As researchers continue to make strides in learning more about the mosquito-borne viruses that have been plaguing Brazil, a new study has found that the next disease epidemic to hit the country could be Chikungunya.
According to the results of a recently published PLOS Neglected Tropical Diseases
article, Aedes mosquitoes in Aracuja city
in Sergipe State, Brazil, were found to be “naturally infected” with the East-Central-South-African (ECSA) Chikungunya virus genotype. Although there have been thousands of Chikungunya cases identified in Brazil, until now, they have all been identified as travel-related.
The researchers collected 248 mosquitoes from inside and outside of homes in the urban areas of the city. Four mosquito strains were collected, the most common of which were Culex quinquefasciatus
(78.2%) and Aedes aegypti
(20.2%) mosquitoes. The mosquitoes were tested for Zika, Dengue, and Chikungunya using QuantiTect Probe reverse transcription-polymerase chain reaction (qRT-PCR) and Mastercycler Realplex 2 thermocycler.
Mosquitoes from Aracuja were tested for these viruses because the city is known to be endemic for Dengue, and because Zika and Chikungunya cases had been confirmed in the city in 2016. In addition, studies have shown that co-infection with Zika and Chikungunya may lead to complications.
Of the collected mosquito pools, all pools tested negative for Zika and Dengue (genotypes 1-4). One female pool of Ae. aegypti
mosquitoes (38 mosquitoes) tested positive for Chikungunya virus, although all male pools (12 mosquitoes) tested negative. When the female mosquitoes in the Ae. aegypti
pool were individually tested, only one mosquito was positive for Chikungunya. According to the Centers for Disease Control and Prevention, Chikungunya
“is most often spread to people by Aedes aegypti
and Aedes albopictus
mosquitoes.” The authors note that they did not identify any Aedes albopictus
mosquitoes “in the inspected houses, although this species is endemic in Aracuja city.”
“Our findings constitute the first description of Ae
-[Chikungunya] genotype ECSA interaction in Brazil. These results reinforce the role of this species as an important vector of [Chikungunya] in urban areas of northeast regions in Brazil,” stated the authors of the study.