Scholarly Works, Center for Emerging, Zoonotic, and Arthropod-borne Pathogens (CeZAP)

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Browsing Scholarly Works, Center for Emerging, Zoonotic, and Arthropod-borne Pathogens (CeZAP) by Subject "2 Aetiology"

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    First Evidence of Powassan Virus (Flaviviridae) in Ixodes scapularis in Appalachian Virginia, USA
    Cumbie, Alexandra N.; Whitlow, Amanda M.; Eastwood, Gillian (American Society of Tropical Medicine and Hygiene, 2022-03-01)
    Here we report the first detection and confirmation of Powassan virus (POWV) (family: Flaviridae) in Ixodes scapularis ticks collected from Appalachian Virginia. Ixodes scapularis ticks were collected from vegetation across field sites in eight counties of western Virginia from June 2019 to April 2021. From these collections, one nymph and one adult male I. scapularis were determined to be positive for POWV using real-time RT-PCR and Sanger sequencing. Both positive ticks were collected from Floyd county, VA, at residential sites; the nymph in June 2020 and the adult male in April 2021. The presence of POWV in Virginia in its natural tick vector is crucial knowledge in beginning to understand the movement and transmission of this pathogen into new geographical areas and the risk it poses to medical and veterinary health.
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    Hepatitis E virus infects brain microvascular endothelial cells, crosses the blood–brain barrier, and invades the central nervous system
    Tian, Debin; Li, Wen; Heffron, C. Lynn; Wang, Bo; Mahsoub, Hassan M.; Sooryanarain, Harini; Hassebroek, Anna M.; Clark-Deener, Sherrie; LeRoith, Tanya; Meng, Xiang-Jin (Proceedings of the National Academy of Sciences, 2022-06-14)
    Hepatitis E virus (HEV) is an important but understudied zoonotic virus causing both acute and chronic viral hepatitis. A proportion of HEV-infected individuals also developed neurological diseases such as Guillain–Barre syndrome, neuralgic amyotrophy, encephalitis, and myelitis, although the mechanism remains unknown. In this study, by using an in vitro blood–brain barrier (BBB) model, we first investigated whether HEV can cross the BBB and whether the quasi-enveloped HEV virions are more permissible to the BBB than the nonenveloped virions. We found that both quasi-enveloped and nonenveloped HEVs can similarly cross the BBB and that addition of proinflammatory cytokine tumor necrosis factor alpha (TNF-α) has no significant effect on the ability of HEV to cross the BBB in vitro. To explore the possible mechanism of HEV entry across the BBB, we tested the susceptibility of human brain microvascular endothelial cells lining the BBB to HEV infection and showed that brain microvascular endothelial cells support productive HEV infection. To further confirm the in vitro observation, we conducted an experimental HEV infection study in pigs and showed that both quasi-enveloped and nonenveloped HEVs invade the central nervous system (CNS) in pigs, as HEV RNA was detected in the brain and spinal cord of infected pigs. The HEV-infected pigs with detectable viral RNA in CNS tissues had histological lesions in brain and spinal cord and significantly higher levels of proinflammatory cytokines TNF-α and interleukin 18 than the HEV-infected pigs without detectable viral RNA in CNS tissues. The findings suggest a potential mechanism of HEV-associated neuroinvasion.