1
|
Montenegro D, Cortés-Cortés G, Balbuena-Alonso MG, Warner C, Camps M. Wolbachia-based emerging strategies for control of vector-transmitted disease. Acta Trop 2024; 260:107410. [PMID: 39349234 DOI: 10.1016/j.actatropica.2024.107410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 09/21/2024] [Accepted: 09/23/2024] [Indexed: 10/02/2024]
Abstract
Dengue fever is a mosquito-transmitted disease of great public health importance. Dengue lacks adequate vaccine protection and insecticide-based methods of mosquito control are proving increasingly ineffective. Here we review the emerging use of mosquitoes transinfected with the obligate intracellular bacterium Wolbachia pipientis for vector control. Wolbachia often induces cytoplasmic incompatibility in its mosquito hosts, resulting in infertile progeny between an infected male and an uninfected female. Wolbachia infection also suppresses the replication of pathogens in the mosquito, a process known as "pathogen blocking". Two strategies have emerged. The first one releases Wolbachia carriers (both male and female) to replace the wild mosquito population, a process driven by cytoplasmic incompatibility and that becomes irreversible once a threshold is reached. This suppresses disease transmission mainly by pathogen blocking and frequently requires a single intervention. The second strategy floods the field population with an exclusively male population of Wolbachia-carrying mosquitoes to generate infertile hybrid progeny. In this case, transmission suppression depends largely on decreasing the population density of mosquitoes driven by infertility and requires continued mosquito release. The efficacy of both Wolbachia-based approaches has been conclusively demonstrated by randomized and non-randomized studies of deployments across the world. However, results conducted in one setting cannot be directly or easily extrapolated to other settings because dengue incidence is highly affected by the conditions into which the mosquitoes are released. Compared to traditional vector control methods, Wolbachia-based approaches are much more environmentally friendly and can be effective in the medium/long term. On the flip side, they are much more complex and cost-intensive operations, requiring a substantial investment, infrastructure, trained personnel, coordination between agencies, and community engagement. Finally, we discuss recent evidence suggesting that the release of Wolbachia-transinfected mosquitoes has a moderate potential risk of spreading potentially dangerous genes in the environment.
Collapse
Affiliation(s)
- Diego Montenegro
- Corporación Innovation Hub, Monteria 230001, Colombia; Department of Microbiology and Environmental Toxicology, University of California at Santa Cruz, Santa Cruz, CA 95064, USA; Grupo de Investigación: Salud y Tecnología 4.0. Fundación Chilloa, Santa Marta 470001, Colombia
| | - Gerardo Cortés-Cortés
- Department of Microbiology and Environmental Toxicology, University of California at Santa Cruz, Santa Cruz, CA 95064, USA; Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias de la Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, San Manuel, Puebla 72570, Mexico
| | - María Guadalupe Balbuena-Alonso
- Department of Microbiology and Environmental Toxicology, University of California at Santa Cruz, Santa Cruz, CA 95064, USA; Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias de la Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, San Manuel, Puebla 72570, Mexico
| | - Caison Warner
- Department of Microbiology and Environmental Toxicology, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
| | - Manel Camps
- Department of Microbiology and Environmental Toxicology, University of California at Santa Cruz, Santa Cruz, CA 95064, USA.
| |
Collapse
|
2
|
Hollingsworth BD, Cho C, Vella M, Roh H, Sass J, Lloyd AL, Brown ZS. Economic optimization of Wolbachia-infected Aedes aegypti release to prevent dengue. PEST MANAGEMENT SCIENCE 2024; 80:3829-3838. [PMID: 38507220 DOI: 10.1002/ps.8086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/29/2024] [Accepted: 03/20/2024] [Indexed: 03/22/2024]
Abstract
BACKGROUND Dengue virus, primarily transmitted by the Aedes aegypti mosquito, is a major public health concern affecting ≈3.83 billion people worldwide. Recent releases of Wolbachia-transinfected Ae. aegypti in several cities worldwide have shown that it can reduce dengue transmission. However, these releases are costly, and, to date, no framework has been proposed for determining economically optimal release strategies that account for both costs associated with disease risk and releases. RESULTS We present a flexible stochastic dynamic programming framework for determining optimal release schedules for Wolbachia-transinfected mosquitoes that balances the cost of dengue infection with the costs of rearing and releasing transinfected mosquitoes. Using an ordinary differential equation model of Wolbachia and dengue in a hypothetical city loosely describing areas at risk of new dengue epidemics, we determined that an all-or-nothing release strategy that quickly brings Wolbachia to fixation is often the optimal solution. Based on this, we examined the optimal facility size, finding that it was inelastic with respect to the mosquito population size, with a 100% increase in population size resulting in a 50-67% increase in optimal facility size. Furthermore, we found that these results are robust to mosquito life-history parameters and are mostly determined by the mosquito population size and the fitness costs associated with Wolbachia. CONCLUSIONS These results reinforce that Wolbachia-transinfected mosquitoes can reduce the cost of dengue epidemics. Furthermore, they emphasize the importance of determining the size of the target population and fitness costs associated with Wolbachia before releases occur. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Brandon D Hollingsworth
- Department of Entomology, Cornell University, Ithaca, NY, USA
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, NC, USA
| | - Chanheung Cho
- Department of Agricultural and Resource Economics, North Carolina State University, Raleigh, NC, USA
| | - Michael Vella
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, NC, USA
| | - Hyeongyul Roh
- Department of Agricultural and Resource Economics, North Carolina State University, Raleigh, NC, USA
| | - Julian Sass
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, NC, USA
| | - Alun L Lloyd
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, NC, USA
| | - Zachary S Brown
- Department of Agricultural and Resource Economics, North Carolina State University, Raleigh, NC, USA
- Genetic Engineering and Society Center, North Carolina State University, Raleigh, NC, USA
| |
Collapse
|
3
|
Sánchez C. HM, Smith DL, Marshall JM. MGSurvE: A framework to optimize trap placement for genetic surveillance of mosquito populations. PLoS Comput Biol 2024; 20:e1012046. [PMID: 38709820 PMCID: PMC11098508 DOI: 10.1371/journal.pcbi.1012046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 05/16/2024] [Accepted: 04/02/2024] [Indexed: 05/08/2024] Open
Abstract
Genetic surveillance of mosquito populations is becoming increasingly relevant as genetics-based mosquito control strategies advance from laboratory to field testing. Especially applicable are mosquito gene drive projects, the potential scale of which leads monitoring to be a significant cost driver. For these projects, monitoring will be required to detect unintended spread of gene drive mosquitoes beyond field sites, and the emergence of alternative alleles, such as drive-resistant alleles or non-functional effector genes, within intervention sites. This entails the need to distribute mosquito traps efficiently such that an allele of interest is detected as quickly as possible-ideally when remediation is still viable. Additionally, insecticide-based tools such as bednets are compromised by insecticide-resistance alleles for which there is also a need to detect as quickly as possible. To this end, we present MGSurvE (Mosquito Gene SurveillancE): a computational framework that optimizes trap placement for genetic surveillance of mosquito populations such that the time to detection of an allele of interest is minimized. A key strength of MGSurvE is that it allows important biological features of mosquitoes and the landscapes they inhabit to be accounted for, namely: i) resources required by mosquitoes (e.g., food sources and aquatic breeding sites) can be explicitly distributed through a landscape, ii) movement of mosquitoes may depend on their sex, the current state of their gonotrophic cycle (if female) and resource attractiveness, and iii) traps may differ in their attractiveness profile. Example MGSurvE analyses are presented to demonstrate optimal trap placement for: i) an Aedes aegypti population in a suburban landscape in Queensland, Australia, and ii) an Anopheles gambiae population on the island of São Tomé, São Tomé and Príncipe. Further documentation and use examples are provided in project's documentation. MGSurvE is intended as a resource for both field and computational researchers interested in mosquito gene surveillance.
Collapse
Affiliation(s)
- Héctor M. Sánchez C.
- Divisions of Epidemiology and Biostatistics, University of California Berkeley, Berkeley, California, United States of America
| | - David L. Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, University of California Berkeley, Berkeley, California, United States of America
| |
Collapse
|
4
|
Dye D, Cain JW. Efficacy of Wolbachia-based mosquito control: Predictions of a spatially discrete mathematical model. PLoS One 2024; 19:e0297964. [PMID: 38437189 PMCID: PMC10911593 DOI: 10.1371/journal.pone.0297964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 01/14/2024] [Indexed: 03/06/2024] Open
Abstract
Wolbachia is an endosymbiont bacterium present in many insect species. When Wolbachia-carrying male Aedes aegypti mosquitoes mate with non-carrier females, their embryos are not viable due to cytoplasmic incompatibility. This phenomenon has been exploited successfully for the purpose of controlling mosquito populations and the spread of mosquito-borne illnesses: Wolbachia carriers are bred and released into the environment. Because Wolbachia is not harmful to humans, this method of mosquito control is regarded as a safer alternative to pesticide spraying. In this article, we introduce a mathematical framework for exploring (i) whether a one-time release of Wolbachia carriers can elicit a sustained presence of carriers near the release site, and (ii) the extent to which spatial propagation of carriers may allow them to establish fixation in other territories. While some prior studies have formulated mosquito dispersal models using advection-reaction-diffusion PDEs, the predictive power of such models requires careful ecological mapping: advection and diffusion coefficients exhibit significant spatial dependence due to heterogeneity of resources and topography. Here, we adopt a courser-grained view, regarding the environment as a network of discrete, diffusively-coupled "habitats"-distinct zones of high mosquito density such as stagnant ponds. We extend two previously published single-habitat mosquito models to multiple habitats, and calculate rates of migration between pairs of habitats using dispersal kernels. Our primary results are quantitative estimates regarding how the success of carrier fixation in one or more habitats is determined by: the number of carriers released, sizes of habitats, distances between habitats, and the rate of migration between habitats. Besides yielding sensible and potentially useful predictions regarding the success of Wolbachia-based control, our framework applies to other approaches (e.g., gene drives) and contexts beyond the realm of insect pest control.
Collapse
Affiliation(s)
- David Dye
- Department of Mathematics, Harvard University, Cambridge, MA, United States of America
| | - John W. Cain
- Department of Mathematics, Harvard University, Cambridge, MA, United States of America
| |
Collapse
|
5
|
Mashlawi AM, Alqahtani H, Abuelmaali SA, Gloria‐Soria A, Saingamsook J, Kaddumukasa M, Ghzwani AH, Abdulhaq AA, Al‐Mekhlafi HM, Walton C. Microsatellite-based analysis reveals Aedes aegypti populations in the Kingdom of Saudi Arabia result from colonization by both the ancestral African and the global domestic forms. Evol Appl 2024; 17:e13661. [PMID: 38405337 PMCID: PMC10883788 DOI: 10.1111/eva.13661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/18/2023] [Accepted: 01/24/2024] [Indexed: 02/27/2024] Open
Abstract
The Aedes aegypti (Linnaeus, 1762) mosquito is the main vector of dengue, chikungunya and Zika and is well established today all over the world. The species comprises two forms: the ancestral form found throughout Africa and a global domestic form that spread to the rest of the tropics and subtropics. In Saudi Arabia, A. aegypti has been known in the southwest since 1956, and previous genetic studies clustered A. aegypti from Saudi Arabia with the global domestic form. The purpose of this study was to assess the genetic structure of A. aegypti in Saudi Arabia and determine their geographic origin. Genetic data for 17 microsatellites were collected for A. aegypti ranging from the southwestern highlands of Saudi Arabia on the border of Yemen to the north-west in Madinah region as well as from Thailand and Uganda populations (as representatives of the ancestral African and global domestic forms, respectively). The low but significant level of genetic structuring in Saudi Arabia was consistent with long-distance dispersal capability possibly through road connectivity and human activities, that is, passive dispersal. There are two main genetic groupings in Saudi Arabia, one of which clusters with the Ugandan population and the other with the Thailand population with many Saudi Arabian individuals having mixed ancestry. The hypothesis of genetic admixture of the ancestral African and global domestic forms in Saudi Arabia was supported by approximate Bayesian computational analyses. The extent of admixture varied across Saudi Arabia. African ancestry was highest in the highland area of the Jazan region followed by the lowland Jazan and Sahil regions. Conversely, the western (Makkah, Jeddah and Madinah) and Najran populations corresponded to the global domesticated form. Given potential differences between the forms in transmission capability, ecology and behaviour, the findings here should be taken into account in vector control efforts in Saudi Arabia.
Collapse
Affiliation(s)
- Abadi M. Mashlawi
- Department of Biology, College of ScienceJazan UniversityJazanKingdom of Saudi Arabia
| | - Hussain Alqahtani
- Department of Biology, Faculty of ScienceUniversity of TabukTabukKingdom of Saudi Arabia
| | - Sara A. Abuelmaali
- National Public Health LaboratoryFederal Ministry of HealthKhartoumSudan
| | - Andrea Gloria‐Soria
- Department of Entomology, Center for Vector Biology & Zoonotic DiseasesThe Connecticut Agricultural Experiment StationNew HavenConnecticutUSA
| | - Jassada Saingamsook
- Center of Insect Vector Study, Department of Parasitology, Faculty of MedicineChiang Mai UniversityChiang MaiThailand
| | - Martha Kaddumukasa
- Department of Biological Sciences, Faculty of ScienceKyambogo UniversityKampalaUganda
| | | | - Ahmed A. Abdulhaq
- Department of Medical Laboratory Technology, Faculty of Applied Medical SciencesJazan UniversityJazanKingdom of Saudi Arabia
| | - Hesham M. Al‐Mekhlafi
- Department of Parasitology, Faculty of MedicineUniversiti MalayaKuala LumpurMalaysia
- Department of Parasitology, Faculty of Medicine and Health SciencesSana'a UniversitySana'aYemen
| | - Catherine Walton
- Department of Earth and Environmental Sciences, Faculty of Science and EngineeringUniversity of ManchesterManchesterUK
| |
Collapse
|
6
|
Pascar J, Middleton H, Dorus S. Aedes aegypti microbiome composition covaries with the density of Wolbachia infection. MICROBIOME 2023; 11:255. [PMID: 37978413 PMCID: PMC10655336 DOI: 10.1186/s40168-023-01678-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 09/27/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND Wolbachia is a widespread bacterial endosymbiont that can inhibit vector competency when stably transinfected into the mosquito, Aedes aegypti, a primary vector of the dengue virus (DENV) and other arboviruses. Although a complete mechanistic understanding of pathogen blocking is lacking, it is likely to involve host immunity induction and resource competition between Wolbachia and DENV, both of which may be impacted by microbiome composition. The potential impact of Wolbachia transinfection on host fitness is also of importance given the widespread release of mosquitos infected with the Drosophila melanogaster strain of Wolbachia (wMel) in wild populations. Here, population-level genomic data from Ae. aegypti was surveyed to establish the relationship between the density of wMel infection and the composition of the host microbiome. RESULTS Analysis of genomic data from 172 Ae. aegypti females across six populations resulted in an expanded and quantitatively refined, species-level characterization of the bacterial, archaeal, and fungal microbiome. This included 844 species of bacteria across 23 phyla, of which 54 species were found to be ubiquitous microbiome members across these populations. The density of wMel infection was highly variable between individuals and negatively correlated with microbiome diversity. Network analyses revealed wMel as a hub comprised solely of negative interactions with other bacterial species. This contrasted with the large and highly interconnected network of other microbiome species that may represent members of the midgut microbiome community in this population. CONCLUSION Our bioinformatic survey provided a species-level characterization of Ae. aegypti microbiome composition and variation. wMel load varied substantially across populations and individuals and, importantly, wMel was a major hub of a negative interactions across the microbiome. These interactions may be an inherent consequence of heightened pathogen blocking in densely infected individuals or, alternatively, may result from antagonistic Wolbachia-incompatible bacteria that could impede the efficacy of wMel as a biological control agent in future applications. The relationship between wMel infection variation and the microbiome warrants further investigation in the context of developing wMel as a multivalent control agent against other arboviruses. Video Abstract.
Collapse
Affiliation(s)
- Jane Pascar
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY, USA
| | - Henry Middleton
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY, USA
| | - Steve Dorus
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY, USA.
| |
Collapse
|
7
|
Hollingsworth BD, Grubaugh ND, Lazzaro BP, Murdock CC. Leveraging insect-specific viruses to elucidate mosquito population structure and dynamics. PLoS Pathog 2023; 19:e1011588. [PMID: 37651317 PMCID: PMC10470969 DOI: 10.1371/journal.ppat.1011588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Abstract
Several aspects of mosquito ecology that are important for vectored disease transmission and control have been difficult to measure at epidemiologically important scales in the field. In particular, the ability to describe mosquito population structure and movement rates has been hindered by difficulty in quantifying fine-scale genetic variation among populations. The mosquito virome represents a possible avenue for quantifying population structure and movement rates across multiple spatial scales. Mosquito viromes contain a diversity of viruses, including several insect-specific viruses (ISVs) and "core" viruses that have high prevalence across populations. To date, virome studies have focused on viral discovery and have only recently begun examining viral ecology. While nonpathogenic ISVs may be of little public health relevance themselves, they provide a possible route for quantifying mosquito population structure and dynamics. For example, vertically transmitted viruses could behave as a rapidly evolving extension of the host's genome. It should be possible to apply established analytical methods to appropriate viral phylogenies and incidence data to generate novel approaches for estimating mosquito population structure and dispersal over epidemiologically relevant timescales. By studying the virome through the lens of spatial and genomic epidemiology, it may be possible to investigate otherwise cryptic aspects of mosquito ecology. A better understanding of mosquito population structure and dynamics are key for understanding mosquito-borne disease ecology and methods based on ISVs could provide a powerful tool for informing mosquito control programs.
Collapse
Affiliation(s)
- Brandon D Hollingsworth
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
- Cornell Institute for Host Microbe Interaction and Disease, Cornell University, Ithaca, New York, United States of America
| | - Nathan D Grubaugh
- Yale School of Public Health, New Haven, Connecticut, United States of America
- Yale University, New Haven, Connecticut, United States of America
| | - Brian P Lazzaro
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
- Cornell Institute for Host Microbe Interaction and Disease, Cornell University, Ithaca, New York, United States of America
| | - Courtney C Murdock
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
- Cornell Institute for Host Microbe Interaction and Disease, Cornell University, Ithaca, New York, United States of America
- Northeast Regional Center for Excellence in Vector-borne Diseases, Cornell University, Ithaca, New York, United States of America
| |
Collapse
|
8
|
Sánchez C. HM, Smith DL, Marshall JM. MGSurvE: A framework to optimize trap placement for genetic surveillance of mosquito population. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546301. [PMID: 37425729 PMCID: PMC10327167 DOI: 10.1101/2023.06.26.546301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Genetic surveillance of mosquito populations is becoming increasingly relevant as genetics-based mosquito control strategies advance from laboratory to field testing. Especially applicable are mosquito gene drive projects, the potential scale of which leads monitoring to be a significant cost driver. For these projects, monitoring will be required to detect unintended spread of gene drive mosquitoes beyond field sites, and the emergence of alternative alleles, such as drive-resistant alleles or non-functional effector genes, within intervention sites. This entails the need to distribute mosquito traps efficiently such that an allele of interest is detected as quickly as possible - ideally when remediation is still viable. Additionally, insecticide-based tools such as bednets are compromised by insecticide-resistance alleles for which there is also a need to detect as quickly as possible. To this end, we present MGSurvE (Mosquito Gene SurveillancE): a computational framework that optimizes trap placement for genetic surveillance of mosquito populations such that the time to detection of an allele of interest is minimized. A key strength of MGSurvE is that it allows important biological features of mosquitoes and the landscapes they inhabit to be accounted for, namely: i) resources required by mosquitoes (e.g., food sources and aquatic breeding sites) can be explicitly distributed through a landscape, ii) movement of mosquitoes may depend on their sex, the current state of their gonotrophic cycle (if female) and resource attractiveness, and iii) traps may differ in their attractiveness profile. Example MGSurvE analyses are presented to demonstrate optimal trap placement for: i) an Aedes aegypti population in a suburban landscape in Queensland, Australia, and ii) an Anopheles gambiae population on the island of São Tomé, São Tomé and Príncipe. Further documentation and use examples are provided in project's documentation. MGSurvE is freely available as an open-source Python package on pypi (https://pypi.org/project/MGSurvE/). It is intended as a resource for both field and computational researchers interested in mosquito gene surveillance.
Collapse
Affiliation(s)
- Héctor M. Sánchez C.
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - David L. Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- Department of Health Metrics Sciences, School of Medicine, University of Washington, Seattle, WA, USA
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| |
Collapse
|
9
|
Reed EMX, Reiskind MH, Burford Reiskind MO. Life-history stage and the population genetics of the tiger mosquito Aedes albopictus at a fine spatial scale. MEDICAL AND VETERINARY ENTOMOLOGY 2023; 37:132-142. [PMID: 36300547 DOI: 10.1111/mve.12618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
As a widespread vector of disease with an expanding range, the mosquito Aedes albopictus Skuse (Diptera: Culicidae) is a high priority for research and management. A. albopictus has a complex life history with aquatic egg, larval and pupal stages, and a terrestrial adult stage. This requires targeted management strategies for each life stage, coordinated across time and space. Population genetics can aid in A. albopictus control by evaluating patterns of genetic diversity and dispersal. However, how life stage impacts population genetic characteristics is unknown. We examined whether patterns of A. albopictus genetic diversity and differentiation changed with life stage at a spatial scale relevant to management efforts. We first conducted a literature review of field-caught A. albopictus population genetic papers and identified 101 peer-reviewed publications, none of which compared results between life stages. Our study uniquely examines population genomic patterns of egg and adult A. albopictus at five sites in Wake County, North Carolina, USA, using 8425 single nucleotide polymorphisms. We found that the level of genetic diversity and connectivity between sites varied between adults and eggs. This warrants further study and is critical for research aimed at informing local management.
Collapse
Affiliation(s)
- Emily M X Reed
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Michael H Reiskind
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA
| | | |
Collapse
|
10
|
Facchinelli L, Badolo A, McCall PJ. Biology and Behaviour of Aedes aegypti in the Human Environment: Opportunities for Vector Control of Arbovirus Transmission. Viruses 2023; 15:636. [PMID: 36992346 PMCID: PMC10053764 DOI: 10.3390/v15030636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/02/2023] Open
Abstract
Aedes aegypti is a ubiquitous vector of arboviruses mostly in urbanised areas throughout the tropics and subtropics and a growing threat beyond. Control of Ae. aegypti is difficult and costly, and no vaccines are available for most of the viruses it transmits. With practical control solutions our goal, ideally suitable for delivery by householders in affected communities, we reviewed the literature on adult Ae. aegypti biology and behaviour, within and close to the human home, the arena where such interventions must impact. We found that knowledge was vague or important details were missing for multiple events or activities in the mosquito life cycle, such as the duration or location of the many periods when females rest between blood feeding and oviposition. The existing body of literature, though substantial, is not wholly reliable, and evidence for commonly held "facts" range from untraceable to extensive. Source references of some basic information are poor or date back more than 60 years, while other information that today is accepted widely as "fact" is not supported by evidence in the literature. Many topics, e.g., sugar feeding, resting preferences (location and duration), and blood feeding, merit being revisited in new geographical regions and ecological contexts to identify vulnerabilities for exploitation in control.
Collapse
Affiliation(s)
- Luca Facchinelli
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Athanase Badolo
- Laboratoire d’Entomologie Fondamentale et Appliquée, Université Joseph KI-ZERBO, Ouagadougou 03 BP 7021, Burkina Faso
| | - Philip J. McCall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| |
Collapse
|
11
|
Urban population structure and dispersal of an Australian mosquito (Aedes notoscriptus) involved in disease transmission. Heredity (Edinb) 2023; 130:99-108. [PMID: 36539450 PMCID: PMC9905534 DOI: 10.1038/s41437-022-00584-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Dispersal is a critical parameter for successful pest control measures as it determines the rate of movement across target control areas and influences the risk of human exposure. We used a fine-scale spatial population genomic approach to investigate the dispersal ecology and population structure of Aedes notoscriptus, an important disease transmitting mosquito at the Mornington Peninsula, Australia. We sampled and reared Ae. notoscriptus eggs at two time points from 170 traps up to 5 km apart and generated genomic data from 240 individuals. We also produced a draft genome assembly from a laboratory colony established from mosquitoes sampled near the study area. We found low genetic structure (Fst) and high coancestry throughout the study region. Using genetic data to identify close kin dyads, we found that mosquitoes had moved distances of >1 km within a generation, which is further than previously recorded. A spatial autocorrelation analysis of genetic distances indicated genetic similarity at >1 km separation, a tenfold higher distance than for a comparable population of Ae. aegypti, from Cairns, Australia. These findings point to high mobility of Ae. notoscriptus, highlighting challenges of localised intervention strategies. Further sampling within the same area 6 and 12 months after initial sampling showed that egg-counts were relatively consistent across time, and that spatial variation in egg-counts covaried with spatial variation in Wright's neighbourhood size (NS). As NS increases linearly with population density, egg-counts may be useful for estimating relative density in Ae. notoscriptus. The results highlight the importance of acquiring species-specific data when planning control measures.
Collapse
|
12
|
Bridging landscape ecology and urban science to respond to the rising threat of mosquito-borne diseases. Nat Ecol Evol 2022; 6:1601-1616. [DOI: 10.1038/s41559-022-01876-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 08/03/2022] [Indexed: 11/09/2022]
|
13
|
Zhang HD, Gao J, Xing D, Guo XX, Li CX, Dong YD, Zheng Z, Ma Z, Wu ZM, Zhu XJ, Zhao MH, Liu QM, Yan T, Chu HL, Zhao TY. Fine-scale genetic structure and wolbachia infection of aedes albopictus (Diptera: Culicidae) in Nanjing city, China. Front Genet 2022; 13:827655. [PMID: 36110209 PMCID: PMC9468874 DOI: 10.3389/fgene.2022.827655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Background:Aedes albopictus is an indigenous primary vector of dengue and Zika viruses in China. Wolbachia is a gram-negative and common intracellular bacteria, which is maternally inherited endosymbionts and could expand their propagation in host populations by means of various manipulations. Compared with research on the dispersion of Ae. albopictus at the macrospatial level (mainly at the country or continent level), little is known about its variation and Wolbachia infection at the microspatial level, which is essential for its management. Meanwhile, no local cases of dengue fever have been recorded in the history of Nanjing, which implies that few adulticides have been applied in the city. Thus, the present study examines how the Ae. albopictus population varies and the Wolbachia infection status of each population among microspatial regions of Nanjing City. Methods: The genetic structure of 17 Aedes albopictus populations collected from urban, urban fringe, and rural regions of Nanjing City was investigated based on 9 microsatellite loci and the mitochondrial coxI gene. The Wolbachia infection status of each population was also assessed with Wolbachia A- and Wolbachia B-specific primers. Results: Nine out of 58 tested pairs of microsatellite markers were highly polymorphic, with a mean PIC value of 0.560, and these markers were therefore chosen for microsatellite genotyping analysis. The Na value of each Ae. albopictus population was very high, and the urban area populations (7.353 ± 4.975) showed a lower mean value than the urban fringe region populations (7.866 ± 5.010). A total of 19 coxI haplotypes were observed among 329 Ae. albopictus individuals via haplotype genotyping, with the highest diversity observed among the urban fringe Ae. albopictus populations (Hd = 0.456) and the lowest among the urban populations (Hd = 0.277). Each Ae. albopictus population showed significant departure from HWE, and significant population expansion was observed in only three populations from the urban (ZSL), urban fringe (HAJY), and rural areas (HSZY) (p < 0.05). Combined with DAPC analysis, all the Ae. albopictus populations were adequately allocated to two clades with significant genetic differences according to population structure analysis, and the best K value was equal to two. AMOVA results showed that most (96.18%) of the genetic variation detected in Ae. albopictus occurred within individuals (FIT = 0.22238, p < 0.0001), while no significant positive correlation was observed via isolation by distance (IBD) analysis (R2 = 0.03262, p = 0.584). The TCS network of all haplotypes showed that haplotype 1 (H1) and haplotype 4 (H4) were the most frequent haplotypes among all populations, and the haplotype frequency significantly increased from urban regions (36.84%) to rural regions (68.42%). Frequent migration was observed among Ae. albopictus populations from rural to urban regions via the urban fringe region, with four direct migration routes between rural and urban regions. Furthermore, Wolbachia genotyping results showed that most of the individuals of each population were coinfected with Wolbachia A and Wolbachia B. The independent infection rate of Wolbachia A was slightly higher than that of Wolbachia B, and no significant differences were observed among different regions. Conclusion: In the microspatial environment of Nanjing City, the urban fringe region is an important region for the dispersion of Ae. albopictus populations between rural and urban areas, and Wolbachia A and Wolbachia B coinfection is the most common Wolbachia infection status in all Ae. albopictus populations among different regions.
Collapse
Affiliation(s)
- Heng-Duan Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jian Gao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Dan Xing
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xiao-Xia Guo
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Chun-Xiao Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yan-De Dong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhong Zheng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zu Ma
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhi-Ming Wu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xiao-Juan Zhu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Ming-Hui Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Qin-Mei Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Ting Yan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Hong-Liang Chu
- Department of Disinfection and Vector Control, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
- *Correspondence: Hong-Liang Chu, ; Tong-Yan Zhao,
| | - Tong-Yan Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- *Correspondence: Hong-Liang Chu, ; Tong-Yan Zhao,
| |
Collapse
|
14
|
Maffey L, Confalonieri V, Hasson E, Schweigmann N. City puzzles: Does urban land scape affect genetic population structure in Aedes aegypti? PLoS Negl Trop Dis 2022; 16:e0010549. [PMID: 35793338 PMCID: PMC9292108 DOI: 10.1371/journal.pntd.0010549] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 07/18/2022] [Accepted: 06/01/2022] [Indexed: 11/19/2022] Open
Abstract
Cities usually offer a suitable environment for the dengue vector Aedes aegypti, providing oviposition sites, accessibility to human hosts and nectar meals. However, large urban centres are highly heterogeneous environments, forming a patched landscape that could affect Ae. aegypti population dynamics and dispersal. Here, we performed a genome-wide analysis using Rad-seq data from 99 Ae. aegypti specimens collected in three areas within Buenos Aires city with varying levels of urbanization/land use: highly urbanized Area 1, intermediate Area 2 and poorly urbanized Area 3. We found an inverse association between urbanization levels and spatial genetic structure. Populations from highly urbanized Area 1 did not present genetic structure whereas two and three clusters were detected in Areas 2 and 3, respectively. In the case of Area 3, initial analyses showed separation in clusters was mostly due to elevated consanguinity within sites although three clusters were still detected after closely related individuals were discarded. Mosquitoes around each site displayed a high degree of isolation, evidencing a close dependence between the vector and human dwellings. Interestingly, specimens from distant boroughs (within the limits of the city) and the city's outskirts formed a single cluster with inner city sites (Area 1), highlighting the role of passive transport in shaping population structure. Genetic distances were poorly correlated with geographic distances in Buenos Aires, suggesting a stronger influence of passive than active dispersal on population structure. Only Area 2 displayed a significant isolation-by-distance pattern (p = 0.046), with males dispersing more than females (p = 0.004 and p = 0.016, respectively). Kinship analyses allowed us to detect full-siblings located 1.5 km apart in Area 1, which could be due to an extreme event of active female dispersal. Effective population size was higher in Area 2 confirming that cemeteries represent highly favourable environments for Ae. aegypti and need to be specifically targeted. Our results suggest that control programs should take into account urban landscape heterogeneity in order to improve vector control.
Collapse
Affiliation(s)
- Lucía Maffey
- Grupo de Estudio de Mosquitos, Departamento de Ecología, Genética y Evolución (DEGE-UBA)/Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| | - Viviana Confalonieri
- Grupo de Investigación en Filogenias y Filogeografía, Departamento de Ecología, Genética y Evolución (DEGE-UBA)/Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| | - Esteban Hasson
- Laboratorio de Evolución, Departamento de Ecología, Genética y Evolución (DEGE-UBA)/Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| | - Nicolás Schweigmann
- Grupo de Estudio de Mosquitos, Departamento de Ecología, Genética y Evolución (DEGE-UBA)/Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| |
Collapse
|
15
|
Vavassori L, Honnen A, Saarman N, Caccone A, Müller P. Multiple introductions and overwintering shape the progressive invasion of Aedes albopictus beyond the Alps. Ecol Evol 2022; 12:e9138. [PMID: 35903757 PMCID: PMC9313497 DOI: 10.1002/ece3.9138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/03/2022] [Accepted: 07/04/2022] [Indexed: 11/28/2022] Open
Abstract
Aedes albopictus originates from Southeast Asia and is considered one of the most invasive species globally. This mosquito is a nuisance and a disease vector of significant public health relevance. In Europe, Ae. albopictus is firmly established and widespread south of the Alps, a mountain range that forms a formidable biogeographic barrier to many organisms. Recent reports of Ae. albopictus north of the Alps raise questions of (1) the origins of its recent invasion, and (2) if this mosquito has established overwintering populations north of the Alps. To answer these questions, we analyzed population genomic data from >4000 genome-wide SNPs obtained through double-digest restriction site-associated DNA sequencing. We collected SNP data from specimens from six sites in Switzerland, north and south of the Alps, and analyzed them together with specimens from other 33 European sites, five from the Americas, and five from its Asian native range. At a global level, we detected four genetic clusters with specimens from Indonesia, Brazil, and Japan as the most differentiated, whereas specimens from Europe, Hong Kong, and USA largely overlapped. Across the Alps, we detected a weak genetic structure and high levels of genetic admixture, supporting a scenario of rapid and human-aided dispersal along transportation routes. While the genetic pattern suggests frequent re-introductions into Switzerland from Italian sources, the recovery of a pair of full siblings in two consecutive years in Strasbourg, France, suggests the presence of an overwintering population north of the Alps. The suggestion of overwintering populations of Ae. albopictus north of the Alps and the expansion patterns identified points to an increased risk of further northward expansion and the need for increased surveillance of mosquito populations in Northern Europe.
Collapse
Affiliation(s)
- Laura Vavassori
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Ann‐Christin Honnen
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
- Present address:
Kantonales Laboratorium Basel‐StadtBaselSwitzerland
| | - Norah Saarman
- Department of Biology and Ecology CenterUtah State UniversityLoganUSA
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticutUSA
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticutUSA
| | - Pie Müller
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| |
Collapse
|
16
|
Queffelec J, Postma A, Allison JD, Slippers B. Remnants of horizontal transfers of Wolbachia genes in a Wolbachia-free woodwasp. BMC Ecol Evol 2022; 22:36. [PMID: 35346038 PMCID: PMC8962096 DOI: 10.1186/s12862-022-01995-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/14/2022] [Indexed: 11/16/2022] Open
Abstract
Background Wolbachia is a bacterial endosymbiont of many arthropod and nematode species. Due to its capacity to alter host biology, Wolbachia plays an important role in arthropod and nematode ecology and evolution. Sirex noctilio is a woodwasp causing economic loss in pine plantations of the Southern Hemisphere. An investigation into the genome of this wasp revealed the presence of Wolbachia sequences. Due to the potential impact of Wolbachia on the populations of this wasp, as well as its potential use as a biological control agent against invasive insects, this discovery warranted investigation.
Results In this study we first investigated the presence of Wolbachia in S. noctilio and demonstrated that South African populations of the wasp are unlikely to be infected. We then screened the full genome of S. noctilio and found 12 Wolbachia pseudogenes. Most of these genes constitute building blocks of various transposable elements originating from the Wolbachia genome. Finally, we demonstrate that these genes are distributed in all South African populations of the wasp.
Conclusions Our results provide evidence that S. noctilio might be compatible with a Wolbachia infection and that the bacteria could potentially be used in the future to regulate invasive populations of the wasp. Understanding the mechanisms that led to a loss of Wolbachia infection in S. noctilio could indicate which host species or host population should be sampled to find a Wolbachia strain that could be used as a biological control against S. noctilio. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-022-01995-x.
Collapse
Affiliation(s)
- Joséphine Queffelec
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Lunnon Road, Pretoria, 0002, South Africa. .,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.
| | - Alisa Postma
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Lunnon Road, Pretoria, 0002, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Jeremy D Allison
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Lunnon Road, Pretoria, 0002, South Africa.,Great Lakes Forestry Center, Natural Resources Canada, Canadian Forest Service, Sault St Marie, Canada.,Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Bernard Slippers
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Lunnon Road, Pretoria, 0002, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
17
|
Ross PA, Robinson KL, Yang Q, Callahan AG, Schmidt TL, Axford JK, Coquilleau MP, Staunton KM, Townsend M, Ritchie SA, Lau MJ, Gu X, Hoffmann AA. A decade of stability for wMel Wolbachia in natural Aedes aegypti populations. PLoS Pathog 2022; 18:e1010256. [PMID: 35196357 PMCID: PMC8901071 DOI: 10.1371/journal.ppat.1010256] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/07/2022] [Accepted: 01/07/2022] [Indexed: 01/15/2023] Open
Abstract
Mosquitoes carrying Wolbachia endosymbionts are being released in many countries for arbovirus control. The wMel strain of Wolbachia blocks Aedes-borne virus transmission and can spread throughout mosquito populations by inducing cytoplasmic incompatibility. Aedes aegypti mosquitoes carrying wMel were first released into the field in Cairns, Australia, over a decade ago, and with wider releases have resulted in the near elimination of local dengue transmission. The long-term stability of Wolbachia effects is critical for ongoing disease suppression, requiring tracking of phenotypic and genomic changes in Wolbachia infections following releases. We used a combination of field surveys, phenotypic assessments, and Wolbachia genome sequencing to show that wMel has remained stable in its effects for up to a decade in Australian Ae. aegypti populations. Phenotypic comparisons of wMel-infected and uninfected mosquitoes from near-field and long-term laboratory populations suggest limited changes in the effects of wMel on mosquito fitness. Treating mosquitoes with antibiotics used to cure the wMel infection had limited effects on fitness in the next generation, supporting the use of tetracycline for generating uninfected mosquitoes without off-target effects. wMel has a temporally stable within-host density and continues to induce complete cytoplasmic incompatibility. A comparison of wMel genomes from pre-release (2010) and nine years post-release (2020) populations show few genomic differences and little divergence between release locations, consistent with the lack of phenotypic changes. These results indicate that releases of Wolbachia-infected mosquitoes for population replacement are likely to be effective for many years, but ongoing monitoring remains important to track potential evolutionary changes.
Collapse
Affiliation(s)
- Perran A. Ross
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Katie L. Robinson
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Qiong Yang
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Ashley G. Callahan
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Thomas L. Schmidt
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Jason K. Axford
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Marianne P. Coquilleau
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Kyran M. Staunton
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Queensland, Australia
| | - Michael Townsend
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Queensland, Australia
| | - Scott A. Ritchie
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Queensland, Australia
| | - Meng-Jia Lau
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Xinyue Gu
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Ary A. Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
18
|
Releasing incompatible males drives strong suppression across populations of wild and Wolbachia-carrying Aedes aegypti in Australia. Proc Natl Acad Sci U S A 2021; 118:2106828118. [PMID: 34607949 PMCID: PMC8521666 DOI: 10.1073/pnas.2106828118] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2021] [Indexed: 11/18/2022] Open
Abstract
With over 40% of humans at risk from mosquito-borne diseases such as dengue, yellow fever, chikungunya, and Zika, the development of environmentally friendly mosquito-control tools is critical. The release of reproductively incompatible male mosquitoes carrying a Wolbachia bacterium can drive mating events that kill the eggs. Through replicated treatment and control experiments in northern Australia, regular releases of Aedes aegypti males infected with a Wolbachia from Aedes albopictus was shown to drive strong population suppression in mosaic populations of wild-type (no Wolbachia) and wMel-Wolbachia–carrying Ae. aegypti. In a demonstration of bidirectional incompatibility between different Wolbachia strains in the field, we also demonstrate that one season’s suppression experiment can also show an ongoing effect into the following season. Releasing sterile or incompatible male insects is a proven method of population management in agricultural systems with the potential to revolutionize mosquito control. Through a collaborative venture with the “Debug” Verily Life Sciences team, we assessed the incompatible insect technique (IIT) with the mosquito vector Aedes aegypti in northern Australia in a replicated treatment control field trial. Backcrossing a US strain of Ae. aegypti carrying Wolbachia wAlbB from Aedes albopictus with a local strain, we generated a wAlbB2-F4 strain incompatible with both the wild-type (no Wolbachia) and wMel-Wolbachia Ae. aegypti now extant in North Queensland. The wAlbB2-F4 strain was manually mass reared with males separated from females using Verily sex-sorting technologies to obtain no detectable female contamination in the field. With community consent, we delivered a total of three million IIT males into three isolated landscapes of over 200 houses each, releasing ∼50 males per house three times a week over 20 wk. Detecting initial overflooding ratios of between 5:1 and 10:1, strong population declines well beyond 80% were detected across all treatment landscapes when compared to controls. Monitoring through the following season to observe the ongoing effect saw one treatment landscape devoid of adult Ae. aegypti early in the season. A second landscape showed reduced adults, and the third recovered fully. These encouraging results in suppressing both wild-type and wMel-Ae. aegypti confirms the utility of bidirectional incompatibility in the field setting, show the IIT to be robust, and indicate that the removal of this arbovirus vector from human-occupied landscapes may be achievable.
Collapse
|
19
|
Ross PA. Designing effective Wolbachia release programs for mosquito and arbovirus control. Acta Trop 2021; 222:106045. [PMID: 34273308 DOI: 10.1016/j.actatropica.2021.106045] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/04/2021] [Accepted: 07/06/2021] [Indexed: 01/22/2023]
Abstract
Mosquitoes carrying endosymbiotic bacteria called Wolbachia are being released in mosquito and arbovirus control programs around the world through two main approaches: population suppression and population replacement. Open field releases of Wolbachia-infected male mosquitoes have achieved over 95% population suppression by reducing the fertility of wild mosquito populations. The replacement of populations with Wolbachia-infected females is self-sustaining and can greatly reduce local dengue transmission by reducing the vector competence of mosquito populations. Despite many successful interventions, significant questions and challenges lie ahead. Wolbachia, viruses and their mosquito hosts can evolve, leading to uncertainty around the long-term effectiveness of a given Wolbachia strain, while few ecological impacts of Wolbachia releases have been explored. Wolbachia strains are diverse and the choice of strain to release should be made carefully, taking environmental conditions and the release objective into account. Mosquito quality control, thoughtful community awareness programs and long-term monitoring of populations are essential for all types of Wolbachia intervention. Releases of Wolbachia-infected mosquitoes show great promise, but existing control measures remain an important way to reduce the burden of mosquito-borne disease.
Collapse
|
20
|
Jasper ME, Hoffmann AA, Schmidt TL. Estimating dispersal using close kin dyads: The kindisperse R package. Mol Ecol Resour 2021; 22:1200-1212. [PMID: 34597453 DOI: 10.1111/1755-0998.13520] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/21/2021] [Accepted: 09/24/2021] [Indexed: 10/20/2022]
Abstract
Investigating dispersal in animal populations can be difficult, particularly for taxa that are hard to directly observe such as those that are small or rare. A promising solution may come from new approaches that use genome-wide sequence data to detect close kin dyads and estimate dispersal parameters from the distribution of these dyads. These methods have so far only been applied to mosquito populations. However, they should have broad applicability to a range of taxa, although no assessment has yet been made on their performance under different dispersal conditions and study designs. Here we develop an R package and shiny app, kindisperse, that can be used to estimate dispersal parameters from the spatial distribution of close kin. kindisperse can handle study designs that target different life stages and allows for a range of dispersal kernel shapes and organismal life histories; we provide implementation examples for a vertebrate (Antechinus) and an invertebrate (Aedes). We use simulations run in kindisperse to compare the performance of two published close kin methodologies, showing that one method produces unbiased estimates whereas the other produces downward-biased estimates. We also use kindisperse simulations to investigate how study design affects dispersal estimates, and we provide guidelines for the size and shape of sample sites as well as the number of close kin needed for accurate estimates. kindisperse is easily adaptable for application to a variety of research contexts ranging from invasive pests to threatened species where noninvasive DNA sampling can be used to detect close kin.
Collapse
Affiliation(s)
- Moshe E Jasper
- School of Biosciences, the University of Melbourne, Melbourne, Victoria, Australia
| | - Ary A Hoffmann
- School of Biosciences, the University of Melbourne, Melbourne, Victoria, Australia
| | - Thomas L Schmidt
- School of Biosciences, the University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
21
|
Pinto SB, Riback TIS, Sylvestre G, Costa G, Peixoto J, Dias FBS, Tanamas SK, Simmons CP, Dufault SM, Ryan PA, O’Neill SL, Muzzi FC, Kutcher S, Montgomery J, Green BR, Smithyman R, Eppinghaus A, Saraceni V, Durovni B, Anders KL, Moreira LA. Effectiveness of Wolbachia-infected mosquito deployments in reducing the incidence of dengue and other Aedes-borne diseases in Niterói, Brazil: A quasi-experimental study. PLoS Negl Trop Dis 2021; 15:e0009556. [PMID: 34252106 PMCID: PMC8297942 DOI: 10.1371/journal.pntd.0009556] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 07/22/2021] [Accepted: 06/09/2021] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The introduction of the bacterium Wolbachia (wMel strain) into Aedes aegypti mosquitoes reduces their capacity to transmit dengue and other arboviruses. Evidence of a reduction in dengue case incidence following field releases of wMel-infected Ae. aegypti has been reported previously from a cluster randomised controlled trial in Indonesia, and quasi-experimental studies in Indonesia and northern Australia. METHODOLOGY/PRINCIPAL FINDINGS Following pilot releases in 2015-2016 and a period of intensive community engagement, deployments of adult wMel-infected Ae. aegypti mosquitoes were conducted in Niterói, Brazil during 2017-2019. Deployments were phased across four release zones, with a total area of 83 km2 and a residential population of approximately 373,000. A quasi-experimental design was used to evaluate the effectiveness of wMel deployments in reducing dengue, chikungunya and Zika incidence. An untreated control zone was pre-defined, which was comparable to the intervention area in historical dengue trends. The wMel intervention effect was estimated by controlled interrupted time series analysis of monthly dengue, chikungunya and Zika case notifications to the public health surveillance system before, during and after releases, from release zones and the control zone. Three years after commencement of releases, wMel introgression into local Ae. aegypti populations was heterogeneous throughout Niterói, reaching a high prevalence (>80%) in the earliest release zone, and more moderate levels (prevalence 40-70%) elsewhere. Despite this spatial heterogeneity in entomological outcomes, the wMel intervention was associated with a 69% reduction in dengue incidence (95% confidence interval 54%, 79%), a 56% reduction in chikungunya incidence (95%CI 16%, 77%) and a 37% reduction in Zika incidence (95%CI 1%, 60%), in the aggregate release area compared with the pre-defined control area. This significant intervention effect on dengue was replicated across all four release zones, and in three of four zones for chikungunya, though not in individual release zones for Zika. CONCLUSIONS/SIGNIFICANCE We demonstrate that wMel Wolbachia can be successfully introgressed into Ae. aegypti populations in a large and complex urban setting, and that a significant public health benefit from reduced incidence of Aedes-borne disease accrues even where the prevalence of wMel in local mosquito populations is moderate and spatially heterogeneous. These findings are consistent with the results of randomised and non-randomised field trials in Indonesia and northern Australia, and are supportive of the Wolbachia biocontrol method as a multivalent intervention against dengue, chikungunya and Zika.
Collapse
Affiliation(s)
| | | | | | | | - Julia Peixoto
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
| | - Fernando B. S. Dias
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
- Gabinete da Presidência, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Stephanie K. Tanamas
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Cameron P. Simmons
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Suzanne M. Dufault
- Division of Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Peter A. Ryan
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Scott L. O’Neill
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Frederico C. Muzzi
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Simon Kutcher
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Jacqui Montgomery
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Benjamin R. Green
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Ruth Smithyman
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | | | | | - Betina Durovni
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
- Centre for Strategic Studies, Fiocruz, Rio de Janeiro, Brazil
| | - Katherine L. Anders
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Luciano A. Moreira
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
- Instituto Rene Rachou, Fiocruz, Belo Horizonte, Brazil
| |
Collapse
|
22
|
Improving mosquito control strategies with population genomics. Trends Parasitol 2021; 37:907-921. [PMID: 34074606 DOI: 10.1016/j.pt.2021.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/06/2021] [Accepted: 05/06/2021] [Indexed: 01/01/2023]
Abstract
Mosquito control strategies increasingly apply knowledge from population genomics research. This review highlights recent applications to three research domains: mosquito invasions, insecticide resistance evolution, and rear and release programs. Current research trends follow developments in reference assemblies, either as improvements to existing assemblies (particularly Aedes) or assemblies for new taxa (particularly Anopheles). With improved assemblies, studies of invasive and rear and release target populations are better able to incorporate adaptive as well as demographic hypotheses. New reference assemblies are aiding comparisons of insecticide resistance across sister taxa while helping resolve taxon boundaries amidst frequent introgression. Anopheles gene drive deployments and improved Aedes genome assemblies should lead to a convergence in research aims for Anopheles and Aedes in the coming years.
Collapse
|
23
|
Chen MZ, Cao LJ, Li BY, Chen JC, Gong YJ, Yang Q, Schmidt TL, Yue L, Zhu JY, Li H, Chen XX, Hoffmann AA, Wei SJ. Migration trajectories of the diamondback moth Plutella xylostella in China inferred from population genomic variation. PEST MANAGEMENT SCIENCE 2021; 77:1683-1693. [PMID: 33200882 DOI: 10.1002/ps.6188] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/15/2020] [Accepted: 11/17/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The diamondback moth (DBM), Plutella xylostella (Lepidoptera: Plutellidae), is a notorious pest of cruciferous plants. In temperate areas, annual populations of DBM originate from adult migrants. However, the source populations and migration trajectories of immigrants remain unclear. Here, we investigated migration trajectories of DBM in China using genome-wide single nucleotide polymorphisms (SNPs) genotyped using double-digest RAD (ddRAD) sequencing. We first analyzed patterns of spatial and temporal genetic structure among southern source and northern recipient populations, then inferred migration trajectories into northern regions using discriminant analysis of principal components (DAPC), assignment tests, and spatial kinship patterns. RESULTS Temporal genetic differentiation among populations was low, indicating that sources of recipient populations and migration trajectories are stable. Spatial genetic structure indicated three genetic clusters in the southern source populations. Assignment tests linked northern populations to the Sichuan cluster, and central-eastern populations to the southern and Yunnan clusters, indicating that Sichuan populations are sources of northern immigrants and southern and Yunnan populations are sources of central-eastern populations. First-order (full-sib) and second-order (half-sib) kin pairs were always found within populations, but ~ 35-40% of third-order (cousin) pairs were found in different populations. Closely related individuals in different populations were found at distances of 900-1500 km in ~ 35-40% of cases, while some were separated by > 2000 km. CONCLUSION This study unravels seasonal migration patterns in the DBM. We demonstrate how careful sampling and population genomic analyses can be combined to help understand cryptic migration patterns in insects. © 2020 Society of Chemical Industry.
Collapse
Affiliation(s)
- Ming-Zhu Chen
- Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Li-Jun Cao
- Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Bing-Yan Li
- Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Jin-Cui Chen
- Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Ya-Jun Gong
- Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Qiong Yang
- School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Thomas L Schmidt
- School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Lei Yue
- Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jia-Ying Zhu
- Key Laboratory of Forest Disaster Warning and Control of Yunnan Province, College of Forestry, Southwest Forestry University, Kunming, China
| | - Hu Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xue-Xin Chen
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Ary Anthony Hoffmann
- School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Shu-Jun Wei
- Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| |
Collapse
|
24
|
Lau MJ, Ross PA, Hoffmann AA. Infertility and fecundity loss of Wolbachia-infected Aedes aegypti hatched from quiescent eggs is expected to alter invasion dynamics. PLoS Negl Trop Dis 2021; 15:e0009179. [PMID: 33591971 PMCID: PMC7909672 DOI: 10.1371/journal.pntd.0009179] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/26/2021] [Accepted: 01/26/2021] [Indexed: 02/02/2023] Open
Abstract
The endosymbiotic bacterium Wolbachia shows viral blocking in its mosquito host, leading to its use in arboviral disease control. Releases with Wolbachia strains wMel and wAlbB infecting Aedes aegypti have taken place in several countries. Mosquito egg survival is a key factor influencing population persistence and this trait is also important when eggs are stored prior to releases. We therefore tested the viability of mosquitoes derived from Wolbachia wMel and wAlbB-infected as well as uninfected eggs after long-term storage under diurnal temperature cycles of 11-19°C and 22-30°C. Eggs stored at 11-19°C had higher hatch proportions than those stored at 22-30°C. Adult Wolbachia density declined when they emerged from eggs stored for longer, which was associated with incomplete cytoplasmic incompatibility (CI) when wMel-infected males were crossed with uninfected females. Females from stored eggs at both temperatures continued to show perfect maternal transmission of Wolbachia, but storage reduced the fecundity of both wMel and wAlbB-infected females relative to uninfected mosquitoes. Furthermore, we found a very strong negative impact of the wAlbB infection on the fertility of females stored at 22-30°C, with almost 80% of females hatching after 11 weeks of storage being infertile. Our findings provide guidance for storing Wolbachia-infected A. aegypti eggs to ensure high fitness adult mosquitoes for release. Importantly, they also highlight the likely impact of egg quiescence on the population dynamics of Wolbachia-infected populations in the field, and the potential for Wolbachia to suppress mosquito populations through cumulative fitness costs across warm and dry periods, with expected effects on dengue transmission.
Collapse
Affiliation(s)
- Meng-Jia Lau
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Perran A. Ross
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Ary A. Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
25
|
Schmidt TL, Swan T, Chung J, Karl S, Demok S, Yang Q, Field MA, Muzari MO, Ehlers G, Brugh M, Bellwood R, Horne P, Burkot TR, Ritchie S, Hoffmann AA. Spatial population genomics of a recent mosquito invasion. Mol Ecol 2021; 30:1174-1189. [PMID: 33421231 DOI: 10.1111/mec.15792] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/20/2020] [Accepted: 01/04/2021] [Indexed: 02/06/2023]
Abstract
Population genomic approaches can characterize dispersal across a single generation through to many generations in the past, bridging the gap between individual movement and intergenerational gene flow. These approaches are particularly useful when investigating dispersal in recently altered systems, where they provide a way of inferring long-distance dispersal between newly established populations and their interactions with existing populations. Human-mediated biological invasions represent such altered systems which can be investigated with appropriate study designs and analyses. Here we apply temporally restricted sampling and a range of population genomic approaches to investigate dispersal in a 2004 invasion of Aedes albopictus (the Asian tiger mosquito) in the Torres Strait Islands (TSI) of Australia. We sampled mosquitoes from 13 TSI villages simultaneously and genotyped 373 mosquitoes at genome-wide single nucleotide polymorphisms (SNPs): 331 from the TSI, 36 from Papua New Guinea (PNG) and four incursive mosquitoes detected in uninvaded regions. Within villages, spatial genetic structure varied substantially but overall displayed isolation by distance and a neighbourhood size of 232-577. Close kin dyads revealed recent movement between islands 31-203 km apart, and deep learning inferences showed incursive Ae. albopictus had travelled to uninvaded regions from both adjacent and nonadjacent islands. Private alleles and a co-ancestry matrix indicated direct gene flow from PNG into nearby islands. Outlier analyses also detected four linked alleles introgressed from PNG, with the alleles surrounding 12 resistance-associated cytochrome P450 genes. By treating dispersal as both an intergenerational process and a set of discrete events, we describe a highly interconnected invasive system.
Collapse
Affiliation(s)
- Thomas L Schmidt
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, VIC, Australia
| | - Tom Swan
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, Australia
| | - Jessica Chung
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, VIC, Australia.,Melbourne Bioinformatics, University of Melbourne, Parkville, VIC, Australia
| | - Stephan Karl
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Samuel Demok
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Qiong Yang
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, VIC, Australia
| | - Matt A Field
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia.,John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Mutizwa Odwell Muzari
- Medical Entomology, Tropical Public Health Services Cairns, Cairns and Hinterland Hospital & Health Services, Cairns, QLD, Australia
| | - Gerhard Ehlers
- Medical Entomology, Tropical Public Health Services Cairns, Cairns and Hinterland Hospital & Health Services, Cairns, QLD, Australia
| | - Mathew Brugh
- Medical Entomology, Tropical Public Health Services Cairns, Cairns and Hinterland Hospital & Health Services, Cairns, QLD, Australia
| | - Rodney Bellwood
- Medical Entomology, Tropical Public Health Services Cairns, Cairns and Hinterland Hospital & Health Services, Cairns, QLD, Australia
| | - Peter Horne
- Medical Entomology, Tropical Public Health Services Cairns, Cairns and Hinterland Hospital & Health Services, Cairns, QLD, Australia
| | - Thomas R Burkot
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Scott Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, Australia.,Institute of Vector-Borne Disease, Monash University, Clayton, VIC, Australia
| | - Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
26
|
Trense D, Schmidt TL, Yang Q, Chung J, Hoffmann AA, Fischer K. Anthropogenic and natural barriers affect genetic connectivity in an Alpine butterfly. Mol Ecol 2020; 30:114-130. [PMID: 33108010 DOI: 10.1111/mec.15707] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 10/16/2020] [Accepted: 10/19/2020] [Indexed: 12/22/2022]
Abstract
Dispersal is a key biological process serving several functions including connectivity among populations. Habitat fragmentation caused by natural or anthropogenic structures may hamper dispersal, thereby disrupting genetic connectivity. Investigating factors affecting dispersal and gene flow is important in the current era of anthropogenic global change, as dispersal comprises a vital part of a species' resilience to environmental change. Using finescale landscape genomics, we investigated gene flow and genetic structure of the Sooty Copper butterfly (Lycaena tityrus) in the Alpine Ötz valley system in Austria. We found surprisingly high levels of gene flow in L. tityrus across the region. Nevertheless, ravines, forests, and roads had effects on genetic structure, while rivers did not. The latter is surprising as roads and rivers have a similar width and run largely in parallel in our study area, pointing towards a higher impact of anthropogenic compared with natural linear structures. Additionally, we detected eleven loci potentially under thermal selection, including ones related to membranes, metabolism, and immune function. This study demonstrates the usefulness of molecular approaches in obtaining estimates of dispersal and population processes in the wild. Our results suggest that, despite high gene flow in the Alpine valley system investigated, L. tityrus nevertheless seems to be vulnerable to anthropogenically-driven habitat fragmentation. With anthropogenic rather than natural linear structures affecting gene flow, this may have important consequences for the persistence of species such as the butterfly studied here in altered landscapes.
Collapse
Affiliation(s)
- Daronja Trense
- Institute for Integrated Natural Sciences, Zoology, University Koblenz-Landau, Koblenz, Germany
| | - Thomas L Schmidt
- Pest & Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, Parkville, Vic., Australia
| | - Qiong Yang
- Pest & Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, Parkville, Vic., Australia
| | - Jessica Chung
- Pest & Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, Parkville, Vic., Australia
| | - Ary A Hoffmann
- Pest & Environmental Adaptation Research Group, School of Biosciences, Bio21 Institute, Parkville, Vic., Australia
| | - Klaus Fischer
- Institute for Integrated Natural Sciences, Zoology, University Koblenz-Landau, Koblenz, Germany
| |
Collapse
|
27
|
Maffey L, Garzón MJ, Confalonieri V, Chanampa MM, Hasson E, Schweigmann N. Genome-Wide Screening of Aedes aegypti (Culicidae: Diptera) Populations From Northwestern Argentina: Active and Passive Dispersal Shape Genetic Structure. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1930-1941. [PMID: 32692366 DOI: 10.1093/jme/tjaa125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Indexed: 06/11/2023]
Abstract
Aedes aegypti is the primary vector of arboviruses of great impact on human health. Our goal was to assess the spatial genetic structure of Ae. aegypti at the regional and local levels in Northwestern Argentina, an area with high prevalence of dengue fever. We analyzed 59 Ae. aegypti individuals collected from six locations in Northwestern Argentina using nuclear genome-wide Single Nucleotide Polymorphisms (SNPs) generated with double digest Restriction-site Associated DNA Sequencing. We also performed an entomological survey in 70 households in the cities of Orán and Tartagal. An analysis at the regional level indicated that the populations of Ae. aegypti in Northwestern Argentina are spatially structured and present a significant IBD pattern. Our results suggest that passive transport of eggs/immature stages, in both northward and southward directions, plays an important role in structuring Ae. aegypti populations at a regional scale and also as a source for the introduction of novel genetic variants through migration events into established populations. At a local level, we found neither spatial genetic structure nor significant isolation by distance (IBD) in Tartagal, indicating high gene flow within the city and active dispersal. In contrast, samples from Orán formed two clusters with a significant IBD pattern, although weaker than that at a regional level. Both populations showed signs of recent bottleneck events, probably coincident with past eradication campaigns. The entomological survey revealed a high prevalence of Ae. aegypti in both cities, although significantly higher in Tartagal.
Collapse
Affiliation(s)
- Lucía Maffey
- Grupo de Estudio de Mosquitos, Departamento de Ecología, Genética y Evolución (DEGE-UBA) / Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| | - Maximiliano J Garzón
- Grupo de Estudio de Mosquitos, Departamento de Ecología, Genética y Evolución (DEGE-UBA) / Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| | - Viviana Confalonieri
- Grupo de Investigación en Filogenias y Filogeografía, Departamento de Ecología, Genética y Evolución (DEGE-UBA) / Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| | - Mariana M Chanampa
- Instituto de Investigación en Energía No Convencional (INENCO/CONICET Unidad Salud y ambiente), Salta, Argentina
| | - Esteban Hasson
- Laboratorio de Evolución, Departamento de Ecología, Genética y Evolución (DEGE-UBA) / Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| | - Nicolás Schweigmann
- Grupo de Estudio de Mosquitos, Departamento de Ecología, Genética y Evolución (DEGE-UBA) / Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA-CONICET), Buenos Aires, Argentina
| |
Collapse
|
28
|
Wolbachia Genome Stability and mtDNA Variants in Aedes aegypti Field Populations Eight Years after Release. iScience 2020; 23:101572. [PMID: 33083739 PMCID: PMC7527712 DOI: 10.1016/j.isci.2020.101572] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/23/2020] [Accepted: 09/14/2020] [Indexed: 11/23/2022] Open
Abstract
A dengue suppression strategy based on release of Aedes aegypti mosquitoes infected with the bacterium Wolbachia pipientis is being trialed in many countries. Wolbachia inhibits replication and transmission of dengue viruses. Questions remain regarding the long-term stability of virus-suppressive effects. We sequenced the Wolbachia genome and analyzed Ae. aegypti mitochondrial DNA markers isolated from mosquitoes sampled 2-8 years after releases in the greater Cairns region, Australia. Few changes were detected when Wolbachia genomes of field mosquitoes were compared with Wolbachia genomes of mosquitoes obtained soon after initial releases. Mitochondrial variants associated with the initial Wolbachia release stock are now the only variants found in release sites, highlighting maternal leakage as a possible explanation for rare Wolbachia-negative mosquitoes and not migration from non-release areas. There is no evidence of changes in the Wolbachia genome that indicate selection against its viral-suppressive effects or other phenotypes attributable to infection with the bacterium.
Collapse
|
29
|
Lau MJ, Ross PA, Endersby-Harshman NM, Hoffmann AA. Impacts of Low Temperatures on Wolbachia (Rickettsiales: Rickettsiaceae)-Infected Aedes aegypti (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1567-1574. [PMID: 32307514 PMCID: PMC7566743 DOI: 10.1093/jme/tjaa074] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Indexed: 05/10/2023]
Abstract
In recent decades, the occurrence and distribution of arboviral diseases transmitted by Aedes aegypti mosquitoes has increased. In a new control strategy, populations of mosquitoes infected with Wolbachia are being released to replace existing populations and suppress arboviral disease transmission. The success of this strategy can be affected by high temperature exposure, but the impact of low temperatures on Wolbachia-infected Ae. aegypti is unclear, even though low temperatures restrict the abundance and distribution of this species. In this study, we considered low temperature cycles relevant to the spring season that are close to the distribution limits of Ae. aegypti, and tested the effects of these temperature cycles on Ae. aegypti, Wolbachia strains wMel and wAlbB, and Wolbachia phage WO. Low temperatures influenced Ae. aegypti life-history traits, including pupation, adult eclosion, and fertility. The Wolbachia-infected mosquitoes, especially wAlbB, performed better than uninfected mosquitoes. Temperature shift experiments revealed that low temperature effects on life history and Wolbachia density depended on the life stage of exposure. Wolbachia density was suppressed at low temperatures but densities recovered with adult age. In wMel Wolbachia there were no low temperature effects specific to Wolbachia phage WO. The findings suggest that Wolbachia-infected Ae. aegypti are not adversely affected by low temperatures, indicating that the Wolbachia replacement strategy is suitable for areas experiencing cool temperatures seasonally.
Collapse
Affiliation(s)
- Meng-Jia Lau
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Perran A Ross
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Nancy M Endersby-Harshman
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
30
|
Xia S, Cosme LV, Lutomiah J, Sang R, Ngangue MF, Rahola N, Ayala D, Powell JR. Genetic structure of the mosquito Aedes aegypti in local forest and domestic habitats in Gabon and Kenya. Parasit Vectors 2020; 13:417. [PMID: 32791977 PMCID: PMC7427282 DOI: 10.1186/s13071-020-04278-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 08/03/2020] [Indexed: 12/14/2022] Open
Abstract
Background The mosquito Aedes aegypti is a devastating disease vector transmitting several important human arboviral diseases. In its native range in Africa, the mosquito can be found in both the ancestral forest habitat and anthropogenic habitats such as villages. How do the different habitats impact the population genetic structure of the local mosquito populations? Methods To address this question, we simultaneously sampled Ae. aegypti from the forest and local villages in La Lopé, Gabon and Rabai, Kenya. The mosquitoes were genotyped at 12 microsatellite loci and a panel of ~25,000 single nucleotide polymorphisms (SNPs), which allowed us to estimate their genetic ancestries and the population genetic structure related to habitats and sampling sites. Results In the context of the global population genetic structure of Ae. aegypti, clustering analysis showed that mosquitoes from the same locality (La Lopé or Rabai) have similar genetic ancestry, regardless of their habitats. Further analysis at the local scale also found no strong genetic differentiation between the forest and village mosquitoes in both La Lopé and Rabai. Interestingly, these results from our 2017 samples from Rabai, Kenya contrast to the documentation of genetic differentiation between village and forest mosquito collections from 1975–1976 and 2009. Between-habitat measures of genetic difference (Fst) vary across the genome, with a peak of high divergence observed at the third chromosome only in the La Lopé populations. Conclusion Collectively, these results demonstrated that there is little genetic isolation between forest and village habitats, which suggests possible extensive gene flow between them. From an epidemiological perspective, the forest habitat could act as a refuge for mosquitoes against vector control programmes in the domestic settings. Moreover, sylvatic populations could play a role in zoonotic pathogen transferred to humans. Therefore, future studies on disease transmission and vector control planning in the study area should take natural populations into consideration.![]()
Collapse
Affiliation(s)
- Siyang Xia
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.
| | - Luciano V Cosme
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
| | - Joel Lutomiah
- Arbovirus/Viral Hemorrhagic Fever Laboratory, Center for Virus Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Rosemary Sang
- Arbovirus/Viral Hemorrhagic Fever Laboratory, Center for Virus Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | | | - Nil Rahola
- CIRMF, Franceville, Gabon.,MIVEGEC, IRD, CNRS, Univ. Montpellier, Montpellier, France
| | - Diego Ayala
- CIRMF, Franceville, Gabon.,MIVEGEC, IRD, CNRS, Univ. Montpellier, Montpellier, France
| | - Jeffrey R Powell
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
| |
Collapse
|
31
|
Schmidt TL, Chung J, Honnen AC, Weeks AR, Hoffmann AA. Population genomics of two invasive mosquitoes (Aedes aegypti and Aedes albopictus) from the Indo-Pacific. PLoS Negl Trop Dis 2020; 14:e0008463. [PMID: 32678817 PMCID: PMC7390453 DOI: 10.1371/journal.pntd.0008463] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 07/29/2020] [Accepted: 06/08/2020] [Indexed: 01/09/2023] Open
Abstract
The arbovirus vectors Aedes aegypti (yellow fever mosquito) and Ae. albopictus (Asian tiger mosquito) are both common throughout the Indo-Pacific region, where 70% of global dengue transmission occurs. For Ae. aegypti all Indo-Pacific populations are invasive, having spread from an initial native range of Africa, while for Ae. albopictus the Indo-Pacific includes invasive populations and those from the native range: putatively, India to Japan to Southeast Asia. This study analyses the population genomics of 480 of these mosquitoes sampled from 27 locations in the Indo-Pacific. We investigated patterns of genome-wide genetic differentiation to compare pathways of invasion and ongoing gene flow in both species, and to compare invasive and native-range populations of Ae. albopictus. We also tested landscape genomic hypotheses that genetic differentiation would increase with geographical distance and be lower between locations with high connectivity to human transportation routes, the primary means of dispersal at these scales. We found that genetic distances were generally higher in Ae. aegypti, with Pacific populations the most highly differentiated. The most differentiated Ae. albopictus populations were in Vanuatu, Indonesia and Sri Lanka, the latter two representing potential native-range populations and potential cryptic subspeciation respectively. Genetic distances in Ae. aegypti increased with geographical distance, while in Ae. albopictus they decreased with higher connectivity to human transportation routes. Contrary to the situation in Ae. aegypti, we found evidence of long-distance Ae. albopictus colonisation events, including colonisation of Mauritius from East Asia and of Fiji from Southeast Asia. These direct genomic comparisons indicate likely differences in dispersal ecology in these species, despite their broadly sympatric distributions and similar use of human transport to disperse. Our findings will assist biosecurity operations to trace the source of invasive material and for biocontrol operations that benefit from matching genetic backgrounds of released and local populations.
Collapse
Affiliation(s)
- Thomas L. Schmidt
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Jessica Chung
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
- Melbourne Bioinformatics, University of Melbourne, Parkville, Victoria, Australia
| | - Ann-Christin Honnen
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Andrew R. Weeks
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
- cesar Pty Ltd, Parkville, Victoria, Australia
| | - Ary A. Hoffmann
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
32
|
Sánchez C HM, Bennett JB, Wu SL, Rašić G, Akbari OS, Marshall JM. Modeling confinement and reversibility of threshold-dependent gene drive systems in spatially-explicit Aedes aegypti populations. BMC Biol 2020; 18:50. [PMID: 32398005 PMCID: PMC7218562 DOI: 10.1186/s12915-020-0759-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 02/26/2020] [Indexed: 12/17/2022] Open
Abstract
Background The discovery of CRISPR-based gene editing and its application to homing-based gene drive systems has been greeted with excitement, for its potential to control mosquito-borne diseases on a wide scale, and concern, for the invasiveness and potential irreversibility of a release. Gene drive systems that display threshold-dependent behavior could potentially be used during the trial phase of this technology, or when localized control is otherwise desired, as simple models predict them to spread into partially isolated populations in a confineable manner, and to be reversible through releases of wild-type organisms. Here, we model hypothetical releases of two recently engineered threshold-dependent gene drive systems—reciprocal chromosomal translocations and a form of toxin-antidote-based underdominance known as UDMEL—to explore their ability to be confined and remediated. Results We simulate releases of Aedes aegypti, the mosquito vector of dengue, Zika, and other arboviruses, in Yorkeys Knob, a suburb of Cairns, Australia, where previous biological control interventions have been undertaken on this species. We monitor spread to the neighboring suburb of Trinity Park to assess confinement. Results suggest that translocations could be introduced on a suburban scale, and remediated through releases of non-disease-transmitting male mosquitoes with release sizes on the scale of what has been previously implemented. UDMEL requires fewer releases to introduce, but more releases to remediate, including of females capable of disease transmission. Both systems are expected to be confineable to the release site; however, spillover of translocations into neighboring populations is less likely. Conclusions Our analysis supports the use of translocations as a threshold-dependent drive system capable of spreading disease-refractory genes into Ae. aegypti populations in a confineable and reversible manner. It also highlights increased release requirements when incorporating life history and population structure into models. As the technology nears implementation, further ecological work will be essential to enhance model predictions in preparation for field trials.
Collapse
Affiliation(s)
- Héctor M Sánchez C
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA, 94720, USA
| | - Jared B Bennett
- Biophysics Graduate Group, University of California, Berkeley, CA, 94720, USA
| | - Sean L Wu
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA, 94720, USA
| | - Gordana Rašić
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Omar S Akbari
- Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, CA, 92093, USA
| | - John M Marshall
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA, 94720, USA. .,Innovative Genomics Institute, Berkeley, CA, 94720, USA.
| |
Collapse
|
33
|
Futami K, Iwashita H, Higa Y, Lutiali PA, Sonye GO, Mwatele C, Njenga SM, Minakawa N. Geographical Distribution of Aedes aegypti aegypti and Aedes aegypti formosus (Diptera: Culicidae) in Kenya and Environmental Factors Related to Their Relative Abundance. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:772-779. [PMID: 31815285 DOI: 10.1093/jme/tjz233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Indexed: 06/10/2023]
Abstract
The mosquito Aedes aegypti (L.) is the primary vector of various infectious viruses and is typified by a polymorphic color and abundance of white scales on the body. It has been conventionally separated into two subspecies, Ae. aeg. formosus (Walker) (Aaf) and Ae. aeg. aegypti (L.) (Aaa), with Aaf considered a 'sylvan' form and Aaa a 'domestic' form. Because the two subspecies show different susceptibilities to dengue viruses it is important to understand their distribution. In this study, we collected larvae from artificial and natural habitats in southern Kenya and reared them to adults to morphologically identify subspecies. We describe the geographical distribution and relative abundance of Aaa and Aaf in Kenya, and estimate the environmental factors associated with their distributions by GIS using climate and environment data. A total of 5,243 Ae. aegypti adults were collected from 249 sites, with Aaa accounting for 22% of the specimens. The relative abundance of Aaa was higher in coastal areas versus sites in western Kenya. Aaa abundance was also higher in urbanized than forested areas, which is consistent with known ecology. In contrast and inconsistent with previous studies, both Aaa and Aaf were sympatric in artificial and natural habitats. The high relative abundance of Aaa in coastal areas might derive from old populated cities, climate, and/or introduction from abroad.
Collapse
Affiliation(s)
- K Futami
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - H Iwashita
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Department of Bacteriology, Graduate School of Medicine, University of the Ryukyus, Nishiharacho, Okinawa, Japan
| | - Y Higa
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan
| | - P A Lutiali
- Center for Research in Tropical Medicine and Community Development (CRTMCD), Nairobi, Kenya
| | - G O Sonye
- ASK Community Based Organization located in Mbita, Homabay, Kenya
| | - C Mwatele
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - S M Njenga
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute, Nairobi, Kenya
| | - N Minakawa
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| |
Collapse
|
34
|
Endersby‐Harshman NM, Schmidt TL, Chung J, Rooyen A, Weeks AR, Hoffmann AA. Heterogeneous genetic invasions of three insecticide resistance mutations in Indo‐Pacific populations of
Aedes aegypti
(L.). Mol Ecol 2020; 29:1628-1641. [DOI: 10.1111/mec.15430] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 03/02/2020] [Accepted: 03/17/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Nancy M. Endersby‐Harshman
- Pest and Environmental Adaptation Research Group School of BioSciences Bio21 Institute The University of Melbourne Parkville Vic. Australia
| | - Thomas L. Schmidt
- Pest and Environmental Adaptation Research Group School of BioSciences Bio21 Institute The University of Melbourne Parkville Vic. Australia
| | - Jessica Chung
- Pest and Environmental Adaptation Research Group School of BioSciences Bio21 Institute The University of Melbourne Parkville Vic. Australia
- Melbourne Bioinformatics The University of Melbourne Parkville Vic. Australia
| | | | - Andrew R. Weeks
- Pest and Environmental Adaptation Research Group School of BioSciences Bio21 Institute The University of Melbourne Parkville Vic. Australia
- Cesar Pty Ltd Parkville Vic. Australia
| | - Ary A. Hoffmann
- Pest and Environmental Adaptation Research Group School of BioSciences Bio21 Institute The University of Melbourne Parkville Vic. Australia
| |
Collapse
|
35
|
Champer J, Zhao J, Champer SE, Liu J, Messer PW. Population Dynamics of Underdominance Gene Drive Systems in Continuous Space. ACS Synth Biol 2020; 9:779-792. [PMID: 32142612 DOI: 10.1021/acssynbio.9b00452] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Underdominance systems can quickly spread through a population, but only when introduced in considerable numbers. This promises a gene drive mechanism that is less invasive than homing drives, potentially enabling new approaches in the fight against vector-borne diseases. If regional confinement can indeed be achieved, the decision-making process for a release would likely be much simpler compared to other, more invasive types of drives. The capacity of underdominance gene drive systems to spread in a target population without invading other populations is typically assessed via network models of panmictic demes linked by migration. However, it remains less clear how such systems would behave in more realistic population models where organisms move over a continuous landscape. Here, we use individual-based simulations to study the dynamics of several proposed underdominance systems in continuous-space. We find that all these systems can fail to persist in such environments, even after an initially successful establishment in the release area, confirming previous theoretical results from diffusion theory. At the same time, we find that a two-locus two-toxin-antidote system can invade connected demes through a narrow migration corridor. This suggests that the parameter space where underdominance systems can establish and persist in a release area while at the same time remaining confined to that area could be quite limited, depending on how a population is spatially structured. Overall, these results indicate that realistic spatial context must be considered when assessing strategies for the deployment of underdominance drives.
Collapse
|
36
|
Ryan PA, Turley AP, Wilson G, Hurst TP, Retzki K, Brown-Kenyon J, Hodgson L, Kenny N, Cook H, Montgomery BL, Paton CJ, Ritchie SA, Hoffmann AA, Jewell NP, Tanamas SK, Anders KL, Simmons CP, O'Neill SL. Establishment of wMel Wolbachia in Aedes aegypti mosquitoes and reduction of local dengue transmission in Cairns and surrounding locations in northern Queensland, Australia. Gates Open Res 2020; 3:1547. [PMID: 31667465 DOI: 10.12688/gatesopenres.13061.1] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2019] [Indexed: 01/13/2023] Open
Abstract
Background: The wMel strain of Wolbachia has been successfully introduced into Aedes aegypti mosquitoes and subsequently shown in laboratory studies to reduce transmission of a range of viruses including dengue, Zika, chikungunya, yellow fever, and Mayaro viruses that cause human disease. Here we report the entomological and epidemiological outcomes of staged deployment of Wolbachia across nearly all significant dengue transmission risk areas in Australia. Methods: The wMel strain of Wolbachia was backcrossed into the local Aedes aegypti genotype (Cairns and Townsville backgrounds) and mosquitoes were released in the field by staff or via community assisted methods. Mosquito monitoring was undertaken and mosquitoes were screened for the presence of Wolbachia. Dengue case notifications were used to track dengue incidence in each location before and after releases. Results: Empirical analyses of the Wolbachia mosquito releases, including data on the density, frequency and duration of Wolbachia mosquito releases, indicate that Wolbachia can be readily established in local mosquito populations, using a variety of deployment options and over short release durations (mean release period 11 weeks, range 2-22 weeks). Importantly, Wolbachia frequencies have remained stable in mosquito populations since releases for up to 8 years. Analysis of dengue case notifications data demonstrates near-elimination of local dengue transmission for the past five years in locations where Wolbachia has been established. The regression model estimate of Wolbachia intervention effect from interrupted time series analyses of case notifications data prior to and after releases, indicated a 96% reduction in dengue incidence in Wolbachia treated populations (95% confidence interval: 84 - 99%). Conclusion: Deployment of the wMel strain of Wolbachia into local Ae. aegypti populations across the Australian regional cities of Cairns and most smaller regional communities with a past history of dengue has resulted in the reduction of local dengue transmission across all deployment areas.
Collapse
Affiliation(s)
- Peter A Ryan
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Andrew P Turley
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Geoff Wilson
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Tim P Hurst
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,Biosecurity and Agricultural Services, Department of Jobs, Precincts and Regions, Victoria State Government, Atwood, Victoria, Australia
| | - Kate Retzki
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Jack Brown-Kenyon
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Lauren Hodgson
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Nichola Kenny
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Helen Cook
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Brian L Montgomery
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,Metro South Public Health Unit, Queensland Health, Coopers Plains, Queensland, Australia
| | - Christopher J Paton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
| | - Scott A Ritchie
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
| | - Ary A Hoffmann
- School of Biosciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Nicholas P Jewell
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, USA.,Centre for Statistical Methodology, London School of Hygiene and Tropical Medicine, London, UK
| | - Stephanie K Tanamas
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Katherine L Anders
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Cameron P Simmons
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Scott L O'Neill
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| |
Collapse
|
37
|
Ryan PA, Turley AP, Wilson G, Hurst TP, Retzki K, Brown-Kenyon J, Hodgson L, Kenny N, Cook H, Montgomery BL, Paton CJ, Ritchie SA, Hoffmann AA, Jewell NP, Tanamas SK, Anders KL, Simmons CP, O'Neill SL. Establishment of wMel Wolbachia in Aedes aegypti mosquitoes and reduction of local dengue transmission in Cairns and surrounding locations in northern Queensland, Australia. Gates Open Res 2020; 3:1547. [PMID: 31667465 PMCID: PMC6801363 DOI: 10.12688/gatesopenres.13061.2] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2020] [Indexed: 01/14/2023] Open
Abstract
Background: The
wMel strain of
Wolbachia has been successfully introduced into
Aedes aegypti mosquitoes and subsequently shown in laboratory studies to reduce transmission of a range of viruses including dengue, Zika, chikungunya, yellow fever, and Mayaro viruses that cause human disease. Here we report the entomological and epidemiological outcomes of staged deployment of
Wolbachia across nearly all significant dengue transmission risk areas in Australia. Methods: The
wMel strain of
Wolbachia was backcrossed into the local
Aedes aegypti genotype (Cairns and Townsville backgrounds) and mosquitoes were released in the field by staff or via community assisted methods. Mosquito monitoring was undertaken and mosquitoes were screened for the presence of
Wolbachia. Dengue case notifications were used to track dengue incidence in each location before and after releases. Results: Empirical analyses of the
Wolbachia mosquito releases, including data on the density, frequency and duration of
Wolbachia mosquito releases, indicate that
Wolbachia can be readily established in local mosquito populations, using a variety of deployment options and over short release durations (mean release period 11 weeks, range 2-22 weeks). Importantly,
Wolbachia frequencies have remained stable in mosquito populations since releases for up to 8 years. Analysis of dengue case notifications data demonstrates near-elimination of local dengue transmission for the past five years in locations where
Wolbachia has been established. The regression model estimate of
Wolbachia intervention effect from interrupted time series analyses of case notifications data prior to and after releases, indicated a 96% reduction in dengue incidence in
Wolbachia treated populations (95% confidence interval: 84 – 99%). Conclusion: Deployment of the
wMel strain of
Wolbachia into local
Ae. aegypti populations across the Australian regional cities of Cairns and most smaller regional communities with a past history of dengue has resulted in the reduction of local dengue transmission across all deployment areas.
Collapse
Affiliation(s)
- Peter A Ryan
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Andrew P Turley
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Geoff Wilson
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Tim P Hurst
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,Biosecurity and Agricultural Services, Department of Jobs, Precincts and Regions, Victoria State Government, Atwood, Victoria, Australia
| | - Kate Retzki
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Jack Brown-Kenyon
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Lauren Hodgson
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Nichola Kenny
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Helen Cook
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Brian L Montgomery
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,Metro South Public Health Unit, Queensland Health, Coopers Plains, Queensland, Australia
| | - Christopher J Paton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
| | - Scott A Ritchie
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
| | - Ary A Hoffmann
- School of Biosciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Nicholas P Jewell
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, USA.,Centre for Statistical Methodology, London School of Hygiene and Tropical Medicine, London, UK
| | - Stephanie K Tanamas
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Katherine L Anders
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| | - Cameron P Simmons
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia.,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Scott L O'Neill
- Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
| |
Collapse
|
38
|
Reed EMX, Serr ME, Maurer AS, Burford Reiskind MO. Gridlock and beltways: the genetic context of urban invasions. Oecologia 2020; 192:615-628. [PMID: 32056021 DOI: 10.1007/s00442-020-04614-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 01/30/2020] [Indexed: 01/16/2023]
Abstract
The rapid expansion of urban land across the globe presents new and numerous opportunities for invasive species to spread and flourish. Ecologists historically rejected urban ecosystems as important environments for ecology and evolution research but are beginning to recognize the importance of these systems in shaping the biology of invasion. Urbanization can aid the introduction, establishment, and spread of invaders, and these processes have substantial consequences on native species and ecosystems. Therefore, it is valuable to understand how urban areas influence populations at all stages in the invasion process. Population genetic tools are essential to explore the driving forces of invasive species dispersal, connectivity, and adaptation within cities. In this review, we synthesize current research about the influence of urban landscapes on invasion genetics dynamics. We conclude that urban areas are not only points of entry for many invasive species, they also facilitate population establishment, are pools for genetic diversity, and provide corridors for further spread both within and out of cities. We recommend the continued use of genetic studies to inform invasive species management and to understand the underlying ecological and evolutionary processes governing successful invasion.
Collapse
Affiliation(s)
- E M X Reed
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA.
| | - M E Serr
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - A S Maurer
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - M O Burford Reiskind
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| |
Collapse
|
39
|
Yang Q, Umina PA, Rašić G, Bell N, Fang J, Lord A, Hoffmann AA. Origin of resistance to pyrethroids in the redlegged earth mite (Halotydeus destructor) in Australia: repeated local evolution and migration. PEST MANAGEMENT SCIENCE 2020; 76:509-519. [PMID: 31259466 DOI: 10.1002/ps.5538] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/17/2019] [Accepted: 06/26/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Halotydeus destructor is a major pest of crops and pastures across southern parts of Australia. This invasive mite has been chemically controlled for over 50 years, but resistance to synthetic pyrethroids and organophosphates is developing. Understanding processes behind the emerging resistance is important for effective management efforts. We undertook a ddRAD pool-sequencing approach to analyse genome-wide single nucleotide polymorphism variation in H. destructor population samples at two scales: local resistance across a set of fields, and regional resistance across their Australian range, along with toxicology bioassays to screen for pyrethroid resistance. RESULTS Spatial patterns of genomic variation and resistance at a local scale indicated that genetic similarity among samples was more closely correlated with distance along roads and fence-lines than with straight-line geographic distance. This pattern was particularly strong in resistant samples, which were also more related than susceptible samples, suggesting local spread of resistance within an area after it emerged. By contrast, regional data suggest resistance has emerged repeatedly within parts of Australia. Our de novo annotation of the H. destructor draft genome sequence and Bayesian analysis identified several candidate loci strongly associated with population-level resistance to pyrethroids, located in genomic regions that code for transmembrane transport and signalling proteins that have previously been linked to insecticide resistance in other arthropods. CONCLUSION Our findings highlight multiple independent evolutionary events leading to resistance in H. destructor, and demonstrate the utility and cost-effectiveness of a cross-population, genome-wide association study to reveal processes underlying adaptive evolution in a non-model invasive species. © 2019 Society of Chemical Industry.
Collapse
Affiliation(s)
- Qiong Yang
- Pest and Environmental Adaptation Research Group, School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Paul A Umina
- Pest and Environmental Adaptation Research Group, School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
- Sustainable Agriculture, cesar, Parkville, VIC, Australia
| | - Gordana Rašić
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Nicholas Bell
- Pest and Environmental Adaptation Research Group, School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| | - Jichao Fang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Alan Lord
- Department of Primary Industries and Regional Development, Government of Western Australia, South Perth, WA, Australia
| | - Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
40
|
Ross PA, Axford JK, Yang Q, Staunton KM, Ritchie SA, Richardson KM, Hoffmann AA. Heatwaves cause fluctuations in wMel Wolbachia densities and frequencies in Aedes aegypti. PLoS Negl Trop Dis 2020; 14:e0007958. [PMID: 31971938 PMCID: PMC6977724 DOI: 10.1371/journal.pntd.0007958] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 11/27/2019] [Indexed: 11/21/2022] Open
Abstract
Aedes aegypti mosquitoes infected with the wMel strain of Wolbachia are being released into natural mosquito populations in the tropics as a way of reducing dengue transmission. High temperatures adversely affect wMel, reducing Wolbachia density and cytoplasmic incompatibility in some larval habitats that experience large temperature fluctuations. We monitored the impact of a 43.6°C heatwave on the wMel infection in a natural population in Cairns, Australia, where wMel was first released in 2011 and has persisted at a high frequency. Wolbachia infection frequencies in the month following the heatwave were reduced to 83% in larvae sampled directly from field habitats and 88% in eggs collected from ovitraps, but recovered to be near 100% four months later. Effects of the heatwave on wMel appeared to be stage-specific and delayed, with reduced frequencies and densities in field-collected larvae and adults reared from ovitraps but higher frequencies in field-collected adults. Laboratory experiments showed that the effects of heatwaves on cytoplasmic incompatibility and density are life stage-specific, with first instar larvae being the most vulnerable to temperature effects. Our results indicate that heatwaves in wMel-infected populations will have only temporary effects on Wolbachia frequencies and density once the infection has established in the population. Our results are relevant to ongoing releases of wMel-infected Ae. aegypti in several tropical countries. Mosquitoes infected with Wolbachia bacteria are being released in the tropics to replace natural mosquito populations and suppress dengue transmission. Aedes aegypti mosquitoes with the wMel strain of Wolbachia were first released in Cairns, Australia in 2011 and releases were then expanded to the entire city and surrounding suburbs. Today, wMel is at a high frequency within the Ae. aegypti population and local dengue transmission in Cairns has declined to nearly zero. Wolbachia infections are vulnerable to high temperatures and the ability of wMel to persist in populations and block dengue may be constrained by climate. Cairns experienced a record heatwave of 43.6°C in November 2018 and we wanted to see whether this affected the wMel-infected Ae. aegypti population. Our results show that the frequency and density of wMel declined after the heatwave, with effects depending on the mosquito life stage tested. When we monitored the population again in April 2019, wMel had returned to a high frequency. We suggest that heatwaves of the magnitude experienced in Cairns will not have long-term impacts on the wMel infection but may affect invasion during releases or interfere with dengue blockage. Heatwaves may affect interventions with wMel-infected Ae. aegypti that are being deployed in several countries. Effects may depend on the proportion of larval habitats that are protected from extreme temperature fluctuations.
Collapse
Affiliation(s)
- Perran A. Ross
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Jason K. Axford
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Qiong Yang
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Kyran M. Staunton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, Queensland, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Queensland, Australia
| | - Scott A. Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, Queensland, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Queensland, Australia
| | - Kelly M. Richardson
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Ary A. Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
41
|
Lau MJ, Endersby-Harshman NM, Axford JK, Ritchie SA, Hoffmann AA, Ross PA. Measuring the Host-Seeking Ability of Aedes aegypti Destined for Field Release. Am J Trop Med Hyg 2020; 102:223-231. [PMID: 31769394 PMCID: PMC6947783 DOI: 10.4269/ajtmh.19-0510] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/04/2019] [Indexed: 12/24/2022] Open
Abstract
Host seeking is an essential process in mosquito reproduction. Field releases of modified mosquitoes for population replacement rely on successful host seeking by female mosquitoes, but host-seeking ability is rarely tested in a realistic context. We tested the host-seeking ability of female Aedes aegypti mosquitoes using a semi-field system. Females with different Wolbachia infection types (wMel-, wAlbB-infected, and uninfected) or from different origins (laboratory and field) were released at one end of a semi-field cage and recaptured as they landed on human experimenters 15 m away. Mosquitoes from each population were then identified with molecular tools or through minimal dusting with fluorescent powder. Wolbachia-infected and uninfected populations had similar average durations to landing and overall recapture proportions, as did laboratory and field-sourced Ae. aegypti. These results indicate that the host-seeking ability of mosquitoes is not negatively affected by Wolbachia infection or long-term laboratory maintenance. This method provides an approach to study the host-seeking ability of mosquitoes in a realistic setting, which will be useful when evaluating strains of mosquitoes that are planned for releases into the field to suppress arbovirus transmission.
Collapse
Affiliation(s)
- Meng-Jia Lau
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Australia
| | - Nancy M. Endersby-Harshman
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Australia
| | - Jason K. Axford
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Australia
| | - Scott A. Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Australia
| | - Ary A. Hoffmann
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Australia
| | - Perran A. Ross
- Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Australia
| |
Collapse
|
42
|
Marcantonio M, Reyes T, Barker CM. Quantifying
Aedes aegypti
dispersal in space and time: a modeling approach. Ecosphere 2019. [DOI: 10.1002/ecs2.2977] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- Matteo Marcantonio
- Department of Pathology, Microbiology, and Immunology School of Veterinary Medicine University of California Davis California 95616 USA
| | - Trinidad Reyes
- Madera Mosquito & Vector Control Madera California 93637 USA
| | - Christopher M. Barker
- Department of Pathology, Microbiology, and Immunology School of Veterinary Medicine University of California Davis California 95616 USA
| |
Collapse
|
43
|
McCue MD, Javal M, Clusella‐Trullas S, Le Roux JJ, Jackson MC, Ellis AG, Richardson DM, Valentine AJ, Terblanche JS. Using stable isotope analysis to answer fundamental questions in invasion ecology: Progress and prospects. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13327] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Marshall D. McCue
- Sable Systems International Las Vegas NV USA
- Department of Conservation Ecology and Entomology Centre for Invasion Biology Stellenbosch University Stellenbosch South Africa
| | - Marion Javal
- Department of Conservation Ecology and Entomology Centre for Invasion Biology Stellenbosch University Stellenbosch South Africa
| | - Susana Clusella‐Trullas
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - Johannes J. Le Roux
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
- Department of Biological Sciences Macquarie University NSW Australia
| | - Michelle C. Jackson
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
- Department of Life Sciences Imperial College London Ascot UK
- Department of Zoology Oxford University Oxford UK
| | - Allan G. Ellis
- Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - David M. Richardson
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - Alex J. Valentine
- Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - John S. Terblanche
- Department of Conservation Ecology and Entomology Centre for Invasion Biology Stellenbosch University Stellenbosch South Africa
| |
Collapse
|
44
|
Sánchez C. HM, Wu SL, Bennett JB, Marshall JM. MGD
riv
E: A modular simulation framework for the spread of gene drives through spatially explicit mosquito populations. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13318] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Héctor M. Sánchez C.
- Division of Epidemiology and Biostatistics School of Public Health University of California Berkeley CA USA
| | - Sean L. Wu
- Division of Epidemiology and Biostatistics School of Public Health University of California Berkeley CA USA
| | - Jared B. Bennett
- Biophysics Graduate Group Division of Biological Sciences College of Letters and Science University of California Berkeley CA USA
| | - John M. Marshall
- Division of Epidemiology and Biostatistics School of Public Health University of California Berkeley CA USA
- Innovative Genomics Institute Berkeley CA USA
| |
Collapse
|
45
|
O'Neill SL, Ryan PA, Turley AP, Wilson G, Retzki K, Iturbe-Ormaetxe I, Dong Y, Kenny N, Paton CJ, Ritchie SA, Brown-Kenyon J, Stanford D, Wittmeier N, Jewell NP, Tanamas SK, Anders KL, Simmons CP. Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses. Gates Open Res 2019; 2:36. [PMID: 30596205 DOI: 10.12688/gatesopenres.12844.2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2018] [Indexed: 11/20/2022] Open
Abstract
Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km 2 in four stages over 28 months with full community support. A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km 2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission.
Collapse
Affiliation(s)
- Scott L O'Neill
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Peter A Ryan
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Andrew P Turley
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Geoff Wilson
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Kate Retzki
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | | | - Yi Dong
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Nichola Kenny
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Christopher J Paton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, 4878, Australia
| | - Scott A Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, 4878, Australia
| | - Jack Brown-Kenyon
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Darren Stanford
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Natalie Wittmeier
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Nicholas P Jewell
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, USA.,Centre for Statistical Methodology, London School of Hygiene and Tropical Medicine, London, UK.,Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Stephanie K Tanamas
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Katherine L Anders
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Cameron P Simmons
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| |
Collapse
|
46
|
Guagliardo SAJ, Lee Y, Pierce AA, Wong J, Chu YY, Morrison AC, Astete H, Brosi B, Vazquez-Prokopec G, Scott TW, Kitron U, Stoddard ST. The genetic structure of Aedes aegypti populations is driven by boat traffic in the Peruvian Amazon. PLoS Negl Trop Dis 2019; 13:e0007552. [PMID: 31532762 PMCID: PMC6750575 DOI: 10.1371/journal.pntd.0007552] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 06/14/2019] [Indexed: 11/19/2022] Open
Abstract
In the Americas, as in much of the rest of the world, the dengue virus vector Aedes aegypti is found in close association with human habitations, often leading to high population densities of mosquitoes in urban settings. In the Peruvian Amazon, this vector has been expanding to rural communities over the last 10–15 years, but to date, the population genetic structure of Ae. aegypti in this region has not been characterized. To investigate the relationship between Ae. aegypti gene flow and human transportation networks, we characterized mosquito population structure using a panel of 8 microsatellite markers and linked results to various potential mechanisms for long-distance dispersal. Adult and immature Ae. aegypti (>20 individuals per site) were collected from Iquitos city and from six neighboring riverine communities, i.e., Nauta, Indiana, Mazan, Barrio Florida, Tamshiaco, and Aucayo. FST statistics indicate significant, but low to moderate differentiation for the majority of study site pairs. Population structure of Ae. aegypti is not correlated with the geographic distance between towns, suggesting that human transportation networks provide a reasonable explanation for the high levels of population mixing. Our results indicate that Ae. aegypti gene flow among sub-populations is greatest between locations with heavy boat traffic, such as Iquitos-Tamshiaco and Iquitos-Indiana-Mazan, and lowest between locations with little or no boat/road traffic between them such as Barrio Florida-Iquitos. Bayesian clustering analysis showed ancestral admixture among three genetic clusters; no single cluster was exclusive to any site. Our results are consistent with the hypothesis that human transportation networks, particularly riverways, are responsible for the geographic spread of Ae. aegypti in the Peruvian Amazon. Our findings are applicable to other regions of the world characterized by networks of urban islands connected by fluvial transport routes. Aedes aegypti, the primary mosquito vector of dengue, is a highly invasive species that is expanding from urban to peri-urban and rural areas throughout the Americas. Previous studies documented the role of human transportation networks in Ae. aegypti long-distance dispersal. We examined whether patterns of Ae. aegypti gene flow are consistent with this observation. Mosquitoes were collected from seven locations, including the large Amazonian city of Iquitos, Peru, and six neighboring rural communities, and their genetic relatedness was compared using 8 microsatellite markers. Our results showed ample gene flow among mosquito populations in this region, with greater gene flow observed among sites that are connected by fluvial routes. These findings are consistent with the hypothesis that human transportation networks, especially via boats, are a primary contributing factor to the spread of Ae. aegypti in the Peruvian Amazon.
Collapse
Affiliation(s)
- Sarah Anne J. Guagliardo
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
| | - Yoosook Lee
- Department of Pathology, Microbiology and Immunology School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Amanda A. Pierce
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
| | - Jacklyn Wong
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| | - Yui Yin Chu
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| | - Amy C. Morrison
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| | - Helvio Astete
- Department of Virology and Emerging Infections, Naval Medical Research Unit No.6 (NAMRU-6) Iquitos Laboratory, Iquitos, Loreto, Peru
| | - Berry Brosi
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Gonzalo Vazquez-Prokopec
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Thomas W. Scott
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| | - Uriel Kitron
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Steven T. Stoddard
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| |
Collapse
|
47
|
Abstract
Wolbachia is an endosymbiotic Alphaproteobacteria that can suppress insect-borne diseases through decreasing host virus transmission (population replacement) or through decreasing host population density (population suppression). We contrast natural Wolbachia infections in insect populations with Wolbachia transinfections in mosquitoes to gain insights into factors potentially affecting the long-term success of Wolbachia releases. Natural Wolbachia infections can spread rapidly, whereas the slow spread of transinfections is governed by deleterious effects on host fitness and demographic factors. Cytoplasmic incompatibility (CI) generated by Wolbachia is central to both population replacement and suppression programs, but CI in nature can be variable and evolve, as can Wolbachia fitness effects and virus blocking. Wolbachia spread is also influenced by environmental factors that decrease Wolbachia titer and reduce maternal Wolbachia transmission frequency. More information is needed on the interactions between Wolbachia and host nuclear/mitochondrial genomes, the interaction between invasion success and local ecological factors, and the long-term stability of Wolbachia-mediated virus blocking.
Collapse
Affiliation(s)
- Perran A Ross
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, The University of Melbourne, Victoria 3052, Australia
| | - Michael Turelli
- Department of Evolution and Ecology, University of California, Davis, California 95616, USA;
| | - Ary A Hoffmann
- Pest and Environmental Adaptation Research Group, School of BioSciences, Bio21 Institute, The University of Melbourne, Victoria 3052, Australia
| |
Collapse
|
48
|
Bennett KL, Gómez-Martínez C, Chin Y, Saltonstall K, McMillan WO, Rovira JR, Loaiza JR. Dynamics and diversity of bacteria associated with the disease vectors Aedes aegypti and Aedes albopictus. Sci Rep 2019; 9:12160. [PMID: 31434963 PMCID: PMC6704126 DOI: 10.1038/s41598-019-48414-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/17/2019] [Indexed: 01/02/2023] Open
Abstract
Aedes aegypti and Aedes albopictus develop in the same aquatic sites where they encounter microorganisms that influence their life history and capacity to transmit human arboviruses. Some bacteria such as Wolbachia are currently being considered for the control of Dengue, Chikungunya and Zika. Yet little is known about the dynamics and diversity of Aedes-associated bacteria, including larval habitat features that shape their tempo-spatial distribution. We applied large-scale 16S rRNA amplicon sequencing to 960 adults and larvae of both Ae. aegypti and Ae. albopictus mosquitoes from 59 sampling sites widely distributed across nine provinces of Panama. We find both species share a limited, yet highly variable core microbiota, reflecting high stochasticity within their oviposition habitats. Despite sharing a large proportion of microbiota, Ae. aegypti harbours higher bacterial diversity than Ae. albopictus, primarily due to rarer bacterial groups at the larval stage. We find significant differences between the bacterial communities of larvae and adult mosquitoes, and among samples from metal and ceramic containers. However, we find little support for geography, water temperature and pH as predictors of bacterial associates. We report a low incidence of natural Wolbachia infection for both Aedes and its geographical distribution. This baseline information provides a foundation for studies on the functions and interactions of Aedes-associated bacteria with consequences for bio-control within Panama.
Collapse
Affiliation(s)
- Kelly L Bennett
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama.
| | - Carmelo Gómez-Martínez
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
- Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Ciudad del Saber, Apartado, 0843-01103, Ciudad de Panamá, Panama
| | - Yamileth Chin
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
| | - Kristin Saltonstall
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
| | - W Owen McMillan
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
| | - Jose R Rovira
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
- Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Ciudad del Saber, Apartado, 0843-01103, Ciudad de Panamá, Panama
| | - Jose R Loaiza
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama.
- Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Ciudad del Saber, Apartado, 0843-01103, Ciudad de Panamá, Panama.
- Programa Centroamericano de Maestría en Entomología, Universidad de Panamá, Ciudad de Panamá, Panama.
| |
Collapse
|
49
|
O'Neill SL, Ryan PA, Turley AP, Wilson G, Retzki K, Iturbe-Ormaetxe I, Dong Y, Kenny N, Paton CJ, Ritchie SA, Brown-Kenyon J, Stanford D, Wittmeier N, Jewell NP, Tanamas SK, Anders KL, Simmons CP. Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses. Gates Open Res 2019. [PMID: 30596205 DOI: 10.12688/gatesopenres.12844.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km 2 in four stages over 28 months with full community support. A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km 2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission.
Collapse
Affiliation(s)
- Scott L O'Neill
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Peter A Ryan
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Andrew P Turley
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Geoff Wilson
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Kate Retzki
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | | | - Yi Dong
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Nichola Kenny
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Christopher J Paton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, 4878, Australia
| | - Scott A Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, 4878, Australia
| | - Jack Brown-Kenyon
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Darren Stanford
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Natalie Wittmeier
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Nicholas P Jewell
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, USA.,Centre for Statistical Methodology, London School of Hygiene and Tropical Medicine, London, UK.,Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Stephanie K Tanamas
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Katherine L Anders
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Cameron P Simmons
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| |
Collapse
|
50
|
O'Neill SL, Ryan PA, Turley AP, Wilson G, Retzki K, Iturbe-Ormaetxe I, Dong Y, Kenny N, Paton CJ, Ritchie SA, Brown-Kenyon J, Stanford D, Wittmeier N, Jewell NP, Tanamas SK, Anders KL, Simmons CP. Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses. Gates Open Res 2019; 2:36. [PMID: 30596205 PMCID: PMC6305154 DOI: 10.12688/gatesopenres.12844.3] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2019] [Indexed: 11/21/2022] Open
Abstract
Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of
Wolbachia in the northern Australian city of Townsville. Methods: The
wMel strain of
Wolbachia was backcrossed into a local
Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of
Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results:
Wolbachia was successfully established into local
Ae. aegypti mosquitoes across 66 km
2 in four stages over 28 months with full community support. A feature of the program was the development of a scaled approach to community engagement.
Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after
Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of
Wolbachia into
Ae. aegypti populations can be readily scaled to areas of ~60km
2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission
Collapse
Affiliation(s)
- Scott L O'Neill
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Peter A Ryan
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Andrew P Turley
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Geoff Wilson
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Kate Retzki
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | | | - Yi Dong
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Nichola Kenny
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Christopher J Paton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, 4878, Australia
| | - Scott A Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, 4878, Australia
| | - Jack Brown-Kenyon
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Darren Stanford
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Natalie Wittmeier
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Nicholas P Jewell
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, USA.,Centre for Statistical Methodology, London School of Hygiene and Tropical Medicine, London, UK.,Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Stephanie K Tanamas
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Katherine L Anders
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| | - Cameron P Simmons
- Institute of Vector-Borne Disease, Monash University, Clayton, VIC, 3800, Australia
| |
Collapse
|