West Nile Research Articles

Experimental West Nile virus infection provides lessons for recovery from enteric neuropathies.

Loss of enteric neurons leading to long-term gastrointestinal dysfunction is common to many diseases, and the path to functional recovery is unclear. In this issue of the JCI, Janova et al. report that West Nile virus killed enteric neurons and glia via CD4+ and CD8+ T cells acting through the perforin and Fas ligand pathways. Enteric glial cells contributed to neurogenesis and at least partial replacement of affected neurons. While neurogenesis is important for recovery, dysmotility and disruptions to the network structure persisted. Following enteric injury, the contribution of neurogenesis and the conditions that support restoration of enteric neural circuits for functional recovery remain for further investigation.

Neuroinvasive West Nile Virus Infections in the Trakya Region of Türkiye.

Neuroinvasive West Nile Virus Infections in the Trakya Region of Türkiye.

Emerging mosquito-borne flaviviruses.

Flaviviruses comprise a genus of enveloped, positive-sense, single-stranded RNA viruses typically transmitted between susceptible and permissive hosts by arthropod vectors. Established flavivirus threats include dengue viruses (DENV), yellow fever virus (YFV), Zika virus (ZIKV), and West Nile virus (WNV), which continue to cause over 400 million infections annually and are significant global health and economic burdens. Additionally, numerous closely related but largely understudied viruses circulate in animals and can conceivably emerge in human populations. Previous flaviviruses that were recognized to have this potential include ZIKV and WNV, which only became extensively studied after causing major outbreaks in humans. More than 50 species exist within the flavivirus genus, which can be further classified as mosquito-borne, tick-borne, insect-specific, or with no known vector. Historically, many of these flaviviruses originated in Africa and have mainly affected tropical and subtropical regions due to the ecological niche of mosquitoes. However, climate change, as well as vector and host migration, has contributed to geographical expansion, thereby posing a potential risk to global populations. For the purposes of this minireview, we focus on the mosquito-borne subgroup and highlight viruses that cause significant pathology or lethality in at least one animal species and/or have demonstrated an ability to infect humans. We discuss current knowledge of these viruses, existing animal models to study their pathogenesis, and potential future directions. Emerging viruses discussed include Usutu virus (USUV), Wesselsbron virus (WSLV), Spondweni virus (SPOV), Ilheus virus (ILHV), Rocio virus (ROCV), Murray Valley encephalitis virus (MVEV), and Alfuy virus (ALFV).

Malaria mosquitoes, Plasmodium parasites and skin microbiota, towards control of malaria: A review

Vector-borne pathogens are transmitted by bites of infected arthropod species. The pathogens require two different host species to complete their lifecycle, usually a vertebrate and an invertebrate host, of which the latter transmits the pathogen between vertebrate hosts. Blood-feeding mosquitoes are important vectors of several human pathogens, including arboviruses namely: chikungunya, dengue fever, Rift Valley fever, yellow fever and Zika transmitted by Aedes mosquitoes amongst others. Culex mosquitoes on the other hand transmit Saint Louis and Japanese encephalitis, lymphatic filariasis, West Nile fever and Rift Valley Fever virus while Anopheles mosquitoes transmit malaria. The contact rate between vectors and their vertebrate hosts affects the intensity of pathogen transmission, and hence disease epidemiology. The ability of vectors to locate their blood hosts therefore is crucial in disease maintenance and perseverance. Host odour is known to play an important role in mosquito host-seeking behaviour and hence influences the contact rate between vectors and hosts. This literature review focuses on interactions between malaria parasites, humans, mosquitoes and how skin bacterial volatiles mediate host-seeking behaviour of mosquitoes.

Etiology of Acute Encephalitis Syndrome in Adults in a Tertiary Care Center in Eastern Uttar Pradesh

Seasonal outbreaks of acute encephalitis syndrome (AES) with high case fatality rates have been commonly reported among adults in India. With an increase in Japanese encephalitis virus (JEV) vaccination, the etiology of AES is also changing. However, most studies on AES in India have focused only on children and on JEV. This study was conducted in the Department of Medicine, Institute of Medical Sciences, Banaras Hindu University between 2020 and 2022 to determine the etiology of AES in adults. Blood and cerebrospinal fluid (CSF) were collected from patients 18 years or older with fever and altered sensorium for ≤15 days. We did IgM ELISA for dengue, chikungunya, West Nile virus, scrub typhus, leptospirosis from serum, CSF-IgM for JEV, and CSF–polymerase chain reaction for herpes simplex virus 1 and 2, varicella-zoster virus, enterovirus, and cartridge-based nucleic acid amplification test (CBNAAT) for tuberculous meningitis (TBM). The most common cause of AES identified in our study was TBM (16.7%), followed by leptospirosis (15.1%) and scrub typhus (11.9%). The high occurrence of TBM in our study highlights the importance of CSF-CBNAAT for all AES patients. As leptospirosis and scrub typhus are easily treatable, early detection and treatment of these infections should be recommended.

Using Wolbachia Bacteria to Control Mosquito-Borne Disease

This publication is intended for both the general public and mosquito control professionals. It outlines the use of the bacterium Wolbachia pipientis as a tool to control mosquito populations and reduce the spread of mosquito-borne disease. Biting mosquitoes transmit many pathogens that cause deadly diseases in people, our pets, and our livestock. Collectively, malaria, dengue, West Nile, filariasis, and other mosquito-borne diseases result in millions of infections and hundreds of thousands of deaths every year. Effective vaccines for most of these have not been developed or are not yet available to the general public, and disease management is focused on controlling mosquito populations. Insecticides have become less effective over the past fifty years as mosquito populations all over the world have developed resistance. This has driven scientists to explore new options for controlling mosquitoes, including using the bacterium Wolbachia pipientis.

Distribution of the Culex pipiens mosquito in mainland Portugal: a geospatial modelling study

Abstract Background The mosquito Culex pipiens is a vector for several pathogens, such as the West Nile virus. As the most abundant mosquito in Portugal, understanding its spatial distribution can support vector-borne diseases control and robust public health planning, given the mainland’s favourable climate for this vector. Information on its spatial distribution at a national level is limited, especially its association with climate variables. Thus we aimed to predict the suitability of Culex pipiens distribution in mainland Portugal, considering climate factors. Methods We used presence records for adult and larvae of Culex pipiens mosquitoes sampled across mainland Portugal from January 2017 to October 2023, as part of the Portuguese Vector Surveillance Network program (REVIVE). Between May-October, in random locations and throughout the year in point-of-entry sites, adult mosquito collection used CDC light traps and BG-Sentinel traps, and larvae collection used dippers in breeding sites. Sampling bias was corrected by filtering presence sites, retaining one record per each cell grid of 1 km2. Climatic data (including temperature, precipitation and elevation) were used as predictors in a maximum entropy (MaxEnt) model of the Culex pipiens geographical distribution. Results From the dataset of 6859 records, 1416 unique sites were obtained after filtering. Suitable habitats seem to be mainly distributed on the coast, particularly in Minho, Porto and Lisbon metropolitan areas, and Tagus Valley, with precipitation as the most important predictor. Conclusions Most West Nile Virus case reports come from the south of Portugal, but the potential distribution of Culex pipiens covers the whole mainland territory, with seemingly higher distribution on the north coast. However, bias due to convenience sampling could be present. West Nile vector surveillance should be a priority across all regions to accurately assess transmission risk and implement effective control measures. Key messages • The suitability of Culex pipiens distribution covers the entire mainland of Portugal, with higher presence in the north. • The distribution of Culex pipiens in the country points towards a need for developing region-specific strategies regarding West Nile Virus prevention and control.

Effect of climate change on West Nile virus transmission in Italy: a systematic review

Abstract Background West Nile Virus (WNV) is a pathogen transmitted by mosquitoes of the Culex genus, affecting both humans and animals such as horses and birds. The prevalence of WNV infection has increased dramatically in recent years in Europe, especially in Italy, and has been related to climate and environmental changes linked to global warming. Our review aims to assess the relation between the spread of WNV in Italy and the different climate change-related factors. Methods We conducted a literature search in the PubMed, Web of Science, Embase and Scopus databases, actualised as of 20 February 2024, using as search terms WNV, its vectors and climate change, and limiting our analysis to studies conducted in to avoid an overly heterogeneous setting. We registered the review in PROSPERO (CRD42023430636). Results Of the 252 unique records retrieved, we eventually included 25 articles after full-text screening. These studies were published between 2011 and 2023 and evaluated the distribution of WNV or its vectors according to various climatic and environmental factors. Despite rather heterogeneous results, we found a consistently positive association with temperature, especially spring temperature, agricultural land use, demography, and soil moisture, and a negative one with evapotranspiration and wind, while the relationship with other environmental variables and water cycle-related factors was weak, null or conflicting. Conclusions Despite some inconsistencies in the results, likely related to differences in study methodologies as well as complex environmental interactions, we found unequivocal evidence that climate change-related factors, such as the lengthening of the warm season, extensive farming, and invasive human activities towards natural environments, favour WNV spread in Italy. Consequently, actions against global warming and preservation of natural environments may counteract the WNV epidemic. Key messages • WNV epidemic seems to be linked to specific climate change-related factors, such as the lengthening of the warm season, extensive farming, and invasive human activities towards natural environments. • Actions against global warming and preservation of natural environments may counteract WNV spread.

Monitoring of mosquito breeding sites in the municipality of Cascais, Portugal

Abstract Culex pipiens is the primary West Nile Virus vector in Portugal. Additionally, in 2017, Aedes albopictus, vector of various arboviruses, was detected in Northern Portugal. To mitigate viral transmission risks, effective surveillance is crucial, including monitoring egg, larva, and pupa stages. Located on the west of Lisbon, Cascais implemented a surveillance based on monitoring invasive species at Points of Entry and, complementarily, on detecting and intervening in breeding sites. Active searches for new breeding sites and monitoring those that were already identified are conducted weekly during the peak mosquito season (May to October) and biweekly during the colder season (November to April), following the methodology outlined below: • Upon detection, samples of immature stages are collected for submission to the National Institute of Health (INSA); • Corrective measures are requested to the managing entities of the locations where the sites are found; • Date of action, location, collection point, date of report, and status (pending or intervened) are recorded on a database; • Locations with pending status undergo continuous monitoring. In 2023, 16 artificial breeding sites were identified. These findings resulted from 23 actions conducted across 8 locations. 35 samples of immatures were collected, followed by their submission and notification to the respective managing entities. Recurrent detections were noted in 9 breeding sites. The managing entities implemented measures at 13 of the identified sites, leaving 3 with pending intervention. The identification of breeding sites demands continuous monitoring efforts and requires an effective coordination between the Public Health services and the management entities. Based on the achieved outcomes, it is evident that the implementation of corrective measures has been successful, making a significant contribution to reducing mosquito density. Key messages • Effective surveillance and intervention strategies are crucial in mitigating West Nile Virus and arbovirus transmission risks in Portugal. • Continuous monitoring and coordination between public health services and management entities are key for maintaining effective vector control measures.

Preparation and Construction of Chimeric Humanized Broadly Reactive Antibody 10H10 to Protein E of Tick-Borne Encephalitis Virus.

A full-length humanized chimeric antibody 10H10ch that specifically interacts with the surface glycoprotein E of flaviviruses was obtained. To construct it, we used variable fragments of the heavy and light chains of the monoclonal antibody 10H10 that form the active center of the antibody and a fragment of the constant part of the heavy chain of the human IgG1 antibody. The resulting full-length chimeric humanized antibody 10H10ch specifically interacted with the E protein of flaviviruses pathogenic to humans, such as tick-borne encephalitis, Zika, West Nile, and dengue viruses. An immunochemical assessment of the interaction constants of the 10H10ch antibody with a panel of native and recombinant flavivirus antigens by ELISA and biolayer interferometry showed that the dissociation constant (Kd) of the chimeric antibody is in the nanomolar region and is comparable to that of the high-affinity mouse monoclonal antibody 10H10. The possibility of using the resulting chimeric humanized antibody 10H10ch for the diagnosis, prevention, and treatment of various flavivirus infections is discussed.

Genetic characterization of immune adaptor molecule MyD88 in Culex pipiens complex (Diptera: Culicidae) mosquitoes from China.

Mosquitoes of the Culex (Cx.) pipiens complex are vectors of severe diseases including West Nile fever by West Nile virus, Japanese encephalitis by Japanese encephalitis virus, and Lymphatic filariasis by filarial nematode Wuchereria bancrofti. As a major portion of mosquito immune system, the Toll pathway implicates in response against infections of mosquito-borne pathogens and biocontrol agents. The genetic diversity of immune-related molecules is expected to be a feasible and effective introduction to expand our knowledge of the mosquito-microbe interplay. However, a comprehensive description is currently lacking regarding the genetic characteristic of the Toll pathway molecules in Cx. pipiens complex mosquitoes. In the present study, genetic changes in Cx. pipiens complex MyD88 (Myeloid differentiation primary response protein 88) were analyzed as a precedent for the Toll pathway molecules in this taxon. MyD88 is a critical adaptor of the pathway transducing signals from TIR-containing receptors to downstream death domain-containing molecules. Our results revealed that adaptive selection has influenced the genetic changes of the molecule, giving rise to acceleration of diversity at a number of amino acid sites. The adaptively selected sites lie in the death domain, intermediate domain, and C-terminal extension. The characteristics of the genetic changes shed insights into the prominent molecular-level structural basis and the involvement strategy of the adaptor in the arms race against exogenous challenges. This finding would be beneficial for further exploration and deeper understanding of the mosquitoes' vectorial capacity and facilitating the effectiveness and sustainability of the biocontrol agents.

WNV and SLEV coinfection in avian and mosquito hosts: impact on viremia, antibody responses, and vector competence.

West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related flaviviruses that can cause encephalitis in humans and related diseases in animals. In nature, both are transmitted by Culex, with wild birds, including jays, sparrows, and robins, serving as vertebrate hosts. WNV and SLEV circulate in the same environments and have recently caused concurrent disease outbreaks in humans. The extent that coinfection of mosquitoes or birds may alter transmission dynamics, however, is not well characterized. We therefore sought to determine if coinfection alters infection kinetics and virus levels in birds and infection rates in mosquitoes. Accordingly, American robins (Turdus migratorius), two species of mosquitoes, and vertebrate and invertebrate cells were infected with WNV and/or SLEV to assess how simultaneous exposure may alter infection outcomes. There was variable impact of coinfection in vertebrate cells, with some evidence that SLEV can suppress WNV replication. However, robins had comparable viremia and antibody responses regardless of coinfection. Conversely, in Culex cells and mosquitoes, we saw a minimal impact of simultaneous exposure to both viruses on replication, with comparable infection, dissemination, and transmission rates in singly infected and coinfected mosquitoes. Importantly, while WNV and SLEV levels in coinfected mosquito midguts were positively correlated, we saw no correlation between them in salivary glands and saliva. These results reveal that while coinfection can occur in both avian and mosquito hosts, the viruses minimally impact one another. The potential for coinfection to alter virus population structure or the likelihood of rare genotypes emerging remains unknown.IMPORTANCEWest Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related viruses that are transmitted by the same mosquitoes and infect the same birds in nature. Both viruses circulate in the same regions and have caused concurrent outbreaks in humans. It is possible that mosquitoes, birds, and/or humans could be infected with both WNV and SLEV simultaneously, as has been observed with Zika, chikungunya, and dengue viruses. To study the impact of coinfection, we experimentally infected vertebrate and invertebrate cells, American robins, and two Culex species with WNV and/or SLEV. Robins were efficiently coinfected, with no impact of coinfection on virus levels or immune response. Similarly, in mosquitoes, coinfection did not impact infection rates, and mosquitoes could transmit both WNV and SLEV together. These results reveal that WNV and SLEV coinfection in birds and mosquitoes can occur in nature, which may impact public health and human disease risk.

Multiple bloodmeals enhance dissemination of arboviruses in three medically relevant mosquito genera

BackgroundMosquitoes in nature may acquire multiple bloodmeals (BMs) over the course of their lifetime; however, incorporation of frequent feeding behavior in laboratory vector competence studies is rarely done. We have previously shown that acquisition of a second non-infectious BM can enhance early dissemination of Zika virus (ZIKV), dengue virus, and chikungunya virus in Aedes aegypti and ZIKV in Aedes albopictus mosquitoes, yet it is unknown if other taxonomically-diverse virus-vector pairings show a similar trend under a sequential feeding regimen.MethodsTo test this, we evaluated the impact of a second noninfectious BM on the vector competence of Aedes aegypti and Anopheles quadrimaculatus for Mayaro virus, Culex quinquefasciatus for West Nile virus, Aedes triseriatus for La Crosse virus, and Aedes aegypti for Oropouche virus (OROV). Female mosquitoes were fed BMs containing these viruses and half of them were given a second noninfectious BM at 3 or 4-days post infection. Mosquitoes were harvested at various time points and assayed for virus infection in bodies and disseminated infection in legs by performing reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assays.ResultsWe found that a second noninfectious BM had no impact on midgut infection rates but increased virus dissemination for all but one of the virus-vector pairings- Ae. aegypti and OROV. Unlike the other arboviruses under consideration, which are strictly mosquito-borne, biting midges (Culicoides spp.) serve as the main vector of OROV and this virus rarely disseminated to the mosquito leg tissue in our study.ConclusionsTaken together, our findings show that sequential blood feeding enhances virus dissemination across diverse arbovirus-vector pairings, representing three mosquito genera and virus families, but a second BM was insufficient to overcome a strong midgut virus escape barrier in a nonnatural virus–vector pairing.Graphical

An Integrated Approach for Development of a Decision Support System for Early Surveillance of Japanese Encephalitis: a Remote Sensing-based study in Conjunction with Epidemiological Scenario in Assam, India

Abstract. Japanese Encephalitis (JE) is one of the serious mosquito borne viral diseases mostly prevalent in India and many of the South Asian countries. A comprehensive study was conducted in Dibrugarh, a JE endemic district of Assam taking into the account of the environmental and social factors that determine the outbreak of the disease. Effect of environmental and climatic factors on mosquito vector densities was investigated using geospatial tools and techniques. Wetlands were found to be the most preferred habitat type for most of the JE-transmitting mosquitoes followed by paddy-growing areas and ponds. The villages abundant with these habitats or located nearby were found to be more vulnerable to JE risk. Based on the spatial distribution of habitat types, villages in the district were divided into three categories of vector abundance and hence the risk of JE. It is found that rainfall (intensity as well as duration) is the most significant determinant in the modulation of mosquito density followed by temperature. It is also observed that the derived models could explain about 61% to 73% variation in mosquito density due to change in weather variables as indicated by R2 values of the Models. Among socio-economic determinants, pig rearing habit of the villagers was found to be most significant. JE risk map was prepared by integrating vector abundance map with the map of host abundance in GIS domain. Attempts were also made to forecast the intensity of JE cases based on a time series analysis of historical morbidity pattern, whereas forecast for onset of the disease was based on the modulation of weather variables in the study area. A web-based decision support system (DSS) developed by integrating the forecasts of JE onset, intensity and JE prone villages has been provided to the concerned health authorities to take timely intervention measures. The JE early warning system developed for Dibrugarh district was extended to two more JE prone districts viz, Sibsagar and Tinsukia as validation sites and observed that the accuracy of forecast was within the range of 69% to 77%. DSS on JE has opened up new opportunities to study similar vector-borne diseases of the JE serogroup viz., West Nile.

Continuous and Dynamic Circulation of West Nile Virus in Mosquito Populations in Bucharest Area, Romania, 2017-2023.

West Nile virus (WNV) is a mosquito-borne pathogen with a worldwide distribution. Climate change and human activities have driven the expansion of WNV into new territories in Europe during the last two decades. Romania is endemic for WNV circulation since at least 1996 when the presence of lineage 1 was documented during an unprecedented outbreak. Lineage 2 was first identified in this country during a second significant human outbreak in 2010. Its continuous circulation is marked by clade replacement, and even co-circulation of different strains of the same clade was observed until 2016. The present study aims to fill the information gap regarding the WNV strains that were circulating in Romania between 2017 and 2023, providing chiefly viral sequences obtained from mosquito samples collected in the Bucharest metropolitan area, complemented by human and bird viral sequences. WNV was detected mainly in Culex pipiens mosquitoes, the vectors of this virus in the region, but also in the invasive Aedes albopictus mosquito species. Lineage 2 WNV was identified in mosquito samples collected between 2017 and 2023, as well as in human sera from patients in southern and central Romania during the outbreaks of 2017 and 2018. Both 2a and 2b sub-lineages were identified, with evidence of multiple clusters and sub-clusters within sub-lineage 2a, highlighting the complex and dynamic circulation of WNV in Romania, as a consequence of distinct introduction events from neighboring countries followed by in situ evolution.

RNA elements required for the high efficiency of West Nile Virus-induced ribosomal frameshifting.

West Nile Virus (WNV), a member of the Flaviviridae family, requires programmed -1 ribosomal frameshifting (PRF) for translation of the viral genome. The efficiency of WNV frameshifting is among the highest observed to date. Despite structural similarities to frameshifting sites in other viruses, it remains unclear why WNV exhibits such a high frameshifting efficiency. Here we employed dual-luciferase reporter assays in multiple human cell lines to probe the RNA requirements for highly efficient frameshifting by the WNV genome. We find that both the sequence and structure of a predicted RNA pseudoknot downstream of the slippery sequence-the codons in the genome on which frameshifting occurs-are required for efficient frameshifting. We also show that multiple proposed RNA secondary structures downstream of the slippery sequence are inconsistent with efficient frameshifting. We mapped the most favorable distance between the slippery site and the pseudoknot essential for optimal frameshifting, and found the base of the pseudoknot structure likely is unfolded prior to frameshifting. Finally, we find that many mutations in the WNV slippery sequence allow efficient frameshifting, but often result in aberrant shifting into other reading frames. Mutations in the slippery sequence also support a model in which frameshifting occurs concurrent with or after translocation of the mRNA and tRNA on the ribosome. These results provide a comprehensive analysis of the molecular determinants of WNV-programmed ribosomal frameshifting and provide a foundation for the development of new antiviral strategies targeting viral gene expression.

West Nile virus in adults and larvae of Culiseta longiareolata and Culex hortensis (Diptera: Culicidae) captured in Hamedan, western Iran

West Nile virus (WNV) is an emerging arbovirus transmitted by mosquitoes. Although it is considered the most widespread mosquito-borne arbovirus in Iran, vectors of this zoonotic pathogen remain unknown in many regions. This study aimed to assess the presence of WNV in mosquitoes collected in the western city of Hamedan in 2022. Adult mosquitoes were captured using light traps, and mosquito larvae were collected by dipping technique from 45 diverse habitats, including urban, suburban, and rural sites. Specimens were identified and pooled into 69 batches based on their species for viral RNA extraction and Real-Time PCR. In total, 3243 mosquitoes (2209 larvae and 1034 adults) were captured and identified as Culiseta longiareolata, Culex hortensis, Anopheles maculipennis s.l., Culex theileri, Culex pipiens, Anopheles claviger, and Anopheles superpictus s.l. in decreasing order. Molecular screening revealed seven WNV-positive pools of Culiseta longiareolata and Culex hortensis in rural (n = 5) and urban areas (n = 2). Detection of WNV RNA indicates active circulation in mosquitoes and risk of transmission to humans and animals in Hamadan. These findings identify putative vectors in Hamadan, though vectors likely vary regionally in Iran. Further surveillance is needed to elucidate local WNV epidemiology and transmission dynamics fully. Nonetheless, this study provides important baseline evidence of WNV activity to guide prevention strategies in this area.

Microbiological bases of obsessive‑compulsive disorder - the role of viruses, bacteria, and parasites in the onset and progression of OCD.

Obsessive‑compulsive disorder (OCD) is a current topic of discussion nowadays. OCD presents a variety of different etiologies including environmental, viral, cognitive, or genetic aspects. In this article, we focused on the possible correlation between various infectious diseases as well as generally the relationship between viruses, bacteria, and parasites, and an increased OCD risk. In this narrative review, we analyzed different types of articles found on PubMed, Google Scholar, and Scopus, as well as the articles of the National Institute of Mental Health. Searching criteria included articles from 1991 till the end of November, research involving human and animal patients (including monkeys and rats), and research published in English. Research showed a relationship between Herpes simplex virus, Rubella virus, Human immunodeficiency virus, Borna disease virus, Mycoplasma pneumoniae, Toxoplasma gondii, streptococcal infections, as well as gut microbiota and increased OCD risk. The possible mechanisms of this relation include neuroinflammation, brain tissue damage, autoimmune processes, and impairments in neurotransmitter levels. Infections caused by Varicella zoster virus, Measles virus, Mumps virus, Epstein‑Barr virus, Cytomegalovirus, or Borrelia Burgdorferi may also contribute to the increased risk of OCD. Reports showed an increased frequency of OCD occurrence in a group of infected people compared to a healthy group. However, there is no evidence of the influence of Influenza virus, Coxsackie virus, Poliovirus, Parvovirus B19, Enterovirus 71, West Nile virus, Treponema Pallidum, or Toxocara infections on the OCD risk. There is a significant relationship between various infectious diseases and an increased OCD risk. However, further studies are crucial to discover the exact pathomechanisms of these correlations and the potential influence of other pathogens on the onset of OCD.

Vector Competence of Aedes aegypti from São Tomé and Príncipe for West Nile Virus Transmission.

The global distribution of Aedes aegypti mosquitoes, particularly in tropical regions, poses a significant public health risk due to their apparent ability to transmit arboviruses such as West Nile virus (WNV). This study aimed to evaluate the vector competence of Ae. aegypti from São Tomé and Príncipe (STP) for the transmission of the WNV PT6.39 strain, considering its potential role as a bridge vector in a region where Culex quinquefasciatus would be the main vector. Aedes aegypti mosquitoes were collected, reared, and experimentally infected with WNV, with viral dissemination and transmission potential assessed 7, 14, and 21 days post infection (dpi). The results showed an increasing trend in infection rates, from 5% at 7 dpi to 35% at 21 dpi, with corresponding dissemination rates of 0%, 100%, and 43%. The transmission rates also increased from 0% at 7 dpi to 67% at 21 dpi, with a maximum transmission efficiency of 10% observed at the final time point. Although Ae. aegypti from STP demonstrated the potential to transmit WNV, the overall transmission efficiency remained relatively low. These findings provide necessary insights into the vector competence of Ae. aegypti in this region, highlighting the importance of continued monitoring and targeted vector control measures to mitigate the risk of potential WNV outbreaks.

West Nile Virus Presenting as Optic Perineuritis with Complete Recovery: Light at the End of the Tunnel

West Nile Virus Presenting as Optic Perineuritis with Complete Recovery: Light at the End of the Tunnel