RESUMEN
BACKGROUND: The spread of vector-borne infectious diseases is determined, among other things, by temperature. Thus, climate change will have an influence on their global distribution. In the future, Europe will approach the temperature optimum for the transmission of ZIKV and CHIKV. Climate scenarios and climate models can be used to depict future climatic changes and to draw conclusions about future risk areas for vector-borne infectious diseases. METHODS: Based on the RCP 4.5 and RCP 8.5 climate scenarios, a geospatial analysis was carried out for the future temperature suitability of ZIKV and CHIKV in Europe. The results were presented in maps and the percentage of the affected areas calculated. RESULTS: Due to rising temperatures, the risk areas for transmission of ZIKV and CHIKV spread in both RCP scenarios. For CHIKV transmission, Spain, Portugal, the Mediterranean coast and areas near the Black Sea are mainly affected. Due to high temperatures, large areas throughout Europe are at risk for ZIKV and CHIKV transmission. CONCLUSION: Temperature is only one of many factors influencing the spread of vector-borne infectious diseases. Nevertheless, the representation of risk areas on the basis of climate scenarios allows an assessment of future risk development. Monitoring and adaptation strategies are indispensable for coping with and containing possible future autochthonous transmissions and epidemics in Europe.
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Fiebre Chikungunya , Cambio Climático , Sistemas de Información Geográfica , Infección por el Virus Zika , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/transmisión , Humanos , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/transmisión , Europa (Continente)/epidemiología , Virus Zika , Animales , Medición de Riesgo , Virus Chikungunya , TemperaturaRESUMEN
BACKGROUND OBJECTIVES: Aedes aegypti and Ae. albopictus mosquitoes breed in natural and artificial containers, and they transmit dengue and chikungunya. A study was conducted to identify the contribution of bamboo stumps to these disease vectors that were used in the flower garden as pillars to hold the bamboo flex fence. METHODS: Two sizes of whole bamboo were used to hold fences around gardens at Dhaka University, Bangladesh, and were painted red and green. Mosquito larvae and pupae were collected from bamboo stumps between July and August, and vectors were identified up to the species level. The data were analyzed using the STATA/MP 14.2 version. RESULTS: 83.5% and 0.2% were Ae. albopictus and Ae. aegypti, respectively, and the remaining were Culex and Ar-migeres species. Ae. albopictus, Ae. aegypti, and both species-positive bamboo stumps were 46.9, 0.7, and 47.1%, respectively. 54.5% of the bamboo stumps had at least one mosquito species. The average stump depth for Aedes positive stumps (mean=11.7 cm, SE = 0.5) was significantly (p <0.001) higher than the Aedes negative stumps (mean = 9.5 cm, SE = 0.4). 53.8% and 38.0% stumps were found Aedes positive on the ground and upper sides of fences, respectively, and found significant (p<0.01) differences between both sides. A zero-inflated negative binomial count model is significant at a 5% level of significance, χ2(4) = 11.8, p = 0.019 (<0.05) for Ae. albopictus. Stump depth is found to have a significant positive effect on the number of Aedes-positive stumps. INTERPRETATION CONCLUSION: Artificially used natural containers are adding pressure to current mosquito control activities as mosquitoes are breeding on them, which needs additional attention.
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Aedes , Fiebre Chikungunya , Dengue , Larva , Control de Mosquitos , Mosquitos Vectores , Animales , Bangladesh/epidemiología , Dengue/transmisión , Dengue/prevención & control , Aedes/fisiología , Aedes/virología , Control de Mosquitos/métodos , Mosquitos Vectores/fisiología , Mosquitos Vectores/virología , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/prevención & control , Larva/fisiología , Pupa/fisiología , Sasa , Culex/fisiología , HumanosRESUMEN
PURPOSE OF REVIEW: Arbovirus infections are a challenge for immunocompromised hosts who travel to or live in endemic regions or who receive organs or tissues from donors who travel or live in such areas. This review addresses Dengue (DENV), Chikungunya (CHIKV), and Zika (ZIKV) infections in hematological patients, hematopoietic cell or solid organ transplant recipients, and people with HIV (PWH). RECENT FINDINGS: Transmission is mainly due through Aedes mosquito bite. DENV and ZIKV may also be transmitted through blood, tissues or donor grafts. Clinical manifestations are quite similar and diagnosis requires laboratory confirmation to provide appropriate management. The best diagnostic method is PCR since serology may present false negative results in immunocompromised patients, or cross-reactivity as in the case of DENV and ZIKV. There is no specific treatment for any of these infections. SUMMARY: Educational and preventive measures are the best strategy: vector control, knowledge of the vector's habits, protection against mosquito bites, avoiding travel to endemic areas or with a current epidemic, and avoiding nonvector transmission according to local recommendations for donor deferral. Vaccination, currently only available for DENV, has not yet been studied in immunocompromised patients and is not currently recommended.
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Fiebre Chikungunya , Dengue , Huésped Inmunocomprometido , Infección por el Virus Zika , Humanos , Dengue/inmunología , Dengue/epidemiología , Dengue/transmisión , Fiebre Chikungunya/inmunología , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/transmisión , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/transmisión , Infección por el Virus Zika/epidemiología , Enfermedades Endémicas , AnimalesRESUMEN
BACKGROUND: The large dengue (DENV) and chikungunya (CHIKV) outbreaks observed during the last decade across the world, as well as local transmissions in non-endemic areas are a growing concern for blood safety. The aim of this study was to evaluate and compare the sensitivity of nucleic acid tests (NAT) detecting DENV and CHIKV RNA. MATERIALS AND METHODS: Using DENV 1 to 4 International Standards, the limits of detection (LODs) calculated by probit analysis of two NAT assays; the cobas CHIKV/DENV assay (Roche Diagnostics) and the Procleix Dengue Virus Assay (Grifols) were compared. In addition, CHIKV-RNA LOD of the cobas CHIKV/DENV assay was evaluated. RESULTS: For dengue, the 95% LOD of the cobas assay ranged between 4.10 [CI95%: 2.70-8.19] IU/mL (DENV-2) and 7.07 [CI95%: 4.34-14.89] IU/mL (DENV-4), and between 2.19 [CI95%: 1.53-3.83] IU/mL (DENV-3) and 5.84 [CI95%: 3.84-10.77] IU/mL (DENV-1) for Procleix assay. The Procleix assay had a significant lower LOD for DENV-3 (2.19 vs. 5.89 IU/mL) when compared to the cobas assay (p = 0.005). The 95% LOD for CHIKV-RNA detection of the cobas assay was 4.76 [CI95%: 3.08-8.94] IU/mL. DISCUSSION: The two NAT assays developed for blood donor screening evaluated in this study demonstrated high and similar analytical performance. Subject to an appropriate risk-benefit assessment, they can be used to support blood safety during outbreaks in endemic areas or in non-endemic areas as an alternative to deferring blood donors during local transmission likely to affect the blood supply. The development of multiplex assays is expected to optimize laboratory organization.
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Fiebre Chikungunya , Virus Chikungunya , Virus del Dengue , Dengue , ARN Viral , Humanos , Dengue/transmisión , Dengue/diagnóstico , Dengue/prevención & control , Dengue/sangre , Fiebre Chikungunya/diagnóstico , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/sangre , Fiebre Chikungunya/prevención & control , ARN Viral/sangre , ARN Viral/análisis , Técnicas de Amplificación de Ácido Nucleico/métodos , Seguridad de la Sangre/métodos , Transfusión Sanguínea , Sensibilidad y Especificidad , Límite de DetecciónRESUMEN
Zika (ZIKV) and chikungunya (CHIKV) are arboviruses that cause infections in humans and can cause clinical complications, representing a worldwide public health problem. Aedes aegypti is the primary vector of these pathogens and Culex quinquefasciatus may be a potential ZIKV vector. This study aimed to evaluate fecundity, fertility, survival, longevity, and blood feeding activity in Ae. aegypti after exposure to ZIKV and CHIKV and, in Cx. quinquefasciatus exposed to ZIKV. Three colonies were evaluated: AeCamp (Ae. aegypti-field), RecL (Ae. aegypti-laboratory) and CqSLab (Cx. quinquefasciatus-laboratory). Seven to 10 days-old females from these colonies were exposed to artificial blood feeding with CHIKV or ZIKV. CHIKV caused reduction in fecundity and fertility in AeCamp and reduction in survival and fertility in RecL. ZIKV impacted survival in RecL, fertility in AeCamp and, fecundity and fertility in CqSLab. Both viruses had no effect on blood feeding activity. These results show that CHIKV produces a higher biological cost in Ae. aegypti, compared to ZIKV, and ZIKV differently alters the biological performance in colonies of Ae. aegypti and Cx. quinquefasciatus. These results provide a better understanding over the processes of virus-vector interaction and can shed light on the complexity of arbovirus transmission.
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Aedes , Virus Chikungunya , Culex , Fertilidad , Mosquitos Vectores , Infección por el Virus Zika , Virus Zika , Animales , Aedes/virología , Aedes/fisiología , Virus Chikungunya/fisiología , Virus Chikungunya/patogenicidad , Virus Zika/fisiología , Virus Zika/patogenicidad , Culex/virología , Culex/fisiología , Mosquitos Vectores/virología , Mosquitos Vectores/fisiología , Femenino , Infección por el Virus Zika/transmisión , Infección por el Virus Zika/virología , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/virología , Conducta Alimentaria/fisiología , Humanos , LongevidadRESUMEN
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.
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Aedes , Virus Chikungunya , Microbioma Gastrointestinal , Mosquitos Vectores , Animales , Femenino , Aedes/microbiología , Aedes/virología , Bacterias/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/virología , Virus Chikungunya/genética , Virus Chikungunya/aislamiento & purificación , Virus Chikungunya/fisiología , Mosquitos Vectores/microbiología , Mosquitos Vectores/virología , ARN Ribosómico 16S/genética , TailandiaRESUMEN
Chikungunya virus (CHIKV) has emerged as a significant public health concern due to its rapid spread and potential for causing debilitating epidemics. In Argentina, the virus has garnered attention since its introduction to the Americas in 2013, due to its growing incidence and impact in neighbouring countries. Here we present a comprehensive analysis of the spatiotemporal dynamics of CHIKV in Argentina, focusing on the evolutionary trajectory of its genetic variants. Through a combination of active surveillance, screening of historical and recent samples, and whole-genome sequencing, we traced the evolutionary history of CHIKV lineages circulating within the country. Our results reveal that two distinct genotypes circulated in Argentina: The Asian lineage during the 2016 epidemic and the ECSA lineage in 2023. This distribution reflects the dominance of particular variants across Latin America. Since 2023, the ECSA lineage has led to a surge in cases throughout the Americas, marking a significant shift. The replacement of lineages in the American region constitutes a major epidemiological event, potentially affecting the dynamics of virus transmission and the clinical outcomes in impacted populations. The spatiotemporal analysis highlights CHIKV's distribution across Argentina and underscores the significant role of human mobility, especially when considering recent epidemics in neighbouring countries such as Paraguay and Uruguay, which have facilitated the spread and introduction of the viral strain into different districts. By integrating epidemiological data with genomic insights, we elucidate the patterns of virus dissemination, highlighting key areas of transmission and potential factors contributing to its spread.
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Fiebre Chikungunya , Virus Chikungunya , Evolución Molecular , Genotipo , Filogenia , Argentina/epidemiología , Virus Chikungunya/genética , Virus Chikungunya/clasificación , Virus Chikungunya/aislamiento & purificación , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/virología , Fiebre Chikungunya/transmisión , Humanos , Genoma Viral , América Latina/epidemiología , Secuenciación Completa del Genoma , Análisis Espacio-Temporal , Variación GenéticaRESUMEN
Invasive Aedes aegypti and Aedes albopictus mosquitoes transmit viruses such as dengue, chikungunya and Zika, posing a huge public health burden as well as having a less well understood economic impact. We present a comprehensive, global-scale synthesis of studies reporting these economic costs, spanning 166 countries and territories over 45 years. The minimum cumulative reported cost estimate expressed in 2022 US$ was 94.7 billion, although this figure reflects considerable underreporting and underestimation. The analysis suggests a 14-fold increase in costs, with an average annual expenditure of US$ 3.1 billion, and a maximum of US$ 20.3 billion in 2013. Damage and losses were an order of magnitude higher than investment in management, with only a modest portion allocated to prevention. Effective control measures are urgently needed to safeguard global health and well-being, and to reduce the economic burden on human societies. This study fills a critical gap by addressing the increasing economic costs of Aedes and Aedes-borne diseases and offers insights to inform evidence-based policy.
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Aedes , Mosquitos Vectores , Animales , Dengue , Humanos , Fiebre Chikungunya/transmisión , Salud Global , Enfermedades Transmitidas por Vectores/prevención & control , Especies Introducidas , Control de Mosquitos/economía , Control de Mosquitos/métodos , Enfermedades Transmitidas por MosquitosRESUMEN
The Chikungunya Virus (CHIKV) already has endemic circulation in about 100 countries and the number of infected patients increases every year, due to the effectiveness of the vector and human universal susceptibility to infection. The virus can also be transmitted from mother to child, more frequently intrapartum. About 50 % of neonates with CHIKV symptoms will have neurodevelopmental delay. It is therefore an infection of worldwide concern with a great impact on people's quality of life. The objective of this work is to describe two cases of confirmed vertical transmission by chikungunya virus, one of them with intrauterine infection and death of the neonate. Neonates with vertical chikungunya infection may present with clinical sepsis in the first few days of life, which is why this is a very important diagnosis, especially during outbreaks of the infection.
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Fiebre Chikungunya , Transmisión Vertical de Enfermedad Infecciosa , Humanos , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/diagnóstico , Recién Nacido , Femenino , Embarazo , Virus Chikungunya , Resultado Fatal , Complicaciones Infecciosas del Embarazo/virología , MasculinoRESUMEN
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.
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Aedes , Fiebre Chikungunya , Virus Chikungunya , Mosquitos Vectores , Animales , Aedes/virología , Virus Chikungunya/genética , Virus Chikungunya/clasificación , Virus Chikungunya/fisiología , Virus Chikungunya/aislamiento & purificación , Brasil/epidemiología , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/virología , Fiebre Chikungunya/epidemiología , Ratones , Mosquitos Vectores/virología , Genotipo , Femenino , FilogeniaRESUMEN
OBJECTIVES: To monitor the oviposition activity of the mosquito Aedes aegypti and of dengue and chikungunya cases in four localities of temperate Argentina, during the 2023 epidemic. METHODS: During the summer and autumn of 2023, the oviposition activity of the mosquito vector was monitored weekly using ovitraps, and the arrival of cases with dengue or chikungunya in Tandil, Olavarría, Bahía Blanca and Laprida were registered. RESULTS: Monthly variations of the percentage of positive traps were similar in the first three locations; in Laprida the mosquito was not detected. On the contrary, a significant difference was observed in the percentage of total traps that ever tested positive in each locality, being higher in Olavarría (83.3%) than in Bahía Blanca (68.6%) and Tandil (48.7%). Regarding diseases, 18 imported cases of dengue and 3 of chikungunya were registered. In addition, the first autochthonous case of dengue in the region was recorded, being the southernmost until known. CONCLUSION: It is essential to raise awareness and train the members of the health systems of the new regions exposed to Ae. aegypti for early detection of cases, and to the general population to enhance prevention actions.
OBJETIVOS: Monitorear la actividad de oviposición del mosquito Aedes aegypti y de casos de dengue y chikungunya en cuatro localidades de Argentina templada, durante la epidemia del 2023. Métodos: Durante el verano y otoño del 2023, se monitoreó semanalmente mediante ovitrampas la actividad de oviposición del mosquito vector, y se registró el arribo de casos con dengue o chikungunya a Tandil, Olavarría, Bahía Blanca y Laprida. RESULTADOS: La variación mensual del porcentaje de trampas positivas fue similar en las tres primeras localidades; en Laprida no se detectó el mosquito. Por el contrario, se observó una diferencia significativa del porcentaje de trampas que alguna vez resultó positiva en cada localidad, siendo mayor en Olavarría (83%), que en Bahía Blanca (67%) y Tandil (49%). Respecto a las enfermedades, se registraron 18 casos importados de dengue y 3 de chikungunya. Además, se registró el primer caso autóctono de dengue en la región, siendo el más austral hasta el momento. Conclusión: Es imprescindible sensibilizar y capacitar a los integrantes de los sistemas de salud de las nuevas regiones expuestas al Ae. aegypti para la detección temprana de casos, y a la población en general para potenciar las acciones de prevención.
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Aedes , Fiebre Chikungunya , Dengue , Mosquitos Vectores , Estaciones del Año , Argentina/epidemiología , Dengue/epidemiología , Dengue/transmisión , Dengue/prevención & control , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/prevención & control , Animales , Aedes/virología , Aedes/fisiología , Mosquitos Vectores/fisiología , Humanos , Epidemias , Femenino , Oviposición/fisiologíaRESUMEN
BACKGROUND: Chikungunya virus (CHIKV) is an alphavirus (genus Alphavirus, family Togaviridae) that is primarily transmitted to humans by Aedes mosquitoes, and can be transmitted from mother to child. Little is known about CHIKV transmission in Vietnam, where dengue is endemic and Aedes mosquitoes are abundant. This study aimed to determine the prevalence and characteristics of vertical CHIKV infection in a birth cohort, and seroprevalence of anti-CHIKV antibodies with or without confirmation by neutralization tests among women bearing children in Vietnam. METHODS: We collected umbilical cord blood plasma samples from each newly delivered baby in Nha Trang, Central Vietnam, between July 2017 and September 2018. Samples were subjected to molecular assay (quantitative real-time RT-PCR) and serological tests (anti-CHIKV IgM capture and IgG indirect enzyme-linked immunosorbent assay, and neutralization tests). RESULTS: Of the 2012 tested cord blood samples from newly delivered babies, the CHIKV viral genome was detected in 6 (0.3%) samples by RT-PCR, whereas, 15 samples (0.7%) were anti-CHIKV-IgM positive. Overall, 18 (0.9%, 95% CI: 0.6-1.5) samples, including three positives for both CHIKV IgM and viral genome on RT-PCR, were regarded as vertical transmission of CHIKV infection. Of the 2012 cord blood samples, 10 (0.5%, 95% CI: 0.2-0.9) were positive for both anti-CHIKV IgM and IgG. Twenty-nine (1.4%, 95% CI: 1.0-2.1) were seropositive for anti-CHIKV IgG while 26 (1.3%, 95% CI: 0.8-1.9) of them were also positive for neutralizing antibodies, and regarded as seropositive with neutralization against CHIKV infection. CONCLUSION: This is the first report of a possible CHIKV maternal-neonatal infection in a birth cohort in Vietnam. The findings indicate that follow-up and a differential diagnosis of CHIKV infection in pregnant women are needed to clarify the potential for CHIKV vertical transmission and its impact in the newborn.
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Anticuerpos Antivirales , Fiebre Chikungunya , Virus Chikungunya , Sangre Fetal , Inmunoglobulina G , Inmunoglobulina M , Transmisión Vertical de Enfermedad Infecciosa , Humanos , Vietnam/epidemiología , Sangre Fetal/virología , Transmisión Vertical de Enfermedad Infecciosa/estadística & datos numéricos , Femenino , Anticuerpos Antivirales/sangre , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/epidemiología , Virus Chikungunya/aislamiento & purificación , Virus Chikungunya/inmunología , Virus Chikungunya/genética , Inmunoglobulina M/sangre , Adulto , Estudios Seroepidemiológicos , Inmunoglobulina G/sangre , Recién Nacido , Embarazo , Cohorte de Nacimiento , Masculino , Prevalencia , Adulto Joven , Anticuerpos Neutralizantes/sangre , Ensayo de Inmunoadsorción Enzimática , Pruebas de NeutralizaciónRESUMEN
Several outbreaks of chikungunya and dengue occurred on Mediterranean coasts during the hot season in the last two decades. Aedes albopictus was the vector involved in all the events. As a consequence of climate change, the 'Tiger' mosquito is now spreading through central Europe, and in the summer of 2023, for the first time, mosquito control measures were implemented in Paris to prevent autochthonous transmission of dengue. Rapid changes in the distribution of tropical disease vectors need to be taken into account in future risk assessment activities.
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Aedes , Cambio Climático , Mosquitos Vectores , Animales , Aedes/virología , Europa (Continente)/epidemiología , Mosquitos Vectores/virología , Humanos , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/prevención & control , Fiebre Chikungunya/virología , Dengue/transmisión , Dengue/epidemiología , Dengue/prevención & control , Brotes de Enfermedades , Control de Mosquitos/métodosRESUMEN
Over the last decade, the release of Wolbachia-infected Aedes aegypti into the natural habitat of this mosquito species has become the most sustainable and long-lasting technique to prevent and control vector-borne diseases, such as dengue, zika, or chikungunya. However, the limited resources to generate such mosquitoes and their effective distribution in large areas dominated by the Aedes aegypti vector represent a challenge for policymakers. Here, we introduce a mathematical framework for the spread of dengue in which competition between wild and Wolbachia-infected mosquitoes, the cross-contagion patterns between humans and vectors, the heterogeneous distribution of the human population in different areas, and the mobility flows between them are combined. Our framework allows us to identify the most effective areas for the release of Wolbachia-infected mosquitoes to achieve a large decrease in the global dengue prevalence.
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Aedes/microbiología , Fiebre Chikungunya/prevención & control , Dengue/prevención & control , Mosquitos Vectores/microbiología , Wolbachia/fisiología , Infección por el Virus Zika/prevención & control , Animales , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/transmisión , Dengue/epidemiología , Dengue/transmisión , Humanos , Control de Mosquitos/economía , Wolbachia/crecimiento & desarrollo , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/transmisiónRESUMEN
In this paper, a nonlinear fractional-order chikungunya disease model that incorporates asymptomatic infectious individuals is proposed and analyzed. The main interest of this work is to investigate the role of memory effects on the dynamics of chikungunya. Qualitative analysis of the model's equilibria showed that there exists a threshold quantity which governs persistence and extinction of the disease. Model parameters were estimated based on the 2015 weekly reported cases in Colombia. The Adams-Bashforth-Moulton method was used to numerically solve the proposed model. We investigated the role of asymptomatic infectious patients on short- and long-term dynamics of the diseases. We also determined threshold levels for the efficacy of preventative strategies that results in effective management of the disease. We believe that our model can provide invaluable insights for public health authorities to predict the effect of chikungunya transmission and analyze its underlying factors and to guide new control efforts.
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Fiebre Chikungunya/epidemiología , Modelos Epidemiológicos , Animales , Infecciones Asintomáticas/epidemiología , Fiebre Chikungunya/prevención & control , Fiebre Chikungunya/transmisión , Biología Computacional , Simulación por Computador , Humanos , Mosquitos Vectores/virología , Dinámicas no LinealesRESUMEN
BACKGROUND: Aedes albopictus and Aedes japonicus, two invasive mosquito species in the United States, are implicated in the transmission of arboviruses. Studies have shown interactions of these two mosquito species with a variety of vertebrate hosts; however, regional differences exist and may influence their contribution to arbovirus transmission. METHODS: We investigated the distribution, abundance, host interactions, and West Nile virus infection prevalence of Ae. albopictus and Ae. japonicus by examining Pennsylvania mosquito and arbovirus surveillance data for the period between 2010 and 2018. Mosquitoes were primarily collected using gravid traps and BG-Sentinel traps, and sources of blood meals were determined by analyzing mitochondrial cytochrome b gene sequences amplified in PCR assays. RESULTS: A total of 10,878,727 female mosquitoes representing 51 species were collected in Pennsylvania over the 9-year study period, with Ae. albopictus and Ae. japonicus representing 4.06% and 3.02% of all collected mosquitoes, respectively. Aedes albopictus was distributed in 39 counties and Ae. japonicus in all 67 counties, and the abundance of these species increased between 2010 and 2018. Models suggested an increase in the spatial extent of Ae. albopictus during the study period, while that of Ae. japonicus remained unchanged. We found a differential association between the abundance of the two mosquito species and environmental conditions, percent development, and median household income. Of 110 Ae. albopictus and 97 Ae. japonicus blood meals successfully identified to species level, 98% and 100% were derived from mammalian hosts, respectively. Among 12 mammalian species, domestic cats, humans, and white-tailed deer served as the most frequent hosts for the two mosquito species. A limited number of Ae. albopictus acquired blood meals from avian hosts solely or in mixed blood meals. West Nile virus was detected in 31 pools (n = 3582 total number of pools) of Ae. albopictus and 12 pools (n = 977 total pools) of Ae. japonicus. CONCLUSIONS: Extensive distribution, high abundance, and frequent interactions with mammalian hosts suggest potential involvement of Ae. albopictus and Ae. japonicus in the transmission of human arboviruses including Cache Valley, Jamestown Canyon, La Crosse, dengue, chikungunya, and Zika should any of these viruses become prevalent in Pennsylvania. Limited interaction with avian hosts suggests that Ae. albopictus might occasionally be involved in transmission of arboviruses such as West Nile in the region.
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Aedes , Infecciones por Arbovirus/transmisión , Conducta Alimentaria , Mosquitos Vectores , Análisis Espacio-Temporal , Aedes/fisiología , Aedes/virología , Animales , Arbovirus , Aves/virología , Fiebre Chikungunya/transmisión , Ciervos/virología , Reservorios de Enfermedades/virología , Humanos , Especies Introducidas , Mamíferos/virología , Mosquitos Vectores/fisiología , Mosquitos Vectores/virología , Pennsylvania , Densidad de Población , Especificidad de la Especie , Virus del Nilo Occidental , Virus Zika , Infección por el Virus Zika/transmisión , Zoonosis/virologíaRESUMEN
Chikungunya virus (CHIKV) is a reemerging arthropod-borne alphavirus and a serious threat to human health. Therefore, efforts toward elucidating how this virus causes disease and the molecular mechanisms underlying steps of the viral replication cycle are crucial. Using an in vivo transmission system that allows intrahost evolution, we identified an emerging CHIKV variant carrying a mutation in the E1 glycoprotein (V156A) in the serum of mice and saliva of mosquitoes. E1 V156A has since emerged in humans during an outbreak in Brazil, cooccurring with a second mutation, E1 K211T, suggesting an important role for these residues in CHIKV biology. Given the emergence of these variants, we hypothesized that they function to promote CHIKV infectivity and subsequent disease. Here, we show that E1 V156A and E1 K211T modulate virus attachment and fusion and impact binding to heparin, a homolog of heparan sulfate, a key entry factor on host cells. These variants also exhibit differential neutralization by antiglycoprotein monoclonal antibodies, suggesting structural impacts on the particle that may be responsible for altered interactions at the host membrane. Finally, E1 V156A and E1 K211T exhibit increased titers in an adult arthritic mouse model and induce increased foot-swelling at the site of injection. Taken together, this work has revealed new roles for E1 where discrete regions of the glycoprotein are able to modulate cell attachment and swelling within the host. IMPORTANCE Alphaviruses represent a growing threat to human health worldwide. The reemerging alphavirus chikungunya virus (CHIKV) has rapidly spread to new geographic regions in the last several decades, causing overwhelming outbreaks of disease, yet there are no approved vaccines or therapeutics. The CHIKV glycoproteins are key determinants of CHIKV adaptation and virulence. In this study, we identify and characterize the emerging E1 glycoprotein variants, V156A and K211T, that have since emerged in nature. We demonstrate that E1 V156A and K211T function in virus attachment to cells, a role that until now has only been attributed to specific residues of the CHIKV E2 glycoprotein. We also demonstrate E1 V156A and K211T increase foot-swelling of the ipsilateral foot in mice infected with these variants. Observing that these variants and other pathogenic variants occur at the E1-E1 interspike interface, we highlight this structurally important region as critical for multiple steps during CHIKV infection. Together, these studies further define the function of E1 in CHIKV infection and can inform the development of therapeutic or preventative strategies.
Asunto(s)
Virus Chikungunya/fisiología , Virus Chikungunya/patogenicidad , Proteínas del Envoltorio Viral/metabolismo , Acoplamiento Viral , Aedes/virología , Animales , Anticuerpos Monoclonales/inmunología , Fiebre Chikungunya/patología , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/virología , Virus Chikungunya/genética , Virus Chikungunya/inmunología , Modelos Animales de Enfermedad , Heparina/metabolismo , Humanos , Inflamación , Ratones , Mutación , Pruebas de Neutralización , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/inmunología , Internalización del Virus , Replicación ViralRESUMEN
The global spread of invasive mosquito species increases arbovirus infections. In addition to the invasive species Aedes albopictus and Aedes japonicus, Aedes koreicus has spread within Central Europe. Extensive information on its vector competence is missing. Ae. koreicus from Germany were investigated for their vector competence for chikungunya virus (CHIKV), Zika virus (ZIKV) and West Nile virus (WNV). Experiments were performed under different climate conditions (27 ± 5 °C; 24 ± 5 °C) for fourteen days. Ae. koreicus had the potential to transmit CHIKV and ZIKV but not WNV. Transmission was exclusively observed at the higher temperature, and transmission efficiency was rather low, at 4.6% (CHIKV) or 4.7% (ZIKV). Using a whole virome analysis, a novel mosquito-associated virus, designated Wiesbaden virus (WBDV), was identified in Ae. koreicus. Linking the WBDV infection status of single specimens to their transmission capability for the arboviruses revealed no influence on ZIKV transmission. In contrast, a coinfection of WBDV and CHIKV likely has a boost effect on CHIKV transmission. Due to its current distribution, the risk of arbovirus transmission by Ae. koreicus in Europe is rather low but might gain importance, especially in regions with higher temperatures. The impact of WBDV on arbovirus transmission should be analyzed in more detail.
Asunto(s)
Aedes/virología , Infecciones por Arbovirus/transmisión , Mosquitos Vectores/virología , Interferencia Viral , Animales , Fiebre Chikungunya/transmisión , Infección por el Virus Zika/transmisiónRESUMEN
BACKGROUND: Australia is theoretically at risk of epidemic chikungunya virus (CHIKV) activity as the principal vectors are present on the mainland Aedes aegypti) and some islands of the Torres Strait (Ae. aegypti and Ae. albopictus). Both vectors are highly invasive and adapted to urban environments with a capacity to expand their distributions into south-east Queensland and other states in Australia. We sought to estimate the epidemic potential of CHIKV, which is not currently endemic in Australia, by considering exclusively transmission by the established vector in Australia, Ae. aegypti, due to the historical relevance and anthropophilic nature of the vector. METHODOLOGY/PRINCIPAL FINDINGS: We estimated the historical (1995-2019) epidemic potential of CHIKV in eleven Australian locations, including the Torres Strait, using a basic reproduction number equation. We found that the main urban centres of Northern Australia could sustain an epidemic of CHIKV. We then estimated future trends in epidemic potential for the main centres for the years 2020 to 2029. We also conducted uncertainty and sensitivity analyses on the variables comprising the basic reproduction number and found high sensitivity to mosquito population size, human population size, impact of vector control and human infectious period. CONCLUSIONS/SIGNIFICANCE: By estimating the epidemic potential for CHIKV transmission on mainland Australia and the Torres Strait, we identified key areas of focus for controlling vector populations and reducing human exposure. As the epidemic potential of the virus is estimated to rise towards 2029, a greater focus on control and prevention measures should be implemented in at-risk locations.