scholarly journals Optimizing PCR Detection of West Nile Virus from Body Fluid Specimens to Delineate Natural History in an Infected Human Cohort

2019 ◽  
Vol 20 (8) ◽  
pp. 1934 ◽  
Author(s):  
Rodion Gorchakov ◽  
Bonnie E. Gulas-Wroblewski ◽  
Shannon E. Ronca ◽  
Jeanne C. Ruff ◽  
Melissa S. Nolan ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Natural History ◽  
Diagnostic Testing ◽  
Rna Extraction ◽  
Pcr Detection ◽  
Viral Rna ◽  
Health Concern ◽  
West Nile ◽  
Viral Loads ◽  
History Of

West Nile virus (WNV), a mosquito-borne arbovirus, remains a major global health concern. In this study, we optimized PCR methods then assessed serially-collected whole blood (WB), urine (UR), saliva, and semen specimens from a large cohort of WNV-positive participants to evaluate the natural history of infection and persistent shedding of WNV RNA. Viral RNA extraction protocols for frozen WB and UR specimens were optimized and validated through spiking experiments to maximize recovery of viral RNA from archived specimens and to assess the degradation of WNV RNA in stored UR specimens. The resultant procedures were used in conjunction with PCR detection to identify WNV-positive specimens and to quantify their viral loads. A total of 59 of 352 WB, 10 of 38 UR, and 2 of 34 saliva specimens tested positive for WNV RNA. Although a single semen specimen was positive 22 days post onset, we could not definitively confirm the presence of WNV RNA in the remaining specimens. WNV RNA-positive UR specimens exhibited profound loss of viral RNA during storage, highlighting the need for optimal preservation pre-storage. This study provides optimized methods for WNV RNA detection among different fluid types and offers alternative options for diagnostic testing during the acute stages of WNV.

scholarly journals West Nile virus in Europe: understanding the present to gauge the future

2010 ◽  
Vol 15 (10) ◽  
Author(s):  
P Reiter
Keyword(s):  
New York ◽  
West Nile Virus ◽  
Natural History ◽  
Research Effort ◽  
Western Hemisphere ◽  
Current Understanding ◽  
Major Research ◽  
West Nile ◽  
Old World ◽  
History Of

The appearance of West Nile virus in New York in 1999 and the unprecedented panzootic that followed, have stimulated a major research effort in the western hemisphere and a new interest in the presence of this virus in the Old World. This review considers current understanding of the natural history of this pathogen, with particular regard to transmission in Europe.

scholarly journals Contrasted Epidemiological Patterns of West Nile Virus Lineages 1 and 2 Infections in France from 2015 to 2019

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 908 ◽  
Author(s):  
Cécile Beck ◽  
Isabelle Leparc Goffart ◽  
Florian Franke ◽  
Gaelle Gonzalez ◽  
Marine Dumarest ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
West Nile Virus ◽  
Invasive Disease ◽  
Northern Italy ◽  
Breaking Point ◽  
Organ Donors ◽  
West Nile ◽  
Organ Donations ◽  
History Of ◽  
Lineage 2

Since 2015, annual West Nile virus (WNV) outbreaks of varying intensities have been reported in France. Recent intensification of enzootic WNV circulation was observed in the South of France with most horse cases detected in 2015 (n = 49), 2018 (n = 13), and 2019 (n = 13). A WNV lineage 1 strain was isolated from a horse suffering from West Nile neuro-invasive disease (WNND) during the 2015 episode in the Camargue area. A breaking point in WNV epidemiology was achieved in 2018, when WNV lineage 2 emerged in Southeastern areas. This virus most probably originated from WNV spread from Northern Italy and caused WNND in humans and the death of diurnal raptors. WNV lineage 2 emergence was associated with the most important human WNV epidemics identified so far in France (n = 26, including seven WNND cases and two infections in blood and organ donors). Two other major findings were the detection of WNV in areas with no or limited history of WNV circulation (Alpes-Maritimes in 2018, Corsica in 2018–2019, and Var in 2019) and distinct spatial distribution of human and horse WNV cases. These new data reinforce the necessity to enhance French WNV surveillance to better anticipate future WNV epidemics and epizootics and to improve the safety of blood and organ donations.

scholarly journals West Nile virus strain Kunjin NS5 polymerase is a phosphoprotein localized at the cytoplasmic site of viral RNA synthesis

2007 ◽  
Vol 88 (4) ◽  
pp. 1163-1168 ◽  
Author(s):  
Jason M. Mackenzie ◽  
Mark T. Kenney ◽  
Edwin G. Westaway
Keyword(s):  
West Nile Virus ◽  
Rna Polymerase ◽  
Virus Strain ◽  
Viral Rna ◽  
West Nile ◽  
Replication Complex ◽  
Virus Rna ◽  
West Nile Virus Strain ◽  
First Time ◽  
Cytoplasmic Location

Using West Nile virus strain Kunjin virus (WNVKUN) as a model system for flavivirus replication, we showed that the virus replication complex (RC) is associated with the dsRNA template located in induced membranes only in the cytoplasm. In this report we established for the first time that the RNA-dependent RNA polymerase NS5 is located in flavivirus-induced membranes, including the site of viral RNA replication. We found no evidence for nuclear localization of the essential RC components NS5 and its dsRNA template for WNVKUN or the closely related WNV strain Sarafend, by immuno-electron microscopy or by immunofluorescence. Metabolic radiolabelling with [32P]orthophosphate revealed that WNVKUN NS5 was phosphorylated and this was confirmed by Western blotting with antibodies specific for phosphorylated serine and threonine only. These observations of a cytoplasmic location for the WNV polymerase and its phosphorylation state correspond to the characteristics of the hepatitis C virus RNA polymerase NS5B.

scholarly journals Early detection of West Nile virus in France: quantitative assessment of syndromic surveillance system using nervous signs in horses

2016 ◽  
Vol 145 (5) ◽  
pp. 1044-1057 ◽  
Author(s):  
C. FAVERJON ◽  
F. VIAL ◽  
M. G. ANDERSSON ◽  
S. LECOLLINET ◽  
A. LEBLOND
Keyword(s):  
West Nile Virus ◽  
Early Detection ◽  
Surveillance System ◽  
Syndromic Surveillance ◽  
Real Data ◽  
Detection Algorithm ◽  
Health Concern ◽  
False Alarms ◽  
West Nile ◽  
Syndromic Surveillance System

SUMMARYWest Nile virus (WNV) is a growing public health concern in Europe and there is a need to develop more efficient early detection systems. Nervous signs in horses are considered to be an early indicator of WNV and, using them in a syndromic surveillance system, might be relevant. In our study, we assessed whether or not data collected by the passive French surveillance system for the surveillance of equine diseases can be used routinely for the detection of WNV. We tested several pre-processing methods and detection algorithms based on regression. We evaluated system performances using simulated and authentic data and compared them to those of the surveillance system currently in place. Our results show that the current detection algorithm provided similar performances to those tested using simulated and real data. However, regression models can be easily and better adapted to surveillance objectives. The detection performances obtained were compatible with the early detection of WNV outbreaks in France (i.e. sensitivity 98%, specificity >94%, timeliness 2·5 weeks and around four false alarms per year) but further work is needed to determine the most suitable alarm threshold for WNV surveillance in France using cost-efficiency analysis.

scholarly journals Neuroinvasive West Nile Virus Disease in Canada. The Saskatchewan Experience

2013 ◽  
Vol 40 (4) ◽  
pp. 580-584 ◽  
Author(s):  
José F. Téllez-Zenteno ◽  
Gary Hunter ◽  
Lizbeth Hernández-Ronquillo ◽  
Edrish Haghir
Keyword(s):  
West Nile Virus ◽  
Virus Disease ◽  
Neurological Complications ◽  
Human Infection ◽  
Infected Mosquito ◽  
Surveillance Program ◽  
West Nile ◽  
Outdoor Sports ◽  
History Of ◽  
The Government

Abstract:Background:West Nile virus (WNV) is a virus of the family Flaviviridae. The main route of human infection is through the bite of an infected mosquito. Approximately 90% of WNV infections in humans are asymptomatic, but neurologic manifestations can be severe.Methods:This study reviews the clinical profile of cases with neuroinvasive West Nile infection (NWNI) reported by the Surveillance program of the government of Saskatchewan in the Saskatoon Health Region (SHR). In 2007, 1456 cases of human West Nile cases were reported by the government of Saskatchewan in the whole province. One hundred and thirteen cases had severe symptoms of NWNI (8%), 1172 (80%) cases had mild symptoms of WNI and 171 (12%) had asymptomatic disease. Three hundred and fifty six cases were reported in the SHR, where 57 (16%) fulfilled criteria for NWNI.Results:From the 57 cases, 39 (68%) were females. Nine (16%) patients had a history of recent camping, two (4%) reported outdoor sports and four (8%) reported outdoor activities not otherwise specified. Twenty five patients had headache (43.9%), 25 confusion (42.1%), 23 meningitis (40.4%), 17 encephalitis (29.8%), 14 encephalopathy (24.6%), 11 meningoencephalitis (19.3%), 10 tremor (17.5%), acute flaccid paralysis 10 (17.5%), myoclonus 1 (1.8%), nystagmus 2 (3.5%), diplopia 2 (3.5%), dizziness 2 (3.5%). Three patients died related with comorbidities during admission.Conclusion:During a year of high occurrence of WNI in Saskatchewan, 16% of cases developed NWNI. The recognition of neurological complications associated with WNI is important to improve their referral to tertiary centers.

scholarly journals Cell Proteins TIA-1 and TIAR Interact with the 3′ Stem-Loop of the West Nile Virus Complementary Minus-Strand RNA and Facilitate Virus Replication

2002 ◽  
Vol 76 (23) ◽  
pp. 11989-12000 ◽  
Author(s):  
W. Li ◽  
Y. Li ◽  
N. Kedersha ◽  
P. Anderson ◽  
M. Emara ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Rna Binding ◽  
Peptide Sequencing ◽  
Viral Rna ◽  
Cell Protein ◽  
Affinity Column ◽  
Rna Recognition Motif ◽  
The West ◽  
West Nile ◽  
Stem Loop

ABSTRACT It was reported previously that four baby hamster kidney (BHK) proteins with molecular masses of 108, 60, 50, and 42 kDa bind specifically to the 3′-terminal stem-loop of the West Nile virus minus-stand RNA [WNV 3′(−) SL RNA] (P. Y. Shi, W. Li, and M. A. Brinton, J. Virol. 70:6278-6287, 1996). In this study, p42 was purified using an RNA affinity column and identified as TIAR by peptide sequencing. A 42-kDa UV-cross-linked viral RNA-cell protein complex formed in BHK cytoplasmic extracts incubated with the WNV 3′(−) SL RNA was immunoprecipitated by anti-TIAR antibody. Both TIAR and the closely related protein TIA-1 are members of the RNA recognition motif (RRM) family of RNA binding proteins. TIA-1 also binds to the WNV 3′(−) SL RNA. The specificity of these viral RNA-cell protein interactions was demonstrated using recombinant proteins in competition gel mobility shift assays. The binding site for the WNV 3′(−) SL RNA was mapped to RRM2 on both TIAR and TIA-1. However, the dissociation constant (Kd ) for the interaction between TIAR RRM2 and the WNV 3′(−) SL RNA was 1.5 × 10−8, while that for TIA-1 RRM2 was 1.12 × 10−7. WNV growth was less efficient in murine TIAR knockout cell lines than in control cells. This effect was not observed for two other types of RNA viruses or two types of DNA viruses. Reconstitution of the TIAR knockout cells with TIAR increased the efficiency of WNV growth, but neither the level of TIAR nor WNV replication was as high as in control cells. These data suggest a functional role for TIAR and possibly also for TIA-1 during WNV replication.

scholarly journals Stress hormones predict a host superspreader phenotype in the West Nile virus system

2017 ◽  
Vol 284 (1859) ◽  
pp. 20171090 ◽  
Author(s):  
Stephanie S. Gervasi ◽  
Sarah C. Burgan ◽  
Erik Hofmeister ◽  
Thomas R. Unnasch ◽  
Lynn B. Martin
Keyword(s):  
West Nile Virus ◽  
Stress Hormones ◽  
Activity Levels ◽  
West Nile ◽  
Viral Loads ◽  
Pathogen Dynamics ◽  
Host Competence ◽  
Host Mortality ◽  
Host Metabolism ◽  
Virus System

Glucocorticoid stress hormones, such as corticosterone (CORT), have profound effects on the behaviour and physiology of organisms, and thus have the potential to alter host competence and the contributions of individuals to population- and community-level pathogen dynamics. For example, CORT could alter the rate of contacts among hosts, pathogens and vectors through its widespread effects on host metabolism and activity levels. CORT could also affect the intensity and duration of pathogen shedding and risk of host mortality during infection. We experimentally manipulated songbird CORT, asking how CORT affected behavioural and physiological responses to a standardized West Nile virus (WNV) challenge. Although all birds became infected after exposure to the virus, only birds with elevated CORT had viral loads at or above the infectious threshold. Moreover, though the rate of mortality was faster in birds with elevated CORT compared with controls, most hosts with elevated CORT survived past the day of peak infectiousness. CORT concentrations just prior to inoculation with WNV and anti-inflammatory cytokine concentrations following viral exposure were predictive of individual duration of infectiousness and the ability to maintain physical performance during infection (i.e. tolerance), revealing putative biomarkers of competence. Collectively, our results suggest that glucocorticoid stress hormones could directly and indirectly mediate the spread of pathogens.

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