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Methods in Molecular Biology (Clifton,... 2016West Nile virus (WNV) can cause severe neuroinvasive disease in humans and currently no vaccine or specific treatments are available. As aging is the most prominent risk... (Review)
Review
West Nile virus (WNV) can cause severe neuroinvasive disease in humans and currently no vaccine or specific treatments are available. As aging is the most prominent risk factor for WNV, age-related immune dysregulation likely plays an essential role in host susceptibility to infection with WNV. In this review, we summarize recent findings in effects of aging on immune responses to WNV infection. In particular, we focus on the age-dependent dysregulation of innate immune cell types-neutrophils, macrophages, and dendritic cells-in response to WNV infection, as well as age-related alterations in NK cells and γδ T cells that may associate with increased WNV susceptibility in older people. We also highlight two advanced technologies, i.e., mass cytometry and microRNA profiling, which significantly contribute to systems-level study of immune dysregulation in aging and should facilitate new discoveries for therapeutic intervention against WNV.
Topics: Adaptive Immunity; Aging; Disease Susceptibility; Gene Expression Regulation; Humans; Immunity, Innate; MicroRNAs; Viral Load; West Nile Fever; West Nile virus
PubMed: 27188562
DOI: 10.1007/978-1-4939-3670-0_18 -
Emerging Infectious Diseases Apr 2020We detected West Nile virus (WNV) nucleic acid in crocodiles (Crocodylus niloticus) in Zambia. Phylogenetically, the virus belonged to lineage 1a, which is predominant...
We detected West Nile virus (WNV) nucleic acid in crocodiles (Crocodylus niloticus) in Zambia. Phylogenetically, the virus belonged to lineage 1a, which is predominant in the Northern Hemisphere. These data provide evidence that WNV is circulating in crocodiles in Africa and increases the risk for animal and human transmission.
Topics: Alligators and Crocodiles; Animals; Humans; West Nile Fever; West Nile virus; Zambia
PubMed: 32187004
DOI: 10.3201/eid2604.190954 -
Methods in Molecular Biology (Clifton,... 2023Primary neurons are very valuable cells to study the pathogenesis of neurotropic viruses, such as West Nile virus. The mouse primary neurons can be used to assess viral...
Primary neurons are very valuable cells to study the pathogenesis of neurotropic viruses, such as West Nile virus. The mouse primary neurons can be used to assess viral infection profiles and cellular immune responses to a viral infection. However, successful isolation and culture of mouse neurons can be challenging. Here, we report a step-by-step method to prepare a primary neuron culture from adult mice.
Topics: Animals; Mice; West Nile Fever; West Nile virus; Neurons; Immunity, Cellular
PubMed: 36331762
DOI: 10.1007/978-1-0716-2760-0_4 -
Viruses Aug 2020West Nile virus (WNV) and Usutu virus (USUV) are genetically related neurotropic mosquito-borne flaviviruses, which frequently co-circulate in nature. Despite USUV... (Comparative Study)
Comparative Study
West Nile virus (WNV) and Usutu virus (USUV) are genetically related neurotropic mosquito-borne flaviviruses, which frequently co-circulate in nature. Despite USUV seeming to be less pathogenic for humans than WNV, the clinical manifestations induced by these two viruses often overlap and may evolve to produce severe neurological complications. The aim of this study was to investigate the effects of WNV and USUV infection on human induced pluripotent stem cell-derived neural stem cells (hNSCs), as a model of the neural progenitor cells in the developing fetal brain and in adult brain. Zika virus (ZIKV), a flavivirus with known tropism for NSCs, was used as the positive control. Infection of hNSCs and viral production, effects on cell viability, apoptosis, and innate antiviral responses were compared among viruses. WNV displayed the highest replication efficiency and cytopathic effects in hNSCs, followed by USUV and then ZIKV. In these cells, both WNV and USUV induced the overexpression of innate antiviral response genes at significantly higher levels than ZIKV. Expression of interferon type I, interleukin-1β and caspase-3 was significantly more elevated in WNV- than USUV-infected hNSCs, in agreement with the higher neuropathogenicity of WNV and the ability to inhibit the interferon response pathway.
Topics: Apoptosis; Cell Survival; Cells, Cultured; Flavivirus; Humans; Immunity, Innate; Induced Pluripotent Stem Cells; Kinetics; Neural Stem Cells; Virulence; Virus Replication; West Nile virus
PubMed: 32806715
DOI: 10.3390/v12080882 -
MBio Oct 2022RNA viruses include respiratory viruses, such as coronaviruses and influenza viruses, as well as vector-borne viruses, like dengue and West Nile virus. RNA viruses like... (Review)
Review
RNA viruses include respiratory viruses, such as coronaviruses and influenza viruses, as well as vector-borne viruses, like dengue and West Nile virus. RNA viruses like these encounter various environments when they copy themselves and spread from cell to cell or host to host. differences, such as geographical location and humidity, affect their stability and transmission, while differences, such as pH and host gene expression, impact viral receptor binding, viral replication, and the host immune response against the viral infection. A critical factor affecting RNA viruses both and , and defining the outcome of viral infections and the direction of viral evolution, is temperature. In this minireview, we discuss the impact of temperature on viral replication, stability, transmission, and adaptation, as well as the host innate immune response. Improving our understanding of how RNA viruses function, survive, and spread at different temperatures will improve our models of viral replication and transmission risk analyses.
Topics: Humans; Temperature; Virus Replication; RNA Viruses; West Nile virus; RNA Virus Infections
PubMed: 35980031
DOI: 10.1128/mbio.02021-22 -
Viruses Dec 2021Mosquitoes collected from mid-December 2020 to early March 2021 from hibernacula in northeastern Germany, a region of West Nile virus (WNV) activity since 2018, were...
Mosquitoes collected from mid-December 2020 to early March 2021 from hibernacula in northeastern Germany, a region of West Nile virus (WNV) activity since 2018, were examined for WNV-RNA. Among the 6101 mosquitoes tested in 722 pools of up to 12 specimens, one pool of 10 complex mosquitoes collected in early March 2021 in the cellar of a medieval castle in Rosslau, federal state of Saxony-Anhalt, tested positive. Subsequent mosquito DNA analysis produced biotype . The pool homogenate remaining after nucleic acid extraction failed to grow the virus on Vero and C6/36 cells. Sequencing of the viral coding region, however, demonstrated high homology with virus strains previously collected in Germany, e.g., from humans, birds, and mosquitoes, which have been designated the East German WNV clade. The finding confirms the expectation that WNV can overwinter in mosquitoes in Germany, facilitating an early start to the natural transmission season in the subsequent year. On the other hand, the calculated low infection prevalence of 0.016-0.20%, depending on whether one or twelve of the mosquitoes in the positive pool was/were infected, indicates a slow epidemic progress and mirrors the still-hypoendemic situation in Germany. In any case, local overwintering of the virus in mosquitoes suggests its long-term persistence and an enduring public health issue.
Topics: Animals; Culicidae; Germany; Humans; Mosquito Vectors; Seasons; West Nile Fever; West Nile virus
PubMed: 34960732
DOI: 10.3390/v13122463 -
Tropical Medicine & International... Oct 2017Screening of mosquitoes for viruses is an important forecasting tool for emerging and re-emerging arboviruses. Iran has been known to harbour medically important...
OBJECTIVE
Screening of mosquitoes for viruses is an important forecasting tool for emerging and re-emerging arboviruses. Iran has been known to harbour medically important arboviruses such as West Nile virus (WNV) and dengue virus (DENV) based on seroepidemiological data. However, there are no data about the potential mosquito vectors for arboviruses in Iran. This study was performed to provide mosquito and arbovirus data from Iran.
MATERIALS AND METHODS
A total of 32 317 mosquitos were collected at 16 sites in five provinces of Iran in 2015 and 2016. RT-PCR for detection of flaviviruses was performed. The PCR amplicons were sequenced, and 109 WNV sequences, including one obtained in this study, were used for phylogenetic analyses.
RESULTS
The 32 317 mosquito specimens belonging to 25 species were morphologically distinguished and distributed into 1222 pools. Culex pipiens s.l. comprised 56.429%. One mosquito pool (0.08%), containing 46 unfed Cx. pipiens pipiens form pipiens (Cpp) captured in August 2015, was positive for flavivirus RNA. Subsequent sequencing and phylogenetic analyses revealed that the detected Iranian WNV strain belongs to lineage 2 and clusters with a strain recently detected in humans. No flaviviruses other than WNV were detected in the mosquito pools.
CONCLUSION
Cpp could be a vector for WNV in Iran. Our findings indicate recent circulation of WNV lineage-2 strain in Iran and provide a solid base for more targeted arbovirus surveillance programs.
Topics: Animals; Culex; Humans; Insect Vectors; Iran; Polymerase Chain Reaction; West Nile Fever; West Nile virus
PubMed: 28746985
DOI: 10.1111/tmi.12935 -
Emerging Infectious Diseases Jan 2023We collected >40,000 mosquitoes from 5 provinces in South Africa during 2011-2018 and screened for zoonotic flaviviruses. We detected West Nile virus in mosquitoes from...
We collected >40,000 mosquitoes from 5 provinces in South Africa during 2011-2018 and screened for zoonotic flaviviruses. We detected West Nile virus in mosquitoes from conservation and periurban sites and potential new mosquito vectors; Banzi virus was rare. Our results suggest flavivirus transmission risks are increasing in South Africa.
Topics: Animals; Culicidae; South Africa; Culex; Flavivirus; West Nile virus; Mosquito Vectors; West Nile Fever
PubMed: 36573591
DOI: 10.3201/eid2901.220036 -
Euro Surveillance : Bulletin Europeen... Oct 2018Between 28 June and 17 September 2018, 27 cases of human West Nile virus infections were recorded in Austria; four cases of West Nile neuroinvasive disease, 11 cases of...
Between 28 June and 17 September 2018, 27 cases of human West Nile virus infections were recorded in Austria; four cases of West Nile neuroinvasive disease, 11 cases of West Nile fever, six infections detected by blood donation screening and six imported cases. In addition, 18 cases of human Usutu virus infections (all blood donors) were recorded. This is the highest number of annual infections recorded in Austria since the introduction of both viruses.
Topics: Austria; Disease Notification; Flavivirus; Flavivirus Infections; Humans; West Nile Fever; West Nile virus
PubMed: 30376913
DOI: 10.2807/1560-7917.ES.2018.23.43.1800545 -
Environmental Monitoring and Assessment Mar 2021The present work investigates the increase of confirmed cases of West Nile virus and the relationship between weather-related patterns and the geographical expansion of...
The present work investigates the increase of confirmed cases of West Nile virus and the relationship between weather-related patterns and the geographical expansion of West Nile virus in Greece, with a special focus on West Attica, Central Greece, a semi-arid, ecologically fragile Mediterranean area. Using data from the European Environment Agency, European Drought Observatory of Joint Research Centre, the pairwise relationship between surface air temperature anomalies, precipitation anomalies, soil moisture index anomalies, and the fraction of absorbed photosynthetically active radiation anomalies (fAPAR) was evaluated during summer time of 2018, a particularly intense virus outbreak. The empirical results of this study indicate that total precipitation during 2018 was extremely high, nearly 500% above the average. These conditions contributed to the increase of soil moisture index anomaly and fAPAR, creating an ideal microenvironment (wet soils and green pastures) for mosquito breeding. This phenomenon was directly associated with a drastic outbreak of West Nile virus cases in the area, compared with earlier years. Our results indicate how unusually high values of summer precipitation may have contributed (both through direct and indirect ecological channels) to the rapid spread of the West Nile virus in West Attica, causing a significant number of confirmed cases and fatalities. Climate change may bring forth other issues aside from natural disasters, including-but not limited to-virus expansion.
Topics: Animals; Culicidae; Environmental Monitoring; Greece; West Nile Fever; West Nile virus
PubMed: 33772423
DOI: 10.1007/s10661-021-09011-3