Scientists Develop Infection Model.
A research gap has been filled by developing a laboratory model to study ticks that transmit flaviviruses, such as Powassan virus--which was implicated in the death of a New York man last year--by scientists at the National Institutes of Health, Bethesda, Md.
The unusual model involves culturing organs taken from Ixodes scapularis ticks and infecting those organ cultures with flaviviruses, according to researchers at Rocky Mountain Laboratories, part of NIH's National Institute of Allergy and Infectious Diseases. The researchers say the culture model greatly will increase knowledge about how flaviviruses infect ticks and could become a tool to evaluate medical countermeasures against tick-borne viruses.
Flaviviruses are the cause of diseases spread by mosquitoes (e.g., dengue and West Nile) and by ticks (e.g., Powassan and encephalitis). Powassan virus and the closely related deer tick virus are the only flaviviruses known to be spread by ticks in North America.
In the last 10 years, about 75 U.S. cases of Powassan virus infection have been reported, according to the Centers for Disease Control and Prevention, Atlanta, Ga. Powassan can result in fever, headache, vomiting, weakness, confusion, seizures, memory loss, and death. No licensed treatments or vaccines are available.
The scientists developed their model by dissecting three tick organs--the midgut, salivary glands, and nervous tissue--and then culturing flaviviruses in those organs, evaluating their viability over several days. They found that Powassan virus and the related Langat virus could infect and spread in salivary glands and midgut. Langat virus typically is found in Southeast Asia and is an ideal model virus for study because it causes only rare, mild infections in people.
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|Title Annotation:||TICK-BORNE FLAVIVIRUSES|
|Publication:||USA Today (Magazine)|
|Date:||Jun 1, 2018|
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