Category Archives: Food and Health

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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Water testing program helps get the lead out

Emily Hutchins of Blacksburg, Virginia, fills water collection bottles.

Emily Hutchins of Blacksburg, Virginia, fills water collection bottles.

Virginia Tech’s recent discovery of abnormally high amounts of lead in the Flint, Michigan, water system has made safe drinking water a hot topic. But while the water in Flint came from a municipal source, private water systems, such as wells, springs, and cisterns, are not immune to this problem.

Testing conducted though Virginia Cooperative Extension’s Virginia Household Water Quality Program has found high levels of lead in private systems around the state.

Kelsey Pieper, a researcher on the Flint team who received her doctorate from Virginia Tech, was the primary author on the study that found 1 in 5 private systems had lead concentrations above the Environmental Protection Agency standard for municipal systems. About 45 percent of the samples contained coliform bacteria and 10 percent contained E. coli.

The study determined that, like Flint, much of the lead in private systems is due to corrosive water.

“Homeowners may associate lead in water problems with older homes, but we are finding high lead in water from newer homes as well,” said Pieper. “Until 2014, lead-free plumbing could contain up to 8 percent lead. These components are still present in many homes, and exposure to corrosive water may cause the lead to leach.”

Nearly one-quarter of Virginia’s population — 1.7 million people — rely on private water systems for their source of household water.

“The safest thing you can do is have your water tested,” said Erin Ling, a senior Extension associate in the Department of Biological Systems Engineering and the Virginia Household Water Quality Program coordinator. Ling recommends that private systems be routinely tested every one to three years.

Jeremy and Emily Hutchins of Blacksburg are among thousands of families across Virginia that have had their water tested through the Virginia Household Water Quality Program. Emily Hutchins had heard about the program from a friend at work. She wanted to have her water tested and was also concerned about the water at her parent’s home in Craig County. She convinced her parents to have their water tested at the same time.

“It’s good to know what is in your water,” said Jeremy Hutchins. “Look at how much stuff can end up in your water. Why wouldn’t you want to know?”

“Our program works through local Extension offices to offer low-cost, confidential water testing for Virginia’s well and spring users. Since these are private systems, the owner is completely responsible for maintaining the quality of their drinking water,” said Ling. “In addition to learning about their water quality, we work to empower well owners with information about system care and maintenance and to address any problems.”

Clinics begin with a kickoff meeting that introduces the program and gives instructions for collecting the samples. After participants collect their water samples, the samples are taken to two labs at Virginia Tech to be analyzed. An interpretation meeting is held to review each participant’s results and discuss options for addressing maintenance or water quality problems. More than 50 clinics will be held across the commonwealth in 2016.

“As more testing is done, we will continue to develop a better understanding of the occurrence, sources, and remediation approaches of lead in private systems,” said Ling.

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