The human and animal health impacts of introduction and spread of an exotic strain of West Nile virus in Australia

West Nile virus (WNV) is a neurovirulent mosquito-borne Flavivirus that is maintained in nature by a zoonotic transmissioncycle between avian hosts and ornithophilic mosquito vectors, mostly from the Culex genus. Until the 1990s, WNV wasconsidered to be an old-world arbovirus, but in 1999, WNV emerged in the United States (US) and spread rapidly, becoming amajor threat to public health. WNV adapted to the transmission cycle involving American mosquitoes and birds and reachedCentral and South America in subsequent years. In 2003, the National West Nile Fever Surveillance System was created in Brazilbased on serological screening of animals and sentinel vectors, as recommended by the Pan American Health Organization(PAHO) and the World Health Organization (WHO). Since 2008, serological evidence of WNV infection in Brazilian horseshas been reported, and the circulation of WNV has been monitored through the regular serological screening of sentinel horsesand reporting of encephalomyelitis cases. Horses are highly susceptible to WNV infection, and outbreaks of neurologicaldisease among horses often precede human cases. In this regard, equine surveillance has been essential in providing earlywarning to public and animal health authorities in several countries, including Brazil. This demonstrates the need for animaland public health intervention programs to allocate resources to make veterinarians aware of the role they can play in thehuman surveillance processes by monitoring horses. This review discusses the importance of equine surveillance and the gapthat veterinarians can fill on the front line in human surveillance, in Brazil and worldwide, in the context of “One Health”

Download Full-text

WEST NILE VIRUS SURVEILLANCE PROGRAM IN SERBIA

Archives of Veterinary Medicine ◽

10.46784/e-avm.v7i2.130 ◽

2015 ◽

Vol 7 (2) ◽

pp. 29-45

Author(s):

Tamaš Petrović ◽

Šekler Milenko ◽

Dušan Petrić ◽

Sava Lazić ◽

Diana Lupulović ◽

...

Keyword(s):

West Nile Virus ◽

Human Health ◽

Animal Health ◽

Monitoring Program ◽

Bird Species ◽

Control Measures ◽

Surveillance Program ◽

West Nile ◽

Veterinary Service ◽

The Republic

Serological and virological examination of the presence of human and animal infection caused by West Nile Virus (WNV) as well as the presence of the virus in vectors, which has been conducted during the past few years, confi rmed an active virus circulation in the territory of the Republic of Serbia. Based on the obtained results and anticipated intense circulation of WNV, which poses substantial risks for both public and animal health in Serbia, and having in mind its crucial role in the protection of public health, Veterinary Directorate of the Ministry of Agriculture and Environmental Protection infront the Veterinary Service launched and funded the national WNV monitoring program starting from April 2014. The Program encompassed the entire territory of the Republic of Serbia and was conducted by scientific and specialized veterinary institutes and fi eld veterinary service in close collaboration with qualifi ed entomologists and ornithologists. The principal objective of the monitoring – surveillance program is early detection of WNV in monitored regions, timely reporting of the virus presence and activation of human health service institutions and local authorities aimed at establishing the control measures - eradication of mosquitoes, informing the local community and taking all relevant preventive measures for human health protection. Th e surveillance program of the WNV occurrence and spread is based on direct and indirect surveillance of WNV in natural environment. Indirect surveillance encompasses serological testing of seronegative sentinel horses and poultry for the presence of WNV infection, and it is performing continuously and periodically during the most intensive mosquito activity (May – September). The number of sentinel animals that should be tested was defi ned at the district level, according to the rate of anticipated risk of WNV infection. Direct surveillance was performed through periodical and continuous testing of pooled mosquitoes samples collected at two-week intervals during peak mosquito season (May – September) and samples of wild birds (tissues of dead birds and throat swabs of captured live susceptible bird species). The number of samples was stipulated according to the anticipated risk rate in particular regions.

Download Full-text

West Nile Virus: Emerging Threat to Public Health and Animal Health

Journal of Veterinary Medical Education ◽

10.3138/jvme.30.2.143 ◽

2003 ◽

Vol 30 (2) ◽

pp. 143-144 ◽

Cited By ~ 4

Author(s):

Robert G. McLean

Keyword(s):

Public Health ◽

West Nile Virus ◽

Animal Health ◽

West Nile

Download Full-text

West Nile Virus and Tick-Borne Encephalitis Virus Are Endemic in Equids in Eastern Austria

Viruses ◽

10.3390/v13091873 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1873

Author(s):

Phebe de Heus ◽

Jolanta Kolodziejek ◽

Zdenĕk Hubálek ◽

Katharina Dimmel ◽

Victoria Racher ◽

...

Keyword(s):

West Nile Virus ◽

Quantitative Polymerase Chain Reaction ◽

Animal Health ◽

Encephalitis Virus ◽

Serum Samples ◽

West Nile ◽

Cross Sectional ◽

Tick Borne Encephalitis ◽

Eastern Austria ◽

Tick Borne Encephalitis Virus

The emergence of West Nile virus (WNV) and Usutu virus (USUV) in addition to the autochthonous tick-borne encephalitis virus (TBEV) in Europe causes rising concern for public and animal health. The first equine case of West Nile neuroinvasive disease in Austria was diagnosed in 2016. As a consequence, a cross-sectional seroprevalence study was conducted in 2017, including 348 equids from eastern Austria. Serum samples reactive by ELISA for either flavivirus immunoglobulin G or M were further analyzed with the plaque reduction neutralization test (PRNT-80) to identify the specific etiologic agent. Neutralizing antibody prevalences excluding vaccinated equids were found to be 5.3% for WNV, 15.5% for TBEV, 0% for USUV, and 1.2% for WNV from autochthonous origin. Additionally, reverse transcription quantitative polymerase chain reaction (RT-qPCR) was performed to detect WNV nucleic acid in horse sera and was found to be negative in all cases. Risk factor analysis did not identify any factors significantly associated with seropositivity.

Download Full-text

Macroecology of birds potentially susceptible to West Nile virus

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.2178 ◽

2018 ◽

Vol 285 (1893) ◽

pp. 20182178 ◽

Cited By ~ 6

Author(s):

María J. Tolsá ◽

Gabriel E. García-Peña ◽

Oscar Rico-Chávez ◽

Benjamin Roche ◽

Gerardo Suzán

Keyword(s):

West Nile Virus ◽

Spatial Scales ◽

Animal Health ◽

Bird Species ◽

Field Studies ◽

Zoonotic Diseases ◽

West Nile ◽

Bird Populations ◽

Time Space ◽

Wildlife Pathogens

Zoonotic diseases transmitted by wildlife affect biological conservation, public and animal health, and the economy. Current research efforts are aimed at finding wildlife pathogens at a given location. However, a meta-analytical approach may reveal emerging macroecological patterns in the host–pathogen relationship at different temporal and spatial scales. West Nile virus (WNV) is a pathogen with worldwide detrimental impacts on bird populations. To understand macroecological patterns driving WNV infection, we aimed to recognize unknown competent reservoirs using three disease metrics—serological prevalence (SP), molecular prevalence (MP) and mortality (M)—and test if these metrics are correlated with the evolutionary history, geographical origin of bird species, viral strain, time–space and methodology. We performed a quantitative review of field studies on birds sampled for WNV. We obtained 4945 observations of 949 species from 39 countries. Our analysis supported the idea that MP and M are good predictors of reservoir competence, and allowed us to identify potential competent reservoirs. Furthermore, results indicated that the variability of these metrics was attributable to phylogeny, time–space and sample size. A macroecological approach is needed to recognize susceptible species and competent reservoirs, and to identify other factors driving zoonotic diseases originating from wildlife.

Download Full-text

West Nile virus surveillance in Europe: moving towards an integrated animal-human-vector approach

Eurosurveillance ◽

10.2807/1560-7917.es.2017.22.18.30526 ◽

2017 ◽

Vol 22 (18) ◽

Cited By ~ 44

Author(s):

Céline M Gossner ◽

Laurence Marrama ◽

Marianne Carson ◽

Franz Allerberger ◽

Paolo Calistri ◽

...

Keyword(s):

Public Health ◽

West Nile Virus ◽

Animal Health ◽

European Countries ◽

Effective Vaccine ◽

Vector Surveillance ◽

West Nile ◽

Zoonotic Infections ◽

Health Authorities ◽

Public Health Authorities

This article uses the experience of five European countries to review the integrated approaches (human, animal and vector) for surveillance and monitoring of West Nile virus (WNV) at national and European levels. The epidemiological situation of West Nile fever in Europe is heterogeneous. No model of surveillance and monitoring fits all, hence this article merely encourages countries to implement the integrated approach that meets their needs. Integration of surveillance and monitoring activities conducted by the public health authorities, the animal health authorities and the authorities in charge of vector surveillance and control should improve efficiency and save resources by implementing targeted measures. The creation of a formal interagency working group is identified as a crucial step towards integration. Blood safety is a key incentive for public health authorities to allocate sufficient resources for WNV surveillance, while the facts that an effective vaccine is available for horses and that most infected animals remain asymptomatic make the disease a lesser priority for animal health authorities. The examples described here can support other European countries wishing to strengthen their WNV surveillance or preparedness, and also serve as a model for surveillance and monitoring of other (vector-borne) zoonotic infections.

Download Full-text

A panel of real-time PCR assays for the detection of Bourbon virus, Heartland virus, West Nile virus, and Trypanosoma cruzi in major disease–transmitting vectors

Journal of Veterinary Diagnostic Investigation ◽

10.1177/10406387211039549 ◽

2021 ◽

pp. 104063872110395

Author(s):

Anushri Warang ◽

Michael Zhang ◽

Shuping Zhang ◽

Zhenyu Shen

Keyword(s):

West Nile Virus ◽

Trypanosoma Cruzi ◽

Real Time ◽

Reverse Transcription ◽

Real Time Pcr ◽

Animal Health ◽

West Nile ◽

Pcr Assays ◽

Analytical Sensitivities ◽

Pathogen Surveillance

Vector-borne pathogens, such as Bourbon virus (BRBV), Heartland virus (HRTV), West Nile virus (WNV), and Trypanosoma cruzi (TCZ) are a great threat to public health and animal health. We developed a panel of TaqMan real-time PCR assays for pathogen surveillance. PCR targets were selected based on nucleic acid sequences deposited in GenBank. Primers and probes were either designed de novo or selected from publications. The coverages and specificities of the primers and probes were extensively evaluated by performing BLAST searches. Synthetic DNA or RNA fragments (gBlocks) were used as PCR templates in initial assay development and PCR positive controls in subsequent assay validation. For operational efficiency, the same thermocycling profile was used in BRBV, HRTV, and WNV reverse-transcription quantitative PCR (RT-qPCR) assays, and a similar thermocycling profile without the initial reverse-transcription step was used in TCZ qPCR. The assays were optimized by titrating primer and probe concentrations. The analytical sensitivities were 100, 100, 10, and 10 copies of gBlock per reaction for BRBV (Cq = 36.0 ± 0.7), HRTV (Cq = 36.6 ± 0.9), WNV (Cq = 35.5 ± 0.4), and TCZ (Cq = 38.8 ± 0.3), respectively. PCR sensitivities for vector genomic DNA or RNA spiked with gBlock reached 100, 100, 10, and 10 copies per reaction for BRBV, HRTV, WNV, and TCZ, respectively. PCR specificity evaluated against a panel of non-target pathogens showed no significant cross-reactivity. Our BRBV, HRTV, WNV, and TCZ PCR panel could support epidemiologic studies and pathogen surveillance.

Download Full-text

West Nile virus-neutralizing antibodies in wild birds from southern Spain

Epidemiology and Infection ◽

10.1017/s0950268816000133 ◽

2016 ◽

Vol 144 (9) ◽

pp. 1907-1911 ◽

Cited By ~ 11

Author(s):

M. FERRAGUTI ◽

J. MARTÍNEZ-DE LA PUENTE ◽

R. SORIGUER ◽

F. LLORENTE ◽

M. Á. JIMÉNEZ-CLAVERO ◽

...

Keyword(s):

West Nile Virus ◽

Neutralizing Antibodies ◽

Animal Health ◽

Climatic Conditions ◽

Southern Spain ◽

Insect Communities ◽

West Nile ◽

Usutu Virus ◽

Horse Farms ◽

Vector Borne

SUMMARYWest Nile virus (WNV) is an emerging vector-borne arbovirus with a zoonotic life-cycle whose main reservoir hosts are birds. In humans and horses, WNV infections rarely result in clinical disease but on occasions – depending on factors such as climatic conditions, insect communities and background immunity levels in local populations – they can lead to outbreaks that threaten public and animal health. We tested for the presence of WNV antibodies in 149 birds belonging to 32 different species. Samples were first tested using a bird-specific ELISA kit and then both positive and doubtful results were confirmed by neutralization tests using WNV and Usutu virus. WNV antibodies were confirmed in a resident Sylvia melanocephala juvenile, supporting the idea of local transmission of WNV in southern Spain in 2013. In addition, the serum from an adult blackbird (Turdus merula) showed neutralization of both WNV and Usutu virus. We discuss our results in light of the occurrence of WNV on horse farms in southern Spain in 2013.

Download Full-text