subjected to real-time PCR (RT-PCR) for the amplification of a fragment (~ 420 bp) of the NS1 gene. The resultant amplicons of the genes were subsequently analyzed and sequenced. RESULTS: Overall seroprevalence of JE in Tibetan pigs was 6.86%, while five pools of Cx. tritaeniorhynchus were found positive for JEV. Results showed genotype III as the most prevalent (100%) among JEV positive isolates. Furthermore, phylogenetic analysis of the JEV positive strains showed 98.8-99% similarity to four reference strains from China (JEV-Hubei, Whe, HYZ and CQ11-66). INTERPRETATION & CONCLUSION: The present study revealed that JEV has extended its geographic range to high altitude regions of Tibet. The factors like increased tourism and transportation might play key role in the transmission of JE that comprises a potential health risk for humans and animals.