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Chikungunya virus (CHIKV) poses a significant global health threat, re-emerging as a mosquito-transmitted pathogen that caused high fever, rash, and severe arthralgia. In Thailand, a notable CHIKV outbreak in 2019–2020 affected approximately 20,000 cases across 60 provinces, underscoring the need for effective mosquito control protocols. Previous studies have highlighted the role of midgut bacteria in the interaction between mosquito vectors and pathogen infections, demonstrating their ability to protect the insect from invading pathogens. However, research on the midgut bacteria of Aedes (Ae.) aegypti, the primary vector for CHIKV in Thailand remains limited. This study aims to characterize the bacterial communities in laboratory strains of Ae. aegypti, both infected and non-infected with CHIKV. Female mosquitoes from a laboratory strain of Ae. aegypti were exposed to a CHIKV-infected blood meal through membrane feeding, while the control group received a non-infected blood meal. At 7 days post-infection (dpi), mosquito midguts were dissected for 16S rRNA gene sequencing to identify midgut bacteria, and CHIKV presence was confirmed by E1-nested RT-PCR using mosquito carcasses. The study aimed to compare the bacterial communities between CHIKV-infected and non-infected groups. The analysis included 12 midgut bacterial samples, divided into three groups: CHIKV-infected (exposed and infected), non-infected (exposed but not infected), and non-exposed (negative control). Alpha diversity indices and Bray–Curtis dissimilarity matrix revealed significant differences in bacterial profiles among the three groups. The infected group exhibited an increased abundance of bacteria genus Gluconobacter, while Asaia was prevalent in both non-infected and negative control groups. Chryseobacterium was prominent in the negative control group. These findings highlight potential alterations in the distribution and abundance of gut microbiomes in response to CHIKV infection status. This study provides valuable insights into the dynamic relationship between midgut bacteria and CHIKV, underscoring the potential for alterations in bacterial composition depending on infection status. Understanding the relationships between mosquitoes and their microbiota holds promise for developing new methods and tools to enhance existing strategies for disease prevention and control. This research advances our understanding of the circulating bacterial composition, opening possibilities for new approaches in combating mosquito-borne diseases. [ABSTRACT FROM AUTHOR]

Background: Dengue virus (DENV) causes an important disease and directly affects public health, being the arbovirus that presents the highest number of infections and deaths in the Western Brazilian Amazon. This virus is divided into 4 serotypes that have already circulated in the region. Methodology: Molecular characterization of a cohort containing 841 samples collected from febrile patients between 2021 and 2023 was analyzed using a commercial kit to detect the main arboviruses circulating in Brazil: Zika, DENV-1, DENV-2, DENV-3, DENV-4 and, Chikungunya. Subsequently, Sanger sequencing was performed for positive samples. Results: The cohort detected 162 positive samples, 12 for DENV-1 and 150 identified as DENV-2, indicating co-circulation of serotypes. The samples were subjected to sequencing and the analysis of the sequences that obtained good quality revealed that 5 samples belonged to the V genotype of DENV-1 and 46 were characterized as DENV-2 Cosmopolitan genotype—lineage 5. Conclusion: The results allowed us to identify for the first time the Cosmopolitan genotype in Rondônia, Brazilian Western Amazon, and its fast spread dispersion. [ABSTRACT FROM AUTHOR]

Arboviral diseases are serious threats to global health with increasing prevalence and potentially severe complications. Significant arthropod-borne viruses are the dengue viruses (DENV 1-4), the Zika virus (ZIKV), and the chikungunya virus (CHIKV). Among the areas most affected is the South Pacific Region (SPR). Here, arboviruses not only cause a high local burden of disease, but the region has also proven to contribute to their global spread. Outpatient serum samples collected between 08/2016 and 04/2017 on three islands of the island states of Vanuatu and the Cook Islands were tested for anti-DENV- and anti-ZIKV-specific antibodies (IgG) using enzyme-linked immunosorbent assays (ELISA). ELISA test results showed 89% of all test sera from the Cook Islands and 85% of the Vanuatu samples to be positive for anti-DENV-specific antibodies. Anti-ZIKV antibodies were identified in 66% and 52%, respectively, of the test populations. Statistically significant differences in standardized immunity levels were found only at the intranational level. Our results show that in both the Cook Islands and Vanuatu, residents were exposed to significant Flavivirus transmission. Compared to other seroprevalence studies, the marked difference between ZIKV immunity levels and previously published CHIKV seroprevalence rates in our study populations is surprising. We propose the timing of ZIKV and CHIKV emergence in relation to recurrent DENV outbreaks and the impact of seasonality as explanatory external factors for this observation. Our data add to the knowledge of arboviral epidemics in the SPR and contribute to a better understanding of virus spread, including external conditions with potential influence on outbreak dynamics. These data may support preventive and rapid response measures in the affected areas, travel-related risk assessment, and infection identification in locals and returning travelers. [ABSTRACT FROM AUTHOR]

Genetic studies preceded by the observation of an unknown mosquito species in Mikołów (Poland) confirmed that it belongs to a new invasive species in Polish fauna, Aedes japonicus (Theobald, 1901), a known vector for numerous infectious diseases. Ae. japonicus is expanding its geographical presence, raising concerns about potential disease transmission given its vector competence for chikungunya virus, dengue virus, West Nile virus, and Zika virus. This first genetically confirmed identification of Ae. japonicus in Poland initiates a comprehensive review of the literature on Ae. japonicus, its biology and ecology, and the viral infections transmitted by this species. This paper also presents the circumstances of the observation of Ae. japonicus in Poland and a methodology for identifying this species. [ABSTRACT FROM AUTHOR]

Chikungunya is an arboviral disease transmitted by Aedes aegypti and Aedes albopictus mosquitoes with a growing global burden linked to climate change and globalisation. We aimed to estimate chikungunya seroprevalence, force of infection (FOI), and prevalence of related chronic disability and hospital admissions in endemic and epidemic settings. In this systematic review, meta-analysis, and modelling study, we searched PubMed, Ovid, and Web of Science for articles published from database inception until Sept 26, 2022, for prospective and retrospective cross-sectional studies that addressed serological chikungunya virus infection in any geographical region, age group, and population subgroup and for longitudinal prospective and retrospective cohort studies with data on chronic chikungunya or hospital admissions in people with chikungunya. We did a systematic review of studies on chikungunya seroprevalence and fitted catalytic models to each survey to estimate location-specific FOI (ie, the rate at which susceptible individuals acquire chikungunya infection). We performed a meta-analysis to estimate the proportion of symptomatic patients with laboratory-confirmed chikungunya who had chronic chikungunya or were admitted to hospital following infection. We used a random-effects model to assess the relationship between chronic sequelae and follow-up length using linear regression. The systematic review protocol is registered online on PROSPERO, CRD42022363102. We identified 60 studies with data on seroprevalence and chronic chikungunya symptoms done across 76 locations in 38 countries, and classified 17 (22%) of 76 locations as endemic settings and 59 (78%) as epidemic settings. The global long-term median annual FOI was 0·007 (95% uncertainty interval [UI] 0·003–0·010) and varied from 0·0001 (0·00004–0·0002) to 0·113 (0·07–0·20). The highest estimated median seroprevalence at age 10 years was in south Asia (8·0% [95% UI 6·5–9·6]), followed by Latin America and the Caribbean (7·8% [4·9–14·6]), whereas median seroprevalence was lowest in the Middle East (1·0% [0·5–1·9]). We estimated that 51% (95% CI 45–58) of people with laboratory-confirmed symptomatic chikungunya had chronic disability after infection and 4% (3–5) were admitted to hospital following infection. We inferred subnational heterogeneity in long-term average annual FOI and transmission dynamics and identified both endemic and epidemic settings across different countries. Brazil, Ethiopia, Malaysia, and India included both endemic and epidemic settings. Long-term average annual FOI was higher in epidemic settings than endemic settings. However, long-term cumulative incidence of chikungunya can be similar between large outbreaks in epidemic settings with a high FOI and endemic settings with a relatively low FOI. International Vaccine Institute. [ABSTRACT FROM AUTHOR]

Chikungunya virus outbreaks have been associated with excess deaths at the ecological level. Previous studies have assessed the risk factors for severe versus mild chikungunya virus disease. However, the risk of death following chikungunya virus disease compared with the risk of death in individuals without the disease remains unexplored. We aimed to investigate the risk of death in the 2 years following chikungunya virus disease. We used a population-based cohort study and a self-controlled case series to estimate mortality risks associated with chikungunya virus disease between Jan 1, 2015, and Dec 31, 2018, in Brazil. The dataset was created by linking national databases for social programmes, notifiable diseases, and mortality. For the matched cohort design, individuals with chikungunya virus disease recorded between Jan 1, 2015, and Dec 31, 2018, were considered as exposed and those who were arbovirus disease-free and alive during the study period were considered as unexposed. For the self-controlled case series, we included all deaths from individuals with a chikungunya virus disease record, and each individual acted as their own control according to different study periods relative to the date of disease. The primary outcome was all-cause natural mortality up to 728 days after onset of chikungunya virus disease symptoms, and secondary outcomes were cause-specific deaths, including ischaemic heart diseases, diabetes, and cerebrovascular diseases. In the matched cohort study, we included 143 787 individuals with chikungunya virus disease who were matched, at the day of symptom onset, to unexposed individuals using sociodemographic factors. The incidence rate ratio (IRR) of death within 7 days of chikungunya symptom onset was 8·40 (95% CI 4·83–20·09) as compared with the unexposed group and decreased to 2·26 (1·50–3·77) at 57–84 days and 1·05 (0·82–1·35) at 85–168 days, with IRR close to 1 and wide CI in the subsequent periods. For the secondary outcomes, the IRR of deaths within 28 days after disease onset were: 1·80 (0·58–7·00) for cerebrovascular diseases, 3·75 (1·33–17·00) for diabetes, and 3·67 (1·25–14·00) for ischaemic heart disease, and there was no evidence of increased risk in the subsequent periods. For the self-controlled case series study, 1933 individuals died after having had chikungunya virus disease and were included in the analysis. The IRR of all-cause natural death within 7 days of symptom onset of chikungunya virus disease was 8·75 (7·18–10·66) and decreased to 1·59 (1·26–2·00) at 57–84 days and 1·09 (0·92–1·29) at 85–168 days. For the secondary outcomes, the IRRs of deaths within 28 days after disease onset were: 2·73 (1·50–4·96) for cerebrovascular diseases, 8·43 (5·00–14·21) for diabetes, and 2·38 (1·33–4·26) for ischaemic heart disease, and there was no evidence of increased risk at 85–168 days. Chikungunya virus disease is associated with an increased risk of death for up to 84 days after symptom onset, including deaths from cerebrovascular diseases, ischaemic heart diseases, and diabetes. This study highlights the need for equitable access to approved vaccines and effective anti-chikungunya virus therapeutics and reinforces the importance of robust vector-control efforts to reduce viral transmission. Brazilian National Research Council (CNPq), Fundação de Amparo à Pesquisa do Estado da Bahia, Wellcome Trust, and UK Medical Research Council. For the Portuguese translation of the abstract see Supplementary Materials section. [ABSTRACT FROM AUTHOR]

Rash and fever are some of the most common chief complaints present in paediatric dermatology emergencies. The spectrum of differential diagnosis is broad, including many different infectious and some non-infectious agents. A systematic approach involving detailed history taking, careful clinical examination along with particular attention to epidemiological features are the most important factors to make a diagnosis. This article reviews the morphological patterns of various causes of fever with rash in children, including infectious as well as non-infectious causes, with special emphasis on the Indian scenario. We intend to highlight the clinical characteristics of each cause, which will not only help make a clinical diagnosis but also distinguish benign versus life-threatening causes of skin rash in febrile paediatric patients and provide early medical intervention. [ABSTRACT FROM AUTHOR]

This retrospective study was conducted in 2017 during the dual dengue and chikungunya outbreak in Bangladesh. Febrile participants underwent blood tests for chikungunya, dengue, and ABO groups and rhesus (Rh) factors. Blood grouping information was gathered from healthy donors. Males and those aged between 18 and 49 years had a higher risk of contracting dengue and chikungunya. Blood group O exhibited the highest infection rates at ∼50%, whereas group AB had the lowest at ∼9% among the participants in the study. Yet, when considering the general population's blood group distribution, the combined odds of infection were 2.0, 3.5, and 1.4 times higher in groups B, O, and AB, respectively, than in group A. Infection rates were greater in Rh-negative people. Blood groups B, O, and AB showed higher susceptibility than blood group A according to adjusted odds ratios. Blood groups ABO and Rh factor hold significance in disease susceptibility and vaccine effectiveness. Keeping these implications in mind, further investigations are necessary to understand the mechanisms underlying these connections and their effects on the efficacy of dengue and chikungunya vaccines. [ABSTRACT FROM AUTHOR]

Background Mosquito-borne diseases pose a significant global public health threat, with Malaysia's Klang Valley experiencing numerous outbreaks in densely populated urban areas. Methods This study aimed to estimate the seroprevalence of anti-dengue and anti-chikungunya antibodies among urban refugees in the Klang Valley, Malaysia, and identify associated risk factors. Results High seroprevalence of anti-dengue immunoglobulin G (IgG) and IgM (60.0% [confidence interval {CI} 55.39 to 64.48] and 9.2% [CI 6.77 to 12.25], respectively) were observed among refugees >18 years of age (χ22=11.720, p=0.003), Kachin ethnicity (χ28=72.253, p<0.001), without formal education (χ21=3.856, p=0.050), homes near waste disposal sites (χ21=10.378, p=0.001) and refugees who have experienced flooding (χ21=5.460, p=0.019). Meanwhile, the overall seroprevalence of anti-chikungunya IgG and IgM was 9.7% (CI 7.15 to 12.73) and 10.8% (CI 8.09 to 13.93), respectively, with ages 12–18 years (χ22=6.075, p=0.048), Rohingya ethnicity (χ28=31.631, p<0.001) and homes close to waste disposal sites (χ21=3.912, p=0.048) being significant risk factors. Results showed a link to poor environmental living conditions, with an increase in the vector population with higher availability of breeding sites and thus exposure to dengue and chikungunya virus. Conclusions Health education among the community is the key to disease prevention, as there are no specific antiviral drugs for treatment and limited vaccine availability. [ABSTRACT FROM AUTHOR]

Chikungunya fever virus (CHIKV) is a mosquito-borne alphavirus that causes wide-spread human infections and epidemics in Asia, Africa and recently, in the Americas. CHIKV is considered a priority pathogen by CEPI and WHO. Despite recent approval of a live-attenuated CHIKV vaccine, development of additional vaccines is warranted due to the worldwide outbreaks of CHIKV. Previously, we developed immunization DNA (iDNA) plasmid capable of launching live-attenuated CHIKV vaccine in vivo. Here we report the use of CHIKV iDNA plasmid to prepare a novel, live-attenuated CHIKV vaccine V5040 with rearranged RNA genome. In V5040, genomic RNA was rearranged to encode capsid gene downstream from the glycoprotein genes. Attenuated mutations derived from experimental CHIKV 181/25 vaccine were also engineered into E2 gene of V5040. The DNA copy of rearranged CHIKV genomic RNA with attenuated mutations was cloned into iDNA plasmid pMG5040 downstream from the CMV promoter. After transfection in vitro, pMG5040 launched replication of V5040 virus with rearranged genome and attenuating E2 mutations. Furthermore, V5040 virus was evaluated in experimental murine models for general safety and immunogenicity. Vaccination with V5040 virus subcutaneously resulted in elicitation of CHIKV-specific, virus-neutralizing antibodies. The results warrant further evaluation of V5040 virus with rearranged genome as a novel live-attenuated vaccine for CHIKV. Author summary: Chikungunya fever virus (CHIKV) is transmitted to humans by infected mosquitoes. The virus causes disease outbreaks and epidemics in Asia, Africa and recently, in the Americas. Despite recent approval of a live-attenuated CHIKV vaccine, additional vaccines are warranted due to the worldwide distribution of CHIKV. We developed bacterial plasmid DNA that codes for CHIKV virus V5040 with rearranged genome as an experimental CHIKV vaccine. The vaccine virus was prepared in cultured cells and tested in mice. The results showed that genome rearrangement did not prevent replication of V5040 virus. Mice injected with V5040 vaccine virus developed immune response that prevented infection with related CHIKV. The results suggest that V5040 CHIKV with genome rearrangement deserves additional studies as a potential vaccine to prevent infections with CHIKV. [ABSTRACT FROM AUTHOR]

Guillain-Barré Syndrome (GBS) is an autoimmune neuropathy. Antecedent infections have been seen to be significant triggering factors for developing GBS. Among them, arboviral infections are rapidly gaining importance as significant triggers, especially in the areas where they are endemic. Chikungunya, an arboviral infection that usually causes a self-limiting acute febrile illness can lead to GBS as one its severe complications. Herein, we describe a case of a 21-year-old female who presented with weakness in all four limbs and paresthesia. Nerve conduction study and cerebrospinal fluid (CSF) analysis showed axonal, demyelinating motor and sensory neuropathy with albuminocytological dissociation indicating Acute Motor and Sensory Axonal Neuropathy (AMSAN) variant of GBS. Serum IgM antibodies against ganglioside GM1 were detected. Anti-Chikungunya IgM antibodies were found in both serum and CSF samples. The patient was initiated with Intravenous Immunoglobulin (IVIG) therapy. In view of hypoxia, she was intubated and was on mechanical ventilation. After 2 weeks of being comatose, the patient gradually improved and was discharged with no sequelae. A literature review on antecedent infections in GBS is presented alongside the case report to better understand the association of GBS with antecedent infections, especially the endemic arboviral infections like Chikungunya, Dengue and Zika. This will help in reinforcing the significance of having robust surveillance and public health control measures for infectious diseases. [ABSTRACT FROM AUTHOR]

Chikungunya can have longstanding effects on health and quality of life. Alongside the recent approval of the world's first chikungunya vaccine by the US Food and Drug Administration in November 2023 and with new chikungunya vaccines in the pipeline, it is important to understand the perspectives of stakeholders before vaccine rollout. Our study aim is to identify key programmatic considerations and gaps in Evidence-to-Recommendation criteria for chikungunya vaccine introduction. We used purposive and snowball sampling to identify global, national, and subnational stakeholders from outbreak prone areas, including Latin America, Asia, and Africa. Semi-structured in-depth interviews were conducted and analysed using qualitative descriptive methods. We found that perspectives varied between tiers of stakeholders and geographies. Unknown disease burden, diagnostics, non-specific disease surveillance, undefined target populations for vaccination, and low disease prioritisation were critical challenges identified by stakeholders that need to be addressed to facilitate rolling out a chikungunya vaccine. Future investments should address these challenges to generate useful evidence for decision-making on new chikungunya vaccine introduction. Author summary: The first vaccine to prevent chikungunya fever has been recently approved in November 2023 by the US FDA and multiple chikungunya vaccine candidates are in different phases of the development pipeline. These will be the first-ever vaccines against an alphavirus and offer new technologies for vaccine development against other viruses of the same family that may cause future epidemics. We interviewed stakeholders from areas at risk of chikungunya outbreaks across Latin America, Asia and Africa, and identified gaps in Evidence-to-Recommendation criteria that should be addressed alongside vaccine introduction. Our findings show that stakeholders from different regions prioritised chikungunya differently, but all stakeholders agreed that the unknown burden of disease, undefined target populations for vaccination and non-specific disease surveillance were challenges that needed to be addressed imminently. To address these gaps, the involvement of stakeholders in all phases of vaccine development and rollout will be crucial to uncover future challenges and to ensure vaccine equity. [ABSTRACT FROM AUTHOR]

The incidence of chikungunya has dramatically surged worldwide in recent decades, imposing an expanding burden on public health. In recent years, South America, particularly Brazil, has experienced outbreaks that have ravaged populations following the rapid dissemination of the chikungunya virus (CHIKV), which was first detected in 2014. The primary vector for CHIKV transmission is the urban mosquito species Aedes aegypti, which is highly prevalent throughout Brazil. However, the impact of the locally circulating CHIKV genotypes and specific combinations of local mosquito populations on vector competence remains unexplored. Here, we experimentally analyzed and compared the infectivity and transmissibility of the CHIKV-ECSA lineage recently isolated in Brazil among four Ae. aegypti populations collected from different regions of the country. When exposed to CHIKV-infected AG129 mice for blood feeding, all the mosquito populations displayed high infection rates and dissemination efficiency. Furthermore, we observed that all the populations were highly efficient in transmitting CHIKV to a vertebrate host (naïve AG129 mice) as early as eight days post-infection. These results demonstrate the high capacity of Brazilian Ae. aegypti populations to transmit the locally circulating CHIKV-ECSA lineage. This observation could help to explain the high prevalence of the CHIKV-ECSA lineage over the Asian lineage, which was also detected in Brazil in 2014. However, further studies comparing both lineages are necessary to gain a better understanding of the vector's importance in the epidemiology of CHIKV in the Americas. [ABSTRACT FROM AUTHOR]

Background and purpose: Aedes mosquitoes, especially Aedes aegypti and A. albopictus, due to their special biological and ecological characteristics, have high adaptability and establishment power in different weather conditions, including Iran, and for this reason, they are called invasive mosquitoes. These mosquitoes, which are known as a serious problem for human health, are very important in terms of transmission of very important arboviral diseases such as dengue fever, chikungunya, Zika virus, and yellow fever. Considering the importance of these diseases on the health system and human health, as well as numerous reports of the spread of arboviral diseases through Aedes mosquitoes in different countries, various programs have been proposed to control Aedes mosquitoes. As a result, introducing suitable methods to control Aedes mosquitoes can play a significant role in reducing the transmission of these diseases and maintaining human health. Therefore, in this review, we evaluate the use of each of the Aedes mosquito control methods. Materials and methods: This article is a narrative review of the introduction and effectiveness of different methods of controlling Aedes mosquitoes. Collecting information about control methods of A. aegypti and A. albopictus has been compiled without time and language restrictions from international scientific databases including Pub Med, Web of Science, Google Scholar, (ScienceDirect, Scopus, Elsevier, Lilacs) and Internal databases including, Scientific Information Database(SID), Iranian Medical Library(MedLib), Magiran, Civilica. The information collected based on the performance of each of the mentioned methods was extracted, categorized, analyzed, and used in compiling this article. Finally, out of a total of 10202 extracted articles, 123 articles were used in this research considering the inclusion and exclusion criteria. Results: In general, the goals related to the use of different methods of controlling Aedes mosquitoes are different depending on the country, epidemiological conditions, resources, and local priorities. But overall, disease prevention, reduction of mosquito population, stopping of disease transmission, prevention of mosquito establishment, disease spread, reduction of nuisances and finally identification of new invasive species are prioritized. The most appropriate methods of controlling Aedes are divided into five categories: 1. Environmental methods that include reducing the habitats and growth resources of mosquitoes 2. Chemical methods that are based on the use of various insecticides chemicals and insect growth regulators 3. Mechanical methods that include the use of various traps 4. Biological methods that include the use of natural enemies 5. Genetic methods include genetic engineering and mosquito sterilization techniques. It should be noted that each of these methods can play a significant role in the establishment of Aedes mosquitoes and the spread of arboviral diseases, and as a result, reducing the number of cases of infection and death in the health system. Conclusion: Considering the introduction of different control methods for A. aegypti and A. albopictus and the priority of each of the control methods presented; it is important to mention that the method of controlling Aedes depends a lot on the environmental conditions of the region, the stage of mosquito establishment, the population phase of mosquitoes and diseases caused by it. Therefore implementation of Aedes mosquito control programs through integrated vector management strategy is recommended, which requires the effective collaboration and coordination of national and local authorities and the general public for cost-effective control and lasting effects. [ABSTRACT FROM AUTHOR]

Chikungunya, a viral disease transmitted by Aedes aegypti or Aedes albopictus mosquitoes, poses a significant public health threat. In Wonoboyo Village, according to data from the Wonogiri Health Office, there were 119 reported cases in 2020, and 61 cases in 2021, highlighting the local impact of this disease within Wonogiri Regency. This study endeavors to investigate the factors contributing to the Chikungunya outbreak specifically in Wonoboyo Village. The research adopts an analytical observational approach with a cross-sectional design. The study's variables include the state of the landfill, the presence of larvae, occupancy density, landfill maintenance habits, hygiene practices, and mosquito repellent usage. The dependent variable is the occurrence of the Chikungunya outbreak (KLB Chikungunya). Data collection involves questionnaires and observations among the residents of Wonoboyo Village, with a sample size of 357 households selected through simple random sampling. Analysis utilizing Chi-square tests, with a significance level of 5%, reveals correlations between various factors and the Chikungunya outbreak. Specifically, the condition of the landfill, presence of larvae, occupancy density, landfill maintenance habits, hygiene practices, and mosquito repellent usage are significantly associated with the outbreak. Based on the findings, it is recommended that residents of Wonoboyo Village adhere to PSN 3M activities regularly and maintain cleanliness both indoors and outdoors to mitigate the transmission of Chikungunya. [ABSTRACT FROM AUTHOR]

Rough set theory is an advanced uncertainty tool that is capable of processing sophisticated real-world data satisfactorily. Rough approximation operators are used to determine the confirmed and possible data that can be obtained by using subsets. Numerous rough approximation models, inspired by neighborhood systems, have been proposed in earlier studies for satisfying axioms of Pawlak approximation spaces (P-approximation spaces) and improving the accuracy measures. This work provides a formulation a novel type of generalized approximation spaces (G-approximation spaces) based on new neighborhood systems inspired by Ij-neighborhoods and ideal structures. The originated G-approximation spaces are offered to fulfill the axiomatic requirements of P-approximation spaces and give more information based on the data subsets under study. That is, they are real simulations of the P-approximation spaces and provide more accurate decisions than the previous models. Several examples are provided to compare the suggested G-approximation spaces with existing ones. To illustrate the application potentiality and efficiency of the provided approach, a numerical example for Chikungunya disease is presented. Ultimately, we conclude our study with a summary and direction for further research. [ABSTRACT FROM AUTHOR]

The transmission of infectious illnesses, including dengue and chikungunya fevers, is accelerated by climate change. The Kimakonde language is where the word "chikungunya" means "to dry up or become contorted." One arthropod-borne virus disease that has been documented since 1824 is chikungunya fever (CHIKF). There have been 4,086 confirmed cases of dengue fever in the Jaipur districts alone, accounting for 32% of the state's overall dengue cases. The probability of infectious diseases, particularly those carried by vectors, is expected to rise as a result of global warming since more extreme precipitation episodes are anticipated. Illness management requires public health initiatives and ongoing monitoring. The frequency of dengue and chikungunya fever in Jaipur, India, was investigated in this study. Descriptive statistics were used to synthesize the data retrieved from various sources, including government databases, monitoring programmes, and hospital records. We used correlation analysis for 104 samples to look for links between weather and the incidence of Dengue and Chikungunya. There is a robust positive association between temperature and chikungunya cases, demonstrating that climate plays a substantial role in disease transmission. When developing therapies for vector-borne diseases, it is crucial to take demographic variables, environmental factors, and disease incidence patterns into account, as shown in this study. Understanding and managing these disorders requires a comprehensive strategy. It is essential to monitor patients continuously for improved treatment and prevention. [ABSTRACT FROM AUTHOR]

Communications between immune cells are essential to ensure appropriate coordination of their activities. Here, we observed the infiltration of activated macrophages into the joint-footpads of chikungunya virus (CHIKV)-infected animals. Large numbers of CD64+MHCII+ and CD64+MHCII- macrophages were present in the joint-footpad, preceded by the recruitment of their CD11b+Ly6C+ inflammatory monocyte precursors. Recruitment and differentiation of these myeloid subsets were dependent on CD4+ T cells and GM-CSF. Transcriptomic and gene ontology analyses of CD64+MHCII+ and CD64+MHCII- macrophages revealed 89 differentially expressed genes, including genes involved in T cell proliferation and differentiation pathways. Depletion of phagocytes, including CD64+MHCII+ macrophages, from CHIKV-infected mice reduced disease pathology, demonstrating that these cells play a pro-inflammatory role in CHIKV infection. Together, these results highlight the synergistic dynamics of immune cell crosstalk in driving CHIKV immunopathogenesis. This study provides new insights in the disease mechanism and offers opportunities for development of novel anti-CHIKV therapeutics. Synopsis: Activated CD64+MHCII+ macrophages are present in the joint-footpad during CHIKV infection and participate in a pathogenic immune crosstalk with CD4+ T cells to drive immunopathogenesis. CD64+MHCII+ macrophages could be an alternative host-directed therapeutic target against CHIKV infection. Mass cytometry reveals the presence of CD64+MHCII+ macrophages in the CHIKV-infected joint-footpad. IFNγ and GM-CSF secreted by CD4+ T cells are two mediators capable of regulating the levels of CD64+MHCII+ macrophages in CHIKV-infected joints. In vivo depletion of GM-CSF reduces CHIKV disease severity. CD64+MHCII+ macrophages are involved in multiple T-cell-related pathways as revealed by RNAseq analyses. CD64+MHCII+ macrophages are potential novel targets for the future development of anti-CHIKV therapeutics. Activated CD64+MHCII+ macrophages are present in the joint-footpad during CHIKV infection and participate in a pathogenic immune crosstalk with CD4+ T cells to drive immunopathogenesis. CD64+MHCII+ macrophages could be an alternative host-directed therapeutic target against CHIKV infection. [ABSTRACT FROM AUTHOR]

Alphaviruses are vector-borne, medically relevant, positive-stranded RNA viruses that cause disease in animals and humans worldwide. Of this group, chikungunya virus (CHIKV) is the most significant human pathogen, responsible for generating millions of infections leading to severe febrile illness and debilitating chronic joint pain. Currently, there are limited treatments to protect against alphavirus disease; thus, there is a tremendous need to generate safe and effective vaccines. Live-attenuated vaccines (LAVs) are cost-effective and potent immunization strategies capable of generating long-term protection in a single dose. However, LAVs often produce systemic viral replication, which can lead to unwanted post-vaccination side effects and pose a risk of reversion to a pathogenic phenotype and transmission to mosquitoes. Here, we utilized a chimeric infectious clone of CHIKV engineered with the domain C of the E2 gene of Semliki Forest virus (SFV) to express IFNγ and IL-21—two potent antiviral and immunomodulatory cytokines—in order to improve the LAV's attenuation while maintaining immunogenicity. The IFNγ- and IL-21-expressing vaccine candidates were stable during passage and significantly attenuated post-vaccination, as mice experienced reduced footpad swelling with minimal systemic replication and dissemination capacity compared to the parental vaccine. Additionally, these candidates provided complete protection to mice challenged with WT CHIKV. Our dual attenuation strategy represents an innovative way to generate safe and effective alphavirus vaccines that could be applied to other viruses. [ABSTRACT FROM AUTHOR]

To evaluate the frequency of errors in the diagnosis of medical laboratory-diagnosed Chikungunya virus (CHIKV) infections in Australia, we studied 42 laboratory-diagnosed CHIKV serum samples from one Queensland medical laboratory by ELISA IgG/IgM and measured the specific neutralization antibodies (Nab) against Barmah Forest virus (BFV), CHIKV and Ross River virus (RRV). The sero-positivity rates for the sera were as follows: anti-BFV IgG+ 19% (8/42), IgM+ 2.4% (1/42) and Nab+ 16.7% (7/42); anti-CHIKV IgG+ 90.5% (38/42), IgM+ 21.4% (9/42) and Nab+ 90.5% (38/42); anti-RRV IgG+ 88.1% (37/42), IgM+ 28.6% (12/42) and Nab+ 83.2% (35/42), respectively. Among the samples with multiple antibody positivity, 2.4% (1/42) showed triple ELISA IgM+, and 14.3% (6/42) exhibited double IgM RRV+CHIKV+; 9.5% (4/42) showed triple IgG+, 76.2% (32/42) displayed double IgG RRV+CHIKV+, 4.8% (2/42) showed IgG BFV+RRV+ and 4.8% (2/42) showed IgG BFV++CHIKV+; and 9.5% (4/42) showed triple Nab+ and 69% (29/42) exhibited double Nab RRV+CHIKV+, respectively. Our analysis of the single-virus infection control Nab results suggested no cross-neutralization between RRV and BFV, and only mild cross-neutralization between CHIKV and RRV, BFV and CHIKV, all with a ≥4-fold Nab titre ratio difference between the true virus infection and cross-reactivity counterpart virus. Subsequently, we re-diagnosed these 42 patients as 1 BFV+, 8 CHIKV+ and 23 RRV+ single-virus infections, along with five RRV+/BFV+ and four RRV+/CHIKV+ double infections, and one possible RRV+/BFV+ or RRV+CHIKV+, respectively. These findings suggests that a substantial proportion of medically attended RRV and BFV infections were misdiagnosed as CHIKV infections, highlighting the imperative need for diagnostic laboratory tests capable of distinguishing between CHIKV infections and actively co-circulating RRV and BFV. For a correct diagnosis, it is crucial to consider reliable diagnostic methods such as the neutralization assay to exclude RRV and BFV. [ABSTRACT FROM AUTHOR]

Uncaria tomentosa (UT) is a medicinal plant popularly known as cat's claw belonging to the Rubiaceae family that has been reported to display antiviral and anti-inflammatory activities. The chikungunya virus (CHIKV) outbreaks constitute a Brazilian public health concern. CHIKV infection develops an abrupt onset of fever, usually accompanied by a skin rash, besides incapacitating polyarthralgia. There is no vaccine available or treatment for CHIKV infection. The present study evaluates the hydroalcoholic extract of UT bark as a potential antiviral against CHIKV. The in vitro antiviral activity of the UT extract against the Brazilian CHIKV strain was assessed using quantitative reverse transcription polymerase chain reaction, flow cytometry, and plaque assay. Results obtained demonstrated that UT inhibits CHIKV infection in a dose-dependent manner. At the non-cytotoxic concentration of 100 µg/mL, UT exhibited antiviral activity above 90% as determined by plaque reduction assay, and it reduced the viral cytopathic effect. Similarly, a significant virucidal effect of 100 µg/mL UT was observed after 24 and 48 h post-infection. This is the first report on the antiviral activity of UT against CHIKV infection, and the data presented here suggests UT as a potential antiviral to treat CHIKV infection. [ABSTRACT FROM AUTHOR]

Background Chikungunya is an important travel-related disease because of its rapid geographical expansion and potential for prolonged morbidity. Improved understanding of the epidemiology of travel-related chikungunya infections may influence prevention strategies including education and vaccination. Methods We analysed data from travellers with confirmed or probable chikungunya reported to GeoSentinel sites from 2005 to 2020. Confirmed chikungunya was defined as a compatible clinical history plus either virus isolation, positive nucleic acid test or seroconversion/rising titre in paired sera. Probable chikungunya was defined as a compatible clinical history with a single positive serology result. Results 1202 travellers (896 confirmed and 306 probable) with chikungunya were included. The median age was 43 years (range 0–91; interquartile range [IQR]: 31–55); 707 (58.8%) travellers were female. Most infections were acquired in the Caribbean (28.8%), Southeast Asia (22.8%), South Central Asia (14.2%) and South America (14.2%). The highest numbers of chikungunya cases reported to GeoSentinel were in 2014 (28.3%), 2015 (14.3%) and 2019 (11.9%). The most frequent reasons for travel were tourism (n  = 592; 49.3%) and visiting friends or relatives (n  = 334; 27.7%). The median time to presentation to a GeoSentinel site was 23 days (IQR: 7–52) after symptom onset. In travellers with confirmed chikungunya and no other reported illnesses, the most frequently reported symptoms included musculoskeletal symptoms (98.8%), fever/chills/sweats (68.7%) and dermatologic symptoms (35.5%). Among 917 travellers with information available, 296 (32.3%) had a pretravel consultation. Conclusions Chikungunya was acquired by international travellers in almost 100 destinations globally. Vector precautions and vaccination where recommended should be integrated into pretravel visits for travellers going to areas with chikungunya or areas with the potential for transmission. Continued surveillance of travel-related chikungunya may help public health officials and clinicians limit the transmission of this potentially debilitating disease by defining regions where protective measures (e.g. pretravel vaccination) should be strongly considered. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Chikungunya encephalitis, though rare, warrants clinical attention due to its severe complications. Early identification and appropriate management are crucial for improved outcomes in patients with this rare manifestation of chikungunya virus (CHIKV) infection. CHIKV infection is commonly associated with fever and joint pains, but neurological complications such as encephalitis are rare. Here, we present a unique case of confirmed chikungunya encephalitis in a 12‐year‐old male exhibiting atypical neurological symptoms. The diagnostic journey involved comprehensive neuroimaging and serological investigations, revealing intriguing findings on magnetic resonance imaging and positive CHIKV RNA in serum and cerebrospinal fluid. We discuss the clinical presentation, radiological characteristics, and management strategies, emphasizing the importance of recognizing this uncommon neurological manifestation of CHIKV infection. [ABSTRACT FROM AUTHOR]

The mosquito vector Aedes aegypti L., plays an important role in transmission of diseases including dengue, chikungunya and zika fever. In this study, citronella leaf oil extracted by hydro-distillation technique has been evaluated for its efficacy against this vector. Citronella leaf oil (100, 125, 150, 175 and 200 ppm) when tested, 150 ppm was found to be the effective larvicidal concentration against 4th instar larvae. LC50 and LC90 toxicity values were observed to be 107.10 and 141.59 ppm, respectively. GC-MS analysis indicated the presence of β-citronellal, geraniol, elemol and β-citronellol as the major components, which might be causing the larval mortality. Retention efficacy of the oil was found to be up to 84 hr in terms of larval killing and during this retention period, a significant delay in development (L4 to adult) was also observed. No effect of storage was observed on its larvicidal efficacy even after six months. [ABSTRACT FROM AUTHOR]

Dengue, Zika and chikungunya outbreaks pose a significant public health risk to Pacific Island communities. Differential diagnosis is challenging due to overlapping clinical features and limited availability of laboratory diagnostic facilities. There is also insufficient information regarding the complications of these arboviruses, particularly for Zika and chikungunya. We conducted a systematic review and meta‐analysis to calculate pooled prevalence estimates with 95% confidence intervals (CI) for the clinical manifestations of dengue, Zika and chikungunya in the Pacific Islands. Based on pooled prevalence estimates, clinical features that may help to differentiate between the arboviruses include headache, haemorrhage and hepatomegaly in dengue; rash, conjunctivitis and peripheral oedema in Zika; and the combination of fever and arthralgia in chikungunya infections. We estimated that the hospitalisation and mortality rates in dengue were 9.90% (95% CI 7.67–12.37) and 0.23% (95% CI 0.16–0.31), respectively. Severe forms of dengue occurred in 1.92% (95% CI 0.72–3.63) of reported cases and 23.23% (95% CI 13.58–34.53) of hospitalised patients. Complications associated with Zika virus included Guillain‐Barré syndrome (GBS), estimated to occur in 14.08 (95% CI 11.71–16.66) per 10,000 reported cases, and congenital brain malformations such as microcephaly, particularly with first trimester maternal infection. For chikungunya, the hospitalisation rate was 2.57% (95% CI 1.30–4.25) and the risk of GBS was estimated at 1.70 (95% CI 1.06–2.48) per 10,000 reported cases. Whilst ongoing research is required, this systematic review enhances existing knowledge on the clinical manifestations of dengue, Zika and chikungunya infections and will assist Pacific Island clinicians during future arbovirus outbreaks. [ABSTRACT FROM AUTHOR]

Polio-associated paralysis is one of the diseases under national surveillance in the Democratic Republic of the Congo (DRC). Although it has become relatively rare due to control measures, non-polio paralysis cases are still reported and constitute a real problem, especially for etiological diagnosis, which is necessary for better management and response. From September 2022 to April 2023, we investigated acute flaccid paralysis (AFP) cases in Kinshasa following an alert from the Provincial Division of Health. All suspected cases and their close contacts were investigated and sampled. Among the 57 sampled patients, 21 (36.8%) were suspects, and 36 (63.2%) were contacts. We performed several etiological tests available in the laboratory, targeting viruses, including Poliovirus, Influenza virus, SARS-CoV-2, Enterovirus, and arboviruses. No virus material was detected, but the serological test (ELISA) detected antibodies against Chikungunya Virus, i.e., 47.4% (27/57) for IgM and 22.8% (13/57) for IgG. Among suspected cases, we detected 33.3% (7/21) with anti-Chikungunya IgM and 14.3% (3/21) of anti-Chikungunya IgG. These results highlight the importance of enhancing the epidemiological surveillance of Chikungunya. [ABSTRACT FROM AUTHOR]

Arthritogenic alphaviruses pose a significant public health concern due to their ability to cause joint inflammation, with emerging evidence of potential neurological consequences. In this review, we examine the immunopathology and immune evasion strategies employed by these viruses, highlighting their complex mechanisms of pathogenesis and neurological implications. We delve into how these viruses manipulate host immune responses, modulate inflammatory pathways, and potentially establish persistent infections. Further, we explore their ability to breach the blood-brain barrier, triggering neurological complications, and how co-infections exacerbate neurological outcomes. This review synthesizes current research to provide a comprehensive overview of the immunopathological mechanisms driving arthritogenic alphavirus infections and their impact on neurological health. By highlighting knowledge gaps, it underscores the need for research to unravel the complexities of virus-host interactions. This deeper understanding is crucial for developing targeted therapies to address both joint and neurological manifestations of these infections.

Objectives: Encephalitis is a severe neurological syndrome for which herpesvirus and enteroviruses are the most common etiological agents. Arboviruses, a wildly diverse group of pathogens, are also critical epidemiological agents associated with encephalitis. In Brazil, little is known about the causative agents of encephalitis. Methods: We conducted a hospital surveillance for encephalitis between 2020 and 2022. Molecular (RT-PCR and qPCR) and serological (virus-specific IgM and viral antigens) techniques were performed in cerebrospinal fluid and serum samples obtained from study participants. Results: In the 43 participants evaluated, the etiologic agent or the presence of IgM was detected in 16 (37.2%). Nine (20.9%) cases were positive for chikungunya virus (CHIKV), three (7.0%) for dengue virus, two (4.7%) for human adenovirus, one (2.3%) for varicella-zoster virus, and one (2.3%) for enterovirus. Whole-genome sequencing revealed that the CHIKV identified belongs to the East/Central/South African lineage. Conclusion: Herein, CHIKV is a common pathogen identified in encephalitis cases. Our results reinforce previous evidence that chikungunya represents a significant cause of encephalitis during CHIKV outbreaks and epidemics and add to existing information on the epidemiology of encephalitis in Brazil.

Chikungunya virus (CHIKV), a single-stranded RNA virus transmitted by Aedes mosquitoes, poses a significant global health threat, with severe complications observed in vulnerable populations. The only licensed vaccine, IXCHIQ, approved by the US FDA, is insufficient to address the growing disease burden, particularly in endemic regions lacking herd immunity. Monoclonal antibodies (mAbs), explicitly targeting structural proteins E1/E2, demonstrate promise in passive transfer studies, with mouse and human-derived mAbs showing protective efficacy. This article explores various vaccine candidates, including live attenuated, killed, nucleic acid-based (DNA/RNA), virus-like particle, chimeric, subunit, and adenovirus vectored vaccines. RNA vaccines have emerged as promising candidates due to their rapid response capabilities and enhanced safety profile. This review underscores the importance of the E1 and E2 proteins as immunogens, emphasizing their antigenic potential. Several vaccine candidates, such as CHIKV/IRES, measles vector (MV-CHIK), synthetic DNA-encoded antibodies, and mRNA-lipid nanoparticle vaccines, demonstrate encouraging preclinical and clinical results. In addition to identifying potential molecular targets for antiviral therapy, the study looks into the roles played by Toll-like receptors, RIG-I, and NOD-like receptors in the immune response to CHIKV. It also offers insights into novel tactics and promising vaccine candidates. This article discusses potential antiviral targets, the significance of E1 and E2 proteins, monoclonal antibodies, and RNA vaccines as prospective Chikungunya virus vaccine candidates.

IntroductionHuman Erythrovirus (parvovirus) B19 infection can produce symptoms similar to those produced by Dengue, Chikungunya, and Zika viruses, making clinical diagnosis difficult. The importance of erythrovirus B19 in human pathology has been increased and reported in numerous studies published globally.MethodsThe B19V infection was investigated by real-time PCR in sera samples from patients with signs and symptoms related to classic arboviral symptoms. This study was conducted to provide information on the genetic diversity of Human Erythrovirus B19 (B19V) circulating in the state of Mato Grosso do Sul, Midwest region of Brazil, from 2017 to 2022. A total of 773 sera samples of patients with negative diagnostic results for Dengue, Chikungunya, and Zika, during the study period were analyzed.ResultsErythrovirus DNA was found in 10.6% (82/773) of patients, among them 10 were pregnant women. Four samples were completely sequenced, and the other five partially, to genotype by phylogenetic reconstruction. All samples belong to worldwide dispersed genotype 1, subgenotype 1a.DiscussionThe findings of the study demonstrate the importance of including B19V in differential laboratory diagnosis for epidemiological purposes and appropriate patient management. The diagnosis for B19V should be performed, particularly among pregnant women, immunocompromised patients, and individuals with hemolytic diseases, given that the infection is more severe in these cases.

Background: This study aims to describe post-chikungunya complications chronically developed cases in returning travelers from some epidemic/endemic regions, and the variables that are associated with the progression of acute or subacute cases to the chronic phase. Methods: This single-center retrospective cohort study included chikungunya fever cases treated at La Paz-Carlos III University Hospital in Madrid, Spain, April 2014 to September 2016, when the chikungunya outbreak in Latin America started through the time of its greatest impact. Results: The analysis included 119 cases. Of these, 67.2 % were male, with a median age of 41.0 years [IQR 16.0 to 76.0] years. Only 25.6 % of the patients attended a pre-travel advice consultation. Most patients reported arthralgias, which significantly impacted their daily quality of life (86 %). The mean duration of joint symptoms was 129.4 days, with a median of 90 days [IQR 0 to 715]. Factors found to be associated with chronic arthralgia include female sex, country of infection, age at diagnosis, previous diseases, symptoms during the acute phase, pain in previously injured tendons/joints, acute phase severity, and various laboratory markers such as hemoglobin, hematocrit, total serum bilirubin, and creatinine. Progression to chronic arthralgia significantly increased the need for changes in daily activity. Furthermore, 42.6 % of patients with chronic arthralgia reported recurrence of symptoms once they felt they had disappeared. Targeted treatment regimens led to significant improvements in these patients. Conclusions: The results of this study underscore the need for: (1) comprehensive pre-travel advice; (2) effective management of patients in specialized units, alongside early diagnosis and treatment, to prevent trivialization of these viral infections; and (3) the development of interdisciplinary recommendations to assist physicians in treating patients and enhancing outcomes.

The increase in incidence and geographical expansion of viruses transmitted by the Aedes mosquitoes, such as dengue (DENV) and zika (ZIKV) in the Americas, represents a burden for healthcare systems in tropical and subtropical regions. These and other under-detected arboviruses co-circulate in Costa Rica, adding additional complexity to their management due to their shared epidemiological behavior and similarity of symptoms in early stages. Since diagnostics of febrile illness is mostly based on clinical symptoms alone, we gathered acute-phase serum and urine from 399 samples of acute dengue-like cases from two healthcare facilities of Costa Rica, during an outbreak of arboviruses from July 2017 to May 2018, and tested them using molecular and serological methods. The analyses showed that of the clinically presumptive arbovirus cases that were reported, only 39.4% (n=153) of the samples were confirmed positive by RT-PCR to be DENV (DENV (10.3%), CHIKV (0.2%), ZIKV (27.3%), or mixed infections (1.5%). RT-PCR for other alphaviruses and flaviviruses, and PCR for Leptospira sp were negative. Furthermore, to assess flavivirus positivity in post-acute patients, the negative sera were tested against Dengue-IgM. 20% of sera were found positive, confounding even more the definitive number of cases, and emphasizing the need of several distinct diagnostic tools for accurate diagnostics. Molecular characterization of the prM and E genes from isolated viruses revealed that the American/Asian genotype of DENV-2 and the Asian lineage of ZIKV were circulating during this outbreak. Two different clades of DENV-2 American/Asian genotype were identified to co-circulate in the same region and a difference in the platelet and leukocyte count was noted between people infected with each clade, suggesting a putative distinct virulence. Our study sheds light on the necessity for healthcare strategies in managing arbovirus outbreaks, emphasizing the importance of comprehensive molecular and serological diagnostic approaches, as well as molecular characterization. This approach aids in enhancing our understanding of the clinical and epidemiological aspects of arboviral diseases during outbreaks. Our research highlights the need to strengthen training programs for health professionals and the need to increase research-based on laboratory evidence for diagnostic accuracy, guidance, development and implementation of public health interventions and epidemiological surveillance.

There are an estimated 3 million Chikungunya virus (CHIKV) infections per year, but no vaccines or specific pharmaceutical treatments are available. RNA-dependent RNA polymerase (RdRp) of CHIKV, encoded by nonstructural protein 4 (nsP4), was targeted to identify potential antiviral compounds in this study. A 3D model of the nsP4 was generated by homology modeling technique and Pockdrug-Server was used to predict ligand binding sites. The pharmacophore hypothesis was developed followed by virtual screening. 300 most potential ligands were selected from a library of 3000 compounds, after filtering for the molecules satisfying Lipinski's Rule of Five. Using molecular docking followed by ADMET analysis, 27 leads were then selected. We used MD simulations of the three best compounds that bind to the catalytic, palm, and thumb domains to find out how the ligand-protein interactions change over time. RMSD, RMSF, radius of gyration, free energy landscapes, and principal component analyses revealed that complexes nsP4-ZINC-12820763 and nsP4-ZINC-33280972 were more stable. Simulated trajectories were further used to compute MMGBSA binding energies of PubChem-135638918 (-22.33 kcal/mol), ZINC-12820763 (-50.19 kcal/mol) and ZINC-33280972 (-32.69 kcal/mol) bound to catalytic, palm and thumb domains, respectively. HOMO and LUMO of potential molecules were also investigated using density functional theory computations. With the support of computational simulations, three compounds were shown to have the potential to inhibit RdRp of CHIKV and need further evaluation using in-vitro and in-vivo analysis.

Abstract Communications between immune cells are essential to ensure appropriate coordination of their activities. Here, we observed the infiltration of activated macrophages into the joint-footpads of chikungunya virus (CHIKV)-infected animals. Large numbers of CD64+MHCII+ and CD64+MHCII- macrophages were present in the joint-footpad, preceded by the recruitment of their CD11b+Ly6C+ inflammatory monocyte precursors. Recruitment and differentiation of these myeloid subsets were dependent on CD4+ T cells and GM-CSF. Transcriptomic and gene ontology analyses of CD64+MHCII+ and CD64+MHCII- macrophages revealed 89 differentially expressed genes, including genes involved in T cell proliferation and differentiation pathways. Depletion of phagocytes, including CD64+MHCII+ macrophages, from CHIKV-infected mice reduced disease pathology, demonstrating that these cells play a pro-inflammatory role in CHIKV infection. Together, these results highlight the synergistic dynamics of immune cell crosstalk in driving CHIKV immunopathogenesis. This study provides new insights in the disease mechanism and offers opportunities for development of novel anti-CHIKV therapeutics.

Abstract Background Aedes albopictus is the secondary vector for dengue virus (DENV) in the Philippines, and also harbors chikungunya (CHIKV) and Zika (ZIKV) viruses. This study aimed to determine the minimum infection rates (MIRs) of CHIKV, DENV serotypes, and ZIKV in Ae. albopictus collected from selected two-site categories by altitude (highland [H] and lowland [L] sites) in Cebu city, Philippines during the wet (WS) and dry seasons (DS) of 2021–2022, and to explore the relationships between these arboviral MIRs and the local weather. Methods The viral RNA extracts in pooled and reared adult Ae. albopictus collected during the DS and WS from two-site categories were subjected to RT-PCR to amplify and detect gene loci specific for CHIKV, DENV-1 to DENV-4, and ZIKV and analyzed with the weather data. Results The range of CHIKV MIRs was higher in the WS (13.61–107.38 infected individuals per 1,000 mosquitoes) than in the DS (13.22–44.12), but was similar between the two-site categories. Rainfall (RF) influenced the CHIKV MIR. The MIR ranges of both DENV-2 (WS: H = 0, L = 0; DS: H = 0–5.92; L = 0–2.6) and DENV-4 (WS: H = 0, L = 0–2.90; DS: H = 2.96–6.13, L = 0–15.63) differed by season but not between the two-site categories. Relative humidity (RH), RF, and temperature did not influence DENVs’ MIRs. The MIR range of ZIKV was similar in both seasons (WS: 11.36–40.27; DS: 0–46.15) and two-site categories (H = 0–90.91, L = 0–55.56). RH and temperature influenced ZIKV MIR. Conclusions RF influenced CHIKV MIR in Ae. albopictus, whereas RH and temperature influenced that of ZIKV. Season influenced the MIRs of CHIKV and DENVs but not in ZIKV. Ae. albopictus were co-infected with CHIKV, DENVs, and ZIKV in both highland and lowland sites in Cebu city. Recommendations include all-year-round implementation of the Philippine Department of Health’s 4S enhanced strategy and installation of water pipelines in rural highlands for vector and disease control. Our findings are relevant to protect public health in the tropics in this climate change.

Background & objectives: Dengue and chikungunya infections are one of the major health problems that have plagued the human population globally. All dengue virus (DENV) serotypes circulate within Malaysia with particular serotypes dominating in different years/outbreaks. In the state of Kelantan, an increasing number of DENV and chikungunya virus (CHIKV) new cases have been reported, including several deaths. This study aimed to isolate and detect these arboviruses from adult mosquitoes in Kelantan. Methods: Adult mo squito samples were collected from January to August 2019 and were identified according to gender, species and locality. The isolation of the virus was done in C6/36 cells. Dengue NS1 antigen was carried out using direct mosquito lysate and mosquito culture supernatant. Detection and serotyping of the DENV was performed using multiplex RT-PCR and CHIKV detection using a one-step RT-PCR assay. Results: Of 91 mosquito pools, four were positive for NS1 antigen comprising two pools (2.2%) of male Ae. albopictus (Pulau Melaka and Kubang Siput) and two pools (2.2%) of Ae. aegypti (Kampung Demit Sungai). DENV 1 was detected in one pool (0.9%) of female Ae. albopictus among 114 tested Aedes pools. Two pools of 114 pools (1.7%) from both male Aedes species were positive with double serotypes, DENV 1 and DENV 2 (Pulau Melaka). However, no pool was positive for CHIKV. Interpretation & conclusion: The presence of DENV and the main vectors of arboviruses in Kelantan are pertinent indicators of the need to improve vector controls to reduce arbovirus infections among people in the localities.

Chikungunya, transmitted by Aedes mosquitoes, manifests with fever, joint pain, and a distinctive cutaneous feature known as the "Chik sign" or "Brownie nose." The Chik sign is an asymptomatic freckled hyperpigmentation of the tip and ala of the nose and may persist in the post-infective period. This nasal pigmentation can aid in diagnosing this viral infection, especially in resourcepoor settings where serological confirmation is not feasible. Pigmentary changes, though asymptomatic, can persist for months and can be managed conservatively with sun protection, topical moisturisers, and depigmenting creams. The present case series describes three patients with nasal pigmentation that developed after an episode of chikungunya fever. The first patient was a one-month-old female neonate who developed fever at 15 days of age, followed by nasal hyperpigmentation, with a positive maternal history of chikungunya. The second case was a 29-year-old female patient, who developed fever and joint pain, followed by nasal hyperpigmentation one week later, and was diagnosed as a case of chikungunya based on clinical and serological evidence. The third case involved a 62-year-old male patient, who developed fever and joint pain two months ago, followed by nasal hyperpigmentation one week later, and was diagnosed as a case of chikungunya based on clinical and serological evidence. [ABSTRACT FROM AUTHOR]

Introducción: La Enfermedad por el virus del Chikungunya (CHIKV) es una virosis que se caracteriza por fiebre acompañada de dolores articulares. La epidemia de esta enfermedad en los últimos dos años causó más de cien mil casos confirmados y sospechosos, incluido personas con Lupus Eritematoso Sistémico (LES). Objetivo: Los objetivos del siguiente trabajo consistieron en determinar la evolución de la Enfermedad por el CHIKV en pacientes con LES, caracterizar a la población incluida en el estudio, determinar la frecuencia de la Enfermedad por el CHIKV en pacientes con LES, describir las manifestaciones clínicas de la Enfermedad por el CHIKV en pacientes con LES y registrar la impresión de los pacientes en relación con la actividad de la enfermedad y las manifestaciones clínicas que aparecieron posterior a la Enfermedad por el CHIKV. Metodología: El estudio realizado fue de tipo descriptivo de corte transversal. Se incluyeron 101 pacientes con Lupus Eritematoso Sistémico, a quienes se les encuestó mediante un formulario virtual. Los investigadores establecieron contacto con los pacientes a través de llamadas telefónicas o mensajería, y si los pacientes aceptaban participar en el estudio, se les enviaba el formulario o, en algunos casos, se completaba durante la llamada telefónica, si el paciente lo solicitaba. Resultados: El valor de la media de edad es de 38,2 ± 11,8 años. El 85,1% (86/101) de los pacientes corresponden al sexo femenino, mientras que el 14,9% (15/101) corresponde al sexo masculino. El 37,6% (38/101) presentó la enfermedad por el CHIKV, la cual se caracterizó en la fase aguda por la presencia de artralgias en un 84,2% (32/38), fiebre en un 71,1% (27/38), debilidad en un 57,9% (22/38) y cefalea en un 55,3% (21/38). En la fase subaguda, las artralgias se manifestaron mayoritariamente en un 73,7% (28/38) de los pacientes. La fase crónica estuvo presente en el 71,1% (27/38) con la persistencia de artralgias en un 81,48% (22/27) de los pacientes acompañada de otros síntomas como la artritis en un 40,74% (11/27). A causa de la enfermedad por el CHIKV, el 21,1% (8/38) recibió la indicación en la fase subaguda o crónica de realizar cambios en su medicación para el LES. El 62,5% (5/8) recibió la indicación de aumentar la dosis del corticoesteroide, mientras que el 50% (4/8) de aumentar la dosis del inmunosupresor. Según la impresión de los pacientes, en cuanto a la actividad de la enfermedad de base, posterior a la enfermedad por el CHIKV, presentaron una exacerbación del LES en un 10,5% (4/38) de los pacientes, de los cuales un 50% (2/4) refirieron exacerbación de síntomas ya existentes antes de la infección y la aparición de nuevos síntomas en un 50% (2/4). El 5,2% (2/38) tuvo requerimiento de hospitalización debido a la enfermedad por el CHIKV en la fase aguda. Conclusión: Las artralgias fueron frecuentes en las fases aguda, subaguda y crónica. En términos de tratamiento, algunos pacientes ajustaron sus medicaciones para el LES, aumentando la dosis de inmunosupresores o corticoides. En cuanto a la evolución, la mayoría de los pacientes no experimentaron una exacerbación de la enfermedad de base debido a la enfermedad por el CHIKV, al igual que solo un par de pacientes requirió hospitalización.

La fiebre Chikungunya es causada por un arbovirus ARN perteneciente a la familia Togaviridae del género alphavirus, llamado “virus del chikungunya”, este virus tiene como vector el Aedes aegypti y el Aedes albopictus. En su fase aguda la enfermedad se manifiesta por fiebre, artritis o artralgias severas, mialgias, cefalea, fotofobia, linfadenopatías y brotes cutáneos, los síntomas pueden progresar a una fase subaguda hasta crónica, donde persisten las manifestaciones articulares y la fatiga. Se realizó una revisión sistemática en las bases de PubMed, Cochrane, Dovepress y SciELO, utilizando las palabras claves: chikungunya y chikunguña, cruzadas con las palabras: artritis crónica y tratamiento. Se incluyeron en el estudio un total de 16 artículos, 6 artículos de revisión, 4 artículos originales, 2 ensayos clínicos, 2 reportes de caso, 1 revisión sistemática y 1 carta al editor. Entre las opciones farmacológicas, el metotrexato es el fármaco más estudiado y compite con los efectos de los AINE. Como terapias no farmacológicas se encuentran la fisioterapia y la terapia física, utilizados como complementos a la terapia farmacológica. El uso de terapias caseras, incluso la homeopatía, también podrían agregarse, atendiendo principalmente el factor psíquico y cultural de los pacientes.

Background: Chikungunya is emerging and reemerging word-widely in the past decades. It is non-endemic in Zhejiang Province, Southeast China. Aedes albopictus, one of major vectors of chikungunya, is widely-distribution in Zhejiang, and autochthonous transmission is possible after introducing chikungunya virus. Methods: Retrospectively collected the epidemiological, clinical and genetic data of chikungunya and conducted the descriptive analysis and gene sequence analysis. Results: From 2008 to 2022, 29 chikungunya cases, including 26 overseas imported and 3 local cases, were reported and no cases died of chikungunya. More than half of the imported cases (53.85%) were from Southeast Asia. Seasonal peak of the imported cases was noted between August and September, and 42.31% cases onset in those 2 months. Eight prefecture-level cities and 16 counties reported cases during the study period, with Jinghua (27.59%) and Hangzhou (24.14%) reporting the largest number of cases. The 3 local cases were all reported in Qujiang, Quzhou in 2017. For imported cases, the male-female gender ratio was 2.71:1, 20–30 years old cases (46.15%) and commercial service (42.31%) accounted for the highest proportion. Clinically, fever (100%), fatigue (94.44%), arthralgia (79.17%), headache (71.43%) and erythra (65.22%) were the most common reported symptoms. Eight whole-genome sequences were obtained and belonged to East/Central/South African (ECSA) or Asian genotype. Conclusions: With the change of immigration policy, the surveillance of chikungunya should be strengthened and the ability of the case discovery and diagnosis should be improved in Zhejiang in the post-COVID-19 era.

AbstractIntroduction Mosquito-borne infections are of global health concern because of their rapid spread and upsurge, which creates a risk for coinfections. DENV and ZIKV are transmitted by Aedes aegypti and A. albopictus and are prevalent in Nigeria and neighbouring countries. However, their seroprevalence, burden, hidden endemicity and possible cocirculation are poorly understood in Nigeria.Methods We conducted a cross-sectional study of 871 participants from three regions of Nigeria. All serum samples were analysed using malaria RDT and the immunoblot molecular diagnostic assay recomLine Tropical Fever for the presence of arboviral antibody serological marker IgG (Mikrogen Diagnostik, Neuried, Germany) with DENV and ZIKV Nonstructural protein 1 (NS 1), DENV and ZIKV Equad (variant of the envelope protein with designated mutations to increase specificity), according to the manufacturer’s instructions.Results The overall IgG antibody seropositivity against DENV-flavivirus was 44.7% (389/871); 95% CI (41.41–47.99), while ZIKV-flavivirus was 19.2% (167/871); 95% CI (0.16–0.21), and DENV-ZIKV-flavivirus cocirculation antibody seropositivity was 6.2%5 (54/871); 95% CI (0.6–0.7) in the three study regions of Nigeria. The study cohort presented similar clinical signs and symptoms of flaviviruses (DENV and ZIKV) in all three study regions.Conclusion This study highlighted an unexpectedly high antibody seropositivity, burden, hidden endemicity, and regional spread of mono- and co-circulating flaviviruses (DENV and ZIKV) in Nigeria.Key messagesDengue flavivirus sero-cross-reactivity drives antibody-dependent enhancement of ZIKV infection.Both viruses share common hosts (humans) and vectors (primarily Aedes aegypti), and are thus influenced by similar biological, ecological, and economic factors, resulting in epidemiological synergy.Additionally, the actual burden in epidemic and interepidemic periods is grossly or chronically unknown and underreported. Despite this trend and the potential public health threat, there are no reliable data, and little is known about these arboviral co-circulation infections.

Chikungunya virus (CHIKV) infection is characterized by febrile illness, severe joint pain, myalgia, and cardiovascular complications. Given that CHIKV stimulates reactive oxygen species (ROS) and pro- and anti-inflammatory cytokines, events that disrupt vascular homeostasis, we hypothesized that CHIKV induces arterial dysfunction by directly impacting redox-related mechanisms in vascular cells. Wild-type (WT) and iNOS knockout (iNOS−/−) mice were administered either CHIKV (1.0 × 106 PFU/µL) or Mock vehicle via the intracaudal route. In vivo, CHIKV infection induced vascular dysfunction (assessed by a wire myograph), decreased systolic blood pressure (tail-cuff plethysmography), increased IL-6 and IFN-γ, but not TNF-α levels (determined by ELISA), and increased protein content by Western blot. Marked contractile hyporesponsiveness to phenylephrine was observed 48 h post-infection, which was restored by endothelium removal. L-NAME, 1400W, Tiron, and iNOS gene deletion prevented phenylephrine hyporesponsiveness. CHIKV infection increased vascular nitrite concentration (Griess reaction) and superoxide anion (O2•−) generation (lucigenin chemiluminescence), and decreased hydrogen peroxide (H2O2, by Amplex Red) levels 48 h post-infection, alongside increased TBARS levels. In vitro, CHIKV infected endothelial cells (EA.hy926) and upregulated ICAM-1 and iNOS protein expression (determined by Western blot). These data support the conclusion that CHIKV-induced alterations in vascular ROS/NF-kB/iNOS/NO signaling potentially contribute to cardiovascular events associated with Chikungunya infection.

This study aimed to determine the incidence of post-chikungunya chronic rheumatism (pCHIK-CR) and its impact on quality of life (QoL) and chronic fatigue in adults seven years after the 2014–2015 CHIKV outbreak in Piedecuesta, Colombia. We evaluated 78 adults (median age: 30 years, IQR: 21.0; women 60.3%) with confirmed CHIKV infection. In 2022, participants underwent a GALS examination and completed surveys on disability, stiffness, health status, and fatigue. A rheumatologist evaluated patients who reported arthralgia, morning stiffness, and abnormal GALS examination. Chronic fatigue was defined as fatigue persisting for over six months. Seven years after infection, 14.1% of participants were classified as pCHIK-CR cases, 41.0% as having non-inflammatory pain, likely degenerative (NIP-LD), and 44.9% without rheumatic disease (Wo-RM). Patients with pCHIK-CR and NIP-LD exhibited significantly worse QoL compared to Wo-RM cases. Chronic fatigue prevalence increased from 8.6% in Wo-RM patients to 25.0% in NIP-LD and 54.6% in pCHIK-CR cases. This study implemented a comprehensive clinical assessment to objectively estimate and characterize the incidence of chronic rheumatological disease attributed to CHIKV infection. One in seven cases with CHIKV infection develops pCHIK-CR, which impacts both QoL and chronic fatigue. This study contributes to understanding the burden of these arboviruses in the medium term.

Chikungunya fever is a mosquito-borne infectious disease caused by the chikungunya virus (CHIKV). Recently, CHIKV has spread rapidly worldwide, raising global concerns. However, there is only one approved vaccine is available to prevent CHIKV infection; therefore, different platform vaccines development is a public health priority. The CHIKV genome encodes four non-structural polyproteins (nsP1-4) and one structural polyprotein (capsid, envelope 3, envelope 2, 6 K, and envelope 1). Previous studies have shown that N-linked glycans in viral proteins play important roles in regulating immune responses. Accordingly, in this study, we designed four CHIKV DNA vaccine candidates with mutated N-glycosylation sites in the full-length E and E I/II proteins. Our results indicated that immunization of mice with the vaccine elevated the cytokines levels, including IFN-γ, associated with T cell immune response. Furthermore, the truncated E protein with a deleted E III domain (E I/II) exhibited better immunogenicity than the full-length E protein, and N-linked glycosylation of E I/II protein induced a higher cell-mediated immune response. Overall, our study demonstrates that N-linked glycosylation of the E I/II proteins of CHIKV significantly enhances cell-mediated immune responses, laying the foundation for the development of potential vaccination strategies against CHIKV.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus causing a debilitating febrile illness with rheumatic disease symptoms of arthralgia and arthritis. Since its spread outside of Africa in 2005, it continues to cause outbreaks and disseminates into new territories. Intervention strategies are urgently required, including vaccination and antiviral approaches. To test efficacy, the use of small animal models is required. Two mouse strains, A129, with a deficiency in their type-I interferon (IFN) receptor, and C57BL/6 are widely used. A direct comparison of these strains alongside the wild-type parental strain of the A129 mice, 129Sv/Ev, was undertaken to assess clinical disease progression, viral loads in key tissues, histological changes and levels of sera biomarkers. Our results confirm the severe disease course in A129 mice which was not observed in the parental 129Sv/Ev strain. Of the two wild-type strains, viral loads were higher in 129Sv/Ev mice compared to C57BL/6 counterparts. Our results have established these models and parameters for the future testing of vaccines and antiviral approaches.