Original Article

Citation: Emerging Microbes & Infections (2016) 5, e102; doi:10.1038/emi.2016.102
Published online 7 September 2016

Culex pipiens quinquefasciatus: a potential vector to transmit Zika virus
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Xiao-xia Guo1,*, Chun-xiao Li1,*, Yong-qiang Deng2,*, Dan Xing1, Qin-mei Liu1, Qun Wu1, Ai-juan Sun1, Yan-de Dong1, Wu-chun Cao3, Cheng-feng Qin2 and Tong-yan Zhao1

  1. 1Department of Vector Biology and Control, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing 100071, China
  2. 2Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing 100071, China
  3. 3Department of Epidemiology, State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing 100071, China

Correspondence: CF Qin; TY Zhao, E-mail: qincf@bmi.ac.cn; tongyanzhao@126.com

*These authors contributed equally to this work.

Received 24 June 2016; Revised 27 July 2016; Accepted 8 August 2016

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ABSTRACT

Zika virus (ZIKV) has become a threat to global health since the outbreak in Brazil in 2015. Although ZIKV is generally considered an Aedes-transmitted pathogen, new evidence has shown that parts of the virus closely resemble Culex-transmitted viruses. Therefore, it is important to evaluate the competence of Culex species for ZIKV to understand their potential as vectors. In this study, female Culex pipiens quinquefasciatus were orally exposed to ZIKV. Mosquito midguts, salivary glands and ovaries were tested for ZIKV to measure infection and dissemination at 2, 4, 6, 8, 12, 16 and 18 days post exposure (pe). In addition, saliva was collected from mosquitoes after infection and infant mice were bitten by infected mosquitoes to measure the transmission ability of Cx. p. quinquefasciatus. The results showed that the peak time of virus appearance in the salivary glands was day 8 pe, with 90% infection rate and an estimated virus titer of 3.92±0.49 lg RNA copies/mL. Eight of the nine infant mice had positive brains after being bitten by infected mosquitoes, which meant that Cx. p. quinquefasciatus could be infected with and transmit ZIKV following oral infection. These laboratory results clearly demonstrate the potential role of Cx. p. quinquefasciatus as a vector of ZIKV in China. Because there are quite different vector management strategies required to control Aedes (Stegomyia) species and Cx. p. quinquefasciatus, an integrated approach may be required should a Zika epidemic occur.

Keywords:

Culex pipiens quinquefasciatus; transmission; vector competence; Zika virus (ZIKV)