GENETIC DIVERSITY OF YELLOW-BILLED MAGPIES (PICA NUTALLI) BEFORE AND AFTER A WEST NILE VIRUS EPIDEMIC

2019 ◽  
Vol 55 (2) ◽  
pp. 316
Keyword(s):  
Genetic Diversity ◽  
West Nile Virus ◽  
West Nile ◽  
Before And After

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

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.

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

2005 ◽  
Vol 86 (8) ◽  
pp. 2175-2183 ◽  
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.

scholarly journals Genetic Diversity in the Collaborative Cross Model Recapitulates Human West Nile Virus Disease Outcomes

mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Jessica B. Graham ◽  
Sunil Thomas ◽  
Jessica Swarts ◽  
Aimee A. McMillan ◽  
Martin T. Ferris ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
West Nile Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
West Nile Virus Infection ◽  
Collaborative Cross ◽  
Adaptive Immune Responses ◽  
West Nile ◽  
Adaptive Immune ◽  
Wide Range

ABSTRACT West Nile virus (WNV) is an emerging neuroinvasive flavivirus that now causes significant morbidity and mortality worldwide. The innate and adaptive immune responses to WNV infection have been well studied in C57BL/6J inbred mice, but this model lacks the variations in susceptibility, immunity, and outcome to WNV infection that are observed in humans, thus limiting its usefulness to understand the mechanisms of WNV infection and immunity dynamics. To build a model of WNV infection that captures human infection outcomes, we have used the Collaborative Cross (CC) mouse model. We show that this model, which recapitulates the genetic diversity of the human population, demonstrates diversity in susceptibility and outcomes of WNV infection observed in humans. Using multiple F1 crosses of CC mice, we identified a wide range of susceptibilities to infection, as demonstrated through differences in survival, clinical disease score, viral titer, and innate and adaptive immune responses in both peripheral tissues and the central nervous system. Additionally, we examined the Oas1b alleles in the CC mice and confirmed the previous finding that Oas1b plays a role in susceptibility to WNV; however, even within a given Oas1b allele status, we identified a wide range of strain-specific WNV-associated phenotypes. These results confirmed that the CC model is effective for identifying a repertoire of host genes involved in WNV resistance and susceptibility. The CC effectively models a wide range of WNV clinical, virologic, and immune phenotypes, thus overcoming the limitations of the traditional C57BL/6J model, allowing genetic and mechanistic studies of WNV infection and immunity in differently susceptible populations. IMPORTANCE Mouse models of West Nile virus infection have revealed important details regarding the innate and adaptive immune responses to this emerging viral infection. However, traditional mouse models lack the genetic diversity present in human populations and therefore limit our ability to study various disease outcomes and immunologic mechanisms subsequent to West Nile virus infection. In this study, we used the Collaborative Cross mouse model to more effectively model the wide range of clinical, virologic, and immune phenotypes present upon West Nile virus infection in humans.

scholarly journals An amplicon-based sequencing framework for accurately measuring intrahost virus diversity using PrimalSeq and iVar

2018 ◽  
Author(s):  
Nathan D Grubaugh ◽  
Karthik Gangavarapu ◽  
Joshua Quick ◽  
Nathaniel L. Matteson ◽  
Jaqueline Goes De Jesus ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
West Nile Virus ◽  
Virus Concentration ◽  
Nanopore Sequencing ◽  
Computational Tool ◽  
Experimental Protocol ◽  
West Nile ◽  
Sequencing Coverage ◽  
Virus Diversity ◽  
Oxford Nanopore

AbstractHow viruses evolve within hosts can dictate infection outcomes; however, reconstructing this process is challenging. We evaluated our multiplexed amplicon approach - PrimalSeq - to demonstrate how virus concentration, sequencing coverage, primer mismatches, and replicates influence the accuracy of measuring intrahost virus diversity. We developed an experimental protocol and computational tool (iVar) for using PrimalSeq to measure virus diversity using Illumina and compared the results to Oxford Nanopore sequencing. We demonstrate the utility of PrimalSeq by measuring Zika and West Nile virus diversity from varied sample types and show that the accumulation of genetic diversity is influenced by experimental and biological systems.

scholarly journals West Nile Virus Genetic Diversity is Maintained during Transmission by Culex pipiens quinquefasciatus Mosquitoes

PLoS ONE ◽  
2011 ◽  
Vol 6 (9) ◽  
pp. e24466 ◽  
Author(s):  
Doug E. Brackney ◽  
Kendra N. Pesko ◽  
Ivy K. Brown ◽  
Eleanor R. Deardorff ◽  
Jon Kawatachi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
West Nile Virus ◽  
Culex Pipiens ◽  
West Nile ◽  
Culex Pipiens Quinquefasciatus

scholarly journals Phylodynamics, vectorial competence and genetic diversity of West Nile virus in Africa: implications for global emergence of West Nile

2011 ◽  
Vol 5 (S1) ◽  
Author(s):  
Gamou Fall ◽  
Mawlouth Diallo ◽  
Ousmane Faye ◽  
Moussa Dia ◽  
Anne Dupressoir ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
West Nile Virus ◽  
West Nile ◽  
Vectorial Competence

scholarly journals Genetic diversity and purifying selection in West Nile virus populations are maintained during host switching

Virology ◽  
2008 ◽  
Vol 374 (2) ◽  
pp. 256-260 ◽  
Author(s):  
Greta V.S. Jerzak ◽  
Ivy Brown ◽  
Pei-Yong Shi ◽  
Laura D. Kramer ◽  
Gregory D. Ebel
Keyword(s):  
Genetic Diversity ◽  
West Nile Virus ◽  
Purifying Selection ◽  
Host Switching ◽  
West Nile

scholarly journals High genetic diversity in the Culex pipiens complex from a West Nile Virus epidemic area in Southern Europe

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Mauro Simonato ◽  
Isabel Martinez-Sañudo ◽  
Giacomo Cavaletto ◽  
Giacomo Santoiemma ◽  
Andrea Saltarin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
West Nile Virus ◽  
Culex Pipiens ◽  
Southern Europe ◽  
West Nile ◽  
High Genetic Diversity ◽  
Culex Pipiens Complex ◽  
Epidemic Area

scholarly journals Experimental Evolution of West Nile Virus at Higher Temperatures Facilitates Broad Adaptation and Increased Genetic Diversity

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1889
Author(s):  
Rachel L. Fay ◽  
Kiet A. Ngo ◽  
Lili Kuo ◽  
Graham G. Willsey ◽  
Laura D. Kramer ◽  
...  
Keyword(s):  
West Nile Virus ◽  
West Nile ◽  
Replicative Fitness ◽  
Natural Systems ◽  
Mosquito Cells ◽  
Before And After ◽  
Increasing Temperature ◽  
Genetic Signatures ◽  
Temperature Impacts ◽  
The Impact

West Nile virus (WNV, Flaviviridae, Flavivirus) is a mosquito-borne flavivirus introduced to North America in 1999. Since 1999, the Earth’s average temperature has increased by 0.6 °C. Mosquitoes are ectothermic organisms, reliant on environmental heat sources. Temperature impacts vector–virus interactions which directly influence arbovirus transmission. RNA viral replication is highly error-prone and increasing temperature could further increase replication rates, mutation frequencies, and evolutionary rates. The impact of temperature on arbovirus evolutionary trajectories and fitness landscapes has yet to be sufficiently studied. To investigate how temperature impacts the rate and extent of WNV evolution in mosquito cells, WNV was experimentally passaged 12 times in Culex tarsalis cells, at 25 °C and 30 °C. Full-genome deep sequencing was used to compare genetic signatures during passage, and replicative fitness was evaluated before and after passage at each temperature. Our results suggest adaptive potential at both temperatures, with unique temperature-dependent and lineage-specific genetic signatures. Further, higher temperature passage was associated with significantly increased replicative fitness at both temperatures and increases in nonsynonymous mutations. Together, these data indicate that if similar selective pressures exist in natural systems, increases in temperature could accelerate emergence of high-fitness strains with greater phenotypic plasticity.

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