While more than 13,000 cases of Chikungunya viral disease were reported in Brazil in 2015, scientists had never before detected the virus in a captured mosquito in this country. Now, researchers reporting in PLOS Neglected Tropical Diseases have identified a mosquito--caught in the Brazilian city of Aracaju--that's naturally infected with the East-Central-South-African (ECSA) genotype of Chikungunya.
Chikungunya, which often causes a fever and joint pain, is endemic in Africa and Asia and was first reported to be transmitted within Brazil in 2014. Researchers have identified three genotypes of Chikungunya virus (CHIKV)--ECSA, West African, and Asian. Both ECSA and Asian genotypes of CHIKV have been reported in patients in Brazil, and all Brazilian states are infested with Aedes aegypti and Ae. albopictus mosquitos, which have both been shown to be possible vectors of CHIKV in the lab.
In the new work, Margareth Capurro, of the University of Sao Paulo, Brazil, and colleagues collected 248 mosquitos from both inside and outside homes in urban areas of Aracaju, where residents were complaining of symptoms consistent with CHIKV or related diseases. They then tested the mosquitos for CHIKV, as well as dengue virus and Zika virus.
Four strains of mosquitos were captured, with Culex quinquefasciatus the most common, making up 78.2%, and Ae. aegypti making up 20.2% of the mosquitos. One female Aedes aegypti mosquito was identified as carrying CHIKV and when the genome was sequenced, it was found to be the ECSA genotype. No mosquitos carrying dengue or Zika were identified in the current study.
"The surveillance of the Aedes mosquito should be expanded in order to prevent new CHIKV outbreaks in Brazil, since this country presents adequate conditions for the establishment of an endemic situation, which can also expose other countries at risk," the authors write.
In your coverage please use this URL to provide access to the freely available article in PLOS Neglected Tropical Diseases: http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0005630
Citation: Costa-da-Silva AL, Ioshino RS, Petersen V, Lima AF, Cunha MdP, Wiley MR, et al. (2017) First report of naturally infected Aedes aegypti with chikungunya virus genotype ECSA in the Americas. PLoS Negl Trop Dis 11(6): e0005630. https://doi.org/10.1371/journal.pntd.0005630
Funding: This work was funded by grants #2013/19921-9, #2014/27172-9 and #2014/17766-9 from São Paulo Research Foundation - FAPESP, National Institutes of Health/National Institute of Allergy and Infectious Diseases (NIH/NIAID) UO1 AI115595, National Institute of Science and Technology - Molecular Entomology - INCT-EM (http://inct.cnpq.br/web/inct-em) and by a grant from The Defense Advanced Research Projects Agency (DARPA, PI: C. Kane). The views expressed in this article are those of the authors and do not reflect the official policy or position of the U.S. Department of Defense or the U.S. Army. This work was supported by Pan American Health Organization (PAHO). ALCS was supported by fellowship #1252482 from Postdoctoral National Program of the Coordination for the Improvement of Higher Education Personnel - PNPD/CAPES. RSI was supported by graduate fellowship from Coordination for the Improvement of Higher Education Personnel - CAPES. VP was supported by fellowship 140032/2013-4 from Brazilian National Research Council - CNPq. MPC was supported by fellowship 2016/08204-2 from FAPESP. MLC and LS are fellows of CNPq 305042/2015-7 and #311805/2014-0, respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
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