-
New Microbes and New Infections 2022while the world is concentrated on fighting SARS-CoV-2, other viruses such as West Nile virus (WNV) attack the communities silently. West Nile Virus (WNV) is established...
UNLABELLED
while the world is concentrated on fighting SARS-CoV-2, other viruses such as West Nile virus (WNV) attack the communities silently. West Nile Virus (WNV) is established as one of the infectious agents that transmissible blood transfusion. The present study is cross-sectional, conducted in the central blood bank, Khartoum state, Sudan, and aimed to determine WNV IgG antibodies among blood donors.
METHODS
the antibodies of the IgG class against West Nile virus in the serum were determined using the ELISA technique. Ninety blood donors participated in this study.
RESULTS
the results showed that 67(74.4%) of participants had positive IgG for WNV. The majority of positive participants 28/67(41.8%) had an age between 28-37 years followed by an age group 18-27 years 24/67(35.8), the dominant blood group of the positive WNV IgG participants was A+ 26/67 (38.8%) followed by O+ 19/67(28.4%). The result displayed that 40(59.7%) of the positive IgG had donated blood several times and 58 (86.6%) had a blood transfusion. Statistical analysis showed an insignificant association between age group, blood group, blood donation, blood transfusion, and West Nile Virus.
CONCLUSIONS
the high IgG seroprevalence (which indicated previous infection) in the present study suggests high virus circulation in Sudan. This situation proposed that WNF screening test should be part of blood transfusion screening tests in Sudan.
PubMed: 36568644
DOI: 10.1016/j.nmni.2022.101062 -
Preventive Veterinary Medicine Aug 2023The largest epidemic of West Nile virus (WNV) reported ever in Spain in both humans and equines occurred in 2020, affecting 77 humans and 139 equine herds. Here, we...
The largest epidemic of West Nile virus (WNV) reported ever in Spain in both humans and equines occurred in 2020, affecting 77 humans and 139 equine herds. Here, we aimed to monitor the outbreaks detected in equid herds in Andalusia (southern Spain), the Spanish region where 89.9% of the outbreaks were reported, and to evaluate the virus circulation and risk factor associated with WNV exposure in the affected herds. The first WNV case was detected in mid-July 2020, the number of outbreaks peaked in mid-August and the last one was confirmed on 26th October 2020. WNV lineage 1 was detected in 12 clinically affected horses using real time RT-PCR. Molecular analysis evidenced high nucleotide identity with WNV sequences obtained from humans, birds and mosquitoes from Spain and Italy between 2020 and 2022. Between five and eight months after the WNV epidemic, a total of 724 equids (including 485 unvaccinated and 239 vaccinated animals) from 113 of the 125 affected herds in Andalusia were sampled. IgM and IgG antibodies against WNV were detected in 1.6% (8/485; 95%IC: 0.0-2.5) and 61.9% (300/485; 95%IC: 58.3-65.5) of the unvaccinated individuals, respectively. The seropositivity in vaccinated horses was 86.6% (207/239). The main risk factors associated with WNV exposure in unvaccinated equids were the breed (crossbreed), the location of animals in spring-summer (outside), and the presence of natural water ponds close to the surveyed herds. The high individual seroprevalence obtained in the affected herds indicates that WNV circulation was more widespread than the reported by passive surveillance during the WNV epidemic in 2020. The re-emergence of WNV in 2020 in southern Spain evidenced the needed to improve integrated surveillance systems, minimizing the impact of future cases in equids and humans in high-risk areas.
Topics: Humans; Animals; Horses; West Nile virus; Spain; West Nile Fever; Seroepidemiologic Studies; Antibodies, Viral; Horse Diseases
PubMed: 37481993
DOI: 10.1016/j.prevetmed.2023.105975 -
Viruses Dec 2023West Nile Virus (WNV) is a mosquito vector-borne zoonosis with an increasing incidence in Europe that has become a public health concern. In Spain, although local...
West Nile Virus (WNV) is a mosquito vector-borne zoonosis with an increasing incidence in Europe that has become a public health concern. In Spain, although local circulation has been known for decades, until 2020, when a large outbreak occurred, West Nile Virus cases were scarce and mostly occurred in southern Spain. Since then, there have been new cases every year and the pathogen has spread to new regions. Thus, monitoring of circulating variants and lineages plays a fundamental role in understanding WNV evolution, spread and dynamics. In this study, we sequenced WNV consensus genomes from mosquito pools captured in 2022 as part of a newly implemented surveillance program in southern Spain and compared it to other European, African and Spanish sequences. Characterization of WNV genomes in mosquitoes captured in 2022 reveals the co-circulation of two WNV lineage 1 variants, the one that caused the outbreak in 2020 and another variant that is closely related to variants reported in Spain in 2012, France in 2015, Italy in 2021-2022 and Senegal in 2012-2018. The geographic distribution of these variants indicates that WNV L1 dynamics in southern Europe include an alternating dominance of variants in some territories.
Topics: Animals; Humans; West Nile virus; West Nile Fever; Spain; Culicidae; Europe
PubMed: 38140614
DOI: 10.3390/v15122372 -
Euro Surveillance : Bulletin Europeen... May 2021Cases of West Nile neuroinvasive disease (WNND) in Spain increased in summer 2020. Here we report on this increase and the local, regional and national public health...
Cases of West Nile neuroinvasive disease (WNND) in Spain increased in summer 2020. Here we report on this increase and the local, regional and national public health measures taken in response. We analysed data from regional surveillance networks and the National Epidemiological Surveillance Network, both for human and animal West Nile virus (WNV) infection. During the 2020 season, a total of 77 human cases of WNV infection (median age 65 years; 60% males) were detected in the south-west of Spain; 72 (94%) of these cases developed WNND, presenting as meningoencephalitis, seven of which were fatal. In the previous two decades, only six human cases of WNND were detected in Spain. Reduced activities for vector control this season, together with other factors, might have contributed to the massive increase. Public health measures including vector control, campaigns to raise awareness among physicians and the general population, and interventions to ensure the safety of donations of blood products, organs, cells and tissues were effective to reduce transmission. Going forward, maintenance of vector control activities and an update of the vector-borne diseases response plan in Spain is needed.
Topics: Aged; Animals; Female; Humans; Male; Meningoencephalitis; Seasons; Spain; West Nile Fever; West Nile virus
PubMed: 33988123
DOI: 10.2807/1560-7917.ES.2021.26.19.2002010 -
Journal of the American Mosquito... Dec 2020Identifying the array of vectors that play a role in perpetuating West Nile virus (WNV) infection in endemic foci will help in controlling the disease. Aedes japonicus...
Identifying the array of vectors that play a role in perpetuating West Nile virus (WNV) infection in endemic foci will help in controlling the disease. Aedes japonicus has the potential to be a vector in the wild of at least 3 kinds of encephalitis, including WNV. Aedes japonicus is a nonnative species in the USA that is temperature tolerant and a potential human biter. Detection of WNV in mosquito pools of this field-collected invasive species, combined with their ability to feed on humans, make this mosquito species a possible public health concern. In this study, we collected mosquito abundance data and tested them for WNV-positive mosquito samples from 3 counties in New York State. We found a significant association between the season and land demography and the likelihood of the virus in Ae. japonicus.
Topics: Aedes; Animals; Female; New York; West Nile virus
PubMed: 33647113
DOI: 10.2987/20-6958.1 -
Viruses Apr 2020West Nile virus (WNV) lineage 2 is expanding and causing large outbreaks in Europe. In this study, we analyzed the epidemiological, clinical, and virological features of...
West Nile virus (WNV) lineage 2 is expanding and causing large outbreaks in Europe. In this study, we analyzed the epidemiological, clinical, and virological features of WNV lineage 2 infection during the large outbreak that occurred in northern Italy in 2018. The study population included 86 patients with neuroinvasive disease (WNND), 307 with fever (WNF), and 34 blood donors. Phylogenetic analysis of WNV full genome sequences from patients' samples showed that the virus belonged to the widespread central/southern European clade of WNV lineage 2 and was circulating in the area at least since 2014. The incidence of WNND and WNF progressively increased with age and was higher in males than in females. Among WNND patients, the case fatality rate was 22%. About 70% of blood donors reported symptoms during follow-up. Within the first week after symptom onset, WNV RNA was detectable in the blood or urine of 80% of patients, while 20% and 40% of WNND and WNF patients, respectively, were WNV IgM-seronegative. In CSF samples of WNND patients, WNV RNA was typically detectable when WNV IgM antibodies were absent. Blunted or no WNV IgM response and high WNV IgG levels were observed in seven patients with previous flavivirus immunity.
Topics: Aged; Aged, 80 and over; Animals; Antibodies, Viral; Culicidae; Disease Outbreaks; Female; Genome, Viral; Geography, Medical; Humans; Immunoglobulin G; Immunoglobulin M; Incidence; Male; Middle Aged; Public Health Surveillance; West Nile Fever; West Nile virus
PubMed: 32325716
DOI: 10.3390/v12040458 -
International Journal of Environmental... Jun 2020Despite many studies on West Nile Virus (WNV) in the US, including the reservoir role of bird species and the summer shifts of the mosquito, feeding from birds to... (Review)
Review
Despite many studies on West Nile Virus (WNV) in the US, including the reservoir role of bird species and the summer shifts of the mosquito, feeding from birds to mammals, there have been few equivalent studies in the neighboring regions of Canada where WNV is endemic. Here, a priority list of bird species likely involved in WNV transmission in the greater Montréal area is constructed by combining three sources of data: (i) from WNV surveillance in wild birds (2002-2015); (ii) blood meal analysis of (CPR), the primary enzootic vectors of WNV in the region, collected from surveillance in 2008 and 2014; (iii) literature review on the sero-prevalence/host competence of resident birds. Each of these data sources yielded 18, 23 and 53 species, and overall, 67 different bird species were identified as potential WNV amplifiers/reservoirs. Of those identified from CPR blood meals, Common starlings, American robins, Song sparrows and House sparrows ranked the highest and blood meal analysis demonstrated a seasonal shift in feed preference from birds to mammals by CPR. Our study indicates that there are broad similarities in the ecology of WNV between our region and the northeastern US, although the relative importance of bird species varies somewhat between regions.
Topics: Animals; Bird Diseases; Birds; Canada; Culex; Mosquito Vectors; Quebec; Seroepidemiologic Studies; Species Specificity; West Nile Fever; West Nile virus
PubMed: 32585999
DOI: 10.3390/ijerph17124517 -
Journal of Virology Sep 2021Dengue virus (DENV) and West Nile virus (WNV) are arthropod-transmitted flaviviruses that cause systemic vascular leakage and encephalitis syndromes, respectively, in...
Dengue virus (DENV) and West Nile virus (WNV) are arthropod-transmitted flaviviruses that cause systemic vascular leakage and encephalitis syndromes, respectively, in humans. However, the viral factors contributing to these specific clinical disorders are not completely understood. Flavivirus nonstructural protein 1 (NS1) is required for replication, expressed on the cell surface, and secreted as a soluble glycoprotein, reaching high levels in the blood of infected individuals. Extracellular DENV NS1 and WNV NS1 interact with host proteins and cells, have immune evasion functions, and promote endothelial dysfunction in a tissue-specific manner. To characterize how differences in DENV NS1 and WNV NS1 might function in pathogenesis, we generated WNV NS1 variants with substitutions corresponding to residues found in DENV NS1. We discovered that the substitution NS1-P101K led to reduced WNV infectivity in the brain and attenuated lethality in infected mice, although the virus replicated efficiently in cell culture and peripheral organs and bound at wild-type levels to brain endothelial cells and complement components. The P101K substitution resulted in reduced NS1 antigenemia in mice, and this was associated with reduced WNV spread to the brain. Because exogenous administration of NS1 protein rescued WNV brain infectivity in mice, we conclude that circulating WNV NS1 facilitates viral dissemination into the central nervous system and impacts disease outcomes. Flavivirus NS1 serves as an essential scaffolding molecule during virus replication but also is expressed on the cell surface and is secreted as a soluble glycoprotein that circulates in the blood of infected individuals. Although extracellular forms of NS1 are implicated in immune modulation and in promoting endothelial dysfunction at blood-tissue barriers, it has been challenging to study specific effects of NS1 on pathogenesis without disrupting its key role in virus replication. Here, we assessed WNV NS1 variants that do not affect virus replication and evaluated their effects on pathogenesis in mice. Our characterization of WNV NS1-P101K suggests that the levels of NS1 in the circulation facilitate WNV dissemination to the brain and affect disease outcomes. Our findings facilitate understanding of the role of NS1 during flavivirus infection and support antiviral strategies for targeting circulating forms of NS1.
Topics: Animals; Brain; Dengue Virus; Endothelial Cells; Female; Flavivirus; Immune Evasion; Male; Mice; Mice, Inbred C57BL; Viral Nonstructural Proteins; Virus Replication; West Nile Fever; West Nile virus
PubMed: 34346770
DOI: 10.1128/JVI.00844-21 -
The Journal of General Virology Apr 2020The fidelity of flaviviruses is thought to be tightly regulated for optimal fitness within and between hosts. West Nile virus (WNV) high-fidelity (HiFi) mutations V793I...
The fidelity of flaviviruses is thought to be tightly regulated for optimal fitness within and between hosts. West Nile virus (WNV) high-fidelity (HiFi) mutations V793I and G806R within the RNA-dependent RNA polymerase, and low-fidelity (LoFi) mutation T248I within the methyltransferase, were previously shown to attenuate infectivity and replicative fitness in mosquitoes and (CXT) cells but not in mammalian cells. We hypothesized that fidelity alterations would modify adaptation and maintenance in a host-specific manner. To test this hypothesis, wild-type (WT), HiFi (V793I/G806R) and LoFi (T248I) variants were sequentially passaged eight times in avian (PDE) or mosquito cells, or alternately between the two. Initial characterization confirmed that fidelity mutants are attenuated in mosquito, but not avian, cells. Deep sequencing revealed mutations unique to both cell lines and fidelity mutants, including ENV G1378A, a mutation associated with avian cell adaptation. To characterize maintenance and adaptation, viral outputs were monitored throughout passaging and viral fitness was assessed. The results indicate that fidelity mutants can at times recover fitness during mosquito cell passage, but remain attenuated relative to WT. Despite similar initial fitness, LoFi mutants were impaired during sequential passage in avian cells. Conversely, HiFi mutants passaged in avian cells showed increased adaptation, suggesting that increased fidelity may be advantageous in avian hosts. Although some adaptation occurred with individual mutants, the output titres of fidelity mutants were on average lower and were often lost during host switching. These data confirm that arbovirus fidelity is likely fine-tuned to maximize survival in disparate hosts.
Topics: Adaptation, Physiological; Animals; Birds; Cell Line; Computational Biology; Culicidae; Ducks; Host Microbial Interactions; Mutation; Quasispecies; RNA-Dependent RNA Polymerase; Serial Passage; Viral Envelope Proteins; Virus Replication; West Nile virus
PubMed: 32068528
DOI: 10.1099/jgv.0.001393 -
PLoS Neglected Tropical Diseases Nov 2020The California Arbovirus Surveillance Program was initiated over 50 years ago to track endemic encephalitides and was enhanced in 2000 to include West Nile virus (WNV)...
The California Arbovirus Surveillance Program was initiated over 50 years ago to track endemic encephalitides and was enhanced in 2000 to include West Nile virus (WNV) infections in humans, mosquitoes, sentinel chickens, dead birds and horses. This comprehensive statewide program is a function of strong partnerships among the California Department of Public Health (CDPH), the University of California, and local vector control and public health agencies. This manuscript summarizes WNV surveillance data in California since WNV was first detected in 2003 in southern California. From 2003 through 2018, 6,909 human cases of WNV disease, inclusive of 326 deaths, were reported to CDPH, as well as 730 asymptomatic WNV infections identified during screening of blood and organ donors. Of these, 4,073 (59.0%) were reported as West Nile neuroinvasive disease. California's WNV disease burden comprised 15% of all cases that were reported to the U.S. Centers for Disease Control and Prevention during this time, more than any other state. Additionally, 1,299 equine WNV cases were identified, along with detections of WNV in 23,322 dead birds, 31,695 mosquito pools, and 7,340 sentinel chickens. Annual enzootic detection of WNV typically preceded detection in humans and prompted enhanced intervention to reduce the risk of WNV transmission. Peak WNV activity occurred from July through October in the Central Valley and southern California. Less than five percent of WNV activity occurred in other regions of the state or outside of this time. WNV continues to be a major threat to public and wild avian health in California, particularly in southern California and the Central Valley during summer and early fall months. Local and state public health partners must continue statewide human and mosquito surveillance and facilitate effective mosquito control and bite prevention measures.
Topics: Animals; Base Sequence; Birds; California; Chickens; Culex; Epidemiological Monitoring; Horses; Humans; Mosquito Vectors; RNA, Viral; Seasons; Sequence Analysis, RNA; West Nile Fever; West Nile virus
PubMed: 33206634
DOI: 10.1371/journal.pntd.0008841