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Viruses Sep 2022The beginning decades of the 21st century have been marked by multiple emergence and re-emergence phenomena of viral diseases [...].
The beginning decades of the 21st century have been marked by multiple emergence and re-emergence phenomena of viral diseases [...].
Topics: Humans; Encephalitis Viruses, Tick-Borne; West Nile Fever; West Nile virus; Encephalitis, Tick-Borne; Antibodies, Viral
PubMed: 36298675
DOI: 10.3390/v14102120 -
Methods in Molecular Biology (Clifton,... 2023West Nile virus (WNV) is a mosquito-borne, single-stranded, positive-sense RNA virus belonging to the Flaviviridae family. After WNV gains entry through an infected...
West Nile virus (WNV) is a mosquito-borne, single-stranded, positive-sense RNA virus belonging to the Flaviviridae family. After WNV gains entry through an infected mosquito bite, it replicates in a variety of human cell types and produces a viremia. Although the majority of infected individuals remain asymptomatic, the manifested symptoms in some people range from a mild fever to severe neurological disorder with high morbidity and mortality. In addition, many who recover from WNV neuroinvasive infection present with long-term deficits, including weakness, fatigue, and cognitive problems. Since entering the USA in 1999, WNV has become the most common mosquito-borne virus in North America. Despite the intensive research over 20 years, there are still no approved vaccines or specific treatments for humans, and it remains an urgent need to understand the pathogenesis of WNV and develop specific therapeutics and vaccines.
Topics: Animals; Humans; West Nile virus; West Nile Fever; Viremia; North America
PubMed: 36331759
DOI: 10.1007/978-1-0716-2760-0_1 -
Journal of Medical Microbiology Jul 2023West Nile virus (WNV) is a positive-sense single-stranded RNA virus belonging to the family and is maintained in an enzootic cycle between avian hosts and mosquito...
West Nile virus (WNV) is a positive-sense single-stranded RNA virus belonging to the family and is maintained in an enzootic cycle between avian hosts and mosquito vectors. Humans, horses and other mammals are susceptible to infection but are dead-end hosts due to a low viraemia. The disease can manifest itself in a variety of clinical signs and symptoms in people and horses from mild fever to severe encephalitis and morbidity. There are no vaccines licensed for human protection, but parts of Europe, North America, Africa and Australia have vaccines commercially available for horses.
Topics: Humans; Animals; Horses; West Nile virus; West Nile Fever; Mammals; Europe; Africa
PubMed: 37459154
DOI: 10.1099/jmm.0.001730 -
Journal of Clinical Virology : the... Jun 2020West Nile virus (WNV) lineage 2, and especially the Hungarian clade, predominates in Europe. Most of the Hungarian clade strains cluster into 2 groups:...
BACKGROUND
West Nile virus (WNV) lineage 2, and especially the Hungarian clade, predominates in Europe. Most of the Hungarian clade strains cluster into 2 groups: Central/South-West European and Balkan.
OBJECTIVES
Since there was not any study on WNV in mosquitoes in Bulgaria, the present study was designed to test Culex spp. mosquitoes in areas near the Danube river. The aim of the study was to gain an insight into the recent molecular epidemiology of WNV in Bulgaria.
STUDY DESIGN
A total of 1871 Culex pipiens mosquitoes collected in 2018 and clinical samples from 23 patients with West Nile neuroinavsive disease observed in 2018 and 2019 were tested by TaqMan RT-PCR and RT-nested PCR and PCR products were sequenced.
RESULTS
WNV RNA was detected in clinical samples from 10 patients and in five (12.2 %) of 41 pools of Cx. pipiens mosquitos by realtime RT-PCR, resulting in a minimum infection rate of mosquitoes of 0.27 %. Phylogenetic analysis based on partial NS3 gene sequences from one clinical sample and four mosquito pools showed that all sequences clustered into the Hungarian clade of WNV lineage 2 and all but one were identical to respective sequences from Romania. Whole genome sequences of one mosquito pool belong to the Hungarian group of WNV lineage 2 and cluster in a separate subclade from the Bulgarian strain from 2015, suggesting that at least two different introductions occurred in Bulgaria.
CONCLUSIONS
The current study provides insights into the geographic distribution of WNV in Bulgaria.
Topics: Animals; Bulgaria; Culex; Genome, Viral; Humans; Mosquito Vectors; Phylogeny; West Nile Fever; West Nile virus; Whole Genome Sequencing
PubMed: 32305885
DOI: 10.1016/j.jcv.2020.104365 -
Viruses Nov 2022West Nile virus (WNV) is an emerging pathogen in Hungary, causing severe outbreaks in equines and humans since 2007. The aim of our study was to provide a comprehensive...
West Nile virus (WNV) is an emerging pathogen in Hungary, causing severe outbreaks in equines and humans since 2007. The aim of our study was to provide a comprehensive report on the clinical signs of West Nile neuroinvasive disease (WNND) in horses in Hungary. Clinical details of 124 confirmed equine WNND cases were collected between 2007 and 2019. Data about the seasonal and geographical presentation, demographic data, clinical signs, treatment protocols, and disease progression were evaluated. Starting from an initial case originating from the area of possible virus introduction by migratory birds, the whole country became endemic with WNV over the subsequent 12 years. The transmission season did not expand significantly during the data collection period, but vaccination protocols should be always reviewed according to the recent observations. There was not any considerable relationship between the occurrence of WNND and age, breed, or gender. Ataxia was by far the most common neurologic sign related to the disease, but weakness, behavioral changes, and muscle fasciculation appeared frequently. Apart from recumbency combined with inappetence, no other clinical sign or treatment regime correlated with survival. The survival rate showed a moderate increase throughout the years, possibly due to the increased awareness of practitioners.
Topics: Humans; Horses; Animals; West Nile Fever; Hungary; West Nile virus; Horse Diseases; Disease Outbreaks
PubMed: 36423160
DOI: 10.3390/v14112551 -
Viruses Jul 2020West Nile virus (WNV) is a flavivirus transmitted by mosquitoes. Birds are the reservoir for the virus; humans, horses and other mammals are dead-end hosts. Infections...
West Nile virus (WNV) is a flavivirus transmitted by mosquitoes. Birds are the reservoir for the virus; humans, horses and other mammals are dead-end hosts. Infections caused by WNV in humans can vary from asymptomatic infections to West Nile fever (WNF) or West Nile neuroinvasive disease (WNND). In 1995, a serosurvey was performed in Slovenia on forest workers, and WNV specific IgG antibodies were confirmed in 6.8% of the screened samples, indicating that WNV is circulating in Slovenia. No human disease cases were detected in Slovenia until 2013, when the first case of WNV infection was confirmed in a retrospective study in a 79-year old man with meningitis. In 2018, three patients with WNND were confirmed by laboratory tests, with detection of IgM antibodies in the cerebrospinal fluid of the patients. In one of the patients, WNV RNA was detected in the urine sample. In 2017, 2018 and 2019, a mosquito study was performed in Slovenia. Mosquitoes were sampled on 14 control locations and 35 additional locations in 2019. No WNV was detected in mosquitoes in 2017 and 2019, but we confirmed the virus in a pool of sp. mosquitoes in 2018. The virus was successfully isolated, and complete genome sequence was acquired. The whole genome of the WNV was also sequenced from the patient's urine sample. The whole genome sequences of the WNV virus detected in Slovenian patient and mosquito indicate the virus most likely spread from the north, because of the geographic proximity and because the sequences cluster with the Austrian and Hungarian sequences. A sentinel study was performed on dog sera samples, and we were able to confirm IgG antibodies in 1.8% and 4.3% of the samples in 2017 and 2018, respectively. Though Slovenia is not a highly endemic country for WNV, we have established that the virus circulates in Slovenia.
Topics: Aged; Animals; Antibodies, Viral; Culex; Culicidae; Dog Diseases; Dogs; Female; Genome, Viral; Humans; Male; Middle Aged; Phylogeny; Retrospective Studies; Slovenia; West Nile Fever; West Nile virus
PubMed: 32635155
DOI: 10.3390/v12070720 -
PLoS Neglected Tropical Diseases Oct 2022The detection of the first cases of transfusion-transmitted West Nile virus in 2002 posed a new challenge for transfusion safety. Institutions like the World Health...
BACKGROUND
The detection of the first cases of transfusion-transmitted West Nile virus in 2002 posed a new challenge for transfusion safety. Institutions like the World Health Organization have stated that blood transfusion centers need to know the epidemiology of the different emerging infectious agents and their impact on blood transfusion. The aim of the study is to review the published cases of arbovirus transmission through transfusion of blood or blood components and to analyze their main clinical and epidemiological characteristics.
MATERIAL AND METHODS
Systematic literature searches were conducted in MEDLINE, Embase and Scopus. Pairs of review authors selected a variety of scientific publications reporting cases of transfusion-transmitted arboviruses. Main clinical and epidemiological characteristics were reviewed of the cases described. The study protocol was registered in PROSPERO CRD42021270355.
RESULTS
A total of 74 cases of transfusion-transmitted infections were identified from 10 arboviruses: West Nile virus (n = 42), dengue virus (n = 18), Zika virus (n = 3), yellow fever vaccine virus (n = 3), tick-borne encephalitis virus (n = 2), Japanese encephalitis virus (n = 2), Powassan virus (n = 1), St. Louis encephalitis virus (n = 1), Ross River virus (n = 1) and Colorado tick fever virus (n = 1). The blood component most commonly involved was red blood cells (N = 35, 47.3%; 95% confidence interval [CI] 35.9% to 58.7%). In 54.1% (N = 40; 95% CI: 42.7%-65.47%) of the cases, the recipient was immunosuppressed. Transmission resulted in death in 18.9% (N = 14; 95% CI: 10.0%-27.8%) of the recipients. In addition, 18 additional arboviruses were identified with a potential threat to transfusion safety.
DISCUSSION
In the last 20 years, the number of published cases of transfusion-transmitted arboviruses increased notably, implicating new arboviruses. In addition, a significant number of arboviruses that may pose a threat to transfusion safety were detected. In the coming years, it is expected that transmission of arboviruses will continue to expand globally. It is therefore essential that all responsible agencies prepare for this potential threat to transfusion safety.
Topics: Humans; Arbovirus Infections; Arboviruses; Blood Transfusion; West Nile virus; Yellow Fever Vaccine; Zika Virus; Zika Virus Infection
PubMed: 36201547
DOI: 10.1371/journal.pntd.0010843 -
MMWR. Morbidity and Mortality Weekly... Aug 2023Arthropod-borne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes or ticks, and in the continental United States, West...
Arthropod-borne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes or ticks, and in the continental United States, West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease. Other arboviruses cause sporadic cases of disease as well as occasional outbreaks. This report summarizes 2021 surveillance data reported to CDC by U.S. jurisdictions for nationally notifiable arboviruses; the report excludes chikungunya, dengue, yellow fever, and Zika virus disease cases, because these infections were acquired primarily through travel during 2021. Forty-nine states and the District of Columbia reported 3,035 cases of domestic arboviral disease, including those caused by West Nile (2,911), La Crosse (40), Jamestown Canyon (32), Powassan (24), St. Louis encephalitis (17), unspecified California serogroup (six), and eastern equine encephalitis (five) viruses. Among the WNV disease cases, 2,008 (69%) were classified as neuroinvasive disease, for a national incidence of 0.61 cases per 100,000 population. Because arboviral diseases continue to cause serious illness, maintaining surveillance programs to monitor their transmission and prevalence is important to the direction and promotion of prevention activities. Health care providers should consider arboviral infections in the differential diagnosis of aseptic meningitis and encephalitis, obtain appropriate specimens for laboratory testing, and promptly report cases to public health authorities. Prevention depends on community and household efforts to reduce vector populations and personal protective measures to prevent mosquito and tick bites, such as use of Environmental Protection Agency-registered insect repellent and wearing protective clothing.
Topics: Horses; Animals; Humans; West Nile virus; Mosquito Vectors; Arbovirus Infections; Yellow Fever; District of Columbia; Zika Virus Infection; Culicidae; Zika Virus
PubMed: 37616182
DOI: 10.15585/mmwr.mm7234a1 -
Clinical Infectious Diseases : An... Aug 2021West Nile virus (WNV) is the most commonly reported mosquito-borne disease in the USA. California reports more WNV disease than any other state.
BACKGROUND
West Nile virus (WNV) is the most commonly reported mosquito-borne disease in the USA. California reports more WNV disease than any other state.
METHODS
We identified WNV-associated hospitalizations from 2004 through 2017 in California and estimated hospitalization incidence using Patient Discharge Data. We described demographic, geographic, and clinical characteristics of WNV hospitalizations; identified risk factors for in-hospital death; and tabulated hospitalization charges.
RESULTS
From 2004 through 2017, 3109 Californians were hospitalized with WNV (median, 214 patients/year; range, 72-449). The majority were male (1983; 63.8%) and aged ≥60 years (1766; 56.8%). The highest median annual hospitalization rate (0.88 hospitalizations/100 000 persons) was in the Central Valley, followed by southern California (0.59 hospitalizations/100 000 persons). Most patients (2469; 79.4%) had ≥1 underlying condition, including hypertension, cardiovascular disease, diabetes, chronic kidney disease, or immunosuppression due to medications or disease. Median hospitalization length of stay was 12 days (interquartile range, 6-23 days). During hospitalization, 1317 (42%) patients had acute respiratory failure and/or sepsis/septic shock, 772 (24.8%) experienced acute kidney failure, and 470 (15.1%) had paralysis; 272 (8.8%) patients died. Nearly 47% (1444) of patients were discharged for additional care. During these 14 years, $838 680 664 (mean $59.9 million/year) was charged for WNV hospitalizations, 73.9% through government payers at a median charge of $142 321/patient.
CONCLUSIONS
WNV-associated hospitalizations were substantial and costly in California. Hospitalization incidence was higher in males, elderly persons, and patients with underlying conditions. WNV persists as a costly and severe public health threat in California.
Topics: Aged; Animals; California; Female; Hospital Mortality; Hospitalization; Humans; Male; Vaccines; West Nile Fever; West Nile virus
PubMed: 32525967
DOI: 10.1093/cid/ciaa749 -
Nature Communications Oct 2023It is unclear whether West Nile virus (WNV) circulates between Africa and Europe, despite numerous studies supporting an African origin and high transmission in Europe....
It is unclear whether West Nile virus (WNV) circulates between Africa and Europe, despite numerous studies supporting an African origin and high transmission in Europe. We integrated genomic data with geographic observations and phylogenetic and phylogeographic inferences to uncover the spatial and temporal viral dynamics of WNV between these two continents. We focused our analysis towards WNV lineages 1 (L1) and 2 (L2), the most spatially widespread and pathogenic WNV lineages. Our study shows a Northern-Western African origin of L1, with back-and-forth exchanges between West Africa and Southern-Western Europe; and a Southern African origin of L2, with one main introduction from South Africa to Europe, and no back introductions observed. We also noticed a potential overlap between L1 and L2 Eastern and Western phylogeography and two Afro-Palearctic bird migratory flyways. Future studies linking avian and mosquito species susceptibility, migratory connectivity patterns, and phylogeographic inference are suggested to elucidate the dynamics of emerging viruses.
Topics: Animals; West Nile virus; West Nile Fever; Phylogeny; Europe; South Africa; Birds
PubMed: 37833275
DOI: 10.1038/s41467-023-42185-7