A new study by a team of international researchers revealed that Asian tiger mosquitoes collected from Brazil have shown traces of Zika virus RNA.
Their findings, described in a paper published in the Journal of Medical Entomology, suggest that Aedes albopictus -- commonly known as Asian tiger mosquito -- may potentially become an additional vector for the virus.
"Our results mean that Aedes albopictus may have a role in Zika virus transmission and should be of concern to public health," said Chelsea Smart, Ph.D., associate professor at the Florida Medical Entomology Laboratory at the University of Florida and lead author of the study, in a press release. "This mosquito, found worldwide, has a wide range of hosts and has adapted to colder climates. The role of this mosquito in Zika virus transmission needs to be assessed."
For the study, the researchers collected mosquitoes from Brazil and let them reproduce in a lab. The researchers observed that male Asian tiger mosquitoes that were hatched in the lab tested positive for Zika RNA. This means female Asian tiger mosquitoes collected from Brazil had encountered the Zika virus and passed some of its fragments to their offspring.
Finding fragments of Zika's RNA in Asian tiger mosquitoes does not necessarily mean the "vertical transmission" of the virus from mother to offspring. Without live Zika virus in the offspring, the presence of Zika RNA suggests that either "the female parent was not itself infected with live Zika virus or it was not able to transfer live Zika virus to her eggs," Smartt commented.
Researchers have long been suspecting that other species of mosquitoes can become vectors of Zika virus. However, the Aedes aegypti is still the only confirmed species of mosquito that can transfer the virus to humans.
The detection of Zika RNA in Asian tiger mosquitoes emphasize the need for further research on other mosquito species that can potentially become a vector for the Zika virus. Additionally, the researchers noted that all mosquito species collected in areas with high number of Zika cases should be tested for Zika RNA first before being transferred to other places.