Analyze Diet
Emerging infectious diseases2012; 18(5); 792-800; doi: 10.3201/eid1805.111720

Characterization of virulent West Nile virus Kunjin strain, Australia, 2011.

Abstract: To determine the cause of an unprecedented outbreak of encephalitis among horses in New South Wales, Australia, in 2011, we performed genomic sequencing of viruses isolated from affected horses and mosquitoes. Results showed that most of the cases were caused by a variant West Nile virus (WNV) strain, WNV(NSW2011), that is most closely related to WNV Kunjin (WNV(KUN)), the indigenous WNV strain in Australia. Studies in mouse models for WNV pathogenesis showed that WNV(NSW2011) is substantially more neuroinvasive than the prototype WNV(KUN) strain. In WNV(NSW2011), this apparent increase in virulence over that of the prototype strain correlated with at least 2 known markers of WNV virulence that are not found in WNV(KUN). Additional studies are needed to determine the relationship of the WNV(NSW2011) strain to currently and previously circulating WNV(KUN) strains and to confirm the cause of the increased virulence of this emerging WNV strain.
Publication Date: 2012-04-21 PubMed ID: 22516173PubMed Central: PMC3358055DOI: 10.3201/eid1805.111720Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research is about a 2011 outbreak of encephalitis in horses in New South Wales, Australia. The authors found that the cause was a variant of the West Nile Virus (WNV), which is more virulent and neuroinvasive than the typical strain in Australia.

Background and Purpose of the Research

  • The aim of the study was to identify the cause of an unusual outbreak of encephalitis in horses in New South Wales, Australia, in 2011.
  • To unravel the causative agent, the researchers undertook genomic sequencing of viruses isolated from the affected horses and mosquitoes.
  • The outbreak was suspected to be due to a variation of West Nile virus (WNV).

Findings and Results from the Study

  • Most of the cases in the outbreak were found to be caused by a variant West Nile Virus strain, termed as WNV(NSW2011).
  • Genomic sequencing and analysis revealed that WNV(NSW2011) is most closely connected to WNV Kunjin (WNV(KUN)), the indigenous WNV strain in Australia.
  • In experimental studies using mouse models, it was discovered that WNV(NSW2011) is significantly more neuroinvasive – i.e., it has a higher capacity to infiltrate the central nervous system and cause disease – than the original WNV(KUN) strain.
  • These differences in virulence and neuroinvasiveness were correlated with at least two known markers of WNV virulence that are not found in the WNV(KUN) strain.

Significance and Future Research

  • The research shed light on the presence of a virulent, neuroinvasive strain of WNV in Australia, which caused an outbreak of encephalitis among horses.
  • However, the relationship of the new WNV(NSW2011) strain to current and previously circulating WNV(KUN) strains still needs to be investigated in future studies.
  • Additionally, more research is needed to confirm the reason for the increased virulence of this new strain.

Cite This Article

APA
Frost MJ, Zhang J, Edmonds JH, Prow NA, Gu X, Davis R, Hornitzky C, Arzey KE, Finlaison D, Hick P, Read A, Hobson-Peters J, May FJ, Doggett SL, Haniotis J, Russell RC, Hall RA, Khromykh AA, Kirkland PD. (2012). Characterization of virulent West Nile virus Kunjin strain, Australia, 2011. Emerg Infect Dis, 18(5), 792-800. https://doi.org/10.3201/eid1805.111720

Publication

ISSN: 1080-6059
NlmUniqueID: 9508155
Country: United States
Language: English
Volume: 18
Issue: 5
Pages: 792-800

Researcher Affiliations

Frost, Melinda J
  • Elizabeth Macarthur Agriculture Institute, Menangle, New South Wales, Australia.
Zhang, Jing
    Edmonds, Judith H
      Prow, Natalie A
        Gu, Xingnian
          Davis, Rodney
            Hornitzky, Christine
              Arzey, Kathleen E
                Finlaison, Deborah
                  Hick, Paul
                    Read, Andrew
                      Hobson-Peters, Jody
                        May, Fiona J
                          Doggett, Stephen L
                            Haniotis, John
                              Russell, Richard C
                                Hall, Roy A
                                  Khromykh, Alexander A
                                    Kirkland, Peter D

                                      MeSH Terms

                                      • Animals
                                      • Cell Line
                                      • Cricetinae
                                      • Disease Outbreaks
                                      • Genes, Viral
                                      • Horse Diseases / epidemiology
                                      • Horse Diseases / virology
                                      • Horses
                                      • Mice
                                      • New South Wales / epidemiology
                                      • Open Reading Frames
                                      • Phylogeny
                                      • Virulence
                                      • West Nile Fever / epidemiology
                                      • West Nile Fever / veterinary
                                      • West Nile Fever / virology
                                      • West Nile virus / genetics
                                      • West Nile virus / immunology
                                      • West Nile virus / pathogenicity

                                      References

                                      This article includes 28 references
                                      1. Russell RC, Dwyer DE. Arboviruses associated with human disease in Australia.. Microbes Infect 2000 Nov;2(14):1693-704.
                                        doi: 10.1016/S1286-4579(00)01324-1pubmed: 11137043google scholar: lookup
                                      2. Mackenzie JS, Lindsay MD, Coelen RJ, Broom AK, Hall RA, Smith DW. Arboviruses causing human disease in the Australasian zoogeographic region.. Arch Virol 1994;136(3-4):447-67.
                                        doi: 10.1007/BF01321074pubmed: 8031248google scholar: lookup
                                      3. Hall RA, Broom AK, Smith DW, Mackenzie JS. The ecology and epidemiology of Kunjin virus.. Curr Top Microbiol Immunol 2002;267:253-69.
                                        doi: 10.1007/978-3-642-59403-8_13pubmed: 12082993google scholar: lookup
                                      4. Badman RT, Campbell J, Aldred J. Arbovirus infection in horses—Victoria 1984. Commun Dis Intell 1984;17:5–6.
                                      5. Ostlund EN, Crom RL, Pedersen DD, Johnson DJ, Williams WO, Schmitt BJ. Equine West Nile encephalitis, United States.. Emerg Infect Dis 2001 Jul-Aug;7(4):665-9.
                                        doi: 10.3201/eid0704.010412pmc: PMC2631754pubmed: 11589171google scholar: lookup
                                      6. Russell RC, Doggett SL, Clancy J, Haniotis J, Patsouris K, Hueston L. Arbovirus and vector surveillance in NSW, 1997–2000. Arbovirus Research in Australia 2001;8:304–13.
                                      7. Khromykh AA, Sedlak PL, Westaway EG. trans-Complementation analysis of the flavivirus Kunjin ns5 gene reveals an essential role for translation of its N-terminal half in RNA replication.. J Virol 1999 Nov;73(11):9247-55.
                                      8. Audsley M, Edmonds J, Liu W, Mokhonov V, Mokhonova E, Melian EB, Prow N, Hall RA, Khromykh AA. Virulence determinants between New York 99 and Kunjin strains of West Nile virus.. Virology 2011 May 25;414(1):63-73.
                                        doi: 10.1016/j.virol.2011.03.008pmc: PMC3089702pubmed: 21477835google scholar: lookup
                                      9. Hall RA, Broom AK, Hartnett AC, Howard MJ, Mackenzie JS. Immunodominant epitopes on the NS1 protein of MVE and KUN viruses serve as targets for a blocking ELISA to detect virus-specific antibodies in sentinel animal serum.. J Virol Methods 1995 Feb;51(2-3):201-10.
                                        doi: 10.1016/0166-0934(94)00105-Ppubmed: 7738140google scholar: lookup
                                      10. Eiden M, Vina-Rodriguez A, Hoffmann B, Ziegler U, Groschup MH. Two new real-time quantitative reverse transcription polymerase chain reaction assays with unique target sites for the specific and sensitive detection of lineages 1 and 2 West Nile virus strains.. J Vet Diagn Invest 2010 Sep;22(5):748-53.
                                        doi: 10.1177/104063871002200515pubmed: 20807934google scholar: lookup
                                      11. Adams SC, Broom AK, Sammels LM, Hartnett AC, Howard MJ, Coelen RJ, Mackenzie JS, Hall RA. Glycosylation and antigenic variation among Kunjin virus isolates.. Virology 1995 Jan 10;206(1):49-56.
                                        doi: 10.1016/S0042-6822(95)80018-2pubmed: 7530394google scholar: lookup
                                      12. Hall RA, Kay BH, Burgess GW, Clancy P, Fanning ID. Epitope analysis of the envelope and non-structural glycoproteins of Murray Valley encephalitis virus.. J Gen Virol 1990 Dec;71 ( Pt 12):2923-30.
                                        doi: 10.1099/0022-1317-71-12-2923pubmed: 1703213google scholar: lookup
                                      13. Hall RA, Burgess GW, Kay BH, Clancy P. Monoclonal antibodies to Kunjin and Kokobera viruses.. Immunol Cell Biol 1991 Feb;69 ( Pt 1):47-9.
                                        doi: 10.1038/icb.1991.7pubmed: 1651286google scholar: lookup
                                      14. Hobson-Peters J, Toye P, Sánchez MD, Bossart KN, Wang LF, Clark DC, Cheah WY, Hall RA. A glycosylated peptide in the West Nile virus envelope protein is immunogenic during equine infection.. J Gen Virol 2008 Dec;89(Pt 12):3063-3072.
                                        doi: 10.1099/vir.0.2008/003731-0pubmed: 19008394google scholar: lookup
                                      15. Hall RA, Tan SE, Selisko B, Slade R, Hobson-Peters J, Canard B, Hughes M, Leung JY, Balmori-Melian E, Hall-Mendelin S, Pham KB, Clark DC, Prow NA, Khromykh AA. Monoclonal antibodies to the West Nile virus NS5 protein map to linear and conformational epitopes in the methyltransferase and polymerase domains.. J Gen Virol 2009 Dec;90(Pt 12):2912-2922.
                                        doi: 10.1099/vir.0.013805-0pubmed: 19710254google scholar: lookup
                                      16. May FJ, Davis CT, Tesh RB, Barrett AD. Phylogeography of West Nile virus: from the cradle of evolution in Africa to Eurasia, Australia, and the Americas.. J Virol 2011 Mar;85(6):2964-74.
                                        doi: 10.1128/JVI.01963-10pmc: PMC3067944pubmed: 21159871google scholar: lookup
                                      17. Guindon S, Gascuel O. A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood.. Syst Biol 2003 Oct;52(5):696-704.
                                        doi: 10.1080/10635150390235520pubmed: 14530136google scholar: lookup
                                      18. Prow NA, May FJ, Westlake DJ, Hurrelbrink RJ, Biron RM, Leung JY, McMinn PC, Clark DC, Mackenzie JS, Lobigs M, Khromykh AA, Hall RA. Determinants of attenuation in the envelope protein of the flavivirus Alfuy.. J Gen Virol 2011 Oct;92(Pt 10):2286-2296.
                                        doi: 10.1099/vir.0.034793-0pubmed: 21733886google scholar: lookup
                                      19. Lanciotti RS, Roehrig JT, Deubel V, Smith J, Parker M, Steele K, Crise B, Volpe KE, Crabtree MB, Scherret JH, Hall RA, MacKenzie JS, Cropp CB, Panigrahy B, Ostlund E, Schmitt B, Malkinson M, Banet C, Weissman J, Komar N, Savage HM, Stone W, McNamara T, Gubler DJ. Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern United States.. Science 1999 Dec 17;286(5448):2333-7.
                                        doi: 10.1126/science.286.5448.2333pubmed: 10600742google scholar: lookup
                                      20. Scherret JH, Poidinger M, Mackenzie JS, Broom AK, Deubel V, Lipkin WI, Briese T, Gould EA, Hall RA. The relationships between West Nile and Kunjin viruses.. Emerg Infect Dis 2001 Jul-Aug;7(4):697-705.
                                        doi: 10.3201/eid0704.010418pmc: PMC2631745pubmed: 11585535google scholar: lookup
                                      21. Hall RA, Nisbet DJ, Pham KB, Pyke AT, Smith GA, Khromykh AA. DNA vaccine coding for the full-length infectious Kunjin virus RNA protects mice against the New York strain of West Nile virus.. Proc Natl Acad Sci U S A 2003 Sep 2;100(18):10460-4.
                                        doi: 10.1073/pnas.1834270100pmc: PMC193583pubmed: 12917491google scholar: lookup
                                      22. Chang DC, Liu WJ, Anraku I, Clark DC, Pollitt CC, Suhrbier A, Hall RA, Khromykh AA. Single-round infectious particles enhance immunogenicity of a DNA vaccine against West Nile virus.. Nat Biotechnol 2008 May;26(5):571-7.
                                        doi: 10.1038/nbt1400pubmed: 18425125google scholar: lookup
                                      23. Beasley DW, Li L, Suderman MT, Barrett AD. Mouse neuroinvasive phenotype of West Nile virus strains varies depending upon virus genotype.. Virology 2002 Apr 25;296(1):17-23.
                                        doi: 10.1006/viro.2002.1372pubmed: 12036314google scholar: lookup
                                      24. Laurent-Rolle M, Boer EF, Lubick KJ, Wolfinbarger JB, Carmody AB, Rockx B, Liu W, Ashour J, Shupert WL, Holbrook MR, Barrett AD, Mason PW, Bloom ME, García-Sastre A, Khromykh AA, Best SM. The NS5 protein of the virulent West Nile virus NY99 strain is a potent antagonist of type I interferon-mediated JAK-STAT signaling.. J Virol 2010 Apr;84(7):3503-15.
                                        doi: 10.1128/JVI.01161-09pmc: PMC2838099pubmed: 20106931google scholar: lookup
                                      25. Brault AC, Huang CY, Langevin SA, Kinney RM, Bowen RA, Ramey WN, Panella NA, Holmes EC, Powers AM, Miller BR. A single positively selected West Nile viral mutation confers increased virogenesis in American crows.. Nat Genet 2007 Sep;39(9):1162-6.
                                        doi: 10.1038/ng2097pmc: PMC2291521pubmed: 17694056google scholar: lookup
                                      26. Wright PJ. Envelope protein of the flavivirus Kunjin is apparently not glycosylated.. J Gen Virol 1982 Mar;59(Pt 1):29-38.
                                        doi: 10.1099/0022-1317-59-1-29pubmed: 6279774google scholar: lookup
                                      27. Hanna SL, Pierson TC, Sanchez MD, Ahmed AA, Murtadha MM, Doms RW. N-linked glycosylation of west nile virus envelope proteins influences particle assembly and infectivity.. J Virol 2005 Nov;79(21):13262-74.
                                      28. Bingham J, Lunt RA, Green DJ, Davies KR, Stevens V, Wong FY. Experimental studies of the role of the little raven (Corvus mellori) in surveillance for West Nile virus in Australia.. Aust Vet J 2010 Jun;88(6):204-10.

                                      Citations

                                      This article has been cited 79 times.