Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Sep 6;10(9):e0004993.
doi: 10.1371/journal.pntd.0004993. eCollection 2016 Sep.

Culex quinquefasciatus from Rio de Janeiro Is Not Competent to Transmit the Local Zika Virus

Rosilainy Surubi Fernandes  1 , Stéphanie Silva Campos  1 , Anielly Ferreira-de-Brito  1 , Rafaella Moraes de Miranda  1 , Keli Antunes Barbosa da Silva  1 , Marcia Gonçalves de Castro  1 , Lidiane M S Raphael  2 , Patrícia Brasil  3 , Anna-Bella Failloux  4 , Myrna C Bonaldo  2 , Ricardo Lourenço-de-Oliveira  1
Affiliations

Culex quinquefasciatus from Rio de Janeiro Is Not Competent to Transmit the Local Zika Virus

Rosilainy Surubi Fernandes et al. PLoS Negl Trop Dis. .

Abstract

Background: The Americas have suffered a dramatic epidemic of Zika since May in 2015, when Zika virus (ZIKV) was first detected in Brazil. Mosquitoes belonging to subgenus Stegomyia of Aedes, particularly Aedes aegypti, are considered the primary vectors of ZIKV. However, the rapid spread of the virus across the continent raised several concerns about the transmission dynamics, especially about potential mosquito vectors. The purpose of this work was to assess the vector competence of the house mosquito Culex quinquefasciatus from an epidemic Zika area, Rio de Janeiro, Brazil, for local circulating ZIKV isolates.

Methodology/principal findings: Culex quinquefasciatus and Ae. aegypti (positive control of ZIKV infection) from Rio de Janeiro were orally exposed to two ZIKV strains isolated from human cases from Rio de Janeiro (Rio-U1 and Rio-S1). Fully engorged mosquitoes were held in incubators at 26 ± 1°C, 12 h:12 h light:dark cycle and 70 ± 10% humidity. For each combination mosquito population-ZIKV strain, 30 specimens were examined for infection, dissemination and transmission rates, at 7, 14 and 21 days after virus exposure by analyzing body (thorax plus abdomen), head and saliva respectively. Infection rates were minimal to completely absent in all Cx. quinquefasciatus-virus combinations and were significantly high for Ae. aegypti. Moreover, dissemination and transmission were not detected in any Cx. quinquefasciatus mosquitoes whatever the incubation period and the ZIKV isolate. In contrast, Ae. aegypti ensured high viral dissemination and moderate to very high transmission.

Conclusions/significance: The southern house mosquito Cx. quinquefasciatus from Rio de Janeiro was not competent to transmit local strains of ZIKV. Thus, there is no experimental evidence that Cx. quinquefasciatus likely plays a role in the ZIKV transmission. Consequently, at least in Rio, mosquito control to reduce ZIKV transmission should remain focused on Ae. aegypti.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1
Viral infection (A), dissemination (B), transmission (C, D) at days 7, 14 and 21 after challenge of Aedes aegypti and Culex quinquefasciatus from Rio de Janeiro, Brazil, with two locally circulating ZIKV isolates (Rio-U1 and Rio-S1) provided at a titer of 106 PFU/mL). Infection rate (IR) refers to the proportion of mosquitoes with infected body (abdomen and thorax) among tested mosquitoes. Disseminated infection rate (DIR) corresponds to the proportion of mosquitoes with infected head among tested mosquitoes (i.e.; abdomen/thorax positive). Transmission efficiency (TE) represents the proportion of mosquitoes with infectious saliva among the initial number of mosquitoes tested. Transmission rate (TR) represents the proportion of mosquitoes with infectious saliva among mosquitoes with disseminated infection. The number of individuals analyzed is given on top of bars.
Fig 2
Fig 2. ZIKV load in bodies and heads of Ae. aegypti from Rio de Janeiro, Brazil, 7, 14 and 21 days after challenge with two locally circulating ZIKV isolates (Rio-U1 and Rio-S1) provided at a titer of 106 PFU/mL).
Viral RNA copies were determined by qPCR in mosquito homogenates. Viral loads with value 0 actually represents mosquitos with viral loads < 40 RNA copies/ml.
Fig 3
Fig 3. ZIKV load in saliva of Ae. aegypti from Rio de Janeiro, Brazil, 14 and 21 days after challenge with two locally circulating ZIKV isolates (Rio-U1 and Rio-S1) provided at a titer of 106 PFU/mL.
Virus was detected plaque forming unit (PFU) assays on Vero cells.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Musso D, Gubler DJ. Zika virus. Clin Microbiol Rev. 2016;29(3):487–524. 10.1128/CMR.00072-15 - DOI - PMC - PubMed
    1. Brasil P, Calvet GA, Siqueira AM, Wakimoto M, de Sequeira PC, Nobre A, et al. Zika Virus Outbreak in Rio de Janeiro, Brazil: Clinical Characterization, Epidemiological and Virological Aspects. PLoS Negl Trop Dis. 2016. April 12;10(4):e0004636 10.1371/journal.pntd.0004636 - DOI - PMC - PubMed
    1. Zanluca C, de Melo VC, Mosimann AL, Dos Santos GI, Dos Santos CN, Luz K. First report of autochthonous transmission of Zika virus in Brazil. Mem Inst Oswaldo Cruz. 2015;110(4):569–72. 10.1590/0074-02760150192 - DOI - PMC - PubMed
    1. Faye O, Freire CC, Iamarino A, Faye O, de Oliveira JV, Diallo M, et al. Molecular evolution of Zika virus during its emergence in the 20(th) century. PLoS Negl Trop Dis. 2014;8(1):e2636 10.1371/journal.pntd.0002636 - DOI - PMC - PubMed
    1. Dick GW. Zika virus. II. Pathogenicity and physical properties. Trans R Soc Trop Med Hyg. 1952;46(5):521–34. - PubMed

Publication types