Tag Archives: pest management

Exploring genetics to combat malaria and Zika

Fralin Life Science Institute’s Vector-Borne Disease Research Group team members, from left: Zhijian “Jake” Tu, professor of biochemistry; Brantley Hall, biochemistry graduate student; Atashi Sharma, entomology graduate student; and Igor Sharakhov, associate professor of entomology

Fralin Life Science Institute’s Vector-Borne Disease Research Group team members, from left: Zhijian “Jake” Tu, professor of biochemistry; Brantley Hall, biochemistry graduate student; Atashi Sharma, entomology graduate student; and Igor Sharakhov, associate professor of entomology

The Zika virus has quickly become a major health threat, and researchers at Virginia Tech are looking for ways to curtail its spread.

The virus, which is primarily spread to humans by the bite of an infected mosquito, has been passed on to a growing number of Americans since early 2016, and the World Health Organization has declared it a Public Health Emergency of International Concern.

Biochemist Zhijian “Jake”  Tu is one of several Virginia Tech researchers zeroing in on the Zika virus. Tu is studying genes that turn biting female mosquitoes into males, and he is exploring genetic strategies to stop the transmission of the Zika virus by reducing the number of female mosquitoes. Male mosquitoes do not bite and are harmless to humans, while female mosquitoes bite humans to get the blood they need for egg production.

With support from an NIH grant and building on their previous discoveries that were published in the journal Science, Tu and some of his colleagues in the Vector-Borne Disease Research Group — Zach Adelman, Jinsong Zhu, and Maria Sharakhova — are investigating the molecular mechanisms and applications of male-determining factor in Aedes agypti mosquitoes, the species that transmits Zika.

Tu, Zhu, and Igor Sharakhov also received NIH funding to study sex determination in a family of malaria-spreading mosquitoes. Working with a large international consortium, the researchers sequenced the “Y” chromosome — the genetic drive of sex determination and male fertility — in Anopheles gambiae mosquitoes. The findings were published in the Proceedings of the National Academy of Sciences.

“Although the master switch genes that govern sex determination are completely different in Aedes and Anopheles mosquitoes, the approach that targets the female mosquitoes will have broad applications in efforts to control numerous mosquito-borne infectious diseases, including old foes such as malaria and emerging threats such as Zika,”  Tu said.

While Zika had only previously been associated with mild symptoms in humans, it can produce more severe symptoms in areas where the virus has recently been introduced because populations have no pre-existing immunity. It has also been linked to a birth defect called “microcephaly,” in which infected pregnant women give birth to brain-damaged babies with abnormally small heads.

About 10 Virginia Tech researchers with expertise in the fields of disease modeling, epidemic mapping, mosquito genetics, and novel insecticides are now focusing on Zika, developing ways to predict the spread of the virus and stop it from doing more damage.

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Taking the bite out of bedbugs

Virginia Tech: Bed bugs from VirginiaTech on Vimeo.


While bedbugs have largely been the bane of landlords and hoteliers, researchers from Virginia Cooperative Extension have discovered that bedbugs are increasingly popping up in spaces such as health care facilities — and that has a lot of people scratching their heads about how to contain the annoying bugs.

Dini Miller, professor of entomology and Extension entomologist, trains health care and social workers on how to get rid of bedbugs and prevent future infestations.

Dini Miller, professor of entomology and Extension entomologist, trains health care and social workers on how to get rid of bedbugs and prevent future infestations.

This latest development means the training and research that Dini Miller, professor of entomology and Extension entomologist, conducts at the Dodson Urban Pest Management Laboratory is more necessary than ever for those looking to contain the urban pest problem.

According to Miller, bedbugs have increasingly spread from individual homes to places where people gather to use social services, such as women’s shelters; medical care facilities, like dialysis centers; and lower-income, elder care facilities. Elderly populations are at high risk for bedbugs because their bodies might not react to the bites with the usual red welts, and poorer eyesight means they don’t see the bugs well enough to report them.

Miller is training health care and social workers — who often encounter infestations in spaces such as these — on how to get rid of the bugs and address the tangential factors of dealing with the pests, such as difficulty in moving personal belongings in a population with limited mobility.

In 2015 the Dodson Center delivered 63 training presentations at 50 different venues, resulting in 6,945 face-to-face interactions.

Much of what Miller combats during trainings is ignorance.

“We have to address the ‘freak out’ factor,” said Miller. “People who cannot live without assistance are now being even more isolated and deprived of care because health care workers are reticent to enter spaces where there are infestations.”

When Miller started the center, she was worried about how to advertise the center’s services, but no longer.

“The bedbugs just kept spreading,” she said.

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