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Policastro PF, Schneider CA, Winkler CW, Leung JM, Peterson KE. Retinoic acid-induced differentiation and oxidative stress inhibitors increase resistance of human neuroblastoma cells to La Crosse virus-induced cell death. J Virol 2024:e0030024. [PMID: 39382324 DOI: 10.1128/jvi.00300-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Accepted: 08/13/2024] [Indexed: 10/10/2024] Open
Abstract
La Crosse Virus (LACV) encephalitis patients are at risk for long-term deficits in cognitive function due to neuronal apoptosis following virus infection. However, the specific etiology underlying neuronal damage remains elusive. In this study, we examined how differentiation and mitotic inhibition of neuroblastoma cells influence their susceptibility to LACV infection and cell death. Treatment of SH-SY5Y cells with retinoic acid induced a neuronal cell phenotype which was similarly susceptible to LACV infection as untreated cells but had significantly delayed virus-induced cell death. Protein and RNA transcript analysis showed that retinoic acid-treated cells had decreased oxidative stress responses to LACV infection compared to untreated cells. Modulation of oxidative stress in untreated cells with specific compounds also delayed cell death, without substantially impacting virus production. Thus, the oxidative stress response of neurons to virus infection may be a key component of neuronal susceptibility to virus-induced cell death. IMPORTANCE Encephalitic viruses like La Crosse Virus (LACV) infect and kill neurons. Disease onset and progression is rapid meaning the time frame to treat patients before significant and long-lasting damage occurs is limited. Examining how neurons, the primary cells infected by LACV in the brain, resist virus-induced cell death can provide avenues for determining which pathways to target for effective treatments. In the current study, we studied how changing neuroblastoma growth and metabolism with retinoic acid treatment impacted their susceptibility to LACV-induced cell death. We utilized this information to test compounds for preventing death in these cells.
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Affiliation(s)
- Paul F Policastro
- Neuroimmunology Section, Laboratory of Neurological Infections and Immunity, Hamilton, Montana, USA
| | - Christine A Schneider
- Neuroimmunology Section, Laboratory of Neurological Infections and Immunity, Hamilton, Montana, USA
- Electron Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Hamilton, Montana, USA
| | - Clayton W Winkler
- Neuroimmunology Section, Laboratory of Neurological Infections and Immunity, Hamilton, Montana, USA
| | - Jacqueline M Leung
- Electron Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Hamilton, Montana, USA
| | - Karin E Peterson
- Neuroimmunology Section, Laboratory of Neurological Infections and Immunity, Hamilton, Montana, USA
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2
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Bergevin MD, Ng V, Ludwig A, Sadeghieh T, Menzies P, Mubareka S, Clow KM. A Scoping Review on the Epidemiology of Orthobunyaviruses of Canadian Public and Animal Health Relevance in the Context of Vector Species. Vector Borne Zoonotic Dis 2024; 24:564-577. [PMID: 38687337 DOI: 10.1089/vbz.2023.0152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Abstract
Background: Mosquito-borne orthobunyaviruses are a growing priority for public and animal health in Canada. It is anticipated that disease incidence will increase due to a warming climate, given that habitats are expanding for reservoir hosts and vectors, particularly in Canada. Little is known about the ecology of primary vectors that perpetuate these orthobunyaviruses, including the viral transmission cycle and the impact of climatic and landscape factors. Methods: A scoping review was conducted to describe the current state of knowledge on the epidemiology of orthobunyaviruses relevant to Canada. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines was used to characterize studies focused on vector species. A literature search was conducted in six databases and gray literature. Eligible studies characterized orthobunyavirus epidemiology related to vector species, including viral competency, geospatial distributions, seasonal trends, and/or risk factors. Results: A total of 1734 unique citations were identified. Screening of these citations revealed 172 relevant studies, from which 87 studies presented primary data related to vectors. The orthobunyaviruses included Cache Valley virus (CVV), Jamestown Canyon virus (JCV), Snowshoe Hare virus (SHV), and La Crosse virus (LACV). Surveillance was the predominant study focus, with most citations representing the United States, specifically, LACV surveillance in Tennessee, followed by CVV and JCV in Connecticut. Orthobunyaviruses were detected in many mosquito species across multiple genera, with high vector specificity only being reported for LACV, which included Aedes triseriatus, Aedes albopictus, and Aedes japonicus. Peridomestic areas were positively associated with infected mosquitoes compared with dense forests. Orthobunyavirus infections, coinfections, and gut microbiota affected mosquito feeding and breeding behavior. Conclusion: Knowledge gaps included Canadian surveillance data, disease modeling, and risk projections. Further research in these areas, especially accounting for climate change, is needed to guide health policy for prevention of orthobunyaviral disease.
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Affiliation(s)
- Michele D Bergevin
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Canada
| | - Victoria Ng
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Canada
- National Microbiology Laboratory Branch, Public Health Agency of Canada, Guelph, Canada
| | - Antoinette Ludwig
- National Microbiology Laboratory Branch, Public Health Agency of Canada, St. Hyacinthe, Canada
| | - Tara Sadeghieh
- Health Promotion and Chronic Disease Prevention Branch, Public Health Agency of Canada, Ottawa, Canada
| | - Paula Menzies
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Canada
| | - Samira Mubareka
- Sunnybrook Research Institute, Toronto, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Katie M Clow
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Canada
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3
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Day CA, Odoi AO, Moncayo A, Doyle MS, Williams CJ, Byrd BD, Trout Fryxell RT. Persistent spatial clustering and predictors of pediatric La Crosse virus neuroinvasive disease risk in eastern Tennessee and western North Carolina, 2003-2020. PLoS Negl Trop Dis 2024; 18:e0012186. [PMID: 38843214 PMCID: PMC11156276 DOI: 10.1371/journal.pntd.0012186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/02/2024] [Indexed: 06/09/2024] Open
Abstract
The combined region of eastern Tennessee and western North Carolina has a persistently high risk of pediatric La Crosse virus neuroinvasive disease (LACV-ND). To guide public health intervention in this region, the objectives of this retrospective ecological study were to investigate the geographic clustering and predictors of pediatric LACV-ND risk at the ZIP code tabulation area (ZCTA) level. Data on pediatric cases of LACV-ND reported between 2003 and 2020 were obtained from Tennessee Department of Health and North Carolina Department of Health and Human Services. Purely spatial and space-time scan statistics were used to identify ZCTA-level clusters of confirmed and probable pediatric LACV-ND cases from 2003-2020, and a combination of global and local (i.e., geographically weighted) negative binomial regression models were used to investigate potential predictors of disease risk from 2015-2020. The cluster investigation revealed spatially persistent high-risk and low-risk clusters of LACV-ND, with most cases consistently reported from a few high-risk clusters throughout the entire study period. Temperature and precipitation had positive but antagonistic associations with disease risk from 2015-2020, but the strength of those relationships varied substantially across the study area. Because LACV-ND risk clustering in this region is focally persistent, retroactive case surveillance can be used to guide the implementation of targeted public health intervention to reduce the disease burden in high-risk areas. Additional research on the role of climate in LACV transmission is warranted to support the development of predictive transmission models to guide proactive public health interventions.
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Affiliation(s)
- Corey A. Day
- Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Agricola O. Odoi
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Abelardo Moncayo
- Tennessee Department of Health, Nashville, Tennessee, United States of America
| | - Michael S. Doyle
- North Carolina Division of Public Health, Raleigh, North Carolina, United States of America
| | - Carl J. Williams
- North Carolina Division of Public Health, Raleigh, North Carolina, United States of America
| | - Brian D. Byrd
- Environmental Health Sciences, Western Carolina University, Cullowhee, North Carolina, United States of America
| | - Rebecca T. Trout Fryxell
- Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America
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4
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Drwiega EN, Danziger LH, Burgos RM, Michienzi SM. Commonly Reported Mosquito-Borne Viruses in the United States: A Primer for Pharmacists. J Pharm Pract 2024; 37:741-752. [PMID: 37018738 DOI: 10.1177/08971900231167929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Mosquito-borne diseases are a public health concern. Pharmacists are often a patient's first stop for health information and may be asked questions regarding transmission, symptoms, and treatment of mosquito borne viruses (MBVs). The objective of this paper is to review transmission, geographic location, symptoms, diagnosis and treatment of MBVs. We discuss the following viruses with cases in the US in recent years: Dengue, West Nile, Chikungunya, LaCrosse Encephalitis, Eastern Equine Encephalitis Virus, and Zika. Prevention, including vaccines, and the impact of climate change are also discussed.
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Affiliation(s)
- Emily N Drwiega
- College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Larry H Danziger
- College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
- College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Rodrigo M Burgos
- College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Sarah M Michienzi
- College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
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5
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Meier-Stephenson V, Drebot MA, Dimitrova K, DiQuinzio M, Fonseca K, Forrest D, Hatchette T, Morshed M, Patriquin G, Poliquin G, Saxinger L, Serhir B, Tellier R, Therrien C, Vrbova L, Wood H. Case Series of Jamestown Canyon Virus Infections with Neurologic Outcomes, Canada, 2011-2016. Emerg Infect Dis 2024; 30:874-881. [PMID: 38666581 PMCID: PMC11060468 DOI: 10.3201/eid3005.221258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Abstract
Jamestown Canyon virus (JCV) is a mosquitoborne orthobunyavirus in the California serogroup that circulates throughout Canada and the United States. Most JCV exposures result in asymptomatic infection or a mild febrile illness, but JCV can also cause neurologic diseases, such as meningitis and encephalitis. We describe a case series of confirmed JCV-mediated neuroinvasive disease among persons from the provinces of British Columbia, Alberta, Quebec, and Nova Scotia, Canada, during 2011-2016. We highlight the case definitions, epidemiology, unique features and clinical manifestations, disease seasonality, and outcomes for those cases. Two of the patients (from Quebec and Nova Scotia) might have acquired JCV infections during travel to the northeastern region of the United States. This case series collectively demonstrates JCV's wide distribution and indicates the need for increased awareness of JCV as the underlying cause of meningitis/meningoencephalitis during mosquito season.
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6
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Gual-Gonzalez L, Dye-Braumuller K, Warner A, Bunting T, Bryant D, Connelly R, Burkhalter K, Nolan MS. Do Aedes triseriatus Respect State Boundaries?: A Paucity of La Crosse Virus in the South Carolina Appalachian Mountains. Vector Borne Zoonotic Dis 2024; 24:129-134. [PMID: 37906122 DOI: 10.1089/vbz.2023.0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023] Open
Abstract
Background: La Crosse virus is an important endemic public health concern in the North Carolina Appalachian Mountains; however, human incidence is not commonly noted in this region on the South Carolina side of the mountain range border. No relevant studies have been performed in South Carolina evaluating mosquito vector populations for La Crosse virus (LACV) infection; thus, a pilot mosquito surveillance study was executed in summer 2020. Material and Methods: Vector surveillance occurred at five South Carolina state parks bordering neighboring state endemic counties from May to August 2020. Collections were approved by the state park authority, as noted in Permit No. N-8-20. Results: All three competent mosquito vectors were collected during the study duration; however, these vectors were collected in low abundance: Aedes triseriatus (4.5% of all collected mosquitos); Aedes albopictus (2.0%); Aedes japonicus (1.4%). Principal mosquito vector specimens, Ae. triseriatus, were sent to Centers for Disease Control and Prevention for testing of LACV by real-time reverse transcription PCR-all were negative. Discussion: While entomologic evidence suggests low transmission risk for this arbovirus in the South Carolina Appalachian Mountain region, further eco-epidemiologic investigations are warranted to understand this endemicity variance within a relatively small geographic area.
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Affiliation(s)
- Lídia Gual-Gonzalez
- Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
| | - Kyndall Dye-Braumuller
- Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
| | - Aiden Warner
- School of Medicine, University of South Carolina, Columbia, South Carolina, USA
| | - Tyler Bunting
- School of Medicine, University of South Carolina, Columbia, South Carolina, USA
| | - Dillon Bryant
- Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
| | - Roxanne Connelly
- Arboviral Diseases Branch, Division of Vector-borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Kristy Burkhalter
- Arboviral Diseases Branch, Division of Vector-borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Melissa S Nolan
- Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
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7
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Day CA, Byrd BD, Trout Fryxell RT. La Crosse virus neuroinvasive disease: the kids are not alright. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:1165-1182. [PMID: 37862102 DOI: 10.1093/jme/tjad090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/04/2023] [Accepted: 06/26/2023] [Indexed: 10/21/2023]
Abstract
La Crosse virus (LACV) is the most common cause of neuroinvasive mosquito-borne disease in children within the United States. Despite more than 50 years of recognized endemicity in the United States, the true burden of LACV disease is grossly underappreciated, and there remain severe knowledge gaps that inhibit public health interventions to reduce morbidity and mortality. Long-standing deficiencies in disease surveillance, clinical diagnostics and therapeutics, actionable entomologic and environmental risk indices, case response capacity, public awareness, and availability of community support groups clearly frame LACV disease as neglected. Here we synthesize salient prior research and contextualize our findings as an assessment of current gaps and opportunities to develop a framework to prevent, detect, and respond to LACV disease. The persistent burdens of LACV disease clearly require renewed public health attention, policy, and action.
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Affiliation(s)
- Corey A Day
- Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, USA
| | - Brian D Byrd
- Environmental Health Sciences, Western Carolina University, Cullowhee, NC, USA
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8
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Geographically persistent clusters of La Crosse virus disease in the Appalachian region of the United States from 2003 to 2021. PLoS Negl Trop Dis 2023; 17:e0011065. [PMID: 36656896 PMCID: PMC9888679 DOI: 10.1371/journal.pntd.0011065] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/31/2023] [Accepted: 01/01/2023] [Indexed: 01/20/2023] Open
Abstract
La Crosse virus (LACV) is a mosquito-borne pathogen that causes more pediatric neuroinvasive disease than any other arbovirus in the United States. The geographic focus of reported LACV neuroinvasive disease (LACV-ND) expanded from the Midwest into Appalachia in the 1990s, and most cases have been reported from a few high-risk foci since then. Here, we used publicly available human disease data to investigate changes in the distribution of geographic LACV-ND clusters between 2003 and 2021 and to investigate socioeconomic and demographic predictors of county-level disease risk in states with persistent clusters. We used spatial scan statistics to identify high-risk clusters from 2003-2021 and a generalized linear mixed model to identify socioeconomic and demographic predictors of disease risk. The distribution of LACV-ND clusters was consistent during the study period, with an intermittent cluster in the upper Midwest and three persistent clusters in Appalachia that included counties in east Tennessee / western North Carolina, West Virginia, and Ohio. In those states, county-level cumulative incidence was higher when more of the population was white and when median household income was lower. Public health officials should target efforts to reduce LACV-ND incidence in areas with consistent high risks.
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9
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Day CA, Trout Fryxell RT. Community efforts to monitor and manage Aedes mosquitoes (Diptera: Culicidae) with ovitraps and litter reduction in east Tennessee. BMC Public Health 2022; 22:2383. [PMID: 36536336 PMCID: PMC9764731 DOI: 10.1186/s12889-022-14792-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND East Tennessee (USA) is burdened by mosquito-borne La Crosse virus disease, but minimal resources for mosquito surveillance, management, or related community education exist in the region. To address these needs, we developed a program to train middle and high school educators in basic medical entomology. The educators then used their skills in the classroom to teach students about La Crosse virus disease and conduct mosquito collection experiments. As a case study of a potential application of classroom-collected data, we also partnered with a local non-profit organization to assess the potential for a volunteer litter cleanup to reduce mosquito populations in a Tennessee neighborhood. METHODS Our first objective was to investigate the ability for educators and their students (schools) to collect high-quality mosquito surveillance data. In 2019 and 2020, we collected Aedes (Diptera: Culicidae) eggs during the same study period as schools and assessed whether data collected by schools reflected the same findings as our own data. Our second objective was to investigate the impact of a volunteer litter cleanup event on Aedes mosquito abundance. In 2021, we collected Aedes eggs before and after a neighborhood trash cleanup while schools conducted their own mosquito egg collections. Using the school collections as non-treatment sites, we used a Before-After-Control-Impact analysis to determine if there was a significant decline in egg abundance after the cleanup. RESULTS In 2019, mosquito abundance trends were similar between our data and school data but differed significantly during some weeks. After refining our protocols in 2020, school data was highly similar to our data, indicating that schools consistently collected high-quality surveillance data in the program's second year. In 2021, we found a significant decline in Aedes egg abundance after the litter cleanup event in comparison to the schools, but the number of adults reared from those eggs did not differ between sites after the cleanup. CONCLUSION The results of our work demonstrate the potential for community-driven programs to monitor mosquito abundance trends and for volunteer-based cleanup events to reduce the burden of Aedes mosquitoes. In the absence of infrastructure and resources, academic-community partnerships like the ones evaluated here, provide opportunities to help resource limited areas.
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Affiliation(s)
- C. A. Day
- grid.411461.70000 0001 2315 1184Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN USA
| | - R. T. Trout Fryxell
- grid.411461.70000 0001 2315 1184Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN USA
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10
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Lu S, Martin-Martin I, Ribeiro JM, Calvo E. A deeper insight into the sialome of male and female Ochlerotatus triseriatus mosquitoes. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 147:103800. [PMID: 35787945 PMCID: PMC9494274 DOI: 10.1016/j.ibmb.2022.103800] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Over the last 20 years, advancements in sequencing technologies have highlighted the unique composition of the salivary glands of blood-feeding arthropods. Further biochemical and structural data demonstrated that salivary proteins can disrupt host hemostasis, inflammation and immunity, which favors pathogen transmission. Previously, a Sanger-based sialome of adult Ochlerotatus triseriatus female salivary glands was published based on 731 expressed sequence tag (ESTs). Here, we revisited O. triseriatus salivary gland contents using an Illumina-based sequencing approach of both male and female tissues. In the current data set, we report 10,317 DNA coding sequences classified into several functional classes. The translated transcripts also served as a reference database for proteomic analysis of O. triseriatus female saliva, in which unique peptides from 101 proteins were found. Finally, comparison of male and female libraries allowed for the identification of female-enriched transcripts that are potentially related to blood acquisition and virus transmission.
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Affiliation(s)
- Stephen Lu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Ines Martin-Martin
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Jose M Ribeiro
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Eric Calvo
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA.
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Laboratory Validation of a Real-Time RT-PCR Assay for the Detection of Jamestown Canyon Virus. Pathogens 2022; 11:pathogens11050536. [PMID: 35631056 PMCID: PMC9146205 DOI: 10.3390/pathogens11050536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 11/29/2022] Open
Abstract
The neuroinvasive disease caused by Jamestown Canyon virus (JCV) infection is rare. However, increasing incidence and widespread occurrence of the infection make JCV a growing public health concern. Presently, clinical diagnosis is achieved through serological testing, and mosquito pool surveillance requires virus isolation and identification. A rapid molecular detection test, such as real-time RT-PCR, for diagnosis and surveillance of JCV has not been widely utilized. To enhance testing and surveillance, here, we describe the development and validation of a real-time RT-PCR test for the detection of JCV RNA. Three primer and probe sets were evaluated for analytical sensitivity and specificity. One probe set, JCV132FAM, was found to be the most sensitive test detecting 7.2 genomic equivalents/µL. While less sensitive, a second probe set JCV231cFAM was the most specific test with limited detection of Keystone virus at high RNA loads. Taken together, these data indicate both probe sets can be utilized for a primary sensitive screening assay and a secondary specific confirmatory assay. While both primer and probe sets detected high viral loads of Keystone virus, these assays did not detect any virus in the California encephalitis virus clade, including negative detection of the medically important La Crosse virus (LACV) and snowshoe hare virus (SSHV). The real-time RT-PCR assay described herein could be utilized in diagnosis and surveillance in regions with co-circulation of JCV and LACV or SSHV to inform public health action.
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12
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Barber RM, Li Q, Levine JM, Ruone SJ, Levine GJ, Kenny P, Tong S, Schatzberg SJ. Screening for Viral Nucleic Acids in the Cerebrospinal Fluid of Dogs With Central Nervous System Inflammation. Front Vet Sci 2022; 9:850510. [PMID: 35400093 PMCID: PMC8987525 DOI: 10.3389/fvets.2022.850510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/16/2022] [Indexed: 01/17/2023] Open
Abstract
Central nervous system (CNS) inflammation is a common cause of neurological dysfunction in dogs. Most dogs with CNS inflammation are diagnosed with presumptive autoimmune disease. A smaller number are diagnosed with an infectious etiology. Additionally, at necropsy, a subset of dogs with CNS inflammation do not fit previously described patterns of autoimmune disease and an infectious cause is not readily identifiable. Because viral infection is a common cause of meningoencephalitis in people, we hypothesize that a subset of dogs presented with CNS inflammation have an occult viral infection either as a direct cause of CNS inflammation or a trigger for autoimmunity. The goal of this research was to screen cerebrospinal fluid from a large number dogs with CNS inflammation for occult viral infection. One hundred seventy-two dogs with neurological dysfunction and cerebrospinal fluid (CSF) pleocytosis were identified. Of these, 42 had meningoencephalitis of unknown origin, six had steroid-responsive meningitis-arteritis, one had eosinophilic meningoencephalitis, five had documented infection, 21 had and undetermined diagnosis, and 97 had a diagnosis not consistent with primary inflammatory disease of the CNS (e.g., neoplasia). CSF samples were subsequently screened with broadly reactive PCR for eight viral groups: adenovirus, bunyavirus, coronavirus, enterovirus, flavivirus, herpesvirus, paramyxovirus, and parechovirus. No viral nucleic acids were detected from 168 cases screened for eight viral groups, which does not support occult viral infection as a cause of CNS inflammation in dogs. La Crosse virus (LACV) nucleic acids were detected from four cases in Georgia. Subclinical infection was supported in two of these cases but LACV could not be ruled-out as a cause of infection in the other two cases, suggesting further research is warranted to determine if LACV is an occult cause of CNS inflammation in dogs.
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Affiliation(s)
- Renee M. Barber
- Department of Small Animal Medicine and Surgery, University of Georgia College of Veterinary Medicine, Athens, GA, United States
- *Correspondence: Renee M. Barber
| | - Qiang Li
- Becker Animal Hospital, Veterinary Centers of America, San Antonio, TX, United States
| | - Jonathan M. Levine
- Department of Small Animal Clinical Sciences, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, TX, United States
| | - Susan J. Ruone
- Division of HIV Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Gwendolyn J. Levine
- Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, TX, United States
| | - Patrick Kenny
- Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, Hertfordshire, United Kingdom
| | - Suxiang Tong
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Scott J. Schatzberg
- Department of Small Animal Medicine and Surgery, University of Georgia College of Veterinary Medicine, Athens, GA, United States
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13
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Henry CJ, Pillai AN, Lednicky JA, Morris JG, Hladish TJ. Ecology and public health burden of Keystone virus in Florida. Epidemics 2022; 39:100555. [PMID: 35367729 PMCID: PMC9531690 DOI: 10.1016/j.epidem.2022.100555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/23/2022] [Accepted: 03/10/2022] [Indexed: 11/03/2022] Open
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14
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Trout Fryxell RT, Camponovo M, Smith B, Butefish K, Rosenberg JM, Andsager JL, Day CA, Willis MP. Development of a Community-Driven Mosquito Surveillance Program for Vectors of La Crosse Virus to Educate, Inform, and Empower a Community. INSECTS 2022; 13:164. [PMID: 35206737 PMCID: PMC8880676 DOI: 10.3390/insects13020164] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 02/06/2023]
Abstract
The fields of entomology, geospatial science, and science communication are understaffed in many areas, resulting in poor community awareness and heightened risks of vector-borne diseases. This is especially true in East Tennessee, where La Crosse encephalitis (LACE) causes pediatric illness each year. In response to these problems, we created a community engagement program that includes a yearlong academy for secondary STEM educators in the 6-12 grade classroom. The objectives of this program were to support inquiry-driven classroom learning to foster student interest in STEM fields, produce community-driven mosquito surveillance, and enhance community awareness of LACE. We trained educators in medical entomology, geospatial science, and science communication, and they incorporated those skills into lesson plans for a mosquito oviposition experiment that tested hypotheses developed in the classroom. Here, we share results from the first two years of the MEGA:BITESS academy, tailored for our community by having students ask questions directly related to Aedes mosquito oviposition biology and La Crosse encephalitis. In year one, we recruited 17 educators to participate in the project, and 15 of those educators returned in year two. All participating educators completed the academy, conducted the oviposition experiment, and informed over 400 students about a variety of careers and disciplines for their students. Here, we present a community-based program that helps to address the problems associated with long-term mosquito surveillance, health and science education and communication, career opportunities, and the community needs of Appalachia, as well as the initial data on the effectiveness of two years of an educator-targeted professional-development program.
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Affiliation(s)
- Rebecca T. Trout Fryxell
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, USA;
| | - Michael Camponovo
- Department of Geography, University of Tennessee, Knoxville, TN 37996, USA;
| | - Brian Smith
- Jefferson Middle School, Oak Ridge Anderson County School District, Oak Ridge, TN 37830, USA;
- Tennessee Geographic Alliance, University of Tennessee, Knoxville, TN 37996, USA;
| | - Kurt Butefish
- Tennessee Geographic Alliance, University of Tennessee, Knoxville, TN 37996, USA;
| | - Joshua M. Rosenberg
- Department of Education, Health, and Human Sciences, University of Tennessee, Knoxville, TN 37996, USA;
| | - Julie L. Andsager
- School of Journalism & Electronic Media, University of Tennessee, Knoxville, TN 37996, USA;
| | - Corey A. Day
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, USA;
| | - Micah P. Willis
- Department of Agricultural Leadership, Education, and Communications, University of Tennessee, Knoxville, TN 37996, USA;
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Ojha D, Winkler CW, Leung JM, Woods TA, Chen CZ, Nair V, Taylor K, Yeh CD, Tawa GJ, Larson CL, Zheng W, Haigh CL, Peterson KE. Rottlerin inhibits La Crosse virus-induced encephalitis in mice and blocks release of replicating virus from the Golgi body in neurons. Nat Microbiol 2021; 6:1398-1409. [PMID: 34675384 DOI: 10.1038/s41564-021-00968-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 08/25/2021] [Indexed: 11/09/2022]
Abstract
La Crosse virus (LACV) is a mosquito-borne orthobunyavirus that causes approximately 60 to 80 hospitalized pediatric encephalitis cases in the United States yearly. The primary treatment for most viral encephalitis, including LACV, is palliative care, and specific antiviral therapeutics are needed. We screened the National Center for Advancing Translational Sciences library of 3,833 FDA-approved and bioactive small molecules for the ability to inhibit LACV-induced death in SH-SY5Y neuronal cells. The top three hits from the initial screen were validated by examining their ability to inhibit virus-induced cell death in multiple neuronal cell lines. Rottlerin consistently reduced LACV-induced death by 50% in multiple human and mouse neuronal cell lines with an effective concentration of 0.16-0.69 µg ml-1 depending on cell line. Rottlerin was effective up to 12 hours post-infection in vitro and inhibited virus particle trafficking from the Golgi apparatus to trans-Golgi vesicles. In human inducible pluripotent stem cell-derived cerebral organoids, rottlerin reduced virus production by one log and cell death by 35% compared with dimethyl sulfoxide-treated controls. Administration of rottlerin in mice by intraperitoneal or intracranial routes starting at 3 days post-infection decreased disease development by 30-50%. Furthermore, rottlerin also inhibited virus replication of other pathogenic California serogroup orthobunyaviruses (Jamestown Canyon and Tahyna virus) in neuronal cell lines.
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Affiliation(s)
- Durbadal Ojha
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Clayton W Winkler
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Jacqueline M Leung
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Tyson A Woods
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Catherine Z Chen
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Vinod Nair
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Katherine Taylor
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Charles D Yeh
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Gregory J Tawa
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Charles L Larson
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Wei Zheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Cathryn L Haigh
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Karin E Peterson
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA.
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Wilson SN, López K, Coutermash-Ott S, Auguste DI, Porier DL, Armstrong PM, Andreadis TG, Eastwood G, Auguste AJ. La Crosse Virus Shows Strain-Specific Differences in Pathogenesis. Pathogens 2021; 10:pathogens10040400. [PMID: 33805389 PMCID: PMC8066585 DOI: 10.3390/pathogens10040400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/19/2021] [Accepted: 03/24/2021] [Indexed: 01/08/2023] Open
Abstract
La Crosse virus (LACV) is the leading cause of pediatric viral encephalitis in North America, and is an important public health pathogen. Historically, studies involving LACV pathogenesis have focused on lineage I strains, but no former work has explored the pathogenesis between or within lineages. Given the absence of LACV disease in endemic regions where a robust entomological risk exists, we hypothesize that some LACV strains are attenuated and demonstrate reduced neuroinvasiveness. Herein, we compared four viral strains representing all three lineages to determine differences in neurovirulence or neuroinvasiveness using three murine models. A representative strain from lineage I was shown to be the most lethal, causing >50% mortality in each of the three mouse studies. However, other strains only presented excessive mortality (>50%) within the suckling mouse neurovirulence model. Neurovirulence was comparable among strains, but viruses differed in their neuroinvasive capacities. Our studies also showed that viruses within lineage III vary in pathogenesis with contemporaneous strains, showing reduced neuroinvasiveness compared to an ancestral strain from the same U.S. state (i.e., Connecticut). These findings demonstrate that LACV strains differ markedly in pathogenesis, and that strain selection is important for assessing vaccine and therapeutic efficacies.
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Affiliation(s)
- Sarah N. Wilson
- Department of Entomology, College of Agriculture and Life Sciences, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; (S.N.W.); (K.L.); (D.I.A.); (D.L.P.); (G.E.)
| | - Krisangel López
- Department of Entomology, College of Agriculture and Life Sciences, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; (S.N.W.); (K.L.); (D.I.A.); (D.L.P.); (G.E.)
| | - Sheryl Coutermash-Ott
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, VA-MD College of Veterinary Medicine, Blacksburg, VA 24061, USA;
| | - Dawn I. Auguste
- Department of Entomology, College of Agriculture and Life Sciences, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; (S.N.W.); (K.L.); (D.I.A.); (D.L.P.); (G.E.)
| | - Danielle L. Porier
- Department of Entomology, College of Agriculture and Life Sciences, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; (S.N.W.); (K.L.); (D.I.A.); (D.L.P.); (G.E.)
| | - Philip M. Armstrong
- Environmental Sciences, Center for Vector Biology and Zoonotic Diseases, The Connecticut Agricultural Experiment Station, New Haven, CT 06504, USA; (P.M.A.); (T.G.A.)
| | - Theodore G. Andreadis
- Environmental Sciences, Center for Vector Biology and Zoonotic Diseases, The Connecticut Agricultural Experiment Station, New Haven, CT 06504, USA; (P.M.A.); (T.G.A.)
| | - Gillian Eastwood
- Department of Entomology, College of Agriculture and Life Sciences, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; (S.N.W.); (K.L.); (D.I.A.); (D.L.P.); (G.E.)
- Center for Emerging, Zoonotic, and Arthropod-Borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Albert J. Auguste
- Department of Entomology, College of Agriculture and Life Sciences, Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; (S.N.W.); (K.L.); (D.I.A.); (D.L.P.); (G.E.)
- Center for Emerging, Zoonotic, and Arthropod-Borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
- Correspondence: ; Tel.: +1-540-231-6158
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Stump E, Childs LM, Walker M. Parasitism of Aedes albopictus by Ascogregarina taiwanensis lowers its competitive ability against Aedes triseriatus. Parasit Vectors 2021; 14:79. [PMID: 33494790 PMCID: PMC7831270 DOI: 10.1186/s13071-021-04581-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/05/2021] [Indexed: 11/10/2022] Open
Abstract
Background Mosquitoes are vectors for diseases such as dengue, malaria and La Crosse virus that significantly impact the human population. When multiple mosquito species are present, the competition between species may alter population dynamics as well as disease spread. Two mosquito species, Aedes albopictus and Aedes triseriatus, both inhabit areas where La Crosse virus is found. Infection of Aedes albopictus by the parasite Ascogregarina taiwanensis and Aedes triseriatus by the parasite Ascogregarina barretti can decrease a mosquito’s fitness, respectively. In particular, the decrease in fitness of Aedes albopictus occurs through the impact of Ascogregarina taiwanensis on female fecundity, larval development rate, and larval mortality and may impact its initial competitive advantage over Aedes triseriatus during invasion. Methods We examine the effects of parasitism of gregarine parasites on Aedes albopictus and triseriatus population dynamics and competition with a focus on when Aedes albopictus is new to an area. We build a compartmental model including competition between Aedes albopictus and triseriatus while under parasitism of the gregarine parasites. Using parameters based on the literature, we simulate the dynamics and analyze the equilibrium population proportion of the two species. We consider the presence of both parasites and potential dilution effects. Results We show that increased levels of parasitism in Aedes albopictus will decrease the initial competitive advantage of the species over Aedes triseriatus and increase the survivorship of Aedes triseriatus. We find Aedes albopictus is better able to invade when there is more extreme parasitism of Aedes triseriatus. Furthermore, although the transient dynamics differ, dilution of the parasite density through uptake by both species does not alter the equilibrium population sizes of either species. Conclusions Mosquito population dynamics are affected by many factors, such as abiotic factors (e.g. temperature and humidity) and competition between mosquito species. This is especially true when multiple mosquito species are vying to live in the same area. Knowledge of how population dynamics are affected by gregarine parasites among competing species can inform future mosquito control efforts and help prevent the spread of vector-borne disease. ![]()
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Affiliation(s)
- Emma Stump
- Systems Biology, Virginia Tech, Hahn Hall South Suite 2108, 24061, Blacksburg, VA, USA
| | - Lauren M Childs
- Department of Mathematics, Virginia Tech, 460 McBryde Hall, 225 Stanger Street, 24061, Blacksburg, VA, USA
| | - Melody Walker
- Department of Mathematics, Virginia Tech, 460 McBryde Hall, 225 Stanger Street, 24061, Blacksburg, VA, USA.
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Edridge AWD, van der Hoek L. Emerging orthobunyaviruses associated with CNS disease. PLoS Negl Trop Dis 2020; 14:e0008856. [PMID: 33112863 PMCID: PMC7652332 DOI: 10.1371/journal.pntd.0008856] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/09/2020] [Accepted: 10/07/2020] [Indexed: 01/08/2023] Open
Abstract
The Orthobunyavirus genus comprises a wide range of arthropod-borne viruses which are prevalent worldwide and commonly associated with central nervous system (CNS) disease in humans and other vertebrates. Several orthobunyaviruses have recently emerged and increasingly more will likely do so in the future. Despite this large number, an overview of these viruses is currently lacking, making it challenging to determine importance from a One Health perspective. Causality is a key feature of determining importance, yet classical tools are unfit to evaluate the causality of orthobunyaviral CNS disease. Therefore, we aimed to provide an overview of orthobunyaviral CNS disease in vertebrates and objectify the causality strength of each virus. In total, we identified 27 orthobunyaviruses described in literature to be associated with CNS disease. Ten were associated with disease in multiple host species of which seven included humans. Seven viruses were associated with both congenital and postnatal CNS disease. CNS disease-associated orthobunyaviruses were spread across all known Orthobunyavirus serogroups by phylogenetic analyses. Taken together, these results indicate that orthobunyaviruses may have a common tendency to infect the CNS of vertebrates. Next, we developed six tailor-made causality indicators and evaluated the causality strength of each of the identified orthobunyaviruses. Nine viruses had a 'strong' causality score and were deemed causal. Eight had a 'moderate' and ten a 'weak' causality score. Notably, there was a lack of case-control studies, which was only available for one virus. We, therefore, stress the importance of proper case-control studies as a fundamental aspect of proving causality. This comprehensible overview can be used to identify orthobunyaviruses which may be considered causal, reveal research gaps for viruses with moderate to low causality scores, and provide a framework to evaluate the causality of orthobunyaviruses that may newly emerge in the future.
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Affiliation(s)
- Arthur Wouter Dante Edridge
- Laboratory of Experimental Virology, Department of Medical Microbiology and Infection Prevention, Amsterdam institute for Infection & Immunity, Amsterdam UMC, University of Amsterdam, the Netherlands
- Global Child Health Group, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, the Netherlands
| | - Lia van der Hoek
- Laboratory of Experimental Virology, Department of Medical Microbiology and Infection Prevention, Amsterdam institute for Infection & Immunity, Amsterdam UMC, University of Amsterdam, the Netherlands
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La Crosse Virus Infection of Human Keratinocytes Leads to Interferon-Dependent Apoptosis of Bystander Non-Infected Cells In Vitro. Viruses 2020; 12:v12030253. [PMID: 32106552 PMCID: PMC7150866 DOI: 10.3390/v12030253] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/20/2020] [Accepted: 02/20/2020] [Indexed: 12/11/2022] Open
Abstract
Resident cells in the skin serve as the first innate line of defense against insect-borne pathogens, but the role of these cell types in promoting or limiting arbovirus replication is not completely understood. Here, we have examined the outcome of infection of cultured human keratinocyte cells with La Crosse virus (LACV), using a spontaneously transformed cell line, HaCaT. In single cycle infections, keratinocyte HaCaT cells supported rapid and high level LACV replication, resulting in high virus yields and extensive caspase-dependent cell death. By contrast, multi-cycle LACV replication in HaCaT cells was restricted by an antiviral response elicited by the production of both IFN-β and IFN-λ. During low multiplicity LACV infections, HaCaT cell death was seen in non-infected bystander cells. Media from LACV-infected cells induced caspase-dependent killing of naïve non-infected HaCaT cells, and this bystander cell death was relieved by IFN-β neutralizing antibodies or by an inhibitor of JAK-STAT signaling. Naïve HaCaT cells showed dose-dependent killing by treatment with exogenous IFN-β but not IFN-λ. Our data suggest a model whereby keratinocytes produce IFNs which limit virus spread through both antiviral signaling and by induction of bystander cell death of potential new target cells for infection.
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Dawes BE, Gao J, Atkins C, Nelson JT, Johnson K, Wu P, Freiberg AN. Human neural stem cell-derived neuron/astrocyte co-cultures respond to La Crosse virus infection with proinflammatory cytokines and chemokines. J Neuroinflammation 2018; 15:315. [PMID: 30442185 PMCID: PMC6236894 DOI: 10.1186/s12974-018-1356-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 10/31/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND La Crosse virus (LACV) causes pediatric encephalitis in the USA. LACV induces severe inflammation in the central nervous system, but the recruitment of inflammatory cells is poorly understood. A deeper understanding of LACV-induced neural pathology is needed in order to develop treatment options. However, there is a severe limitation of relevant human neuronal cell models of LACV infection. METHODS We utilized human neural stem cell (hNSC)-derived neuron/astrocyte co-cultures to study LACV infection in disease-relevant primary cells. hNSCs were differentiated into neurons and astrocytes and infected with LACV. To characterize susceptibility and responses to infection, we measured viral titers and levels of viral RNA, performed immunofluorescence analysis to determine the cell types infected, performed apoptosis and cytotoxicity assays, and evaluated cellular responses to infection using qRT-PCR and Bioplex assays. RESULTS hNSC-derived neuron/astrocyte co-cultures were susceptible to LACV infection and displayed apoptotic responses as reported in previous in vitro and in vivo studies. Neurons and astrocytes are both targets of LACV infection, with neurons becoming the predominant target later in infection possibly due to astrocytic responses to IFN. Additionally, neuron/astrocyte co-cultures responded to LACV infection with strong proinflammatory cytokine, chemokine, as well as MMP-2, MMP-7, and TIMP-1 responses. CONCLUSIONS hNSC-derived neuron/astrocyte co-cultures reproduce key aspects of LACV infection in humans and mice and are useful models to study encephalitic viruses. Specifically, we show astrocytes to be susceptible to LACV infection and that neurons and astrocytes are important drivers of the inflammatory responses seen in LACV infection through the production of proinflammatory cytokines and chemokines.
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Affiliation(s)
- Brian E. Dawes
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, USA
| | - Junling Gao
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, USA
| | - Colm Atkins
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, 77555-0609 USA
| | - Jacob T. Nelson
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, 77555-0609 USA
| | - Kendra Johnson
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, USA
| | - Ping Wu
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, USA
| | - Alexander N. Freiberg
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, 77555-0609 USA
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, USA
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Rocheleau JP, Michel P, Lindsay LR, Drebot M, Dibernardo A, Ogden NH, Fortin A, Arsenault J. Risk factors associated with seropositivity to California serogroup viruses in humans and pet dogs, Quebec, Canada. Epidemiol Infect 2018; 146:1167-1176. [PMID: 29716671 PMCID: PMC9134364 DOI: 10.1017/s0950268818001000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/19/2018] [Accepted: 03/30/2018] [Indexed: 11/07/2022] Open
Abstract
Jamestown Canyon and snowshoe hare viruses are two emerging human pathogens associated with cases of neuroinvasive disease in North America. This study aimed to identify environmental and individual risk factors for seropositivity to these arboviruses in humans and pet dogs from Québec, Canada, 2012-2014. In humans, areas with moderate densities of white-tailed deer (Odocoileus virginianus) were associated with higher odds of seropositivity compared with areas with low densities of white-tailed deer (OR 2.50, P = 0.009) and odds of seropositivity were higher in males than in females (OR 2.03, P = 0.016). Among humans reporting more than 10 mosquito bites weekly, the odds of being seropositive were 4.44 times higher (P = 0.004) for people living in hardwood forested areas. Exposure to areas with coniferous forests was identified as the main environmental risk factor for seroconversion in dogs (OR 2.39, P = 0.04). These findings may help target further public health research, diagnostic and surveillance efforts in Canada.
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Affiliation(s)
- J. P. Rocheleau
- Groupe de recherche en épidémiologie des zoonoses et santé publique, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - P. Michel
- Groupe de recherche en épidémiologie des zoonoses et santé publique, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
- Office of the Chief Science Officer, Public Health Agency of Canada, Ottawa, Ontario, Canada
| | - L. R. Lindsay
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - M. Drebot
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - A. Dibernardo
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - N. H. Ogden
- Groupe de recherche en épidémiologie des zoonoses et santé publique, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
- National Microbiology Laboratory, Public Health Agency of Canada, Saint-Hyacinthe, Québec, Canada
| | - A. Fortin
- Institut national de santé publique, Québec, Québec, Canada
| | - J. Arsenault
- Groupe de recherche en épidémiologie des zoonoses et santé publique, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
- Département de pathologie et microbiologie vétérinaire, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
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Bewick S, Agusto F, Calabrese JM, Muturi EJ, Fagan WF. Epidemiology of La Crosse Virus Emergence, Appalachia Region, United States. Emerg Infect Dis 2018; 22:1921-1929. [PMID: 27767009 PMCID: PMC5088026 DOI: 10.3201/eid2211.160308] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Emergence may involve invasive mosquitoes other than Asian tiger mosquitoes, climate change, and changes in wildlife densities. La Crosse encephalitis is a viral disease that has emerged in new locations across the Appalachian region of the United States. Conventional wisdom suggests that ongoing emergence of La Crosse virus (LACV) could stem from the invasive Asian tiger (Aedes albopictus) mosquito. Efforts to prove this, however, are complicated by the numerous transmission routes and species interactions involved in LACV dynamics. To analyze LACV transmission by Asian tiger mosquitoes, we constructed epidemiologic models. These models accurately predict empirical infection rates. They do not, however, support the hypothesis that Asian tiger mosquitoes are responsible for the recent emergence of LACV at new foci. Consequently, we conclude that other factors, including different invasive mosquitoes, changes in climate variables, or changes in wildlife densities, should be considered as alternative explanations for recent increases in La Crosse encephalitis.
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Hughes HR, Lanciotti RS, Blair CD, Lambert AJ. Full genomic characterization of California serogroup viruses, genus Orthobunyavirus, family Peribunyaviridae including phylogenetic relationships. Virology 2017; 512:201-210. [PMID: 28985574 DOI: 10.1016/j.virol.2017.09.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/21/2017] [Accepted: 09/25/2017] [Indexed: 01/28/2023]
Abstract
Thorough molecular characterization of reference viruses supports the detection of emerging human pathogens as well as studies of evolutionary relationships. However, full characterization of the tripartite RNA genomes of many viruses of the clinically important family Peribunyaviridae remains incomplete, making it difficult to identify emerging strains. Here, we report the full genome sequences of nine viruses belonging to the California serogroup and describe multi-segment analyses of these and previously published California serogroup strain data to determine the role of segment reassortment in the evolution of this serogroup. Phylogenetic trees from the small, medium, and large segments suggest long term, independent evolution of the majority of strains. However, trees from each segment were not entirely congruent and evidence of reassortment among some strains is presented. Of unique interest, the L segment phylogeny reveals divergent branching patterns for encephalitic versus non-encephalitic viruses in both major clades of the California serogroup.
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Affiliation(s)
- Holly R Hughes
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA.
| | - Robert S Lanciotti
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
| | - Carol D Blair
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Amy J Lambert
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
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Krow-Lucal E, Lindsey NP, Lehman J, Fischer M, Staples JE. West Nile Virus and Other Nationally Notifiable Arboviral Diseases - United States, 2015. MMWR-MORBIDITY AND MORTALITY WEEKLY REPORT 2017; 66:51-55. [PMID: 28103209 PMCID: PMC5657660 DOI: 10.15585/mmwr.mm6602a3] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Bara JJ, Parker AT, Muturi EJ. Comparative Susceptibility of Ochlerotatus japonicus, Ochlerotatus triseriatus, Aedes albopictus, and Aedes aegypti (Diptera: Culicidae) to La Crosse Virus. JOURNAL OF MEDICAL ENTOMOLOGY 2016; 53:1415-1421. [PMID: 27605372 DOI: 10.1093/jme/tjw097] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/19/2016] [Indexed: 06/06/2023]
Abstract
Invasive mosquito species can increase the transmission risk of native mosquito-borne diseases by acting as novel vectors. In this study, we examined the susceptibility of three exotic invasive mosquito species Aedes aegypti (L.), Ae. albopictus (Skuse), and Ochlerotatus japonicus (Theobald) to La Crosse virus (LACV) relative to the native primary vector Ochlerotatus triseriatus (Say). Adult females of the four mosquito species were orally challenged with LACV; incubated for 3, 5, 7, 9, or 11 d; and their midgut infection rates, dissemination rates, and effective vector competence were determined. Overall, Oc. japonicus (2.92) had the highest effective vector competence values, followed by Ae. albopictus (1.55), Ae. aegypti (0.88), and Oc. triseriatus (0.64). In addition, we assessed the relationship between mosquito size and LACV susceptibility for field-collected Oc. triseriatus and Oc. japonicus We hypothesized that smaller adults would be more susceptible to LACV; however, our results did not support this hypothesis. Infected Oc. triseriatus tended to be larger than exposed but uninfected females, while infected and uninfected Oc. japonicus were similarly sized. These findings suggest that Oc. japonicus, Ae. albopictus, and Ae. aegypti have significant potential to transmit LACV and more research is needed to uncover their potential role in LACV epidemiology.
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Affiliation(s)
- Jeffrey J Bara
- Current address: Department of Biology, University of Louisville, Louisville KY 40209
- Illinois Natural History Survey, University of Illinois, Champaign, IL 61820 (; )
| | - Allison T Parker
- Illinois Natural History Survey, University of Illinois, Champaign, IL 61820 (; )
| | - Ephantus J Muturi
- Illinois Natural History Survey, University of Illinois, Champaign, IL 61820 (; )
- Current address: Crop Bioprotection Research Unit, USDA, ARS, 1815 N. University St. Peoria, IL 61604
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Abstract
PURPOSE OF REVIEW Arbovirus (arthropod-borne virus) infections are increasingly important causes of neurologic disease in the United States through both endemic transmission and travel-associated infections. This article reviews the major arbovirus infections that can cause neurologic disease likely to be encountered in the United States. RECENT FINDINGS West Nile virus continues to be an important cause of epidemic encephalitis, while emerging arbovirus infections such as dengue and chikungunya have rapidly expanded their geographic distribution. As emerging arboviruses expand in new geographic regions, neurologic abnormalities are reported in new patient populations. SUMMARY Emerging arbovirus infections are increasingly important causes of neurologic disease throughout the world and in the United States. While no US Food and Drug Administration (FDA)-approved therapy is yet available for these infections, prompt recognition and diagnosis from the consulting neurologist will ensure appropriate supportive care for the patient.
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Muturi EJ, Bara JJ, Rooney AP, Hansen AK. Midgut fungal and bacterial microbiota of Aedes triseriatus and Aedes japonicus shift in response to La Crosse virus infection. Mol Ecol 2016; 25:4075-90. [PMID: 27357374 DOI: 10.1111/mec.13741] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/10/2016] [Accepted: 06/27/2016] [Indexed: 01/20/2023]
Abstract
Understanding how midgut microbial communities of field-collected mosquitoes interact with pathogens is critical for controlling vector infection and disease. We used 16S rRNA and internal transcribed spacer sequencing to characterize the midgut bacterial and fungal communities of adult females of Aedes triseriatus and Aedes japonicus collected as pupae in tree holes, plastic bins and waste tires and their response to La Crosse virus (LACV) infection. For both mosquito species and across all habitat and virus treatments, a total of 62 bacterial operational taxonomic units (OTUs) from six phyla and 21 fungal OTUs from two phyla were identified. The majority of bacterial (92%) and fungal (71%) OTUs were shared between the mosquito species; however, several OTUs were unique to each species. Bacterial and fungal communities of individuals that took either infectious or noninfectious bloodmeals were less diverse and more homogeneous compared to those of newly emerged adults. Interestingly, LACV-infected A. triseriatus and A. japonicus had higher bacterial richness and lower fungal richness compared to individuals that took a noninfectious bloodmeal, suggesting that viral infection was associated with an increase in bacterial OTUs and a decrease in fungal OTUs. For both mosquito species, several OTUs were identified that had both high fidelity and specificity to mosquito midguts that were infected with LACV. Overall, these findings demonstrate that bacterial and fungal communities that reside in mosquito midguts respond to host diet and viral infection and could play a role in modulating vector susceptibility to LACV.
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Affiliation(s)
- Ephantus J Muturi
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL, 61820, USA
| | - Jeffrey J Bara
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL, 61820, USA.,Department of Biology, University of Louisville, Louisville, KY, 40292, USA
| | - Alejandro P Rooney
- Crop Bioprotection Research Unit, USDA, ARS, 1815 N. University St., Peoria, IL, 61604, USA
| | - Allison K Hansen
- Department of Entomology, University of Illinois at Urbana-Champaign, 505 S. Goodwin Ave., Urbana, IL, 61801, USA
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Salimi H, Cain MD, Klein RS. Encephalitic Arboviruses: Emergence, Clinical Presentation, and Neuropathogenesis. Neurotherapeutics 2016; 13:514-34. [PMID: 27220616 PMCID: PMC4965410 DOI: 10.1007/s13311-016-0443-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Arboviruses are arthropod-borne viruses that exhibit worldwide distribution, contributing to systemic and neurologic infections in a variety of geographical locations. Arboviruses are transmitted to vertebral hosts during blood feedings by mosquitoes, ticks, biting flies, mites, and nits. While the majority of arboviral infections do not lead to neuroinvasive forms of disease, they are among the most severe infectious risks to the health of the human central nervous system. The neurologic diseases caused by arboviruses include meningitis, encephalitis, myelitis, encephalomyelitis, neuritis, and myositis in which virus- and immune-mediated injury may lead to severe, persisting neurologic deficits or death. Here we will review the major families of emerging arboviruses that cause neurologic infections, their neuropathogenesis and host neuroimmunologic responses, and current strategies for treatment and prevention of neurologic infections they cause.
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Affiliation(s)
- Hamid Salimi
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Matthew D Cain
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Robyn S Klein
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA.
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Kosoy O, Rabe I, Geissler A, Adjemian J, Panella A, Laven J, Basile AJ, Velez J, Griffith K, Wong D, Fischer M, Lanciotti RS. Serological Survey for Antibodies to Mosquito-Borne Bunyaviruses Among US National Park Service and US Forest Service Employees. Vector Borne Zoonotic Dis 2016; 16:191-8. [PMID: 26855300 DOI: 10.1089/vbz.2015.1865] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Serum samples from 295 employees of Great Smoky Mountains National Park (GRSM), Rocky Mountain National Park (ROMO), and Grand Teton National Park with adjacent Bridger-Teton National Forest (GRTE-BTNF) were subjected to serological analysis for mosquito-borne bunyaviruses. The sera were analyzed for neutralizing antibodies against six orthobunyaviruses: La Crosse virus (LACV), Jamestown Canyon virus (JCV), snowshoe hare virus (SSHV), California encephalitis virus, and Trivittatus virus (TVTV) belonging to the California serogroup and Cache Valley virus (CVV) belonging to the Bunyamwera serogroup. Sera were also tested for immunoglobulin (Ig) G antibodies against LACV and JCV by enzyme-linked immunosorbent assay (ELISA). The proportion of employees with neutralizing antibodies to any California serogroup bunyavirus was similar in all three sites, with the prevalence ranging from 28% to 36%. The study demonstrated a seroprevalence of 3% to CVV across the three parks. However, proportions of persons with antibodies to specific viruses differed between parks. Participants residing in the eastern regions had a higher seroprevalence to LACV, with 24% (18/75) GRSM employees being seropositive. In contrast, SSHV seroprevalence was limited to employees from the western sites, with 1.7% (1/60) ROMO and 3.8% (6/160) GRTE-BTNF employees being positive. Seroprevalence to JCV was noted in employees from all sites at rates of 6.7% in GRSM, 21.7% in ROMO, and 15.6% in GRTE-BTNF. One employee each from ROMO (1.7%) and GRTE-BTNF (1.9%) were positive for TVTV. This study also has illustrated the greater sensitivity and specificity of plaque reduction neutralization test compared to IgG ELISA in conducting serosurveys for LACV and JCV.
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Affiliation(s)
- Olga Kosoy
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
| | - Ingrid Rabe
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
| | - Aimee Geissler
- 2 Centers for Disease Control and Prevention , Atlanta, Georgia
| | | | - Amanda Panella
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
| | - Janeen Laven
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
| | - Alison J Basile
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
| | - Jason Velez
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
| | - Kevin Griffith
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
| | - David Wong
- 3 Office of Public Health, United States National Park Service , Washington, District of Columbia
| | - Marc Fischer
- 1 Centers for Disease Control and Prevention , Fort Collins, Colorado
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Lindsey NP, Lehman JA, Staples JE, Fischer M. West Nile Virus and Other Nationally Notifiable Arboviral Diseases - United States, 2014. MMWR-MORBIDITY AND MORTALITY WEEKLY REPORT 2015; 64:929-34. [PMID: 26334477 DOI: 10.15585/mmwr.mm6434a1] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Arthropod-borne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease in the United States (1). However, several other arboviruses also cause sporadic cases and seasonal outbreaks. This report summarizes surveillance data reported to CDC in 2014 for WNV and other nationally notifiable arboviruses, excluding dengue. Forty-two states and the District of Columbia (DC) reported 2,205 cases of WNV disease. Of these, 1,347 (61%) were classified as WNV neuroinvasive disease (e.g., meningitis, encephalitis, or acute flaccid paralysis), for a national incidence of 0.42 cases per 100,000 population. After WNV, the next most commonly reported cause of arboviral disease was La Crosse virus (80 cases), followed by Jamestown Canyon virus (11), St. Louis encephalitis virus (10), Powassan virus (8), and Eastern equine encephalitis virus (8). WNV and other arboviruses cause serious illness in substantial numbers of persons each year. Maintaining surveillance programs is important to help direct prevention activities.
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Affiliation(s)
- Nicole P Lindsey
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC
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Childhood encephalitis in Canada in 2015. CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2015; 26:69-72. [PMID: 26015788 PMCID: PMC4419816 DOI: 10.1155/2015/947602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Jupille H, Vega-Rua A, Rougeon F, Failloux AB. Arboviruses: variations on an ancient theme. Future Virol 2014. [DOI: 10.2217/fvl.14.62] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
ABSTRACT Arboviruses utilize different strategies to complete their transmission cycle between vertebrate and invertebrate hosts. Most possess an RNA genome coupled with an RNA polymerase lacking proofreading activity and generate large populations of genetically distinct variants, permitting rapid adaptation to environmental changes. With mutation rates of between 10- 6 and 10-4 substitutions per nucleotide, arboviral genomes rapidly acquire mutations that can lead to viral emergence. Arboviruses can be described in seven families, four of which have medical importance: Togaviridae, Flaviviridae, Bunyaviridae and Reoviridae. The Togaviridae and Flaviviridae both have ssRNA genomes, while the Bunyaviridae and Reoviridae possess segmented RNA genomes. Recent epidemics caused by these arboviruses have been associated with specific mutations leading to enhanced host ranges, vector shifts and virulence.
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Affiliation(s)
- Henri Jupille
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
| | - Anubis Vega-Rua
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
- Cellule Pasteur UPMC, Université Pierre et Marie Curie, Paris, France
| | | | - Anna-Bella Failloux
- Department of Virology, Arboviruses & Insect Vectors, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
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Wilson R, Harrison R, Riles M, Wasserberg G, Byrd BD. Molecular identification of Aedes triseriatus and Aedes hendersoni by a novel duplex polymerase chain reaction assay. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2014; 30:79-82. [PMID: 25102589 DOI: 10.2987/14-6406.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Aedes triseriatus is the principal vector of La Crosse virus (LACv), which is the most common cause of pediatric arboviral encephalitis in North America. Here we report a novel species-specific polymerase chain reaction (PCR) assay that differentially identifies Ae. triseriatus and Ae. hendersoni. Because these 2 sibling species differ in their abilities to transmit LACv, accurate identification is critical for surveillance, research, and control programs. This duplex assay can detect the presence of both species in a single PCR reaction and is therefore simpler and faster than previously reported methods.
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Abstract
Worldwide, arboviral illnesses constitute the most important international infectious threat to human neurological health and welfare. Before the availability of effective immunizations, approximately 50,000 cases of Japanese encephalitis occurred in the world each year, one-fifth of which cases proved lethal and a much larger number were left with severe neurological handicaps. With global climate change and perhaps other factors, the prevalences of some arboviral illnesses appear to be increasing. Arboviral illnesses, including Japanese encephalitis, tick-borne encephalitis, Yellow fever, and others, are emerging as possible global health care threats because of biological warfare. This chapter will review ecology, pathophysiology, diagnosis, management, and outcome of the forms of arboviral encephalitis that are of greatest importance in North America, together with some of the most important arboviral encephalitides prevalent in other parts of the world.
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Come fly with me: review of clinically important arboviruses for global travelers. J Clin Virol 2012; 55:191-203. [PMID: 22840968 DOI: 10.1016/j.jcv.2012.07.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 07/05/2012] [Accepted: 07/06/2012] [Indexed: 12/30/2022]
Abstract
Western tourists are increasingly traveling to exotic locations often located in tropical or subtropical regions of the world. The magnitude of international travel and the constantly changing dynamics of arbovirus diseases across the globe demand up-to-date information about arbovirus threats to travelers and the countries they visit. In this review, the current knowledge on arbovirus threats to global travelers is summarized and prioritized per region. Based on most common clinical syndromes, currently known arboviruses can be grouped to develop diagnostic algorithms to support decision-making in diagnostics. This review systematically combines and structures the current knowledge on medically important travel-related arboviruses and illustrates the necessity of a detailed patient history (travel history, symptoms experienced, vaccination history, engaged activities, tick or mosquito bite and use of repellent and onset of symptoms), to guide the diagnosis.
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Leisnham PT, Juliano SA. Impacts of climate, land use, and biological invasion on the ecology of immature Aedes mosquitoes: implications for La Crosse emergence. ECOHEALTH 2012; 9:217-228. [PMID: 22692799 PMCID: PMC3416954 DOI: 10.1007/s10393-012-0773-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 04/27/2012] [Accepted: 05/15/2012] [Indexed: 05/26/2023]
Abstract
Arthropod-borne viruses (arboviruses) cause many diseases worldwide and their transmission is likely to change with land use and climate changes. La Crosse virus (LACV) is historically transmitted by the native mosquito Aedes triseriatus (Say) in the upper Midwestern US, but the invasive congeners Aedes albopictus (Skuse) and A. japonicus (Theobald), which co-occur with A. triseriatus in water-holding containers, may be important accessory vectors in the Appalachian region where La Crosse encephalitis is an emerging disease. This review focuses on evidence for how climate, land use, and biological invasions may have direct abiotic and indirect community-level impacts on immature developmental stages (eggs and larvae) of Aedes mosquitoes. Because vector-borne diseases usually vary in space and time and are related to the ecology of the vector species, we propose that the ecology of its mosquito vectors, particularly at their immature stages, has played an important role in the emergence of La Crosse encephalitis in the Appalachian region and represents a model for investigating the effects of environmental changes on other vector-borne diseases. We summarize the health effects of LACV and associated socioeconomic costs that make it the most important native mosquito-borne disease in the US. We review of the transmission of LACV, and present evidence for the impacts of climate, land use, and biological invasions on Aedes mosquito communities. Finally, we discuss important questions about the ecology of LACV mosquito vectors that may improve our understanding of the impacts of environmental changes on LACV and other arboviruses.
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Affiliation(s)
- Paul T Leisnham
- Department of Environmental Science and Technology, University of Maryland, College Park, 20742, USA.
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Orthobunyavirus entry into neurons and other mammalian cells occurs via clathrin-mediated endocytosis and requires trafficking into early endosomes. J Virol 2012; 86:7988-8001. [PMID: 22623766 DOI: 10.1128/jvi.00140-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
La Crosse virus (LACV) is a leading cause of pediatric encephalitis and aseptic meningitis in the midwestern and southern United States, where it is considered an emerging human pathogen. No specific therapies or vaccines are available for LACV or any other orthobunyaviruses. Inhibition of LACV entry into cells is a potential target for therapeutic intervention, but this approach is limited by our current knowledge of the entry process. Here, we determined that clathrin-mediated endocytosis is the primary mechanism of orthobunyavirus entry and identified key cellular factors in this process. First, we demonstrated that LACV colocalized with clathrin shortly after infection in HeLa cells; we then confirmed the functional requirement of dynamin- and clathrin-mediated endocytosis for orthobunyavirus entry using several independent assays and, importantly, extended these findings to primary neuronal cultures. We also determined that macropinocytosis and caveolar endocytosis, both established routes of virus entry, are not critical for cellular entry of LACV. Moreover, we demonstrated that LACV infection is dependent on Rab5, which plays an important regulatory role in early endosomes, but not on Rab7, which is associated with late endosomes. These findings provide the first description of bunyavirus entry into cells of the central nervous system, where infection can cause severe neurological disease, and will aid in the design and development of antivirals and therapeutics that may be useful in the treatment of LACV and, more broadly, arboviral infections of the central nervous system.
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A recombinant chimeric La Crosse virus expressing the surface glycoproteins of Jamestown Canyon virus is immunogenic and protective against challenge with either parental virus in mice or monkeys. J Virol 2011; 86:420-6. [PMID: 22013033 DOI: 10.1128/jvi.02327-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
La Crosse virus (LACV) and Jamestown Canyon virus (JCV), family Bunyaviridae, are mosquito-borne viruses that are endemic in North America and recognized as etiologic agents of encephalitis in humans. Both viruses belong to the California encephalitis virus serogroup, which causes 70 to 100 cases of encephalitis a year. As a first step in creating live attenuated viral vaccine candidates for this serogroup, we have generated a recombinant LACV expressing the attachment/fusion glycoproteins of JCV. The JCV/LACV chimeric virus contains full-length S and L segments derived from LACV. For the M segment, the open reading frame (ORF) of LACV is replaced with that derived from JCV and is flanked by the untranslated regions of LACV. The resulting chimeric virus retained the same robust growth kinetics in tissue culture as observed for either parent virus, and the virus remains highly infectious and immunogenic in mice. Although both LACV and JCV are highly neurovirulent in 21 day-old mice, with 50% lethal dose (LD₅₀) values of 0.1 and 0.5 log₁₀ PFU, respectively, chimeric JCV/LACV is highly attenuated and does not cause disease even after intracerebral inoculation of 10³ PFU. Parenteral vaccination of mice with 10¹ or 10³ PFU of JCV/LACV protected against lethal challenge with LACV, JCV, and Tahyna virus (TAHV). The chimeric virus was infectious and immunogenic in rhesus monkeys and induced neutralizing antibodies to JCV, LACV, and TAHV. When vaccinated monkeys were challenged with JCV, they were protected against the development of viremia. Generation of highly attenuated yet immunogenic chimeric bunyaviruses could be an efficient general method for development of vaccines effective against these pathogenic viruses.
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Haddow AD, Bixler D, Schuh AJ. The demographic and socioeconomic factors predictive for populations at high-risk for La Crosse virus infection in West Virginia. PLoS One 2011; 6:e25739. [PMID: 21980533 PMCID: PMC3182246 DOI: 10.1371/journal.pone.0025739] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 09/11/2011] [Indexed: 12/18/2022] Open
Abstract
Although a large body of literature exists for the environmental risk factors for La Crosse virus (LACV) transmission, the demographic and socioeconomic risk factors for developing LACV infection have not been investigated. Therefore, this study investigated the demographic and socioeconomic risk factors for LACV infection in West Virginia from 2003 to 2007, using two forward stepwise discriminant analyses. The discriminant analyses were used to evaluate a number of demographic and socioeconomic factors for their ability to predict: 1) those census tracts with at least one reported case of LACV infection versus those census tracts with no reported cases of LACV infection and 2) to evaluate significantly high-risk clusters for LACV infection versus significantly low-risk clusters for LACV infection. In the first model, a high school education diploma or a general education diploma or less and a lower housing density were found to be predictive of those census tracts with at least one case of LACV infection. A high school or a general education diploma or less, lower housing density, and housing built in 1969 and earlier were all found to be predictive of those census tracts displaying high-risk clusters versus census tracts displaying low-risk clusters in the second model. The cluster discriminant analysis was found to be more predictive than the census tract discriminant analysis as indicated by the Eigenvalues, canonical correlation, and grouping accuracy. The results of this study indicate that socioeconomically disadvantaged populations are at the highest risk for LACV infection and should be a focus of LACV infection prevention efforts.
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Affiliation(s)
- Andrew D Haddow
- Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, Tennessee, United States of America.
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Haddow AD, Bixler D, Odoi A. The spatial epidemiology and clinical features of reported cases of La Crosse virus infection in West Virginia from 2003 to 2007. BMC Infect Dis 2011; 11:29. [PMID: 21269495 PMCID: PMC3038160 DOI: 10.1186/1471-2334-11-29] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Accepted: 01/26/2011] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND La Crosse virus (LACV) is a major cause of pediatric encephalitis in the United States. Since the mid-1980s, the number of reported cases of LACV infection in West Virginia has continued to rise and the state currently reports the most cases in the United States. The purpose of this study was to investigate and describe the spatial epidemiology and clinical presentation of LACV infection cases reported in West Virginia, as well as to provide a description of the environmental conditions present at the residences of the LACV infection cases. METHODS Descriptive and spatial analyses were performed on LACV infection cases reported to the West Virginia Department of Health from 2003 to 2007. Clinical and environmental variables were available for 96 cases and residence data were available for 68 of these cases. Spatial analyses using the global Moran's I and Kulldorff's spatial scan statistic were performed using the population 15 years and younger at both the county and census tract levels to identify those geographic areas at the highest risk of infection. RESULTS Two statistically significant (p < 0.05) high-risk clusters, involving six counties, were detected at the county level. At the census tract level, one statistically significant high-risk cluster involving 41 census tracts spanning over six counties was identified. The county level cumulative incidence for those counties in the primary high-risk cluster ranged from 100.0 to 189.0 cases per 100,000 persons (median 189.0) and the census tract level cumulative incidence for those counties in the high-risk cluster ranged from 61.7 to 505.9 cases per 100,000 persons (median 99.0). The counties and census tracts within high-risk clusters had a relative risk four to nine times higher when compared to those areas not contained within high-risk clusters. The majority of LACV infection cases were reported during the summer months in children 15 years and younger. Fever, vomiting, photophobia, and nausea were the most commonly reported signs and symptoms. A case fatality rate (CFR) of 3.1% was observed. Wooded areas and containers were present at the majority of case residences. CONCLUSIONS The cumulative incidences of LACV infection from 2003 to 2007 were considerably higher than previously reported for West Virginia, and statistically significant high-risk clusters for LACV infection were detected at both the county and census tract levels. The finding of a high CFR and the identification of those areas at highest risk for infection will be useful for guiding future research and intervention efforts.
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Affiliation(s)
- Andrew D Haddow
- The University of Tennessee, Department of Entomology & Plant Pathology, Knoxville, TN 37996-4560, USA.
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Verbruggen P, Ruf M, Blakqori G, Överby AK, Heidemann M, Eick D, Weber F. Interferon antagonist NSs of La Crosse virus triggers a DNA damage response-like degradation of transcribing RNA polymerase II. J Biol Chem 2010; 286:3681-92. [PMID: 21118815 DOI: 10.1074/jbc.m110.154799] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
La Crosse encephalitis virus (LACV) is a mosquito-borne member of the negative-strand RNA virus family Bunyaviridae. We have previously shown that the virulence factor NSs of LACV is an efficient inhibitor of the antiviral type I interferon system. A recombinant virus unable to express NSs (rLACVdelNSs) strongly induced interferon transcription, whereas the corresponding wt virus (rLACV) suppressed it. Here, we show that interferon induction by rLACVdelNSs mainly occurs through the signaling pathway leading from the pattern recognition receptor RIG-I to the transcription factor IRF-3. NSs expressed by rLACV, however, acts downstream of IRF-3 by specifically blocking RNA polymerase II-dependent transcription. Further investigations revealed that NSs induces proteasomal degradation of the mammalian RNA polymerase II subunit RPB1. NSs thereby selectively targets RPB1 molecules of elongating RNA polymerase II complexes, the so-called IIo form. This phenotype has similarities to the cellular DNA damage response, and NSs was indeed found to transactivate the DNA damage response gene pak6. Moreover, NSs expressed by rLACV boosted serine 139 phosphorylation of histone H2A.X, one of the earliest cellular reactions to damaged DNA. However, other DNA damage response markers such as up-regulation and serine 15 phosphorylation of p53 or serine 1524 phosphorylation of BRCA1 were not triggered by LACV infection. Collectively, our data indicate that the strong suppression of interferon induction by LACV NSs is based on a shutdown of RNA polymerase II transcription and that NSs achieves this by exploiting parts of the cellular DNA damage response pathway to degrade IIo-borne RPB1 subunits.
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Affiliation(s)
- Paul Verbruggen
- Department of Virology, Institute for Medical Microbiology and Hygiene, University of Freiburg, D-79008 Freiburg, Germany
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Hollidge BS, González-Scarano F, Soldan SS. Arboviral encephalitides: transmission, emergence, and pathogenesis. J Neuroimmune Pharmacol 2010; 5:428-42. [PMID: 20652430 PMCID: PMC3286874 DOI: 10.1007/s11481-010-9234-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 07/02/2010] [Indexed: 12/20/2022]
Abstract
Arthropod-borne viruses (arboviruses) are of paramount concern as a group of pathogens at the forefront of emerging and re-emerging diseases. Although some arboviral infections are asymptomatic or present with a mild influenza-like illness, many are important human and veterinary pathogens causing serious illness ranging from rash and arthritis to encephalitis and hemorrhagic fever. Here, we discuss arboviruses from diverse families (Flaviviruses, Alphaviruses, and the Bunyaviridae) that are causative agents of encephalitis in humans. An understanding of the natural history of these infections as well as shared mechanisms of neuroinvasion and neurovirulence is critical to control the spread of these viruses and for the development of effective vaccines and treatment modalities.
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Affiliation(s)
- Bradley S Hollidge
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104-4283, USA
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CALVO ERIC, SANCHEZ-VARGAS IRMA, KOTSYFAKIS MICHALIS, FAVREAU AMANDAJ, BARBIAN KENTD, PHAM VANM, OLSON KENNETHE, RIBEIRO JOSÉMC. The salivary gland transcriptome of the eastern tree hole mosquito, Ochlerotatus triseriatus. JOURNAL OF MEDICAL ENTOMOLOGY 2010; 47:376-86. [PMID: 20496585 PMCID: PMC3394432 DOI: 10.1603/me09226] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Saliva of blood-sucking arthropods contains a complex mixture of peptides that affect their host's hemostasis, inflammation, and immunity. These activities can also modify the site of pathogen delivery and increase disease transmission. Saliva also induces hosts to mount an antisaliva immune response that can lead to skin allergies or even anaphylaxis. Accordingly, knowledge of the salivary repertoire, or sialome, of a mosquito is useful to provide a knowledge platform to mine for novel pharmacological activities, to develop novel vaccine targets for vector-borne diseases, and to develop epidemiological markers of vector exposure and candidate desensitization vaccines. The mosquito Ochlerotatus triseriatus is a vector of La Crosse virus and produces allergy in humans. In this work, a total of 1,575 clones randomly selected from an adult female O. triseriatus salivary gland cDNA library was sequenced and used to assemble a database that yielded 731 clusters of related sequences, 560 of which were singletons. Primer extension experiments were performed in selected clones to further extend sequence coverage, allowing for the identification of 159 protein sequences, 66 of which code for putative secreted proteins. Supplemental spreadsheets containing these data are available at http://exon.niaid.nih.gov/transcriptome/Ochlerotatus_triseriatus/S1/Ot-S1.xls and http://exon.niaid. nih.gov/transcriptome/Ochlerotatus_triseriatus/S2/Ot-S2.xls.
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Affiliation(s)
- ERIC CALVO
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - IRMA SANCHEZ-VARGAS
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523
| | - MICHALIS KOTSYFAKIS
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - AMANDA J. FAVREAU
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, Hamilton, MT 59840
| | - KENT D. BARBIAN
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, Hamilton, MT 59840
| | - VAN M. PHAM
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - KENNETH E. OLSON
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523
| | - JOSÉ M. C. RIBEIRO
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
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Identification of super-infected Aedes triseriatus mosquitoes collected as eggs from the field and partial characterization of the infecting La Crosse viruses. Virol J 2010; 7:76. [PMID: 20412589 PMCID: PMC2873378 DOI: 10.1186/1743-422x-7-76] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 04/22/2010] [Indexed: 12/14/2022] Open
Abstract
Background La Crosse virus (LACV) is a pathogenic arbovirus that is transovarially transmitted by Aedes triseriatus mosquitoes and overwinters in diapausing eggs. However, previous models predicted transovarial transmission (TOT) to be insufficient to maintain LACV in nature. Results To investigate this issue, we reared mosquitoes from field-collected eggs and assayed adults individually for LACV antigen, viral RNA by RT-PCR, and infectious virus. The mosquitoes had three distinct infection phenotypes: 1) super infected (SI+) mosquitoes contained infectious virus, large accumulations of viral antigen and RNA and comprised 17 of 17,825 (0.09%) of assayed mosquitoes, 2) infected mosquitoes (I+) contained no detectable infectious virus, lesser amounts of viral antigen and RNA, and comprised 3.7% of mosquitoes, and 3) non-infected mosquitoes (I-) contained no detectable viral antigen, RNA, or infectious virus and comprised 96.21% of mosquitoes. SI+ mosquitoes were recovered in consecutive years at one field site, suggesting that lineages of TOT stably-infected and geographically isolated Ae. triseriatus exist in nature. Analyses of LACV genomes showed that SI+ isolates are not monophyletic nor phylogenetically distinct and that synonymous substitution rates exceed replacement rates in all genes and isolates. Analysis of singleton versus shared mutations (Fu and Li's F*) revealed that the SI+ LACV M segment, with a large and significant excess of intermediate-frequency alleles, evolves through disruptive selection that maintains SI+ alleles at higher frequencies than the average mutation rate. A QTN in the LACV NSm gene was detected in SI+ mosquitoes, but not in I+ mosquitoes. Four amino acid changes were detected in the LACV NSm gene from SI+ but not I+ mosquitoes from one site, and may condition vector super infection. In contrast to NSm, the NSs sequences of LACV from SI+ and I+ mosquitoes were identical. Conclusions SI+ mosquitoes may represent stabilized infections of Ae. triseriatus mosquitoes, which could maintain LACV in nature. A gene-for-gene interaction involving the viral NSm gene and a vector innate immune response gene may condition stabilized infection.
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Haddow AD, Jones CJ, Odoi A. Assessing risk in focal arboviral infections: are we missing the big or little picture? PLoS One 2009; 4:e6954. [PMID: 19742311 PMCID: PMC2734166 DOI: 10.1371/journal.pone.0006954] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 06/18/2009] [Indexed: 01/24/2023] Open
Abstract
Background Focal arboviral infections affecting a subset of the overall population present an often overlooked set of challenges in the assessment and reporting of risk and the detection of spatial patterns. Our objective was to assess the variation in risk when using different at-risk populations and geographic scales for the calculation of incidence risk and the detection of geographic hot-spots of infection. We explored these variations using a pediatric arbovirus, La Crosse virus (LACV), as our model. Methods and Findings Descriptive and cluster analyses were performed on probable and confirmed cases of LACV infections reported to the Tennessee Department of Health from 1997 to 2006, using three at-risk populations (the total population, the population 18 years and younger, and the population 15 years and younger) and at two geographic levels (county and census tract) to assess the variation in incidence risk and to investigate evidence of clustering using both global and local spatial statistics. We determined that the most appropriate at-risk population to calculate incidence risk and to assess the evidence of clustering was the population 15 years and younger. Based on our findings, the most appropriate geographical level to conduct spatial analyses and report incidence risk is the census tract level. The incidence risk in the population 15 years and younger at the county level ranged from 0 to 226.5 per 100,000 persons (median 41.5) in those counties reporting cases (n = 14) and at the census tract level it ranged from 50.9 to 673.9 per 100,000 persons (median 126.7) in those census tracts reporting cases (n = 51). To our knowledge, this is the highest reported incidence risk for this population at the county level for Tennessee and at the census tract level nationally. Conclusion The results of this study indicate the possibility of missing disease clusters resulting from performing incidence risk investigations of focal diseases using inappropriate at-risk populations and/or at large geographic scales. Improved disease surveillance and health planning will result through the use of well defined at-risk populations and the use of appropriate geographic scales for the analysis and reporting of diseases. The finding of a high incidence risk of LACV infections in eastern Tennessee demonstrates that the vast majority of these infections continue to be under-diagnosed and/or underreported in this region. Persistent prevention and surveillance efforts will be required to reduce exposure to infectious vectors and to detect new cases of infection in this region. Application of this study's observations in future investigations will enhance the quantification of incidence risk and the identification of high-risk groups within the population.
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Affiliation(s)
- Andrew D Haddow
- Department of Entomology & Plant Pathology, The University of Tennessee, Knoxville, Tennessee, United States of America.
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Haddow AD, Odoi A. The incidence risk, clustering, and clinical presentation of La Crosse virus infections in the eastern United States, 2003-2007. PLoS One 2009; 4:e6145. [PMID: 19582158 PMCID: PMC2702082 DOI: 10.1371/journal.pone.0006145] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 06/03/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Although La Crosse virus (LACV) is one of the most common causes of pediatric arboviral infections in the United States, little has been done to assess its geographic distribution, identify areas of higher risk of disease, and to provide a national picture of its clinical presentation. Therefore, the objective of this study was to investigate the geographic distribution of LACV infections reported in the United States, to identify hot-spots of infection, and to present its clinical picture. METHODS AND FINDINGS Descriptive and cluster analyses were performed on probable and confirmed cases of LACV infections reported to the Centers for Disease Control and Prevention from 2003-2007. A total of 282 patients had reported confirmed LACV infections during the study period. Of these cases the majority (81 percent) presented during the summer, occurred in children 15 years and younger (83.3 percent), and were found in male children (64.9 percent). Clinically, the infections presented as meningioencephalitis (56.3 percent), encephalitis (20.7 percent), meningitis (17.2 percent), or uncomplicated fever (5 percent). Deaths occurred in 1.9 percent of confirmed cases, and in 8.6 percent of patients suffering from encephalitis. The majority of these deaths were in patients 15 years and younger. The county-level incidence risk among counties (n = 136) reporting both probable and confirmed cases for children 15 years and younger (n = 355) ranged from 0.2 to 228.7 per 100,000 persons. The southern United States experienced a significantly higher (p<0.05) incidence risk during the months of June, July, August, and October then the northern United States. There was significant (p<0.05) clustering of high risk in several geographic regions with three deaths attributed to complications from LAC encephalitis occurring in two of these hot-spots of infections. CONCLUSIONS Both the incidence risk and case fatality rates were found to be higher than previously reported. We detected clustering in four geographic regions, a shift from the prior geographic distributions, and developed maps identifying high-risk areas. These findings are useful for raising awareness among health care providers regarding areas at a high risk of infections and for guiding targeted multifaceted interventions by public health officials.
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Affiliation(s)
- Andrew D Haddow
- Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, TN, USA.
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Jeger MJ, Madden LV, van den Bosch F. The effect of transmission route on plant virus epidemic development and disease control. J Theor Biol 2009; 258:198-207. [PMID: 19490879 DOI: 10.1016/j.jtbi.2009.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 01/06/2009] [Accepted: 01/06/2009] [Indexed: 10/21/2022]
Abstract
A model for indirect vector transmission and epidemic development of plant viruses is extended to consider direct transmission through vector mating. A basic reproduction number is derived which is the sum of the R(0) values specific for three transmission routes. We analyse the model to determine the effect of direct transmission on plant disease control directed against indirect transmission. Increasing the rate of horizontal sexual transmission means that vector control rate or indirect transmission rate must be increased/decreased substantially to maintain R(0) at a value less than 1. By contrast, proportionately increasing the probability of transovarial transmission has little effect. Expressions are derived for the steady-state values of the viruliferous vector population. There is clear advantage for an insect virus in indirect transmission to plants, especially where the sexual and transovarial transmission rates are low; however information on virulence-transmissibility relationships is required to explain the evolution of a plant virus from an insect virus.
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Affiliation(s)
- Michael J Jeger
- Division of Biology, Imperial College London, Silwood Park, Ascot SL5 7PY, UK.
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Reese SM, Blitvich BJ, Blair CD, Geske D, Beaty BJ, Black WC. Potential for La Crosse virus segment reassortment in nature. Virol J 2008; 5:164. [PMID: 19114023 PMCID: PMC2640380 DOI: 10.1186/1743-422x-5-164] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Accepted: 12/30/2008] [Indexed: 11/29/2022] Open
Abstract
The evolutionary success of La Crosse virus (LACV, family Bunyaviridae) is due to its ability to adapt to changing conditions through intramolecular genetic changes and segment reassortment. Vertical transmission of LACV in mosquitoes increases the potential for segment reassortment. Studies were conducted to determine if segment reassortment was occurring in naturally infected Aedes triseriatus from Wisconsin and Minnesota in 2000, 2004, 2006 and 2007. Mosquito eggs were collected from various sites in Wisconsin and Minnesota. They were reared in the laboratory and adults were tested for LACV antigen by immunofluorescence assay. RNA was isolated from the abdomen of infected mosquitoes and portions of the small (S), medium (M) and large (L) viral genome segments were amplified by RT-PCR and sequenced. Overall, the viral sequences from 40 infected mosquitoes and 5 virus isolates were analyzed. Phylogenetic and linkage disequilibrium analyses revealed that approximately 25% of infected mosquitoes and viruses contained reassorted genome segments, suggesting that LACV segment reassortment is frequent in nature.
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Affiliation(s)
- Sara M Reese
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1692, USA.
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