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Viruses Feb 2024West Nile virus (WNV) infection is a seasonal arbovirosis with the potential to cause severe neurological disease. Outcomes of the infection from WNV depend on viral...
BACKGROUND
West Nile virus (WNV) infection is a seasonal arbovirosis with the potential to cause severe neurological disease. Outcomes of the infection from WNV depend on viral factors (e.g., lineage) and host-intrinsic factors (e.g., age, sex, immunocompromising conditions). Immunity is essential to control the infection but may also prove detrimental to the host. Indeed, the persistence of high levels of pro-inflammatory cytokines and chemokines is associated with the development of blood-brain barrier (BBB) damage. Due to the importance of the inflammatory processes in the development of West Nile neuroinvasive disease (WNND), we reviewed the available literature on the subject.
METHODS
According to the 2020 updated PRISMA guidelines, all peer-reviewed articles regarding the inflammatory response associated with WNND were included.
RESULTS
One hundred and thirty-six articles were included in the data analysis and sorted into three groups (in vitro on-cell cultures, in vivo in animals, and in humans). The main cytokines found to be increased during WNND were IL-6 and TNF-α. We highlighted the generally small quantity and heterogeneity of information about the inflammatory patterns associated with WNND.
CONCLUSIONS
Further studies are needed to understand the pathogenesis of WNND and to investigate the extent and the way the host inflammatory response either helps in controlling the infection or in worsening the outcomes. This might prove useful both for the development of target therapies and for the development of molecular markers allowing early identification of patients displaying an inflammatory response that puts them at a higher risk of developing neuroinvasive disease and who might thus benefit from early antiviral therapies.
Topics: Animals; Humans; Cytokines; Nervous System Diseases; Tumor Necrosis Factor-alpha; West Nile Fever; West Nile virus
PubMed: 38543749
DOI: 10.3390/v16030383 -
Infection and Drug Resistance 2021Flaviviruses are a genus of enveloped single-stranded RNA viruses that include dengue virus (DENV), yellow fever virus, West Nile virus (WNV), Japanese encephalitis... (Review)
Review
INTRODUCTION
Flaviviruses are a genus of enveloped single-stranded RNA viruses that include dengue virus (DENV), yellow fever virus, West Nile virus (WNV), Japanese encephalitis virus, and Zika virus. Nowadays, diverse serological assays are available to diagnose flaviviruses. However, infection with flaviviruses induces cross-reactive antibodies, which are a challenge for serological diagnosis.
OBJECTIVE
This systematic review aimed to assess the magnitude of medically important mosquito-borne flavivirus-induced antibody cross-reactivity and its influence on serological test outcomes.
METHODS
This study was designed based on the PRISMA guidelines. It includes original research articles published between 1994 and 2019 that reported serological cross-reactions between medically important mosquito-borne flaviviruses. Articles were searched on PubMed using controlled vocabulary. Eligibility was assessed by title, abstract, and finally by reading the full paper. The articles included are compared, evaluated, and summarized narratively.
RESULTS
A total of 2,911 articles were identified, and finally 14 were included. About 15.4%-84% of antibodies produced against non-DENV flaviviruses were cross-reactive with DENV on different assays. Up to 30% IgM and up to 60% IgG antibodies produced against non-WNV flaviviruses were cross-reactive with WNV on EIA assays. The magnitude of antibodies produced against flaviviruses that are cross-reactive with chikungunya virus () was minimal (only about 7%). The highest antibody cross-reactivity of flaviviruses was reported in IgG-based assays compared to IgM-based assays and assays based on E-specific immunoglobulin compared to NS1-specific immunoglobulin. It was found that preexisting immunity due to vaccination or prior flavivirus exposure to antigenetically related species enhanced the cross-reactive antibody titer.
CONCLUSION
This review found the highest cross-reaction between DENV and non-DENV flaviviruses, especially yellow fever virus, and the least between chikungunya virus and DENV. Moreover, cross-reaction was higher on IgG assays than IgM ones and assays based on Eprotein compared to NS1protein. This implies that the reliability of serological test results in areas where more than one flavivirus exists is questionable. Therefore, interpretation of the existing serological assays should be undertaken with a great caution. Furthermore, research on novel diagnostic signatures for differential diagnosis of flaviviruses is needed.
PubMed: 34703255
DOI: 10.2147/IDR.S336351 -
Proceedings. Biological Sciences Mar 2024Mathematical models within the Ross-Macdonald framework increasingly play a role in our understanding of vector-borne disease dynamics and as tools for assessing...
Mathematical models within the Ross-Macdonald framework increasingly play a role in our understanding of vector-borne disease dynamics and as tools for assessing scenarios to respond to emerging threats. These threats are typically characterized by a high degree of heterogeneity, introducing a range of possible complexities in models and challenges to maintain the link with empirical evidence. We systematically identified and analysed a total of 77 published papers presenting compartmental West Nile virus (WNV) models that use parameter values derived from empirical studies. Using a set of 15 criteria, we measured the dissimilarity compared with the Ross-Macdonald framework. We also retrieved the purpose and type of models and traced the empirical sources of their parameters. Our review highlights the increasing refinements in WNV models. Models for prediction included the highest number of refinements. We found uneven distributions of refinements and of evidence for parameter values. We identified several challenges in parametrizing such increasingly complex models. For parameters common to most models, we also synthesize the empirical evidence for their values and ranges. The study highlights the potential to improve the quality of WNV models and their applicability for policy by establishing closer collaboration between mathematical modelling and empirical work.
Topics: Humans; Models, Theoretical; West Nile Fever; West Nile virus
PubMed: 38471554
DOI: 10.1098/rspb.2023.2432 -
Transboundary and Emerging Diseases Jul 2021There is some evidence that West Nile virus (WNV), which causes encephalomyelitis in equids, is an emerging disease in Europe. The aim of this study was to perform a... (Meta-Analysis)
Meta-Analysis
There is some evidence that West Nile virus (WNV), which causes encephalomyelitis in equids, is an emerging disease in Europe. The aim of this study was to perform a systematic review and meta-analysis to analyse seroprevalence studies of WNV in equids in European countries between 2001 and 2018. Two electronic databases, PubMed and Scopus, were searched for relevant publications published from 2001 to 2018 using predetermined keywords. A total of 1,484 papers were initially found. After applying the eligibility criteria, 39 papers were finally included in the systematic review. Analysis of 28,089 equids from 16 European countries revealed a pooled seroprevalence of 8% (95% CI 5%-12%, p < .001, I = 99.3%) in Europe. The pooled seroprevalence was slightly higher in Mediterranean basin countries than other countries and when calculated for samples collected between 2001 and 2009 compared to 2010 to 2018. Differences in study design (e.g. sampling associated with recent outbreaks of WNV) contributed to a high degree of variability among studies. Further studies with harmonized study design and reporting of the results are recommended to better estimate and monitor European seroprevalence of WNV in equids.
Topics: Animals; Disease Outbreaks; Europe; Seroepidemiologic Studies; West Nile Fever; West Nile virus
PubMed: 33012076
DOI: 10.1111/tbed.13866 -
Scientific Reports Jan 2023The increasing trend of mosquito-borne pathogens demands more accurate global estimations of infection and transmission risks between mosquitoes. Here, we systematically...
The increasing trend of mosquito-borne pathogens demands more accurate global estimations of infection and transmission risks between mosquitoes. Here, we systematically review field and laboratory studies to assess the natural field infection and experimental laboratory transmission risk in Culex mosquitoes. We studied four worldwide flaviviruses: West Nile, Usutu, Japanese encephalitis, and St. Louis encephalitis, belonging to the Japanese encephalitis Serocomplex (JES). The PRISMA statement was carried out for both approaches. The Transmission-Infection Risk of the diverse mosquito species for the different viruses was estimated through seven variables. We considered 130 and 95 articles for field and experimental approach, respectively. We identified 30 species naturally infected, and 23 species capable to transmit some of the four flaviviruses. For the JES, the highest Transmission-Infection Risk estimate was recorded in Culex quinquefasciatus (North America). The maximum Infection-Transmission Risk values for West Nile was Culex restuans, for Usutu it was Culex pipiens (Europe), for St. Louis encephalitis Culex quinquefasciatus (North America), and for Japanese encephalitis Culex gelidus (Oceania). We conclude that on a worldwide scale, a combination of field and experimental data offers a better way of understanding natural infection and transmission risks between mosquito populations.
Topics: Animals; Encephalitis Viruses, Japanese; Mosquito Vectors; West Nile virus; West Nile Fever; Encephalitis, St. Louis; Encephalitis, Japanese; Flavivirus; Culicidae; Culex
PubMed: 36609450
DOI: 10.1038/s41598-022-27236-1 -
Infectious Diseases of Poverty May 2024West Nile virus (WNV), the most widely distributed flavivirus causing encephalitis globally, is a vector-borne pathogen of global importance. The changing climate is... (Review)
Review
BACKGROUND
West Nile virus (WNV), the most widely distributed flavivirus causing encephalitis globally, is a vector-borne pathogen of global importance. The changing climate is poised to reshape the landscape of various infectious diseases, particularly vector-borne ones like WNV. Understanding the anticipated geographical and range shifts in disease transmission due to climate change, alongside effective adaptation strategies, is critical for mitigating future public health impacts. This scoping review aims to consolidate evidence on the impact of climate change on WNV and to identify a spectrum of applicable adaptation strategies.
MAIN BODY
We systematically analyzed research articles from PubMed, Web of Science, Scopus, and EBSCOhost. Our criteria included English-language research articles published between 2007 and 2023, focusing on the impacts of climate change on WNV and related adaptation strategies. We extracted data concerning study objectives, populations, geographical focus, and specific findings. Literature was categorized into two primary themes: 1) climate-WNV associations, and 2) climate change impacts on WNV transmission, providing a clear understanding. Out of 2168 articles reviewed, 120 met our criteria. Most evidence originated from North America (59.2%) and Europe (28.3%), with a primary focus on human cases (31.7%). Studies on climate-WNV correlations (n = 83) highlighted temperature (67.5%) as a pivotal climate factor. In the analysis of climate change impacts on WNV (n = 37), most evidence suggested that climate change may affect the transmission and distribution of WNV, with the extent of the impact depending on local and regional conditions. Although few studies directly addressed the implementation of adaptation strategies for climate-induced disease transmission, the proposed strategies (n = 49) fell into six categories: 1) surveillance and monitoring (38.8%), 2) predictive modeling (18.4%), 3) cross-disciplinary collaboration (16.3%), 4) environmental management (12.2%), 5) public education (8.2%), and 6) health system readiness (6.1%). Additionally, we developed an accessible online platform to summarize the evidence on climate change impacts on WNV transmission ( https://2xzl2o-neaop.shinyapps.io/WNVScopingReview/ ).
CONCLUSIONS
This review reveals that climate change may affect the transmission and distribution of WNV, but the literature reflects only a small share of the global WNV dynamics. There is an urgent need for adaptive responses to anticipate and respond to the climate-driven spread of WNV. Nevertheless, studies focusing on these adaptation responses are sparse compared to those examining the impacts of climate change. Further research on the impacts of climate change and adaptation strategies for vector-borne diseases, along with more comprehensive evidence synthesis, is needed to inform effective policy responses tailored to local contexts.
Topics: Animals; Humans; Adaptation, Physiological; Climate Change; West Nile Fever; West Nile virus
PubMed: 38790027
DOI: 10.1186/s40249-024-01207-2 -
Burns & Trauma 2019Cutaneous manifestations of purpura fulminans (PF) present many challenges for clinicians and surgeons. In a state of septic shock complicated by limb ischemia, surgical... (Review)
Review
BACKGROUND
Cutaneous manifestations of purpura fulminans (PF) present many challenges for clinicians and surgeons. In a state of septic shock complicated by limb ischemia, surgical interventions are necessary to control the pathological cascade and improve patient outcomes. The objective of this article was to report etiologies and surgical outcomes associated with cutaneous manifestations in adults.
METHODS
This systematic review and meta-analysis compared 190 adult patients with etiologies, signs and symptoms, and surgical outcomes associated with cutaneous manifestations of PF. The PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus databases were systematically and independently searched. Patient and clinical characteristics, surgical interventions, outcomes, and complications were recorded.
RESULTS
Seventy-nine studies were eligible for the systematic review, and 77 were eligible for meta-analysis using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) and Cochrane guidelines. A total of 71/190 (38%) cases reported surgical debridement. Fasciotomies were reported in 12/190 (6%) cases and 20 procedures. Amputations were reported in 154/190 (81%) cases. Reconstruction was reported in 45 cases. Skin grafts were applied in 31 cases. Flaps were used for reconstruction in 28 cases. Median (IQR) surgical procedures per patient were 4 (4, 5) procedures. Infectious organisms causing PF were 32% ( = 55) and 32% ( = 55). Coagulase-negative (95% confidence interval (CI)(8.2-177.9), = 0.032), (95%CI (7.2-133), = 0.029), (95% CI (13.3-75.9), = 0.006), and West Nile Virus (95%CI (8.2-177.9), = 0.032) were associated with significantly more extensive amputations compared to other organisms.
CONCLUSION
This systematic review and patient-level meta-analysis found the most common presentation of PF was septic shock from an infectious organism. and were equally the most common organisms associated with PF. The majority of cases were not treated in a burn center. The most common surgeries were amputations, with below-the-knee-amputations being the most common procedure. Skin grafting was the most commonly performed reconstructive procedure. The most common complications were secondary infections. Organisms with significantly more extensive amputations were coagulase-negative , , , and West Nile Virus. Interpretation of findings should be cautioned due to limited sample data.
PubMed: 31641673
DOI: 10.1186/s41038-019-0168-x -
Journal of Infection and Public Health May 2024West Nile virus (WNV) is a mosquito-borne flavivirus. In humans, 80% of infections are asymptomatic, while approximately 20% experience influenza-like symptoms. Fewer...
BACKGROUND
West Nile virus (WNV) is a mosquito-borne flavivirus. In humans, 80% of infections are asymptomatic, while approximately 20% experience influenza-like symptoms. Fewer than 1% develop the neuroinvasive form which can lead to encephalitis, meningitis, acute flaccid paralysis, and even death. The global spread of the virus to areas where it was not previously present has become a growing concern. Since the 2000 s, there have been numerous outbreaks affecting local and travelling populations worldwide. Given the lack of a vaccine, preventative measures are primarily focused on surveillance, vector control, and the use of personal protective behaviours (PPBs). The importance of PPBs is central to public health recommendations. However, translating these messages into coherent action by the public can prove challenging, as the uptake of such measures is inevitably influenced by socio-economic factors, awareness, knowledge, and risk perception.
METHODS
A PRISMA-based systematic research was conducted on EMBASE, PubMed/MEDLINE, and Web of Science databases. PROSPERO registration number CRD42023459714. Quality of studies included in the final stage was evaluated using the Critical Appraisal Checklist for Cross-Sectional Study (CEBMa).
RESULTS
2963 articles were screened, and 17 studies were included in the final round. Out of these, six were deemed of high quality, ten were of medium quality, and one was of low quality. In almost all studies considered, both awareness and knowledge of WNV transmission were above 90%, while concern about WNV ranged from 50% to 80%. Concern about the safety of repellents, either with or without DEET, ranged from 27% to 70%. The percentage of people actually using repellents ranged from 30% to 75%, with the lowest usage reported among individuals over 60 years old (29%) and pregnant women (33%), and the highest among students aged 9-11 (75%). Concern for West Nile Virus (WNV) was consistently linked to an increase in taking preventative measures, including the use of repellents, by two to four times across studies. The school-based intervention was effective in increasing the practice of removing standing water (AOR=4.6; 2.7-8.0) and wearing long clothing (AOR=2.4; 95%CI: 1.3-4.3), but did not have a significant impact on the use of repellents.
CONCLUSIONS
The present systematic review provides an overview of the knowledge, attitudes, and practices (KAP) of WNV and their determinants. While concern about West Nile Virus (WNV) and its effects can be a significant motivator, it is important to promote evidence-based personal protective behaviours (PPBs) to counter unwarranted fears. For example, the use of repellents among the most vulnerable age groups. Given the geographical expansion of WNV, it is necessary to target the entire population preventively, including those who are difficult to reach and areas not yet endemic. The findings of this investigation could have significant implications for public health and support well-informed and effective communication strategies and interventions.
Topics: Animals; Humans; Female; Pregnancy; Middle Aged; West Nile virus; West Nile Fever; Health Knowledge, Attitudes, Practice; Cross-Sectional Studies; Mosquito Vectors
PubMed: 38555655
DOI: 10.1016/j.jiph.2024.03.012 -
Microorganisms Dec 2023Arboviruses represent a real public health problem globally and in the Central African subregion in particular, which represents a high-risk zone for the emergence and... (Review)
Review
Arboviruses represent a real public health problem globally and in the Central African subregion in particular, which represents a high-risk zone for the emergence and re-emergence of arbovirus outbreaks. Furthermore, an updated review on the current arbovirus burden and associated mosquito vectors is lacking for this region. To contribute to filling this knowledge gap, the current study was designed with the following objectives: (i) to systematically review data on the occurrence and distribution of arboviruses and mosquito fauna; and (ii) to identify potential spillover mosquito species in the Central African region in the last 30 years. A web search enabled the documentation of 2454 articles from different online databases. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the quality of reporting of meta-analyses (QUORUM) steps for a systematic review enabled the selection of 164 articles that fulfilled our selection criteria. Of the six arboviruses (dengue virus (DENV), chikungunya virus (CHIKV), yellow fever virus (YFV), Zika virus (ZIKV), Rift Valley fever virus (RVFV), and West Nile virus (WNV)) of public health concern studied, the most frequently reported were chikungunya and dengue. The entomological records showed >248 species of mosquitoes regrouped under 15 genera, with ( = 100 species), ( = 56 species), and ( = 52 species) having high species diversity. Three genera were rarely represented, with only one species included, namely, , , and , but individuals of the genera and were not identified at the species level. We found that two species ( and ) colonised the same microhabitat and were involved in major epidemics of the six medically important arboviruses, and other less-frequently identified mosquito genera consisted of competent species and were associated with outbreaks of medical and zoonotic arboviruses. The present study reveals a high species richness of competent mosquito vectors that could lead to the spillover of medically important arboviruses in the region. Although epidemiological studies were found, they were not regularly documented, and this also applies to vector competence and transmission studies. Future studies will consider unpublished information in dissertations and technical reports from different countries to allow their information to be more consistent. A regional project, entitled "Ecology of Arboviruses" (EcoVir), is underway in three countries (Gabon, Benin, and Cote d'Ivoire) to generate a more comprehensive epidemiological and entomological data on this topic.
PubMed: 38276174
DOI: 10.3390/microorganisms12010004 -
Antiviral Research Nov 2020Turkey serves as a natural hub for the dissemination of vector-borne viruses and provides many suitable habitats with diverse ecologies for introduction and... (Meta-Analysis)
Meta-Analysis
Turkey serves as a natural hub for the dissemination of vector-borne viruses and provides many suitable habitats with diverse ecologies for introduction and establishment of new pathogens. This manuscript provides an updated systematic review and meta-analysis of the vector-borne viruses documented in Turkey. Following web-based identification, screening and eligibility evaluation, 291 published reports were reviewed. The publications were categorized and listed as a supplementary bibliography accompanying the manuscript. In brief, Crimean-Congo hemorrhagic fever virus (CCHFV) and West Nile virus (WNV) are currently documented as prominent tick and mosquito-borne viral pathogens in Turkey. CCHFV produces a significant number of infections annually, with severe outcome or death in a portion of cases. WNV gained attention following the clustering of cases in 2010. Exposure and infections with sandfly-borne phleboviruses, such as Toscana virus, are indigenous and widespread. Epidemiology, risk factors, symptomatic infections in susceptible hosts, vectors and reservoirs for these pathogens have been explored in detail. Detection of novel viruses in mosquitoes, sandflies and ticks from several regions is of particular interest, despite scarce information on their epidemiology and pathogenicity in vertebrates. Introduction and emergence of viruses transmitted by invasive Aedes mosquitoes constitute a threat, albeit only imported infections have so far been documented. Detection of Rift valley fever virus exposure is also of concern, due to its detrimental effects on livestock and spillover infections in humans. Vigilance to identify and diagnose probable cases as well as vector surveillance for established and potential pathogens is therefore, imperative.
Topics: Aedes; Animals; Bibliographies as Topic; Disease Vectors; Hemorrhagic Fever Virus, Crimean-Congo; Humans; Mosquito Vectors; Psychodidae; Rift Valley fever virus; Ticks; Turkey; Viruses; West Nile virus
PubMed: 32949637
DOI: 10.1016/j.antiviral.2020.104934