Zika virus (ZIKV) is a flavivirus that has recently been associated with an increased incidence of neonatal microcephaly and other neurological disorders. The virus is primarily transmitted by mosquito bite, although other routes of infection have been implicated in some cases. The Aedes aegypti mosquito is considered to be the main vector to humans worldwide; however, there is evidence that other mosquito species, including Culex quinquefasciatus, transmit the virus. To test the potential of Cx. quinquefasciatus to transmit ZIKV, we experimentally compared the vector competence of laboratory-reared Ae. aegypti and Cx. quinquefasciatus. Interestingly, we were able to detect the presence of ZIKV in the midgut, salivary glands and saliva of artificially fed Cx. quinquefasciatus. In addition, we collected ZIKV-infected Cx. quinquefasciatus from urban areas with high microcephaly incidence in Recife, Brazil. Corroborating our experimental data from artificially fed mosquitoes, ZIKV was isolated from field-caught Cx. quinquefasciatus, and its genome was partially sequenced. Collectively, these findings indicate that there may be a wider range of ZIKV vectors than anticipated.

These authors contributed equally to this work. Abstract:Zika virus (ZIKV) is a flavivirus that has recently been associated with increased incidence of neonatal microcephaly and other neurological disorders. The virus is primarily transmitted by mosquito bite, although other routes of infection have been implicated in some cases. The Aedes aegypti mosquito is considered to be the main vector to humans worldwide, but there is evidence of other mosquito species, including Culex quinquefasciatus, playing a role in the Brazilian outbreak. To test this hypothesis, we experimentally compared the vectorial competence of laboratory-reared A. aegypti and C. quinquefasciatus. We found ZIKV in the not peer-reviewed) is the author/funder. All rights reserved. No reuse allowed without permission.The copyright holder for this preprint (which was . http://dx.doi.org/10.1101/073197 doi: bioRxiv preprint first posted online Sep. 2, 2016; 2 midgut, salivary glands, and saliva of artificially fed C. quinquefasciatus. Additionally, we collected ZIKV-infected C. quinquefasciatus from urban areas of high microcephaly incidence in Recife, Brazil. Take into account; these findings indicate that there may be a wider range of vectors for ZIKV than anticipated.Keywords: Zika, microcephaly, Culex, Aedes, vectorial competence, vector control.Zika is classically considered a mild disease whose symptoms include fever, joint pain, rash and, in some cases, conjunctivitis (1). However, the Zika outbreak in Brazil has been associated with an increased incidence of neonatal microcephaly and neurological disorders (2, 3). Zika virus (ZIKV) is a poorly known, small, enveloped RNA virus with ssRNA (+) belonging to the Family Flaviviridae. It was first isolated in April 1947 from a rhesus monkey and in January 1948 from the mosquito species Aedes africanus (4). Since then, several ZIKV strains have been isolated from many samples, mostly mosquitoes, including species from the genera Aedes, Mansonia, Anopheles and Culex (5).The first known Zika epidemic in an urban environment occurred in Micronesia in 2007, with approximately 73% of the human population on Yap island becoming infected (6).Intriguingly, although many Aedes mosquitoes were collected in the field and evaluated for virus detection, no samples were found to be positive for ZIKV (6). Additionally, it is important to highlight that Aedes aegypti (A. aegypti) is absent from most islands in the Micronesia archipelago and is very rare on the islands where it is present (6, 7).There is a global consensus among scientists and health agencies that Aedes spp. are the main ZIKV vector in urban areas (WHO, 2016). This is in part because vector competence experiments for ZIKV have been conducted exclusively for species of this genus, mainly A.aegypti (8, 9). Previous laboratory studies (8, 10) suggested that A. aegypti is a ZIKV vector. not peer-reviewed) is the author/funder. All rights reserved. No reuse allowed without permission.The copyright holder for this preprint (which was . http://dx.doi...

The (re) emergence of arboviruses around the world is a public health concern once severe outbreaks are usually associated with these infections. The co-circulation of Dengue (DENV), Zika (ZIKV) and Chikungunya (CHIKV) viruses in the past few years has caused a unique epidemic situation in Brazil. The northeast region of the country was the most affected by clinical complications from such arboviruses’ infections, including neurological disorders caused by ZIKV. In this particular region, Aedes mosquitoes are the main vectors of DENV, ZIKV and CHIKV, with Culex quinquefasciatus also considered as a potential vector of ZIKV. Therefore, virological surveillance in mosquitoes contributes to understanding the epidemiological profile of these diseases. Here, we report the circulation of DENV, ZIKV and CHIKV in Aedes spp. and Cx. quinquefasciatus female mosquitoes collected in areas with a high arbovirus circulation in humans in the Metropolitan Region of Recife, Pernambuco, Brazil, during the triple-epidemics of 2015-17. All the field-caught mosquitoes were sent to the laboratory for arbovirus screening after RNA extraction and RT-PCR/RT-qPCR. A total of 6,227 females were evaluated and, as a result, DENV, ZIKV and CHIKV were identified in Ae. aegypti, Ae. taeniorhynchus and Cx. quinquefasciatus mosquito pools. In addition, DENV and ZIKV were isolated in C6/36 cells. In conclusion, it is important to highlight that arbovirus surveillance performed in mosquitoes from DENV-ZIKV-CHIKV hotspots areas can serve as an early-warning system to target vector control actions more efficiently in each studied area.