Zika vector transmission risk in temperate Australia: a vector competence study

Virology Journal

Stacey E. Lynch¹  Lee Trinidad²  Prasad Paradkar²  Peter T. Mee²  Jean-Bernard Duchemin²  Ravikiran Vedururu² 

[1] BioScience Research, Agriculture Victoria, AgriBio, The Centre for AgriBioscience, 5 Ring Rd, La Trobe University Campus;CSIRO Health and Biosecurity, Australian Animal Health Laboratory;

关键词: Zika virus;    Vector competence;    Aedes aegypti;    Aedes albopictus;    Culex quinquefasciatus;    Aedes notoscriptus;   

DOI  :  10.1186/s12985-017-0772-y

来源: DOAJ

【 摘 要 】

Abstract Background Zika virus is an emerging pathogen of global importance. It has been responsible for recent outbreaks in the Americas and in the Pacific region. This study assessed five different mosquito species from the temperate climatic zone in Australia and included Aedes albopictus as a potentially invasive species. Methods Mosquitoes were orally challenged by membrane feeding with Zika virus strain of Cambodia 2010 origin, belonging to the Asian clade. Virus infection and dissemination were assessed by quantitative PCR on midgut and carcass after dissection. Transmission was assessed by determination of cytopathogenic effect of saliva (CPE) on Vero cells, followed by determination of 50% tissue culture infectious dose (TCID50) for CPE positive samples. Additionally, the presence of Wolbachia endosymbiont infection was assessed by qPCR and standard PCR. Results Culex mosquitoes were found unable to present Zika virus in saliva, as demonstrated by molecular as well as virological methods. Aedes aegypti, was used as a positive control for Zika infection and showed a high level of virus infection, dissemination and transmission. Local Aedes species, Ae. notoscriptus and, to a lesser degree, Ae. camptorhynchus were found to expel virus in their saliva and contained viral nucleic acid within the midgut. Molecular assessment identified low or no dissemination for these species, possibly due to low virus loads. Ae. albopictus from Torres Strait islands origin was shown as an efficient vector. Cx quinquefasciatus was shown to harbour Wolbachia endosymbionts at high prevalence, whilst no Wolbachia was found in Cx annulirostris. The Australian Ae. albopictus population was shown to harbour Wolbachia at high frequency. Conclusions The risk of local Aedes species triggering large Zika epidemics in the southern parts of Australia is low. The potentially invasive Ae. albopictus showed high prevalence of virus in the saliva and constitutes a potential threat if this mosquito species becomes established in mainland Australia. Complete risk analysis of Zika transmission in the temperate zone would require an assessment of the impact of temperature on Zika virus replication within local and invasive mosquito species.

【 授权许可】

Unknown