Public Release: 

Traces of Zika Found in Asian tiger mosquito in Brazil

Virus fragments detected in species other than Zika's known primary vector

Entomological Society of America

Annapolis, MD; April 10, 2017--In a recent test of Asian tiger mosquitoes collected in Brazil, researchers found fragments of Zika virus RNA, raising concerns that it may be carried by species other than Zika's known primary vector, the yellow fever mosquito.

The research does not conclude that the Asian tiger mosquito (Aedes albopictus) can transmit Zika to humans, but it highlights the need for deeper research into additional potential vectors for the virus that has rapidly spread through the Americas since its initial outbreak in 2015, says Chelsea Smartt, Ph.D., associate professor at the Florida Medical Entomology Laboratory at the University of Florida and lead author on the study to be published this week in the Entomological Society of America's Journal of Medical Entomology.

"Our results mean that Aedes albopictus may have a role in Zika virus transmission and should be of concern to public health," Smartt says. "This mosquito is 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."

Smartt and an international team of researchers collected the mosquitoes from homes in Brazil and hatched eggs from those mosquitoes in the lab. Male Ae. albopictus mosquitoes that hatched tested positive for Zika RNA (ribonucleic acid), meaning that females collected in the field had encountered Zika and passed fragments of the virus to their offspring. Whether that means Ae. albopictus can "vertically transmit" live Zika virus to its offspring is still unclear. "Detecting Zika RNA fragments without finding live Zika virus 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 says.

Thus far, the yellow fever mosquito (Aedes aegypti) is the species known to be the primary transmitter of Zika to humans, though researchers suspect other species may be involved. However, Smartt says "extensive research still needs to be done" to confirm whether the Asian tiger mosquito is also a culprit.

Meanwhile, though, the current findings emphasize the need for abundant caution among insect scientists and medical researchers, as well. "It is important to test all mosquitoes collected in areas with a high number of Zika cases for Zika RNA, and if the mosquitoes are positive for Zika RNA they must be tested for live Zika virus prior to transport or use in a laboratory for experiments."

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"Evidence of Zika Virus RNA Fragments in Aedes albopictus (Diptera: Culicidae) Field-Collected Eggs From Camaçari, Bahia, Brazil," by Chelsea T. Smartt, Tanise M. S. Stenn, Tse-Yu Chen, Maria Gloria Teixeira, Erivaldo P. Queiroz, Luciano Souza Dos Santos, Gabriel A. N. Queiroz, Kathleen Ribeiro Souza, Luciano Kalabric Silva, Dongyoung Shin, and Walter J. Tabachnick, will be published online on April 13 in the Journal of Medical Entomology. Journalists may request advance copies of the study via the contact below.

CONTACT: Joe Rominiecki, jrominiecki@entsoc.org, 301-731-4535 x3009

ABOUT: ESA is the largest organization in the world serving the professional and scientific needs of entomologists and people in related disciplines. Founded in 1889, ESA today has over 6,000 members affiliated with educational institutions, health agencies, private industry, and government. Headquartered in Annapolis, Maryland, the Society stands ready as a non-partisan scientific and educational resource for all insect-related topics. For more information, visit http://www.entsoc.org.

Journal of Medical Entomology publishes research related to all aspects of medical entomology and medical acarology, including the systematics and biology of insects, acarines, and other arthropods of public health and veterinary significance. For more information, visit https://academic.oup.com/jme, or visit http://www.insectscience.org to view the full portfolio of ESA journals and publications.

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