scholarly journals Recent outbreaks of chikungunya virus (CHIKV) in Africa and Asia are driven by a variant carrying mutations associated with increased fitness for Aedes aegypti

2018 ◽  
Author(s):  
Irina Maljkovic Berry ◽  
Fredrick Eyase ◽  
Simon Pollett ◽  
Samson Limbaso Konongoi ◽  
Katherine Figueroa ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Chikungunya Virus ◽  
Control Strategies ◽  
Vector Competence ◽  
Virus Transmission ◽  
New Delhi ◽  
African Countries ◽  
Global Spread ◽  
Large Outbreak ◽  
The Impact

AbstractBackgroundIn 2016, a chikungunya virus (CHIKV) outbreak was reported in Mandera, Kenya. This was the first major CHIKV outbreak in the country since the global re-emergence of this virus, which arose as an initial outbreak in Kenya in 2004. Therefore, we collected samples and sequenced viral genomes from the 2016 Mandera outbreak.Methodology/Principal FindingsAll Kenyan genomes contained two mutations, E1:K211E and E2:V264A, recently reported to have an association with increased infectivity, dissemination and transmission in the Aedes aegypti (Ae. aegypti) vector. Phylogeographic inference of temporal and spatial virus relationships using Bayesian approaches showed that this Ae. aegypti adapted strain emerged within the East, Central, and South African (ECSA) lineage of CHIKV between 2005 and 2008, most probably in India. It was also in India where the first large outbreak caused by this strain appeared, in New Delhi, 2010. More importantly, our results also showed that this strain is no longer contained to India, and that it has more recently caused several major outbreaks of CHIKV, including the 2016 outbreaks in India, Pakistan and Kenya, and the 2017 outbreak in Bangladesh. In addition to its capability to cause large outbreaks in different regions of the world, this CHIKV strain has the capacity to replace less adapted wild type strains in Ae. aegypti-rich regions. Indeed, all the latest full CHIKV genomes of the ECSA Indian Ocean Lineage (IOL), from the regions of high Ae. aegypti prevalence, carry these two mutations, including samples collected in Japan, Australia, and China.Conclusions/SignificanceOur results point to the importance of continued genomic-based surveillance of this strain’s global spread, and they prompt urgent vector competence studies in Asian and African countries, in order to assess the level of vector receptiveness, virus transmission, and the impact this might have on this strain’s ability to cause major outbreaks.Author summaryChikungunya virus (CHIKV) causes a debilitating infection with high fever, intense muscle and bone pain, rash, nausea, vomiting and headaches, and persistent and/or recurrent joint pains for months or years after contracting the virus. CHIKV is spread by two mosquito vectors, Aedes albopictus and Aedes aegypti, with increased presence around the globe. In this study, we report global spread of a CHIKV strain that carries two mutations that have been suggested to increase this virus’ ability to infect the Aedes aegypti mosquito, as well as to increase CHIKV’s ability to be transmitted by this vector. We show that this strain appeared sometime between 2005 and 2008, most probably in India, and has now spread to Africa, Asia, and Australia. We show that this strain is capable of driving large outbreaks of CHIKV in the human population, causing recent major outbreaks in Kenya, Pakistan, India and Bangladesh. Thus, our results stress the importance of monitoring this strain’s global spread, as well as the need of improved vector control strategies in the areas of Aedes aegypti prevalence.

scholarly journals Sequential Infection of Aedes aegypti Mosquitoes with Chikungunya Virus and Zika Virus Enhances Early Zika Virus Transmission

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 177 ◽  
Author(s):  
Tereza Magalhaes ◽  
Alexis Robison ◽  
Michael Young ◽  
William Black ◽  
Brian Foy ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Blood Meal ◽  
Zika Virus ◽  
Chikungunya Virus ◽  
Vector Competence ◽  
Virus Transmission ◽  
Mosquito Vector ◽  
Molecular Aspects ◽  
Virus Interactions ◽  
Sequential Infection

In urban settings, chikungunya, Zika, and dengue viruses are transmitted by Aedes aegypti mosquitoes. Since these viruses co-circulate in several regions, coinfection in humans and vectors may occur, and human coinfections have been frequently reported. Yet, little is known about the molecular aspects of virus interactions within hosts and how they contribute to arbovirus transmission dynamics. We have previously shown that Aedes aegypti exposed to chikungunya and Zika viruses in the same blood meal can become coinfected and transmit both viruses simultaneously. However, mosquitoes may also become coinfected by multiple, sequential feeds on single infected hosts. Therefore, we tested whether sequential infection with chikungunya and Zika viruses impacts mosquito vector competence. We exposed Ae. aegypti mosquitoes first to one virus and 7 days later to the other virus and compared infection, dissemination, and transmission rates between sequentially and single infected groups. We found that coinfection rates were high after sequential exposure and that mosquitoes were able to co-transmit both viruses. Surprisingly, chikungunya virus coinfection enhanced Zika virus transmission 7 days after the second blood meal. Our data demonstrate heterologous arbovirus synergism within mosquitoes, by unknown mechanisms, leading to enhancement of transmission under certain conditions.

scholarly journals Wolbachia pipientis occurs in Aedes aegypti populations in New Mexico and Florida, USA

2018 ◽  
Author(s):  
Aditi Kulkarni ◽  
Wanqin Yu ◽  
Jinjin Jiang ◽  
Concepcion Sanchez ◽  
Ajit K. Karna ◽  
...  
Keyword(s):  
New Mexico ◽  
Aedes Aegypti ◽  
Control Strategies ◽  
Vector Competence ◽  
Virus Transmission ◽  
Lamp Assay ◽  
Harris County ◽  
Pcr Assay ◽  
Wolbachia Pipientis ◽  
Pcr Products

ABSTRACTThe mosquitoes Aedes aegypti (L.) and Ae. albopictus Skuse are the major vectors of dengue, Zika, yellow fever and chikungunya viruses worldwide. Wolbachia, an endosymbiotic bacterium present in many insects, is being utilized in novel vector control strategies to manipulate mosquito life history and vector competence to curb virus transmission. Earlier studies have found that Wolbachia is commonly detected in Ae. albopictus but rarely detected in Ae. aegypti. In this study, we used a two-step PCR assay to detect Wolbachia in wild-collected samples of Ae. aegypti. The PCR products were sequenced to validate amplicons and identify Wolbachia strains. A loop-mediated isothermal amplification (LAMP) assay was developed and used for detecting Wolbachia in selected mosquito specimens as well. We found Wolbachia in 85/148 (57.4%) wild Ae. aegypti specimens from various cities in New Mexico and in 2/46 (4.3%) from St. Augustine, Florida. We did not detect Wolbachia in 94 samples of Ae. aegypti from Deer Park, Harris County, Texas. Wolbachia detected in Ae. aegypti from both New Mexico and Florida was the wAlbB strain of Wolbachia pipientis. A Wolbachia positive colony of Ae. aegypti was established from pupae collected in Las Cruces, New Mexico in 2018. The infected females of this strain transmitted Wolbachia to their progeny when crossed with males of Rockefeller strain of Ae. aegypti, which does not carry Wolbachia. In contrast, none of the progeny of progeny of Las Cruces males mated to Rockefeller females were infected with Wolbachia.

The Global Expansion of Dengue: How Aedes aegypti Mosquitoes Enabled the First Pandemic Arbovirus

2020 ◽  
Vol 65 (1) ◽  
pp. 191-208 ◽  
Author(s):  
Oliver J. Brady ◽  
Simon I. Hay
Keyword(s):  
Invasive Species ◽  
Aedes Aegypti ◽  
Infectious Diseases ◽  
Control Strategies ◽  
Viral Disease ◽  
Rapid Rise ◽  
Disease Vector ◽  
Research Priority ◽  
Global Spread ◽  
Human Habitation

Dengue is an emerging viral disease principally transmitted by the Aedes ( Stegomyia) aegypti mosquito. It is one of the fastest-growing global infectious diseases, with 100–400 million new infections a year, and is now entrenched in a growing number of tropical megacities. Behind this rapid rise is the simple adaptation of Ae. aegypti to a new entomological niche carved out by human habitation. This review describes the expansion of dengue and explores how key changes in the ecology of Ae. aegypti allowed it to become a successful invasive species and highly efficient disease vector. We argue that characterizing geographic heterogeneity in mosquito bionomics will be a key research priority that will enable us to better understand future dengue risk and design control strategies to reverse its global spread.

Selection of Aedes aegypti (Diptera: Culicidae) strains that are susceptible or refractory to Dengue-2 virus

2013 ◽  
Vol 145 (3) ◽  
pp. 273-282 ◽  
Author(s):  
Paola A. Caicedo ◽  
Olga L. Barón ◽  
Mauricio Pérez ◽  
Neal Alexander ◽  
Carl Lowenberger ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Molecular Mechanisms ◽  
Selection Process ◽  
Control Strategies ◽  
Vector Competence ◽  
Survival Rates ◽  
Kaplan Meier ◽  
Genetic And Environmental Factors ◽  
Seven Generations ◽  
Selection Of

AbstractThe vector competence (VC) of Aedes aegypti (Linnaeus) (Diptera: Culicidae) varies geographically and is affected by both genetic and environmental factors. Understanding the molecular mechanisms that influence VC may help develop novel control strategies. The selection of susceptible and refractory strains is the first step in this process. We collected immature A. aegypti in the field and established strains that were susceptible and refractory to Dengue-2 virus by isofamily selection through several generations. Infection was detected by immunofluorescence of head or midgut tissues to determine infection barriers and the % of VC by tissue. We selected three strains: Susceptible (Cali-S) (96.4% susceptible at F19), Refractory with a midgut escape barrier (Cali-MEB) (44.1% refractory at F15), and Refractory with a midgut infection barrier (Cali-MIB) (40% refractory at F16). The effects of the infection were measured using Kaplan–Meier survival rates over the first seven generations. All selected strains showed a similar decrease in survival and in the number of eggs laid/female through the seven generations, suggesting that changes were a result of the selection process rather than the virus infection. The results of this study suggest that VC is associated with multiple genes, which have additive effects on susceptibility.

scholarly journals Systematic Review: The Impact of Socioeconomic Factors on Aedes aegypti Mosquito Distribution in the Mainland United States

2019 ◽  
Author(s):  
Whitney Holeva-Eklund ◽  
Timothy Behrens ◽  
Crystal Hepp
Keyword(s):  
United States ◽  
Aedes Aegypti ◽  
Socioeconomic Factors ◽  
Control Strategies ◽  
Anthropogenic Factors ◽  
Eligibility Criteria ◽  
Screening Process ◽  
Close Relationship ◽  
Meta Analyses ◽  
The Impact

Background: Aedes aegypti mosquitoes are primary vectors of dengue, yellow fever, chikungunya and Zika viruses. A. aegypti is highly anthropophilic and relies nearly exclusively on human blood meals and habitats for reproduction. Socioeconomic factors may influence the spread of A. aegypti due to their close relationship with humans. This paper describes and summarizes the published literature on how socioeconomic variables influence the distribution of A. aegypti mosquitoes in the mainland United States. Methods: A comprehensive search of PubMed/Medline, Scopus, Web of Science, and EBSCO Academic Search Complete through June 12, 2019 was used to retrieve all articles published in English on the association of socioeconomic factors and the distribution of A. aegypti mosquitoes. Articles were screened for eligibility using the process described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: Initially, 3,493 articles were identified through the database searches and previously known literature. After checking for duplicates, 2,145 articles remained. These articles were screened for eligibility using their titles and abstracts, and 2,098 articles were excluded for not meeting the eligibility criteria. Finally, the full text for each of the remaining articles (n = 38) was read to determine eligibility. Through this screening process, 11 articles were identified for inclusion in this review. Conclusions: The findings for these 11 studies revealed inconsistent relationships between the studied socioeconomic factors and the distribution and abundance of A. aegypti. The findings of this review suggest a gap in the literature and understanding of the influence of anthropogenic factors on the distribution of A. aegypti that could hinder efforts to implement effective public health prevention and control strategies should a disease outbreak occur.

Epidemiological profile of diseases caused by aedes aegypti in sanitary districts of São Luis, Brazil

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
ECR Dos Santos ◽  
S C Cohren ◽  
R G R Costa
Keyword(s):  
Aedes Aegypti ◽  
Zika Virus ◽  
Control Strategies ◽  
Public Health Problem ◽  
Female Gender ◽  
The State ◽  
Impact Of Urbanization ◽  
Epidemiological Profile ◽  
The Impact ◽  
Sanitary District

Abstract In recent decades, the diseases caused by the Aedes aegypti have been responsible for a high number of mortality cases worldwide, making it a serious public health problem. This article describes the diseases prevalence caused by Aedes Aegypti: Dengue, Zika and Chikungunya, in the Sanitary Districts of city of São Luis - in the state of Maranhão in Brazil, from 2007 to 2017. This study is based on data analysis recorded by the Information System on Diseases of Compulsory Declaration (SINAN). From 2007 to 2017, 25,124 dengue cases were reported in the city of São Luís, there was an increase in prevalence in 2011 with 5,378 cases, about 53% of recorded cases in the State of Maranhão, probably due to the presence of new circulating serotypes: DENV-1; DENV-2 AND DENV-4, with 14 deaths. Female gender predominated among registered cases, and the age group with the highest number of reported cases was 20 to 39 years. In 2015 started the first reports of the Zika virus and chikungunya, both with epidemiological peak in 2016. São Luis has 229 urban neighborhoods and 165 rural neighborhoods distributed in seven health districts. The Bequimão Sanitary District in the urban area of city of São Luis consists of 64 neighborhoods, has recorded a higher number of dengue cases, 6,239 cases. From 2015 to 2017, it reported 864 cases of Zika virus and 407 cases of chikungunya. It is concluded that the prevalence of diseases, caused by Aedes aegypti, shows endemic variation, in the three arboviruses, related to population density and local sanitary conditions, characteristics which are present in the Sanitary District of Bequimão where it's registered a lack of sanitary infrastructure and intermittent water supply, the study notes the need to adopt control strategies of sanitary officers, and agencies and awareness of the population. Key messages The research produced knowledge about the impact of urbanization on the epidemiology of dengue, zika and chikungunya, enabling knowledge of the sanitation conditions of the studied city. The knowledge produced by the research substantiates strategies and actions to combat the vector by the health authorities and conscious action of the population.

scholarly journals Mosquito Mycobiota: An Overview of Non-Entomopathogenic Fungal Interactions

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 564 ◽  
Author(s):  
Simon Malassigné ◽  
Claire Valiente Moro ◽  
Patricia Luis
Keyword(s):  
Mosquito Control ◽  
Control Strategies ◽  
Vector Competence ◽  
Anopheles Species ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
Fungal Interactions ◽  
And Behavior ◽  
The Impact ◽  
Alternative Control Methods

The growing expansion of mosquito vectors leads to the emergence of vector-borne diseases in new geographic areas and causes major public health concerns. In the absence of effective preventive treatments against most pathogens transmitted, vector control remains one of the most suitable strategies to prevent mosquito-borne diseases. Insecticide overuse raises mosquito resistance and deleterious impacts on the environment and non-target species. Growing knowledge of mosquito biology has allowed the development of alternative control methods. Following the concept of holobiont, mosquito-microbiota interactions play an important role in mosquito biology. Associated microbiota is known to influence many aspects of mosquito biology such as development, survival, immunity or even vector competence. Mosquito-associated microbiota is composed of bacteria, fungi, protists, viruses and nematodes. While an increasing number of studies have focused on bacteria, other microbial partners like fungi have been largely neglected despite their huge diversity. A better knowledge of mosquito-mycobiota interactions offers new opportunities to develop innovative mosquito control strategies. Here, we review the recent advances concerning the impact of mosquito-associated fungi, and particularly nonpathogenic fungi, on life-history traits (development, survival, reproduction), vector competence and behavior of mosquitoes by focusing on Culex, Aedes and Anopheles species.

scholarly journals Vector competence of Aedes aegypti in transmitting Chikungunya virus: effects and implications of extrinsic incubation temperature on dissemination and infection rates

2016 ◽  
Vol 13 (1) ◽  
Author(s):  
Sophiah Mbaika ◽  
Joel Lutomiah ◽  
Edith Chepkorir ◽  
Francis Mulwa ◽  
Christopher Khayeka-Wandabwa ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Chikungunya Virus ◽  
Incubation Temperature ◽  
Vector Competence ◽  
Infection Rates

scholarly journals Three-way interactions between mosquito population, viral strain and temperature underlying chikungunya virus transmission potential

2014 ◽  
Vol 281 (1792) ◽  
pp. 20141078 ◽  
Author(s):  
Karima Zouache ◽  
Albin Fontaine ◽  
Anubis Vega-Rua ◽  
Laurence Mousson ◽  
Jean-Michel Thiberge ◽  
...  
Keyword(s):  
Chikungunya Virus ◽  
Environmental Variability ◽  
Vector Competence ◽  
Virus Transmission ◽  
Mosquito Population ◽  
Mosquito Vector ◽  
Human Pathogens ◽  
Public Health Importance ◽  
Transmission Potential ◽  
Vector Borne Diseases

Interactions between pathogens and their insect vectors in nature are under the control of both genetic and non-genetic factors, yet most studies on mosquito vector competence for human pathogens are conducted in laboratory systems that do not consider genetic and/or environmental variability. Evaluating the risk of emergence of arthropod-borne viruses (arboviruses) of public health importance such as chikungunya virus (CHIKV) requires a more realistic appraisal of genetic and environmental contributions to vector competence. In particular, sources of variation do not necessarily act independently and may combine in the form of interactions. Here, we measured CHIKV transmission potential by the mosquito Aedes albopictus in all combinations of six worldwide vector populations, two virus strains and two ambient temperatures (20°C and 28°C). Overall, CHIKV transmission potential by Ae. albopictus strongly depended on the three-way combination of mosquito population, virus strain and temperature. Such genotype-by-genotype-by-environment (G × G × E) interactions question the relevance of vector competence studies conducted with a simpler set of conditions. Our results highlight the need to account for the complex interplay between vectors, pathogens and environmental factors to accurately assess the potential of vector-borne diseases to emerge.

scholarly journals Experimental risk assessment for chikungunya virus transmission based on vector competence, distribution and temperature suitability in Europe, 2018

2018 ◽  
Vol 23 (29) ◽  
Author(s):  
Anna Heitmann ◽  
Stephanie Jansen ◽  
Renke Lühken ◽  
Michelle Helms ◽  
Björn Pluskota ◽  
...  
Keyword(s):  
Central Europe ◽  
Chikungunya Virus ◽  
Vector Competence ◽  
Virus Transmission ◽  
Control Measures ◽  
Italian Population ◽  
Entomological Surveillance ◽  
Spatial Risk ◽  
Mosquito Saliva ◽  
Vector Distribution

Background Over the last decade, the abundant distribution of the Asian tiger mosquito Aedes albopictus in southern Europe and the import of chikungunya virus (CHIKV) by infected travellers has resulted in at least five local outbreaks of chikungunya fever in France and Italy. Considering the ongoing spread of Ae. albopictus to central Europe, we performed an analysis of the Europe-wide spatial risk of CHIKV transmission under different temperature conditions. Methods: Ae. albopictus specimens from Germany and Italy were orally infected with CHIKV from an outbreak in France and kept for two weeks at 18 °C, 21 °C or 24 °C. A salivation assay was conducted to detect infectious CHIKV. Results: Analyses of mosquito saliva for infectious virus particles demonstrated transmission rates (TRs) of > 35%. Highest TRs of 50% for the mosquito population from Germany were detected at 18 °C, while the Italian population had highest TRs of 63% at 18 °C and 21 °C, respectively. Temperature data indicated a potential risk of CHIKV transmission for extended durations, i.e. sufficiently long time periods allowing extrinsic incubation of the virus. This was shown for areas already colonised by Ae. albopictus, as well as for large parts of central Europe that are not colonised. Conclusion: The current risk of CHIKV transmission in Europe is not primarily restricted by temperature, which allows extrinsic incubation of the virus, but rather by the vector distribution. Accordingly, all European countries with established populations of Ae. albopictus should implement respective entomological surveillance and monitoring systems, as basis for suitable control measures.

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