West Nile Virus Infection Research Articles

The role of CMKLR1 in lymphocyte activation and localization within the CNS during West Nile Virus Encephalitis

Abstract Continued West Nile virus (WNV) outbreaks causing neuroinvasive disease in the US highlight the urgent need to decipher CNS viral control mechanisms. DCs are pivotal in recruiting and reactivating CNS-infiltrating lymphocytes for viral clearance. However, the molecular mechanisms that regulate DC recruitment and activation remain unknown. In CNS-related autoimmune disorders, CMKLR1, a chemokine receptor expressed by a DC subset, aids their recruitment and activation via its ligand, chemerin. To investigate the role of CMKLR1 during WNND, we infected WT and CMKLR1-/- mice with WNV. CMKLR1-/- mice exhibited a slight increase in mortality but elevated clinical scores accompanied by increased CNS viral loads compared to WT. We hypothesize that CMKLR1 restricts WNV neuropathogenesis by regulating the activation and localization of antiviral T cells within the CNS during WNV encephalitis. Determining the role of CMKLR1 in effector T cell activation and migration may provide insights into local molecular mechanisms controlling lymphocyte function and fate within the CNS during WNV.

Vaccination and Control Methods of West Nile Virus Infection in Equids and Humans.

West Nile virus (WNV) is capable of causing severe neurologic disease in both humans and equines, making it a disease of importance in both human medicine and veterinary medicine. No targeted treatments exist for WNV infection in either humans or equines. Infection is treated symptomatically through management of symptoms like fever and seizures. As treatment for WNV is purely supportive, the response to WNV has focused primarily on methods of disease prevention. To this end, research efforts have yielded several effective vaccines for equine use as well as numerous conventional mosquito control techniques. Even with the implementation of these techniques, disease caused by WNV remains a concern since no human vaccine exists. Due to the lack of a human vaccine, novel preventative strategies are under active research and development. Of these strategies, some of the most conceptually promising are techniques using genetically modified mosquitoes, addressing the disease at the vector level with minimal ecological side effects. Taken together, the use of combined, synergistic methods, such as physical barriers, transgenic mosquitoes, and immunological targets, will be the best way to prevent WNV disease.

Seroprevalence of West Nile Virus in Tampa Bay Florida Patients Admitted to Hospital during 2020-2021 for Respiratory Symptoms.

West Nile virus (WNV) is an arbovirus spread primarily by Culex mosquitoes, with humans being a dead-end host. WNV was introduced to Florida in 2001, with 467 confirmed cases since. It is estimated that 80 percent of cases are asymptomatic, with mild cases presenting as a non-specific flu-like illness. Currently, detection of WNV in humans occurs primarily in healthcare settings via RT-PCR or CSF IgM when patients present with severe manifestations of disease including fever, meningitis, encephalitis, or acute flaccid paralysis. Given the short window of detectable viremia and requirement for CSF sampling, most WNV infections never receive an official diagnosis. This study utilized enzyme-linked immunosorbent assay (ELISA) to detect WNV IgG antibodies in 250 patient serum and plasma samples collected at Tampa General Hospital during 2020 and 2021. Plaque reduction neutralization tests were used to confirm ELISA results. Out of the 250 patients included in this study, 18.8% of them were IgG positive, consistent with previous WNV exposure. There was no relationship between WNV exposure and age or sex.

Warm winters are associated to more intense West Nile virus circulation in southern Spain

ABSTRACT West Nile virus (WNV) is the most widely distributed mosquito-borne flavivirus in the world. This flavivirus can infect humans causing in some cases a fatal neurological disease and birds are the main reservoir hosts. WNV is endemic in Spain, and human cases have been reported since 2004. Although different studies analyse how climatic conditions can affect the dynamics of WNV infection, very few use long-term datasets. Between 2003 and 2020 a total of 2,724 serum samples from 1,707 common coots (Fulica atra) were analysed for the presence of WNV-specific antibodies. Mean (SD) annual seroprevalence was 24.67% (0.28) but showed high year-to-year variations ranging from 5.06% (0.17) to 68.89% (0.29). Significant positive correlations (p < 0.01) were observed between seroprevalence and maximum winter temperature and mean spring temperature. The unprecedented WNV outbreak in humans in the south of Spain in 2020 was preceded by a prolonged period of escalating WNV local circulation. Given current global and local climatic trends, WNV circulation is expected to increase in the next decades. This underscores the necessity of implementing One Health approaches to reduce the risk of future WNV outbreaks in humans. Our results suggest that higher winter and spring temperatures may be used as an early warning signal of more intense WNV circulation among wildlife in Spain, and consequently highlight the need of more intense vector control and surveillance in human inhabited areas.

Whole-Blood PCR Preferred for Timely Diagnosis of Neuroinvasive West Nile Virus Infections: Lessons From the 2021 Arizona Outbreak.

In 2021, the state of Arizona experienced the largest focal outbreak of West Nile virus (WNV) in US history. Timely and accurate diagnostic testing remains a challenge for WNV due to transient viremia and limited immunoassay specificity. Recent studies have identified whole blood (WB) and urine as more sensitive specimen types for the detection of WNV RNA. We evaluated ordering practices, test performance, and patient characteristics of probable and confirmed cases. In total, we identified 190 probable and proven cases, including 127 patients (66.8%) with neuroinvasive disease. Among all cases, only 29.5% had WNV polymerase chain reaction (PCR) testing ordered on WB, of which 80.3% resulted as positive, including 7 cases in which WNV serologic testing was negative and 5 cases for which serologic testing was not ordered. In comparison, only 23.7% of cases that had cerebrospinal fluid (CSF) PCR ordered had a positive result, including 3 cases that were negative by PCR on WB. In contrast, WNV PCR on WB detected 12 neuroinvasive cases that were CSF PCR negative. WNV PCR testing in urine was only ordered on 2 patients, both of whom were positive. Crossing cycle threshold (Ct) values were not significantly different between WB and CSF specimen types, nor was there a correlation between Ct value and days from symptom onset at the time of sample collection; all specimen types and time points had Ct values, with 98% above 30. WB was positive by WNV PCR in several patients for >7 days (range, 7-25 days) after symptom onset, as was the CSF PCR. Taken together, these findings indicate that WNV PCR testing on WB may be the best initial test for timely diagnosis of WNV infection, irrespective of clinical manifestation; however, if negative in patients with suspected neuroinvasive disease, WNV PCR testing on CSF should be ordered.

Bilateral multifocal chorioretinitis as the only presentation of acute West Nile virus infection: a case report.

To describe a case of bilateral multifocal chorioretinitis as the only presentation of acute West Nile virus (WNV) infection in the absence of neurological involvement. A 78-year-old Italian woman was admitted to our emergency department because she noticed blurry vision in both eyes. She did not report fever, fatigue, or neurological symptoms in the last few days. Multimodal imaging showed the presence of bilateral hyperfluorescent lesions with a linear distribution, that corresponded to hypocyanescent spots on indocyanine green angiography. Antibody serology showed the presence of IgM antibodies, IgG antibodies, and ribonucleic acid (RNA) for WNV. Magnetic resonance imaging (MRI) of the brain ruled out central nervous system involvement. Three months later, the patient reported spontaneous resolution of her symptoms and remission of the chorioretinal infiltrates. In endemic areas, it is important to think of acute WNV infection as an explanatory etiology in cases of multifocal chorioretinitis, even without neurological involvement.

A Case of Headache Progressing to Coma: Atypical Presentation of West Nile Virus Encephalitis (P9-2.001)

A Case of Headache Progressing to Coma: Atypical Presentation of West Nile Virus Encephalitis (P9-2.001)

West Nile Fever: Analysis of the Epidemiological Situation in the Russian Federation in 2023, Forecast for 2024

An analysis of the epidemiological situation on West Nile fever (WNF) in the Russian Federation in 2023 has revealed an increase in the number of cases (210) relative to the year 2022 by 6.3 times, the long-term average value by 1.2 times. Manifestations of the epidemic process were characterized by a significant expansion in the number of territories, where cases of the disease were confirmed (24 constituent entities, including in 13 – for the first time); a long epidemic season; an increase in the proportion of cases with a severe clinical course and fatality rate, which significantly exceeded the long-term average across Russia (8.5 and 1.2 %, respectively). Patients with fever and other similar manifestations of WNF were examined for the presence of the disease markers in 50 entities of the Russian Federation. Continued trend towards a decrease in the volume of diagnostic studies carried out by medical organizations and an increase in the time required for the etiological deciphering of disease cases has been established. Serological examination of sample groups of healthy population was performed in 65 entities. Epizootiological monitoring was carried out in 74 entities, rate of infection of carriers and vectors with West Nile virus (WNV) was confirmed in 14 entities. In the territory of the European part of Russia and the North Caucasus, the circulation of WNV lineages 1, 2 and 4 with the dominance of WNV lineage 2 has been established. Data on the genetic heterogeneity of WNV lineage 2 strains that circulated in Russia in 2023 have been obtained. Based on an analysis of climatic factors, a forecast of WNF incidence in the Russian Federation for 2024 was prepared.

West Nile Virus Emergence in Germany 2019: Looking for Hidden Human West Nile Virus Infections.

Background: Autochthonous human West Nile virus (WNV) infections were notified in the infectious disease surveillance system in Germany in 2018 for the first time and every year since then. Since clinically apparent infections are infrequent, we conducted two studies to investigate subclinical infections of this emerging disease in Germany in 2019 to detect infections not visible to surveillance based on symptomatic infections: limited-scope blood donor testing and a serosurvey among employees at two Berlin zoos with a history of demonstrated WNV infections in animals. Methods: For the zoo study, employees of the two zoos in Berlin were invited to participate in the study in late 2019. Blood samples were drawn and tested for the presence of antibodies (immunoglobulin M [IgM] and immunoglobulin G [IgG]) against WNV, and two other flaviviruses present in Germany: Usutu virus and Tick-borne encephalitis virus (TBEV). For the study in blood donors, four blood establishments with collection sites in regions with documented WNV-infected animals in 2018 and 2019 participated in the study. All donations in these regions were tested for WNV genome from July to November 2019. Results: In the enzyme-linked immunosorbent assay, none of the 70 tested zoo employees were WNV IgM-positive, 8 were WNV IgG-positive, additional 2 participants had equivocal results. All 10 were negative in the virus neutralization test (VNT) for WNV, but positive in the VNT for TBEV. None of the 4273 samples from blood donors tested in areas with WNV-infected animals was positive for WNV-RNA. Conclusion: Our results indicate that WNV circulation in Germany, though clearly documented in animals in 2019, apparently affected very few humans. Still areas with WNV-positive animals remain risk areas for human infection as well.

Results of a screening examination for the presence of markers of West Nile fever in the central and southern territories of Russia

Objective: to study the intensity of contact with the causative agent of West Nile fever (WNF) of the population of certain central and southern territories of Russia.Materials and methods: the screening survey covered 1,230 people in 11 regions of the Russian Federation. The work used molecular genetic, immunological and statistical methods.Results: WNVmarkers, indicating an acute infectious process, were detected in 1.4% of samples. For the first time, local cases of the disease were confirmed in 9 regions of central Russia and the North Caucasus. The circulation of West Nile virus genotype 1 in the territory of the Republics of Ingushetia and Mordovia, genotype 2 in the Ivanovo and Nizhny Novgorod regions, Chuvash and Kabardino- Balkarian Republics is shown. The results of studying the immune layer revealed the presence of antibodies to the West Nile virus of the IgG class in 4.5% of the examined local population, with the highest rates in the Chechen Republic (10%) and the Republic of North Ossetia-Alania (14%). The maximum level of population immunity was noted among people in the age groups 20–29 years old and amounted to 9.7%, 30–39 years old – 7.8%.Conclusion: the results obtained significantly supplemented our understanding of the spread of WNV in Russia and the activity of disease foci, and can be used in planning and conducting monitoring studies.

Investigating the important proteins in causing West Nile virus infection in retinal pigment cells

Introduction: West Nile virus is an infection transmitted through blood-sucking arthropods. Ocular manifestations are one of the characteristics of West Nile virus infection. They occur mostly in connection with severe neurological disease. In this study، using bioinformatics analysis، we investigated and identified the genes in the pathways related to West Nile virus infection in the retina.&#x0D; Methods: In this study, using bioinformatics methods and referring to the GEO dataset, the appropriate dataset was selected for analysis. This dataset included gene expression profiles in West Nile virus infection with retinal pigment cells. Gene clusters with high and low expression were categorized. For more accurate data evaluation, databases such as Enrichr، STRING and Network analyst were used. The candidate genes were isolated and their protein relationship was also measured using cytoescape software version 3.7.1. The obtained values with P-Value˂0.05 were selected as significant data.&#x0D; Results: The number of 830 genes with high expression and 500 genes with low expression was involved in the development pathways of West Nile virus infection in the eye. Apoptosis، necroptosis، AMPK and MAPK autophagy pathways were clearly observed. After evaluating the relationship between protein networks، RIPK1، STAT1/3 and JAK2 increased expression and GSK3B، MAPK8 and TSC2 genes had decreased expression.&#x0D; Conclusion: The present study showed that important proteins and genes played a major role in strengthening West Nile virus inflammation in the retina, among which RIPK1,TSC2, STAT1 and JAK2 showed a more prominent role in this pathway.

Neuroinvasive West Nile Virus Infection in Immunosuppressed and Immunocompetent Adults

West Nile virus (WNV) is the leading cause of human arboviral disease in the US, peaking during summer. The incidence of WNV, including its neuroinvasive form (NWNV), is increasing, largely due to the expanding distribution of its vector, the Culex mosquito, and climatic changes causing heavy monsoon rains. However, the distinct characteristics and outcomes of NWNV in individuals who are immunosuppressed (IS) and individuals who are not IS remain underexplored. To describe and compare clinical and radiographic features, treatment responses, and outcomes of NWNV infection in individuals who are IS and those who are not IS. This retrospective cohort study used data from the Mayo Clinic Hospital system collected from July 2006 to December 2021. Participants were adult patients (age ≥18 years) with established diagnosis of NWNV infection. Data were analyzed from May 12, 2020, to July 20, 2023. Immunosuppresion. Outcomes of interest were clinical and radiographic features and 90-day mortality among patients with and without IS. Of 115 participants with NWNV infection (mean [SD] age, 64 [16] years; 75 [66%] male) enrolled, 72 (63%) were not IS and 43 (37%) were IS. Neurologic manifestations were meningoencephalitis (98 patients [85%]), encephalitis (10 patients [9%]), and myeloradiculitis (7 patients [6%]). Patients without IS, compared with those with IS, more frequently reported headache (45 patients [63%] vs 18 patients [42%]) and myalgias (32 patients [44%] vs 9 patients [21%]). In contrast, patients with IS, compared with those without, had higher rates of altered mental status (33 patients [77%] vs 41 patients [57%]) and myoclonus (8 patients [19%] vs 8 patients [4%]). Magnetic resonance imaging revealed more frequent thalamic T2 fluid-attenuated inversion recovery hyperintensities in individuals with IS than those without (4 patients [11%] vs 0 patients). Individuals with IS had more severe disease requiring higher rates of intensive care unit admission (26 patients [61%] vs 24 patients [33%]) and mechanical ventilation (24 patients [56%] vs 22 patients [31%]). The 90-day all-cause mortality rate was higher in the patients with IS compared with patients without IS (12 patients [28%] vs 5 patients [7%]), and this difference in mortality persisted after adjusting for Glasgow Coma Scale score (adjusted hazard ratio, 2.22; 95% CI, 1.07-4.27; P = .03). Individuals with IS were more likely to receive intravenous immunoglobulin than individuals without IS (12 individuals [17%] vs 24 individuals [56%]), but its use was not associated with survival (hazard ratio, 1.24; 95% CI, 0.50-3.09; P = .64). In this cohort study of individuals with NWNV infection, individuals with IS had a higher risk of disease complications and poor outcomes than individuals without IS, highlighting the need for innovative and effective therapies to improve outcomes in this high-risk population.

Proinflammatory Chemokine Levels in Cerebrospinal Fluid of Patients with Neuroinvasive Flavivirus Infections.

Tick-borne encephalitis virus (TBEV) and West Nile virus (WNV) are the most important neuroinvasive arboviruses detected in Europe. In this study, we analyzed cerebrospinal fluid (CSF) concentrations of 12 proinflammatory chemokines (CCL2, CCL3, CCL4, CCL11, CCL17, CCL20, CXCL1, CXCL5, CXCL8, CXCL9, CXCL10, and CXCL11) in 77 patients with neuroinvasive diseases (NIDs). Flavivirus infection was confirmed in 62 patients (TBEV and WNV in 31 patients each), while in 15 patients the etiology of NID was not determined (NDE). Similar patterns of high-level expression of chemokines regulating monocyte/macrophage responses (CCL2), neutrophil recruitment (CXCL1 and CXCL8), and interferon-inducible chemoattractants for leukocytes (CXCL10 and CXCL11) have been observed in WNV and TBEV groups. None of the tested chemokines significantly differed between patients with TBEV or WNV. Concentrations of CCL17, CCL20, CXCL5, CXCL10, and CXCL11 were significantly lower in both WNV and TBEV groups compared to NID NDE patients. The logistic regression model showed that CSF concentrations of CXCL11, CXCL5, and CXCL10 could potentially be used for the classification of patients into the WNV or TBEV group versus groups with other NIDs. This study identified, for the first time, similar patterns of CSF chemokine expression in WNV and TBEV infections, suggesting common immunopathogenic mechanisms in neuroinvasive flavivirus infections that should be further evaluated.

Impacts of ground ultra-low volume adulticide applications on Culex pipiens and Culex restuans (Diptera: Culicidae) abundance, age structure, and West Nile virus infection in Cook County, Illinois.

Since the introduction of West Nile virus (WNV) to the United States over 20 years ago, thousands of cases of human disease and death have been reported. Yearly seasonal outbreaks continue to persist, and the city and suburbs of Chicago, Illinois, is considered a "hot spot" for WNV activity. To interrupt WNV transmission, ground ultra-low volume (ULV) adulticide applications are regularly used to reduce Culex pipiens L. and Culex restuans Theobold (Diptera: Culicidae) abundance and infection. The real-world effectiveness of adulticide applications has not been comprehensively assessed, and prior studies, including our own investigation, have yielded inconclusive or conflicting results. Therefore, we expanded our prior work and evaluated the effects of 5 sequential weekly truck-mounted ULV adulticide applications in large residential areas in the northern suburbs of Chicago, Illinois, in 2019 and 2020. Each day, Cx. pipiens and Cx. restuans host-seeking and gravid mosquitoes were collected to assess abundance, age structure, and WNV infection rates. Adulticide applications resulted in significant reductions of both host-seeking and gravid abundance on the night of treatment. The reduction in host-seeking mosquitoes was followed by a reduction in gravid mosquitoes trapped 3 and 4 days after adulticide application and an increase in the proportion of nulliparous mosquitoes. WNV infection rates were significantly reduced in treatment sites as compared to untreated sites when infection rates were higher in 2020. This large-scale study provides comprehensive evidence that ground ULV adulticide applications are an effective tool in an integrated mosquito management program for combating WNV vectors and infection risk.

An equine iPSC-based phenotypic screening platform identifies pro- and anti-viral molecules against West Nile virus.

Outbreaks of West Nile virus (WNV) occur periodically, affecting both human and equine populations. There are no vaccines for humans, and those commercialised for horses do not have sufficient coverage. Specific antiviral treatments do not exist. Many drug discovery studies have been conducted, but since rodent or primate cell lines are normally used, results cannot always be transposed to horses. There is thus a need to develop relevant equine cellular models. Here, we used induced pluripotent stem cells to develop a new in vitro model of WNV-infected equine brain cells suitable for microplate assay, and assessed the cytotoxicity and antiviral activity of forty-one chemical compounds. We found that one nucleoside analog, 2'C-methylcytidine, blocked WNV infection in equine brain cells, whereas other compounds were either toxic or ineffective, despite some displaying anti-viral activity in human cell lines. We also revealed an unexpected proviral effect of statins in WNV-infected equine brain cells. Our results thus identify a potential lead for future drug development and underscore the importance of using a tissue- and species-relevant cellular model for assessing the activity of antiviral compounds.

Epidemiological situation of natural focal infections in the Volgograd region in 2023

Objective: analysis of epizootiological and epidemiological aspects of natural focal infections, namely plague, tularemia, HFRS, West Nile fever, Crimean hemorrhagic fever, Ixodic tick-borne borreliosis, Cu fever, leptospirosis and rabies, in the Volgograd region over 10 months in 2023.Materials and methods: the article analyzes the epidemiological manifestations of natural focal infections (NFI) in the Volgograd region for 10 months of 2023. The work uses official statistical data from institutions of Rospotrebnadzor of the Volgograd region on NFI for 2023. The main research method is epidemiological analysis.Results: the numbers of small mammals, potential carriers of NFI, on the territory of the Volgograd region in the 2023 season were within the same indicators of the previous year (SIPY), while the number of ticks in the spring-summer period was higher than the SIPY, but in the fall the number of arthropods in stationary points was lower than in previous seasons. The number of mosquitoes carrying arbovirus infections exceeded the long-term average. When studying environmental objects for the presence of markers of NFI pathogens, a slight decrease in the proportion of positive samples was noted compared to SIPY for all nosological forms. Over the 10 months of this year, there has been a deterioration in the epidemiological situation in the Volgograd region for several infections compared to the same period in 2022. There were 18 cases of West Nile fever (WNF), 10 cases of ixodid tick-borne borreliosis (ITB), and 6 cases of hemorrhagic fever with renal syndrome (HFRS). No patients with plague, tularemia, rabies, leptospirosis, Crimean hemorrhagic fever (CHF) and Q fever were identified.Conclusion: the presence of natural foci of dangerous infectious diseases of varying degrees of activity on the territory of the Volgograd region requires constant monitoring and an adequate response to changes in the foci in order to prevent complications of the epidemiological situation due to NFI.

Study of the circulation and properties of the West Nile virus in Russia in 2022

Introduction. The relevance of the study is due to the need to assess the real expansion of West Nile fever (WNF) in Russia, analyze the manifestations of epizootic and epidemic processes and study the population structure of West Nile virus (WNV).&#x0D; Aim. To obtain objective data on the intensity of WNV circulation in certain territories of Russia and study the properties of the isolated strains of the pathogen.&#x0D; Materials and methods. 4564 samples of field material from 23 subjects of the Russian Federation and 1547 samples of clinical material from 12 subjects of the Russian Federation were examined. A set of laboratory diagnostic methods was used: ELISA, RT-PCR, virological, sequencing.&#x0D; Results. In 20 out of 1331 (1.5%) examined febrile patients, IgM antibodies to WNV were detected, including positive cases identified for the first time in the Karachay-Cherkess Republic, Tver and Vladimir regions. The presence of immunity to WNV was found on average in 8.6% of 11 federal subjects' population with high seroprevalence rates in Zaporozhye (24,5%), Tula (15,4%) and Kursk (11,1%) regions. Low-avidity IgG antibodies were detected in 44 (33,1%) samples from a population of 9 federal subjects. Intensive circulation of WNV lineage 2 in the epizootic cycle in the southern part of European Russia was confirmed. 12 WNV isolates were obtained, including those isolated for the first time in the Republic of Crimea, the Karachay-Cherkess Republic and the Stavropol Territory. The heterogeneity of circulating WNF causative agent's strains related to the two clades of the WNV lineage 2 formed in 2021 and 2022 was established.&#x0D; Conclusion. In the course of comprehensive monitoring studies, a new northern border of the WNF range was established, which as of 2022 passes through the territory of the Tver region. Data from seroepidemiological studies, including the detection of low-avidity IgG antibodies, confirm fairly intense, but undiagnosed contact of the population of the European part of Russia with the WNF pathogen. In the southern region of the European part of Russia, WNV genotype 2 predominantly circulates, belonging to at least two clades formed in 2021 and 2022.

Green cities and vector-borne diseases: emerging concerns and opportunities.

Aligned with the Sustainable Development Goals, nature-based solutions such as urban greening e.g. public gardens, urban forests, parks and street trees, which aim to protect, sustainably manage or restore an ecosystem, have emerged as a promising tool for improving the health and well-being of an ever-increasing urban population. While urban greening efforts have undeniable benefits for human health and the biological communities inhabiting these green zones, disease vector populations may also be affected, possibly promoting greater pathogen transmission and the emergence of infectious diseases such as dengue, West Nile fever, malaria, leishmaniosis and tick-borne diseases. Evidence for the impact of urban green areas on vector-borne disease (VBD) transmission is scarce. Furthermore, because of vast disparities between cities, variation in green landscapes and differing scales of observation, findings are often contradictory; this calls for careful assessment of how urban greening affects VBD risk. Improved understanding of the effect of urban greening on VBDs would support planning, monitoring and management of green spaces in cities to sustainably mitigate VBD risks for surrounding urban populations.

The results of entomological monitoring West Nile fever on the territory of the Crimean peninsula in the 2022 season

Objective: to evaluate the role of blood-sucking mosquitoes of various species living in the northern and central regions of the Crimean Peninsula in the transmission of West Nile virus (WNV).Materials and methods: the collection of bloodsucking mosquitoes was carried out in 7 administrative units of the Republic of Crimea with automatic traps and a vertical handheld vacuum cleaner from July 1 to August 5, 2022. The species composition of mosquitoes was determined visually using an MSP-1 stereomicroscope (option 22) using standard keys. Detection of WNV RNA in the samples was performed by RT-PCR. Mosquito infection levels and dominance index were calculated.Results: a common eudominant species for urban and rural biotopes of the surveyed areas was determined Ae. caspius, whose dominance index was 72.4% and 31.3%. Mosquitoes of the species Cx. modestus were the most numerous in rural biotopes (dominance index — 48.4%). The invasive species Ae. albopictus in the central part of the Crimean peninsula, which indicates the expansion of its habitat. Of 18.6 thousand mosquitoes of 12 species, merged in 693 samples, WNV RNA was detected in 14 samples (2.02%), 3 isolates of the pathogen were isolated. A high level of WNV infection of mosquitoes in urban biotopes was established, which amounted to 4.12%. WNV circulation was first confirmed in the northern part of Crimea (Krasnoperekopsky district).Conclusion: the epidemiological significance of mosquitoes of various species on the territory of the Crimean Peninsula has been determined. The data on the spread of WNV in the Republic of Crimea were supplemented, taking into account which the estimated zoning of the territory was carried out according to the degree of risk of infection with WNV. Recommendations are given to strengthen epidemiological surveillance and preventive measures.

The use of environmental data in descriptive and predictive models of vector-borne disease in North America.

Vector-borne disease incidence and burden are on the rise. Weather events and climate patterns are known to influence vector populations and disease distribution and incidence. Changes in weather trends and climatic factors can shift seasonal vector activity and host behavior, thus altering pathogen distribution and introducing diseases to new geographic regions. With the upward trend in global temperature, changes in the incidence and distribution of disease vectors possibly linked to climate change have been documented. Forecasting and modeling efforts are valuable for incorporating climate into predicting changes in vector and vector-borne disease distribution. These predictions serve to optimize disease outbreak preparedness and response. The purpose of this scoping review was to describe the use of climate data in vector-borne disease prediction in North America between 2000 and 2022. The most investigated diseases were West Nile virus infection, Lyme disease, and dengue. The uneven geographical distribution of publications could suggest regional differences in the availability of surveillance data required for vector-borne disease predictions and forecasts across the United States, Canada, and Mexico. Studies incorporated environmental data from ground-based sources, satellite data, previously existing data, and field-collected data. While environmental data such as meteorological and topographic factors were well-represented, further research is warranted to ascertain if relationships with less common variables, such as oceanographic characteristics and drought, hold among various vector populations and throughout wider geographical areas. This review provides a catalogue of recently used climatic data that can inform future assessments of the value of such data in vector-borne disease models.