Neuroinvasive West Nile Virus Disease in Canada. The Saskatchewan Experience

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.

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Unique Cytokine Response in West Nile Virus Patients Who Developed Chronic Kidney Disease: A Prospective Cohort Study

Viruses ◽

10.3390/v13020311 ◽

2021 ◽

Vol 13 (2) ◽

pp. 311

Author(s):

Michael Hansen ◽

Melissa S. Nolan ◽

Rodion Gorchakov ◽

Rodrigo Hasbun ◽

Kristy O. Murray ◽

...

Keyword(s):

Chronic Kidney Disease ◽

West Nile Virus ◽

Kidney Disease ◽

Neurological Complications ◽

P Value ◽

West Nile ◽

Adjusted Risk ◽

History Of ◽

Negative Controls ◽

The Impact

West Nile virus (WNV) is a widespread and devastating disease, especially in those who develop neuroinvasive disease. A growing body of evidence describes sequelae years after infection, including neurological complications and chronic kidney disease (CKD). Eighty-nine out of 373 WNV-positive cases were followed for approximately two years and compared to 127 WNV-negative controls with and without CKD. Adjusted risk ratios (aRRs) were calculated via a log binomial regression to determine the impact of WNV exposure and other possible confounders on the likelihood of developing CKD. Cytokine profiles of WNV patients and controls were evaluated to characterize differences and describe potential underlying pathophysiological mechanisms. The associated risk for developing CKD was significantly associated with history of WNV infection (aRR = 1.91, 95% CI 1.13–3.25). Additionally, five distinct cytokines were found to be significantly associated with WNV infection (eotaxin, IL-8, IL-12p70, IP-10, and TNFα) after the p-value was adjusted to <0.0019 due to the Bonferroni correction. These data support that WNV infection is an independent risk factor for CKD, even after accounting for confounding comorbidities. WNV participants who developed CKD had high activity of proinflammatory markers, indicating underlying inflammatory disease. This study provides new insights into CKD resultant of WNV infection.

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1787. The Effects of a Systemwide Diagnostic Stewardship Change on West Nile Virus Disease Ordering Practices

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1650 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S658-S658

Author(s):

Andrew H Karaba ◽

Paul W Blair ◽

Kevin M Martin ◽

Mustapha O Saheed ◽

Karen C Carroll ◽

...

Keyword(s):

West Nile Virus ◽

Virus Disease ◽

Case Fatality ◽

Cost Savings ◽

Primary Objective ◽

Neurological Deficits ◽

West Nile ◽

Hospital System ◽

Elisa Testing ◽

Before And After

Abstract Background Neuroinvasive West Nile Virus (WNV) often leads to prolonged neurological deficits and carries a high case fatality rate. The CSF IgM (MAC-ELISA) is preferred over the CSF nucleic acid-based test (NAAT) by the CDC due to its higher sensitivity. However, our hospital system was observed to have an over-utilization of NAAT testing compared with MAC-ELISA testing. The primary objective was to compare the number of MAC-ELISA and NAAT WNV tests ordered before and after a diagnostic stewardship intervention. The secondary objectives were to determine whether this change to lead to any cost savings and increased detection of probable cases of WNV-ND. Methods In an effort to increase the use of the MAC-ELISA and to decrease unnecessary NAAT testing, the NAAT test was removed in April 2018 from the test menu in the electronic health record of a health system comprising five hospitals in the Maryland and Washington, D.C. area. NAAT testing remained possible via a paper order form. This study was a retrospective review of WNV testing done on CSF samples from July 2016 through December 2018. The seasonal and yearly number of total tests, positive tests, and total costs were determined from the period of July, 2017 to April, 2018 and were compared with May, 2018 to January, 2019. A paired t-test was performed to evaluate for differences in total testing, total positives, and total costs during non-winter months before and after the intervention. Results A total of 12.59 MAC-ELISA tests/month (95% CI: 10.29, 14.89) increased to 41 tests/month (95% CI: 34.35, 47.65) which was significantly different (P < 0.001). In contrast, there were 46.23 NAAT tests/month (95% CI: 39.55, 52.91) which decreased to 0 NAAT tests/month after the intervention (P < 0.001). This resulted in an average decrease in WNV test spending from $7200 per month to $471 per month (P < 0.001). Preceding the intervention in test ordering, 0.23% of WNV CSF tests were positive (NAAT+MAC-ELISA) while 2.44% WNV CSF tests were positive after the intervention (P = 0.03). Conclusion Elimination of electronic WNV NAAT ordering is an effective way of decreasing inappropriate WNV NAAT testing, decreasing associated costs, and may lead to improved diagnosis of WNV-ND. Disclosures All authors: No reported disclosures.

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

Pathogens ◽

10.3390/pathogens9110908 ◽

2020 ◽

Vol 9 (11) ◽

pp. 908 ◽

Cited By ~ 1

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.

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Identification of genetic variants associated with dengue or West Nile virus disease: a systematic review and meta-analysis

BMC Infectious Diseases ◽

10.1186/s12879-018-3186-6 ◽

2018 ◽

Vol 18 (1) ◽

Cited By ~ 14

Author(s):

Megan E. Cahill ◽

Samantha Conley ◽

Andrew T. DeWan ◽

Ruth R. Montgomery

Keyword(s):

Systematic Review ◽

West Nile Virus ◽

Genetic Variants ◽

Virus Disease ◽

Meta Analysis ◽

West Nile

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Meteorological Conditions Associated with Increased Incidence of West Nile Virus Disease in the United States, 2004–2012

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.14-0737 ◽

2015 ◽

Vol 92 (5) ◽

pp. 1013-1022 ◽

Cited By ~ 38

Author(s):

Micah B. Hahn ◽

Roger S. Nasci ◽

Mark J. Delorey ◽

Rebecca J. Eisen ◽

Andrew J. Monaghan ◽

...

Keyword(s):

United States ◽

West Nile Virus ◽

Virus Disease ◽

The United States ◽

Meteorological Conditions ◽

West Nile

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Epidemiologic and phylogenetic analysis of the 2018 West Nile virus (WNV) outbreak in Israel demonstrates human infection of WNV lineage I

Eurosurveillance ◽

10.2807/1560-7917.es.2019.24.1.1800662 ◽

2019 ◽

Vol 24 (1) ◽

Cited By ~ 6

Author(s):

Yaniv Lustig ◽

Ruslan Gosinov ◽

Neta Zuckerman ◽

Yael Glazer ◽

Laor Orshan ◽

...

Keyword(s):

Phylogenetic Analysis ◽

West Nile Virus ◽

Human Infection ◽

European Countries ◽

West Nile

As at 12 November 2018, an outbreak of West Nile virus (WNV) was responsible for 139 WNV infection cases in Israel. Here, we characterise the epidemiology of the outbreak and demonstrate that only WNV lineage I was circulating in mosquitoes and responsible for WNV infection in humans. This suggests that the concurrence of the outbreak in Israel with WNV outbreaks in several European countries is not due to a common, more virulent WNV genotype.

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Surveillance for West Nile Virus Disease — United States, 2009–2018

MMWR Surveillance Summaries ◽

10.15585/mmwr.ss7001a1 ◽

2021 ◽

Vol 70 (1) ◽

pp. 1-15

Author(s):

Emily McDonald ◽

Sarabeth Mathis ◽

Stacey W. Martin ◽

J. Erin Staples ◽

Marc Fischer ◽

...

Keyword(s):

United States ◽

West Nile Virus ◽

Virus Disease ◽

West Nile

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Genetic variation in West Nile virus from naturally infected mosquitoes and birds suggests quasispecies structure and strong purifying selection

Journal of General Virology ◽

10.1099/vir.0.81015-0 ◽

2005 ◽

Vol 86 (8) ◽

pp. 2175-2183 ◽

Cited By ~ 137

Author(s):

Greta Jerzak ◽

Kristen A. Bernard ◽

Laura D. Kramer ◽

Gregory D. Ebel

Keyword(s):

Genetic Diversity ◽

West Nile Virus ◽

Consensus Sequence ◽

Purifying Selection ◽

Infected Mosquito ◽

Structural Protein ◽

Coding Region ◽

West Nile ◽

Transmission Cycle ◽

The Mean

Intrahost genetic diversity was analysed in naturally infected mosquitoes and birds to determine whether West Nile virus (WNV) exists in nature as a quasispecies and to quantify selective pressures within and between hosts. WNV was sampled from ten infected birds and ten infected mosquito pools collected on Long Island, NY, USA, during the peak of the 2003 WNV transmission season. A 1938 nt fragment comprising the 3′ 1159 nt of the WNV envelope (E) coding region and the 5′ 779 nt of the non-structural protein 1 (NS1) coding region was amplified and cloned and 20 clones per specimen were sequenced. Results from this analysis demonstrate that WNV infections are derived from a genetically diverse population of genomes in nature. The mean nucleotide diversity was 0·016 % within individual specimens and the mean percentage of clones that differed from the consensus sequence was 19·5 %. WNV sequences in mosquitoes were significantly more genetically diverse than WNV in birds. No host-dependent bias for particular types of mutations was observed and estimates of genetic diversity did not differ significantly between E and NS1 coding sequences. Non-consensus clones obtained from two avian specimens had highly similar genetic signatures, providing preliminary evidence that WNV genetic diversity may be maintained throughout the enzootic transmission cycle, rather than arising independently during each infection. Evidence of purifying selection was obtained from both intra- and interhost WNV populations. Combined, these data support the observation that WNV populations may be structured as a quasispecies and document strong purifying natural selection in WNV populations.

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West Nile virus transmission: results from the integrated surveillance system in Italy, 2008 to 2015

Eurosurveillance ◽

10.2807/1560-7917.es.2016.21.37.30340 ◽

2016 ◽

Vol 21 (37) ◽

Cited By ~ 42

Author(s):

Caterina Rizzo ◽

Christian Napoli ◽

Giulietta Venturi ◽

Simonetta Pupella ◽

Letizia Lombardini ◽

...

Keyword(s):

West Nile Virus ◽

Data Exchange ◽

Virus Disease ◽

Virus Transmission ◽

Geographic Area ◽

Activity Period ◽

Surveillance Systems ◽

Time Data ◽

West Nile ◽

West Nile Virus Transmission

In Italy a national Plan for the surveillance of imported and autochthonous human vector-borne diseases (chikungunya, dengue, Zika virus disease and West Nile virus (WNV) disease) that integrates human and veterinary (animals and vectors) surveillance, is issued and revised annually according with the observed epidemiological changes. Here we describe results of the WNV integrated veterinary and human surveillance systems in Italy from 2008 to 2015. A real time data exchange protocol is in place between the surveillance systems to rapidly identify occurrence of human and animal cases and to define and update the map of affected areas i.e. provinces during the vector activity period from June to October. WNV continues to cause severe illnesses in Italy during every transmission season, albeit cases are sporadic and the epidemiology varies by virus lineage and geographic area. The integration of surveillance activities and a multidisciplinary approach made it possible and have been fundamental in supporting implementation of and/or strengthening preventive measures aimed at reducing the risk of transmission of WNV trough blood, tissues and organ donation and to implementing further measures for vector control.

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