1
|
Lau CL, Mills DJ, Mayfield H, Gyawali N, Johnson BJ, Lu H, Allel K, Britton PN, Ling W, Moghaddam T, Furuya-Kanamori L. A decision support tool for risk-benefit analysis of Japanese encephalitis vaccine in travellers. J Travel Med 2023; 30:taad113. [PMID: 37602668 DOI: 10.1093/jtm/taad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023]
Abstract
BACKGROUND During pre-travel consultations, clinicians and travellers face the challenge of weighing the risks verus benefits of Japanese encephalitis (JE) vaccination due to the high cost of the vaccine, low incidence in travellers (~1 in 1 million), but potentially severe consequences (~30% case-fatality rate). Personalised JE risk assessment based on the travellers' demographics and travel itinerary is challenging using standard risk matrices. We developed an interactive digital tool to estimate risks of JE infection and severe health outcomes under different scenarios to facilitate shared decision-making between clinicians and travellers. METHODS A Bayesian network (conditional probability) model risk-benefit analysis of JE vaccine in travellers was developed. The model considers travellers' characteristics (age, sex, co-morbidities), itinerary (destination, departure date, duration, setting of planned activities) and vaccination status to estimate the risks of JE infection, the development of symptomatic disease (meningitis, encephalitis), clinical outcomes (hospital admission, chronic neurological complications, death) and adverse events following immunization. RESULTS In low-risk travellers (e.g. to urban areas for <1 month), the risk of developing JE and dying is low (<1 per million) irrespective of the destination; thus, the potential impact of JE vaccination in reducing the risk of clinical outcomes is limited. In high-risk travellers (e.g. to rural areas in high JE incidence destinations for >2 months), the risk of developing symptomatic disease and mortality is estimated at 9.5 and 1.4 per million, respectively. JE vaccination in this group would significantly reduce the risk of symptomatic disease and mortality (by ~80%) to 1.9 and 0.3 per million, respectively. CONCLUSION The JE tool may assist decision-making by travellers and clinicians and could increase JE vaccine uptake. The tool will be updated as additional evidence becomes available. Future work needs to evaluate the usability of the tool. The interactive, scenario-based, personalised JE vaccine risk-benefit tool is freely available on www.VaxiCal.com.
Collapse
Affiliation(s)
- Colleen L Lau
- School of Public Health, Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
- Dr Deb The Travel Doctor, Travel Medicine Alliance, Brisbane, QLD, Australia
| | - Deborah J Mills
- Dr Deb The Travel Doctor, Travel Medicine Alliance, Brisbane, QLD, Australia
| | - Helen Mayfield
- School of Public Health, Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
| | - Narayan Gyawali
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Brian J Johnson
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Hongen Lu
- School of Public Health, Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
| | - Kasim Allel
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Philip N Britton
- Department of Infectious Diseases and Microbiology, Children's Hospital Westmead, Westmead, NSW, Australia
- Child and Adolescent Health and Sydney ID, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Weiping Ling
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
| | - Tina Moghaddam
- School of Information Technology and Electrical Engineering, Faculty of Science, The University of Queensland, St Lucia, QLD, Australia
| | - Luis Furuya-Kanamori
- School of Public Health, Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
| |
Collapse
|
2
|
Xia Q, Yang Y, Zhang Y, Zhou L, Ma X, Xiao C, Zhang J, Li Z, Liu K, Li B, Shao D, Qiu Y, Wei J, Ma Z. Shift in dominant genotypes of Japanese encephalitis virus and its impact on current vaccination strategies. Front Microbiol 2023; 14:1302101. [PMID: 38045034 PMCID: PMC10690641 DOI: 10.3389/fmicb.2023.1302101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/01/2023] [Indexed: 12/05/2023] Open
Abstract
Japanese encephalitis (JE) is a zoonotic ailment from the Japanese encephalitis virus (JEV). JEV belongs to the flavivirus genus and is categorized into a solitary serotype consisting of five genetically diverse genotypes (I, II, III, IV, and V). The JEV genotype III (GIII) was the prevailing strain responsible for multiple outbreaks in countries endemic to JEV until 1990. In recent years, significant improvements have occurred in the epidemiology of JE, encompassing the geographical expansion of the epidemic zone and the displacement of prevailing genotypes. The dominant genotype of the JEV has undergone a progressive shift from GIII to GI due to variations in its adaptability within avian populations. From 2021 to 2022, Australia encountered an epidemic of viral encephalitis resulting from infection with the GIV JEV pathogen. The current human viral encephalitis caused by GIV JEV is the initial outbreak since its initial discovery in Indonesia during the late 1970s. Furthermore, following a time frame of 50 years, the detection and isolation of GV JEV have been reported in Culex mosquitoes across China and South Korea. Evidence suggests that the prevalence of GIV and GV JEV epidemic regions may be on the rise, posing a significant threat to public safety and the sustainable growth of animal husbandry. The global approach to preventing and managing JE predominantly revolves around utilizing the GIII strain vaccine for vaccination purposes. Nevertheless, research has demonstrated that the antibodies generated by the GIII strain vaccine exhibit limited capacity to neutralize the GI and GV strains. Consequently, these antibodies cannot protect against JEV challenge caused by animal GI and GV strains. The limited cross-protective and neutralizing effects observed between various genotypes may be attributed to the low homology of the E protein with other genotypes. In addition, due to the GIV JEV outbreak in Australia, further experiments are needed to evaluate the protective efficiency of the current GIII based JE vaccine against GIV JEV. The alteration of the prevailing genotype of JEV and the subsequent enlargement of the geographical extent of the epidemic have presented novel obstacles in JE prevention and control. This paper examines the emerging features of the JE epidemic in recent years and the associated problems concerning prevention and control.
Collapse
Affiliation(s)
- Qiqi Xia
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yang Yang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yan Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Lujia Zhou
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xiaochun Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Changguang Xiao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Junjie Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zongjie Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Donghua Shao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| |
Collapse
|
3
|
Morris RS, Bingham PC. Japanese encephalitis virus: epidemiology and risk-based surveillance approaches for New Zealand. N Z Vet J 2023; 71:283-294. [PMID: 37621178 DOI: 10.1080/00480169.2023.2248054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/06/2023] [Indexed: 08/26/2023]
Abstract
The introduction and subsequent rapid spread of Japanese encephalitis virus genotype IV across all Australian mainland states and the Northern Territory since late 2021 has increased the risk of an incursion of this mosquito-transmitted zoonotic virus disease into New Zealand, with serious implications for both animal and human health. The potential modes of entry are through introduction of infected mosquitoes as hitchhikers on ships or aircraft, windborne transfer of mosquitoes, or arrival of infected reservoir bird species. A competent vector mosquito, Culex quinquefasciatus, is endemic in New Zealand and other mosquito species may also become involved. If infection becomes established in New Zealand, the scale of transmission may be considerably less than has occurred in Australia because climatic and epidemiological factors are not so favourable. Early evidence of an incursion could come from detection of clinical disease in horses or pigs, or from human cases. Targeted surveillance to confirm or refute indications of an incursion could be undertaken by antibody detection in a number of species. Dogs have been shown to be a particularly valuable sentinel species due to their cohabitation with people and high seroconversion rate. Other novel methods of surveillance could include reverse transcriptase PCR (RT-PCR) on oronasal secretions of pigs. Should evidence of the disease be detected, prompt action would be required to vaccinate at-risk human populations and clarify the epidemiological situation with respect to mammalian hosts and mosquito vector species, including whether a new mosquito species had arrived in the country.Abbreviations: AHL: Animal Health Laboratory; JE: Japanese encephalitis disease; JEV: Japanese encephalitis virus; RT-PCR: Reverse transcriptase PCR.
Collapse
Affiliation(s)
- R S Morris
- MorVet Ltd., Masterton, New Zealand
- Tāwharau Ora - School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P C Bingham
- Diagnostic and Surveillance Services Directorate, Operations Branch, Ministry for Primary Industries, Wallaceville, New Zealand
| |
Collapse
|
4
|
Walsh MG, Webb C, Brookes V. An evaluation of the landscape structure and La Niña climatic anomalies associated with Japanese encephalitis virus outbreaks reported in Australian piggeries in 2022. One Health 2023; 16:100566. [PMID: 37363260 PMCID: PMC10285696 DOI: 10.1016/j.onehlt.2023.100566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 05/12/2023] [Accepted: 05/13/2023] [Indexed: 06/28/2023] Open
Abstract
The widespread activity of Japanese encephalitis virus (JEV) reported in previously unaffected regions of eastern and southern Australia in 2022 represents the most significant local arbovirus emergency in almost 50 years. Japanese encephalitis virus is transmitted by mosquitoes and maintained in wild ardeid birds and amplified in pigs, the latter of which suffer significant reproductive losses as a result of infection. The landscape epidemiology of JEV in mainland Australia is almost entirely unknown, particularly in the eastern and southern parts of the country where the virus has not been previously documented. Although other areas with endemic JEV circulation in the Indo-Pacific region have demonstrated the importance of wild waterbird-livestock interface in agricultural-wetland mosaics, no such investigation has yet determined the composition and configuration of pathogenic landscapes for Australia. Moreover, the recent emergence in Australia has followed substantial precipitation and temperature anomalies associated with the La Niña phase of the El Niño Southern Oscillation. This study investigated the landscape epidemiology of JEV outbreaks in Australian piggeries reported between January and April of 2022 to determine the influence of ardeid habitat suitability, hydrogeography, hydrology, land cover and La Niña-associated climate anomalies. Outbreaks of JEV in domestic pigs were associated with intermediate ardeid species richness, cultivated land and grassland fragmentation, waterway proximity, temporary wetlands, and hydrological flow accumulation. This study has identified the composition and configuration of landscape features that were associated with piggery outbreaks reported in 2022 in Australia. Although preliminary, these findings can inform actionable strategies for the development of new One Health JEV surveillance specific to the needs of Australia.
Collapse
Affiliation(s)
- Michael G. Walsh
- The University of Sydney, Faculty of Medicine and Health, Sydney School of Public Health, Camperdown, New South Wales, Australia
- The University of Sydney, Faculty of Medicine and Health, Sydney Infectious Diseases Institute, Westmead, New South Wales, Australia
- One Health Centre, The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
- The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Cameron Webb
- The University of Sydney, Faculty of Medicine and Health, Sydney Infectious Diseases Institute, Westmead, New South Wales, Australia
- Department of Medical Entomology, NSW Health Pathology, Westmead Hospital, Westmead, New South Wales, Australia
| | - Victoria Brookes
- The University of Sydney, Faculty of Medicine and Health, Sydney Infectious Diseases Institute, Westmead, New South Wales, Australia
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Camperdown, New South Wales, Australia
| |
Collapse
|
5
|
Amorim JA, de Oliveira TMP, de Sá ILR, da Silva TP, Sallum MAM. DNA Barcodes of Mansonia ( Mansonia) Blanchard, 1901 (Diptera, Culicidae). Genes (Basel) 2023; 14:1127. [PMID: 37372310 DOI: 10.3390/genes14061127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/17/2023] [Accepted: 05/21/2023] [Indexed: 06/29/2023] Open
Abstract
Females of the genus Mansonia feed on the blood of humans, livestock, and other vertebrates to develop their eggs. The females' biting behavior may cause severe disturbance to blood hosts, with a negative impact on public health and economics. Certain species have been identified as potential or effective disease vectors. The accurate species identification of field-collected specimens is of paramount importance for the success of monitoring and control strategies. Mansonia (Mansonia) morphological species boundaries are blurred by patterns of intraspecific heteromorphism and interspecific isomorphism. DNA barcodes can help to solve taxonomic controversies, especially if combined with other molecular tools. We used cytochrome c oxidase subunit I (COI) gene 5' end (DNA barcode) sequences to identify 327 field-collected specimens of Mansonia (Mansonia) spp. The sampling encompassed males and females collected from three Brazilian regions and previously assigned to species based on their morphological characteristics. Eleven GenBank and BOLD sequences were added to the DNA barcode analyses. Initial morphospecies assignments were mostly corroborated by the results of five clustering methods based on Kimura two-parameter distance and maximum likelihood phylogeny. Five to eight molecular operational taxonomic units may represent taxonomically unknown species. The first DNA barcode records for Mansonia fonsecai, Mansonia iguassuensis, and Mansonia pseudotitillans are presented.
Collapse
Affiliation(s)
- Jandui Almeida Amorim
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo 01246-904, SP, Brazil
- Departamento de Ciências e Matemática, Instituto Federal de Educação, Ciência e Tecnologia de São Paulo, São Paulo 01109-010, SP, Brazil
| | | | - Ivy Luizi Rodrigues de Sá
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo 01246-904, SP, Brazil
| | - Taires Peniche da Silva
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá, Macapá 68903-419, AP, Brazil
| | - Maria Anice Mureb Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo 01246-904, SP, Brazil
| |
Collapse
|
6
|
Rakotonirina A, Maquart PO, Flamand C, Sokha C, Boyer S. Mosquito diversity (Diptera: Culicidae) and medical importance in four Cambodian forests. Parasit Vectors 2023; 16:110. [PMID: 36945055 PMCID: PMC10029166 DOI: 10.1186/s13071-023-05729-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/06/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND A total of 290 mosquito species are recorded in Cambodia among which 43 are known vectors of pathogens. As Cambodia is heavily affected by deforestation, a potential change in the dynamic of vector-borne diseases (VDBs) could occur through alteration of the diversity and density of sylvatic vector mosquitoes and induce an increase in their interactions with humans. Understanding mosquito diversity is therefore critical, providing valuable data for risk assessments concerning the (re)emergence of local VBDs. Consequently, this study mainly aimed to understand the spatial and temporal distribution of sylvatic mosquito populations of Cambodia by determining which factors impact on their relative abundance and presence. METHODS A study was conducted in 12 sites from four forests in Cambodia. All mosquitoes, collected during the dry and rainy seasons, were morphologically identified. The diversity and relative density of mosquito species in each site were calculated along with the influence of meteorological and geographical factors using a quasi-Poisson generalized linear model. RESULTS A total of 9392 mosquitoes were collected belonging to 13 genera and 85 species. The most represented genera were Culex, accounting for 46% of collected mosquitoes, and Aedes (42%). Besides being the most abundant species, Culex pseudovishnui and Aedes albopictus, which are known vectors of numerous arboviruses, were present in all sites during both dry and rainy seasons. The presence of mosquito species reported to be zoo-anthropophilic feeders was also observed in both forested and urban areas. Finally, this study demonstrated that altitude, temperature and precipitation impacted the abundance of mosquitoes but also influenced species community composition. CONCLUSION The results indicate an important diversity of mosquitoes in the four forests and an influence of meteorological and geographical factors on their community. Additionally, this work highlights in parallel the abundance of species considered to be of medical importance and therefore underlines the high risk of pathogen emergence/re-emergence in the region.
Collapse
Affiliation(s)
- Antsa Rakotonirina
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 983, Phnom Penh, Cambodia.
| | - Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 983, Phnom Penh, Cambodia
| | - Claude Flamand
- Epidemiology Unit, Institut Pasteur du Cambodge, 983, Phnom Penh, Cambodia
- Mathematical Modeling of Infectious Diseases Unit, Institut Pasteur, Université Paris Cité, UMR2000, CNRS, Paris, France
| | - Chea Sokha
- Wildlife Health Program, Wildlife Conservation Society, Phnom Penh, Cambodia
| | - Sébastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 983, Phnom Penh, Cambodia
- Ecology & Emergence of Arthropod-Borne Pathogens Unit, Department of Global Health, Institut Pasteur, CNRS UMR2000, Paris, France
| |
Collapse
|
7
|
Mote AB, Mehta D, Kumar MS, Gupta M, Hussain M, Patel SM, Gandham RK, Dhanze H. Genotypic characterization of Japanese encephalitis virus circulating in swine population of India: Genotype-III still in dominance. Virus Genes 2023; 59:67-78. [PMID: 36357764 DOI: 10.1007/s11262-022-01953-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/29/2022] [Indexed: 11/12/2022]
Abstract
Swine is considered as a suitable sentinel to predict Japanese encephalitis virus (JEV) outbreaks in humans. The present study was undertaken to determine the circulating genotypes of JEV in swine population of India. A total of 702 swine serum samples from four states of western, northern, northern-temperate, and north-eastern zones of India were screened by real-time RT-PCR targeting envelope gene of JEV, which showed positivity of 35.33%. The viral copy number ranged from 3 copies to 6.3 × 104 copies/reaction. Subsequently, the capsid/prM structural gene region of JEV positive samples was amplified by nested RT-PCR, sequenced, and genetically characterized. The phylogenetic analysis of the partial sequences of the capsid gene of 42 JEV positive samples showed that they all belonged to genotype-III (G-III) of JEV. Notably, JEV positive swine samples showed high nucleotide identity with human isolates from China and Nepal which explains the probable spillover of infection between neighboring countries probably by migratory birds. The novel mutations were observed in JEV positive sample B8 at C54 position (Phe → Ser), and JEV positive sample K50 at C62 (Thr → Ala) and C65 (Leu → Pro) positions which were absent from other JEV isolates reported till now. The mutation at the C66 position (Leu → Ser) observed in live attenuated vaccine SA14-14-2 strain was not found in JEV positive samples of our study. The detection of the G-III JE virus from climatically diverse states of India reinforces the need to continue the ongoing human vaccination program in India by extending vaccine coverage in temperate states.
Collapse
Affiliation(s)
- Akash Balasaheb Mote
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Deepa Mehta
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - M Suman Kumar
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Megha Gupta
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Mir Hussain
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Sagar M Patel
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Ravi Kumar Gandham
- Division of Animal Biotechnology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Himani Dhanze
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India.
| |
Collapse
|
8
|
Japanese Encephalitis Virus: The Emergence of Genotype IV in Australia and Its Potential Endemicity. Viruses 2022; 14:v14112480. [PMID: 36366578 PMCID: PMC9698845 DOI: 10.3390/v14112480] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
A fatal case of Japanese encephalitis (JE) occurred in northern Australia in early 2021. Sequence studies showed that the virus belonged to genotype IV (GIV), a genotype previously believed to be restricted to the Indonesian archipelago. This was the first locally acquired case of Japanese encephalitis virus (JEV) GIV to occur outside Indonesia, and the second confirmed fatal human case caused by a GIV virus. A closely related GIV JEV strain subsequently caused a widespread outbreak in eastern Australia in 2022 that was first detected by fetal death and abnormalities in commercial piggeries. Forty-two human cases also occurred with seven fatalities. This has been the first major outbreak of JEV in mainland Australia, and geographically the largest virgin soil outbreak recorded for JEV. This outbreak provides an opportunity to discuss and document the factors involved in the virus' spread and its ecology in a novel ecological milieu in which other flaviviruses, including members of the JE serological complex, also occur. The probable vertebrate hosts and mosquito vectors are discussed with respect to virus spread and its possible endemicity in Australia, and the need to develop a One Health approach to develop improved surveillance methods to rapidly detect future outbreak activity across a large geographical area containing a sparse human population. Understanding the spread of JEV in a novel ecological environment is relevant to the possible threat that JEV may pose in the future to other receptive geographic areas, such as the west coast of the United States, southern Europe or Africa.
Collapse
|
9
|
Raban R, Gendron WAC, Akbari OS. A perspective on the expansion of the genetic technologies to support the control of neglected vector-borne diseases and conservation. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.999273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Genetic-based technologies are emerging as promising tools to support vector population control. Vectors of human malaria and dengue have been the main focus of these development efforts, but in recent years these technologies have become more flexible and adaptable and may therefore have more wide-ranging applications. Culex quinquefasciatus, for example, is the primary vector of avian malaria in Hawaii and other tropical islands. Avian malaria has led to the extinction of numerous native bird species and many native bird species continue to be threatened as climate change is expanding the range of this mosquito. Genetic-based technologies would be ideal to support avian malaria control as they would offer alternatives to interventions that are difficult to implement in natural areas, such as larval source reduction, and limit the need for chemical insecticides, which can harm beneficial species in these natural areas. This mosquito is also an important vector of human diseases, such as West Nile and Saint Louis encephalitis viruses, so genetic-based control efforts for this species could also have a direct impact on human health. This commentary will discuss the current state of development and future needs for genetic-based technologies in lesser studied, but important disease vectors, such as C. quinquefasciatus, and make comparisons to technologies available in more studied vectors. While most current genetic control focuses on human disease, we will address the impact that these technologies could have on both disease and conservation focused vector control efforts and what is needed to prepare these technologies for evaluation in the field. The versatility of genetic-based technologies may result in the development of many important tools to control a variety of vectors that impact human, animal, and ecosystem health.
Collapse
|
10
|
Suresh KP, Nayak A, Dhanze H, Bhavya AP, Shivamallu C, Achar RR, Silina E, Stupin V, Barman NN, Kumar SK, Syed A, Kollur SP, Shreevatsa B, Patil SS. Prevalence of Japanese encephalitis (JE) virus in mosquitoes and animals of the Asian continent: A systematic review and meta-analysis. J Infect Public Health 2022; 15:942-949. [PMID: 35914358 DOI: 10.1016/j.jiph.2022.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/08/2022] [Accepted: 07/21/2022] [Indexed: 10/16/2022] Open
Abstract
BACKGROUND Japanese encephalitis (JE) is a viral zoonotic disease that has been found in several countries of Asia and is responsible for high mortality and morbidity of men and animals in rural and sub-urban endemic areas due to the virus re-circulation among diverse hosts and vectors. The present study estimates the prevalence of the JE virus in the vector and animal population of the Asian continent using a systematic review and meta-analysis. METHODS The Cochran collaborators' Preferred Reporting Items for Systematic Reviews and Meta-Analysis [PRISMA] guidelines were used for systematic review and meta-analysis. The heterogeneity was observed in meta-regression analysis due to several factors including region, species, and different diagnostic assays used in various studies. Thus we did sensitivity and subgroup analysis. RESULTS The prevalence of the JE virus was calculated using a total sample size of 47,391. Subgroup analysis revealed the JE virus prevalence of 39% in the Southeast Asia region, followed by East Asia with 35% and South Asia with 15% prevalence. Hence, the overall pooled prevalence of the JE virus was 26% in the Asian continent. CONCLUSIONS The highest proportion of infection was found in pigs amongst all animals, reinforcing the fact that they can be used as sentinels to predict outbreaks in humans. The findings of this study will enable researchers and policymakers in better understanding the disease's spatial and temporal distribution, as well as in creating and implementing location-specific JE prevention and control measures.
Collapse
Affiliation(s)
| | - Akshata Nayak
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Himani Dhanze
- ICAR-Indian Veterinary Research Institute, Bareilly, UP, India
| | - Anenahalli Panduranga Bhavya
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Chandan Shivamallu
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Raghu Ram Achar
- Division of Biochemistry, School of Life Sciences, JSS Academy of Higher Education and Research, Mysuru, India
| | - Ekaterina Silina
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Victor Stupin
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Nagendra Nath Barman
- Department of Microbiology, College of Veterinary Sciences (AAU), Guwahati, Assam, India
| | - Seethakempanahalli Kempanna Kumar
- Department of Ethnoveterinary Sciences and Practices, The University of Trans-Disciplinary Health Science and Technology, Jarakabandekaval, Yelahanka, Bengaluru, India
| | - Asad Syed
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Shiva Prasad Kollur
- Department of Sciences, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Mysuru Campus, Mysuru, Karnataka, India
| | - Bhargav Shreevatsa
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Sharanagouda S Patil
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India.
| |
Collapse
|
11
|
Modelling Japanese encephalitis virus transmission dynamics and human exposure in a Cambodian rural multi-host system. PLoS Negl Trop Dis 2022; 16:e0010572. [PMID: 35816555 PMCID: PMC9302853 DOI: 10.1371/journal.pntd.0010572] [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: 05/12/2021] [Revised: 07/21/2022] [Accepted: 06/08/2022] [Indexed: 11/26/2022] Open
Abstract
Japanese encephalitis (JE) is a vector-borne zoonosis and the leading cause of human viral encephalitis in Asia. Its transmission cycle is usually described as involving wild birds as reservoirs and pigs as amplifying hosts. JE is endemic in Cambodia, where it circulates in areas with low pig densities (<70 pigs per km2), and could be maintained in a multi-host system composed of pigs, but also poultry as competent hosts, and dogs, cattle and humans as non-competent hosts. We used a mathematical model representing Japanese encephalitis virus (JEV) transmission in a traditional Cambodian village that we calibrated with field data collected in 3 districts of Kandal province, Cambodia. First, R0 calculations allowed us to assess the capacity of the epidemiological system to be invaded by JEV and sustain virus transmission in villages in the 3 districts, and we predicted human exposure at the epidemiological equilibrium, based on simulations. Changes in spatial density of livestock, in agricultural practices, and epizootics (e.g., African swine fever), can profoundly alter the composition of host communities, which could affect JEV transmission and its impact on human health. In a second step, we then used the model to analyse how host community composition affected R0 and the predicted human exposure. Lastly, we evaluated the potential use of dog JE seroprevalence as an indicator of human exposure to JEV. In the modeled villages, the calculated R0 ranged from 1.07 to 1.38. Once the equilibrium reached, predicted annual probability of human exposure ranged from 9% to 47%, and predicted average age at infection was low, between 2 and 11 years old, highlighting the risk of severe forms of JEV infection and the need to intensify child immunization. According to the model, increasing the proportion of competent hosts induced a decrease in age at infection. The simulations also showed that JEV could invade a multi-host system with no pigs, reinforcing the assumption of poultry acting as reservoirs. Finally, the annual human exposure probability appeared linearly correlated with dog seroprevalence, suggesting that in our specific study area, dog seroprevalence would be a good proxy for human exposure. Japanese encephalitis virus (JEV) is endemic in Cambodia and remains the most common cause of acute viral encephalitis, particularly in children and adolescents. The traditionally described cycle of JEV, involving wild birds as reservoirs, pigs as amplifying hosts and Culex mosquitoes as vectors is questioned, with increasing evidence of a more complex multi-host system involved in areas where densities of pigs are low. In Cambodia, the infection could be maintained in a multi-host system consisting of pigs and poultry as competent hosts, and dogs, cattle and humans as non-competent hosts. We defined a compartmental dynamic model of JEV transmission in a multi-host system representing a rural Cambodian village, to predict human exposure to JEV in the studied area, and to analyse how host community composition may affect human exposure and R0 value. Our theoretical approach showed that variations of the composition of the multi-host system may have an impact on human exposure to JEV, and thus on the disease burden in humans, especially in young children. Besides children vaccination in JEV endemic areas, a proper evaluation of the impact on human health is needed to target prevention actions and reduce JEV burden in Cambodia.
Collapse
|
12
|
Hernández-Triana LM, Folly AJ, Sewgobind S, Lean FZX, Ackroyd S, Nuñez A, Delacour S, Drago A, Visentin P, Mansfield KL, Johnson N. Susceptibility of Aedes albopictus and Culex quinquefasciatus to Japanese encephalitis virus. Parasit Vectors 2022; 15:210. [PMID: 35710580 PMCID: PMC9204976 DOI: 10.1186/s13071-022-05329-0] [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: 02/17/2022] [Accepted: 05/19/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Japanese encephalitis virus (JEV) is the principal cause of mosquito-borne encephalitis in human populations within Asia. If introduced into new geographic areas, it could have further implications for public and animal health. However, potential mosquito vectors for virus transmission have not been fully investigated. The Asian tiger mosquito, Aedes albopictus, has emerged in Europe and is now expanding its geographical range into more northerly latitudes. Culex quinquefasciatus, although absent from Europe, has been detected in Turkey, a country with territory in Europe, and could act as a vector for JEV in other regions. To assess the risk of these invasive species acting as vectors for JEV and therefore potentially contributing to its geographical expansion, we have investigated the vector competence of Ae. albopictus and Cx. quinquefasciatus. METHODS Two colonised lines of Ae. albopictus (Italy and Spain) and a line of Cx. quinquefasciatus (Tanzania) were compared for susceptibility to infection by oral feeding with JEV strain SA-14, genotype III at 106 PFU/ml and maintained at 25 °C. Specimens were processed at 7 and 14 days post-inoculation (dpi). Rates of infection, dissemination and transmission were assessed through detection of viral RNA by real-time polymerase chain reaction (RT-PCR) in mosquito body, legs and saliva, respectively, at each time point. Where possible, infection and dissemination were confirmed by immunohistochemical (IHC) detection of the JEV envelope protein. RESULTS Aedes albopictus from Italy showed no susceptibility to infection with JEV strain SA-14. Conversely, Ae. albopictus colonised in Spain was susceptible and 100% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Culex quinquefasciatus was highly susceptible to infection as early as 7 dpi and 50% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Infection and dissemination were confirmed in Cx. quinquefasciatus by IHC detection of JEV envelope protein in both the mid-gut and salivary glands. CONCLUSIONS Aedes albopictus from two different locations in Europe range from being susceptible to JEV and capable of transmission through to being resistant. Culex quinquefasciatus also appears highly susceptible; therefore, both species could potentially act as vectors for JEV and facilitate the emergence of JEV into new regions.
Collapse
Affiliation(s)
| | - Arran J Folly
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Sanam Sewgobind
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Fabian Z X Lean
- Pathology and Animal Sciences Department, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Stuart Ackroyd
- Pathology and Animal Sciences Department, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Alejandro Nuñez
- Pathology and Animal Sciences Department, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Sarah Delacour
- Veterinary Faculty, University of Zaragoza, Zaragoza, Spain
| | - Andrea Drago
- Entostudio SrL, Viale del Lavoro 66, Ponte San Nicolò, Padua, Italy
| | | | - Karen L Mansfield
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Nicholas Johnson
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| |
Collapse
|
13
|
The Emergence of Japanese Encephalitis Virus in Australia in 2022: Existing Knowledge of Mosquito Vectors. Viruses 2022; 14:v14061208. [PMID: 35746679 PMCID: PMC9231386 DOI: 10.3390/v14061208] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 12/10/2022] Open
Abstract
In early 2022, the Japanese encephalitis virus (JEV) was identified as the cause of stillborn and mummified piglets in pig farms in southeastern Australia. Human cases and additional pig farms with infected piglets were subsequently identified across a widespread area encompassing four states. To inform surveillance and control programs, we synthesized existing information on Australian vectors of JEV, much of which was generated in response to incursions of JEV into the northern state of Queensland between 1995 and 2005. Members of the Culex sitiens subgroup, particularly Culex annulirostris, should be considered the primary vectors of JEV in Australia, as they yielded >87% of field detections of JEV, were highly efficient laboratory vectors of the virus, readily fed on pigs and birds (the key amplifying hosts of the virus) when they were available, and are widespread and often occur in large populations. Three introduced species, Culex quinquefasciatus, Culex gelidus and Culex tritaeniorhynchus may also serve as vectors, but more information on their geographical distribution, abundance and bionomics in the Australian context is required. Mosquitoes from other genera, such as Aedes and Verrallina, whilst considered relatively poor vectors, could play a regional or supplemental role in transmission, especially facilitating vertical transmission as a virus overwintering mechanism. Additional factors that could impact JEV transmission, including mosquito survival, dispersal and genetics, are also discussed. Possible directions for investigation are provided, especially in the context of the virus emerging in a region with different mosquito fauna and environmental drivers than northern Australia.
Collapse
|
14
|
Furuya-Kanamori L, Gyawali N, Mills DJ, Hugo LE, Devine GJ, Lau CL. The Emergence of Japanese Encephalitis in Australia and the Implications for a Vaccination Strategy. Trop Med Infect Dis 2022; 7:tropicalmed7060085. [PMID: 35736964 PMCID: PMC9229418 DOI: 10.3390/tropicalmed7060085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 05/27/2022] [Accepted: 05/27/2022] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Until 2022, only six locally transmitted human JE cases had been reported in Australia; five in northern Queensland and one in the Northern Territory. Thus, JE was mainly considered to be a disease of travellers. On 4 March 2022, JE was declared a ‘Communicable Disease Incident of National Significance’ when a locally acquired human case was confirmed in southern Queensland. By 11 May 2022, 41 human JE cases had been notified in four states in Australia, in areas where JE has never been detected before. From this perspective, we discuss the potential reasons for the recent emergence of the JE virus in Australia in areas where JE has never been previously reported as well as the implications of and options for mass immunisation programs if the outbreak escalates in a JE virus-immunologically naïve population.
Collapse
Affiliation(s)
- Luis Furuya-Kanamori
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston 4029, Australia
- Correspondence: (L.F.-K.); (C.L.L.)
| | - Narayan Gyawali
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston 4006, Australia; (N.G.); (L.E.H.); (G.J.D.)
| | - Deborah J. Mills
- Dr Deb The Travel Doctor, Travel Medicine Alliance, Brisbane 4000, Australia;
| | - Leon E. Hugo
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston 4006, Australia; (N.G.); (L.E.H.); (G.J.D.)
| | - Gregor J. Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Herston 4006, Australia; (N.G.); (L.E.H.); (G.J.D.)
| | - Colleen L. Lau
- School of Public Health, Faculty of Medicine, The University of Queensland, Herston 4006, Australia
- Correspondence: (L.F.-K.); (C.L.L.)
| |
Collapse
|
15
|
Japanese Encephalitis Virus Interaction with Mosquitoes: A Review of Vector Competence, Vector Capacity and Mosquito Immunity. Pathogens 2022; 11:pathogens11030317. [PMID: 35335641 PMCID: PMC8953304 DOI: 10.3390/pathogens11030317] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 02/01/2023] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne zoonotic flavivirus and a major cause of human viral encephalitis in Asia. We provide an overview of the knowledge on vector competence, vector capacity, and immunity of mosquitoes in relation to JEV. JEV has so far been detected in more than 30 mosquito species. This does not necessarily mean that these species contribute to JEV transmission under field conditions. Therefore, vector capacity, which considers vector competence, as well as environmental, behavioral, cellular, and biochemical variables, needs to be taken into account. Currently, 17 species can be considered as confirmed vectors for JEV and 10 other species as potential vectors. Culex tritaeniorhynchus and Culex annulirostris are considered primary JEV vectors in endemic regions. Culex pipiens and Aedes japonicus could be considered as potentially important vectors in the case of JEV introduction in new regions. Vector competence is determined by various factors, including vector immunity. The available knowledge on physical and physiological barriers, molecular pathways, antimicrobial peptides, and microbiome is discussed in detail. This review highlights that much remains to be studied about vector immunity against JEV in order to identify novel strategies to reduce JEV transmission by mosquitoes.
Collapse
|
16
|
Metzger ME, Wekesa JW, Kluh S, Fujioka KK, Saviskas R, Arugay A, McConnell N, Nguyen K, Krueger L, Hacker GM, Hu R, Kramer VL. Detection and Establishment of Aedes notoscriptus (Diptera: Culicidae) Mosquitoes in Southern California, United States. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:67-77. [PMID: 34617571 PMCID: PMC8755992 DOI: 10.1093/jme/tjab165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Indexed: 06/13/2023]
Abstract
Aedes notoscriptus (Skuse), the Australian backyard mosquito, is a pestiferous daytime-biting species native to Australia and the surrounding southwestern Pacific region. It is suspected to play a role in the transmission of several arboviruses and is considered a competent vector of dog heartworm, Dirofilaria immitis (Leidy). This highly adaptable mosquito thrives in natural and artificial water-holding containers in both forested and urbanized areas, from tropical to temperate climates, and has benefitted from a close association with humans, increasing in abundance within its native range. It invaded and successfully established in New Zealand as well as in previously unoccupied temperate and arid regions of Australia. Ae. notoscriptus was discovered in Los Angeles County, CA, in 2014, marking the first time this species had been found outside the southwestern Pacific region. By the end of 2019, immature and adult mosquitoes had been collected from 364 unique locations within 44 cities spanning three southern California counties. The discovery, establishment, and rapid spread of this species in urban areas may signal the global movement and advent of a new invasive container-inhabiting species. The biting nuisance, public health, and veterinary health implications associated with the invasion of southern California by this mosquito are discussed.
Collapse
Affiliation(s)
- Marco E Metzger
- Vector-Borne Disease Section, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, 1616 Capitol Avenue, MS-7307, Sacramento, CA 95814, USA
| | - J Wakoli Wekesa
- San Gabriel Valley Mosquito and Vector Control District, 1145 North Azusa Canyon Road, West Covina, CA 91790, USA
- Current Address: East Side Mosquito Abatement District, 2000 Santa Fe Avenue, Modesto, CA 95357, USA
| | - Susanne Kluh
- Greater Los Angeles County Vector Control District, 12545 Florence Avenue, Santa Fe Springs, CA 90670, USA
| | - Kenn K Fujioka
- San Gabriel Valley Mosquito and Vector Control District, 1145 North Azusa Canyon Road, West Covina, CA 91790, USA
| | - Robert Saviskas
- Los Angeles County West Vector & Vector-Borne Disease Control District, 6750 Centinela Avenue, Culver City, CA 90230, USA
| | - Aaron Arugay
- Los Angeles County West Vector & Vector-Borne Disease Control District, 6750 Centinela Avenue, Culver City, CA 90230, USA
| | - Nathan McConnell
- County of San Diego, Department of Environmental Health, Vector Control Program, 5570 Overland Avenue Suite 102, San Diego, CA 92123, USA
| | - Kiet Nguyen
- Orange County Mosquito and Vector Control District, 13001 Garden Grove Boulevard, Garden Grove, CA 92843, USA
| | - Laura Krueger
- Orange County Mosquito and Vector Control District, 13001 Garden Grove Boulevard, Garden Grove, CA 92843, USA
| | - Gregory M Hacker
- Vector-Borne Disease Section, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, 1616 Capitol Avenue, MS-7307, Sacramento, CA 95814, USA
| | - Renjie Hu
- Vector-Borne Disease Section, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, 1616 Capitol Avenue, MS-7307, Sacramento, CA 95814, USA
| | - Vicki L Kramer
- Vector-Borne Disease Section, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, 1616 Capitol Avenue, MS-7307, Sacramento, CA 95814, USA
| |
Collapse
|
17
|
Pyke AT, Shivas MA, Darbro JM, Onn MB, Johnson PH, Crunkhorn A, Montgomery I, Burtonclay P, Jansen CC, van den Hurk AF. Uncovering the genetic diversity within the Aedes notoscriptus virome and isolation of new viruses from this highly urbanised and invasive mosquito. Virus Evol 2021; 7:veab082. [PMID: 34712491 PMCID: PMC8546932 DOI: 10.1093/ve/veab082] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/09/2021] [Accepted: 09/15/2021] [Indexed: 12/21/2022] Open
Abstract
The Australian backyard mosquito, Aedes notoscriptus, is a highly urbanised pest species that has invaded New Zealand and the USA. Importantly, Ae. notoscriptus has been implicated as a vector of Ross River virus, a common and arthritogenic arbovirus in Australia, and is a laboratory vector of numerous other pathogenic viruses, including West Nile, yellow fever, and Zika viruses. To further explore live viruses harboured by field populations of Ae. notoscriptus and, more specifically, assess the genetic diversity of its virome, we processed 495 pools, comprising a total of 6,674 female Ae. notoscriptus collected across fifteen suburbs in Brisbane, Australia, between January 2018 and May 2019. Nine virus isolates were recovered and characterised by metagenomic sequencing and phylogenetics. The principal viral family represented was Flaviviridae. Known viruses belonging to the genera Flavivirus, Orbivirus, Mesonivirus, and Nelorpivirus were identified together with two novel virus species, including a divergent Thogoto-like orthomyxovirus and an insect-specific flavivirus. Among these, we recovered three Stratford virus (STRV) isolates and an isolate of Wongorr virus (WGRV), which for these viral species is unprecedented for the geographical area of Brisbane. Thus, the documented geographical distribution of STRV and WGRV, both known for their respective medical and veterinary importance, has now been expanded to include this major urban centre. Phylogenies of the remaining five viruses, namely, Casuarina, Ngewotan, the novel Thogoto-like virus, and two new flavivirus species, suggested they are insect-specific viruses. None of these viruses have been previously associated with Ae. notoscriptus or been reported in Brisbane. These findings exemplify the rich genetic diversity and viral abundance within the Ae. notoscriptus virome and further highlight this species as a vector of concern with the potential to transmit viruses impacting human or animal health. Considering it is a common pest and vector in residential areas and is expanding its global distribution, ongoing surveillance, and ecological study of Ae. notoscriptus, together with mapping of its virome and phenotypic characterisation of isolated viruses, is clearly warranted. Immanently, these initiatives are essential for future understanding of both the mosquito virome and the evolution of individual viral species.
Collapse
Affiliation(s)
- Alyssa T Pyke
- Department of Health, Public Health Virology Laboratory, Forensic and Scientific Services, Queensland Government, 39 Kessels Road, Coopers Plains, QLD 4108, Australia
| | - Martin A Shivas
- Brisbane City Council, 20 Tradecoast Drive, Eagle Farm, Brisbane, QLD 4009, Australia
| | | | - Michael B Onn
- Brisbane City Council, 20 Tradecoast Drive, Eagle Farm, Brisbane, QLD 4009, Australia
| | | | - Andrew Crunkhorn
- Metro North Public Health Unit, Queensland Health, Bryden Street, Windsor, QLD 4030, Australia
| | - Ivan Montgomery
- Brisbane City Council, 20 Tradecoast Drive, Eagle Farm, Brisbane, QLD 4009, Australia
| | | | - Cassie C Jansen
- Communicable Diseases Branch, Queensland Health, 15 Butterfield Street, Herston, QLD 4006, Australia
| | - Andrew F van den Hurk
- Department of Health, Public Health Virology Laboratory, Forensic and Scientific Services, Queensland Government, 39 Kessels Road, Coopers Plains, QLD 4108, Australia
| |
Collapse
|
18
|
Mee PT, Wong S, Brown K, Lynch SE. Quantitative PCR assay for the detection of Aedes vigilax in mosquito trap collections containing large numbers of morphologically similar species and phylogenetic analysis of specimens collected in Victoria, Australia. Parasit Vectors 2021; 14:434. [PMID: 34454606 PMCID: PMC8401248 DOI: 10.1186/s13071-021-04923-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/03/2021] [Indexed: 11/24/2022] Open
Abstract
Background Aedes vigilax is one of the most significant arbovirus vector and pest species in Australia’s coastal regions. Occurring in multiple countries, this mosquito species occurs as a species complex which has been separated into three clades with two detected in Australia. Until recently, Ae. vigilax has largely been absent from Victoria, only occasionally caught over the years, with no reported detections from 2010 to 2016. Complicating the detection of Ae. vigilax is the shared sympatric distribution to the morphologically similar Ae. camptorhynchus, which can exceed 10,000 mosquitoes in a single trap night in Victoria. Currently, there are no molecular assays available for the detection of Ae. vigilax. We aim to develop a quantitative PCR (qPCR) for the detection of Ae. vigilax, with the specificity and sensitivity of this assay assessed as well as a method to process whole mosquito traps. Methods Trapping was performed during the 2017–2020 mosquito season in Victoria in two coastal areas across these 3 consecutive years. A qPCR assay was designed to allow rapid identification of Ae. vigilax as well as a whole mosquito trap homogenizing and processing methodology. Phylogenetic analysis was performed to determine which clade Ae. vigilax from Victoria was closest to. Results Aedes vigilax was successfully detected each year across two coastal areas of Victoria, confirming the presence of this species. The qPCR assay was proven to be sensitive and specific to Ae. vigilax, with trap sizes up to 1000 mosquitoes showing no inhibition in detection sensitivity. Phylogenetic analysis revealed that Ae. vigilax from Victoria is associated with clade III, showing high sequence similarity to those previously collected in New South Wales, Queensland and Western Australia. Conclusions Aedes vigilax is a significant vector species that shares an overlapping distribution to the morphologically similar Ae. camptorhynchus, making detection difficult. Here, we have outlined the implementation of a specific and sensitive molecular screening assay coupled with a method to process samples for detection of Ae. vigilax in collections with large numbers of non-target species. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04923-y.
Collapse
Affiliation(s)
- Peter T Mee
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, Victoria, Australia.
| | - Shani Wong
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, Victoria, Australia
| | - Karen Brown
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, Victoria, Australia
| | - Stacey E Lynch
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, Victoria, Australia
| |
Collapse
|
19
|
Auerswald H, Maquart PO, Chevalier V, Boyer S. Mosquito Vector Competence for Japanese Encephalitis Virus. Viruses 2021; 13:v13061154. [PMID: 34208737 PMCID: PMC8234777 DOI: 10.3390/v13061154] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 12/30/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a zoonotic pathogen mainly found in East and Southeast Asia and transmitted by mosquitoes. The objective of this review is to summarize the knowledge on the diversity of JEV mosquito vector species. Therefore, we systematically analyzed reports of JEV found in field-caught mosquitoes as well as experimental vector competence studies. Based on the investigated publications, we classified 14 species as confirmed vectors for JEV due to their documented experimental vector competence and evidence of JEV found in wild mosquitoes. Additionally, we identified 11 mosquito species, belonging to five genera, with an experimentally confirmed vector competence for JEV but lacking evidence on their JEV transmission capacity from field-caught mosquitoes. Our study highlights the diversity of confirmed and potential JEV vector species. We also emphasize the variety in the study design of vector competence investigations. To account for the diversity of the vector species and regional circumstances, JEV vector competence should be studied in the local context, using local mosquitoes with local virus strains under local climate conditions to achieve reliable data. In addition, harmonization of the design of vector competence experiments would lead to better comparable data, informing vector and disease control measures.
Collapse
Affiliation(s)
- Heidi Auerswald
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia
- Correspondence:
| | - Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
| | - Véronique Chevalier
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia;
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, 34000 Montpellier, France
| | - Sebastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
- Institut Pasteur, 75015 Paris, France
| |
Collapse
|
20
|
Amos BA, Cardé RT. Efficiency of CO 2 -baited CDC miniature light traps under semi-field conditions and characterizing response behaviors of female Aedes aegypti (Diptera: Culicidae). JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2020; 45:180-187. [PMID: 33207060 DOI: 10.1111/jvec.12388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
Aedes aegypti (L.) (Diptera: Culicidae) is an important vector of viruses causing dengue, Zika, chikungunya, and yellow fever and as such is a threat to public health worldwide. Effective trapping methods are essential for surveillance of both mosquito species and disease presence. The Centers for Disease Control Miniature Light Trap (CDC-MLT) is an updated version of the New Jersey light trap, which was developed early in the 20th century. This trap is widely reported as being less successful for Ae. aegypti than for other mosquito species, although the reason for this is unclear. This trap has engendered more Ae. aegypti-tailored designs that still represent the basic design model. The efficiency of the CDC-MLT alone and with CO2 was tested under semi-field conditions and the behavior of responding female Ae. aegypti was characterized. The CDC-MLT alone failed to capture any mosquitoes and with CO2 the capture efficiency was less than 2%. Understanding the behaviors that mosquitoes exhibit while encountering a particular trap design or trapping concept may suggest trap improvements to increase capture efficiency. Moreover, this work contributes to our understanding of mosquito host-seeking behavior.
Collapse
Affiliation(s)
- B A Amos
- Department of Entomology, University of California Riverside, CA, 92521, U.S.A
| | - R T Cardé
- Department of Entomology, University of California Riverside, CA, 92521, U.S.A
| |
Collapse
|
21
|
Rakotonirina A, Pol M, Kainiu M, Barsac E, Tutagata J, Kilama S, O'Connor O, Tarantola A, Colot J, Dupont-Rouzeyrol M, Richard V, Pocquet N. MALDI-TOF MS: optimization for future uses in entomological surveillance and identification of mosquitoes from New Caledonia. Parasit Vectors 2020; 13:359. [PMID: 32690083 PMCID: PMC7372833 DOI: 10.1186/s13071-020-04234-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 07/15/2020] [Indexed: 12/05/2022] Open
Abstract
Background Mosquito vectors cause a significant human public health burden through the transmission of pathogens. Due to the expansion of international travel and trade, the dispersal of these mosquito vectors and the pathogens they carry is on the rise. Entomological surveillance is therefore required which relies on accurate mosquito species identification. This study aimed to optimize the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for mosquito identification. Methods Aedes aegypti of the Bora-Bora strain and 11 field-sampled mosquito species were used in this study. Analyses were performed to study the impact of the trapping duration on mosquito identification with MALDI-TOF MS. The best preservation methods to use for short, medium and long-term preservation before MALDI-TOF MS analysis were also assessed. In addition, the number of specimens per species required for MALDI-TOF MS database creation was determined. The first MALDI-TOF database of New Caledonian mosquitoes was assembled and the optimal threshold for mosquito species identification according to the sensitivity and specificity of this technique was determined. Results This study showed that the identification scores decreased as the trapping duration increased. High identification scores were obtained for mosquitoes preserved on silica gel and cotton at room temperature and those frozen at − 20 °C, even after two months of preservation. In addition, the results showed that the scores increased according to the number of main spectrum patterns (MSPs) used until they reached a plateau at 5 MSPs for Ae. aegypti. Mosquitoes (n = 67) belonging to 11 species were used to create the MALDI-TOF reference database. During blind test analysis, 96% of mosquitoes tested (n = 224) were correctly identified. Finally, based on MALDI-TOF MS sensitivity and specificity, the threshold value of 1.8 was retained for a secure identification score. Conclusions MALDI-TOF MS allows accurate species identification with high sensitivity and specificity and is a promising tool in public health for mosquito vector surveillance.![]()
Collapse
Affiliation(s)
- Antsa Rakotonirina
- Institut Pasteur de Nouvelle-Calédonie, URE-Entomologie Médicale, Nouméa, 98845, New Caledonia.
| | - Morgane Pol
- Institut Pasteur de Nouvelle-Calédonie, URE-Entomologie Médicale, Nouméa, 98845, New Caledonia
| | - Malia Kainiu
- Institut Pasteur de Nouvelle-Calédonie, Groupe de Recherche en Bactériologie Expérimentale, Nouméa, 98845, New Caledonia
| | - Emilie Barsac
- Institut Pasteur de Nouvelle-Calédonie, Groupe de Recherche en Bactériologie Expérimentale, Nouméa, 98845, New Caledonia
| | - Jordan Tutagata
- Institut Pasteur de Nouvelle-Calédonie, URE-Entomologie Médicale, Nouméa, 98845, New Caledonia
| | - Sosiasi Kilama
- Institut Pasteur de Nouvelle-Calédonie, URE-Entomologie Médicale, Nouméa, 98845, New Caledonia
| | - Olivia O'Connor
- Institut Pasteur de Nouvelle-Calédonie, URE-Dengue et autres Arboviroses, Nouméa, 98845, New Caledonia
| | - Arnaud Tarantola
- Institut Pasteur de Nouvelle-Calédonie, URE-Epidémiologie, Nouméa, 98845, New Caledonia
| | - Julien Colot
- Institut Pasteur de Nouvelle-Calédonie, Groupe de Recherche en Bactériologie Expérimentale, Nouméa, 98845, New Caledonia
| | - Myrielle Dupont-Rouzeyrol
- Institut Pasteur de Nouvelle-Calédonie, URE-Dengue et autres Arboviroses, Nouméa, 98845, New Caledonia
| | - Vincent Richard
- Institut Pasteur, Direction internationale, Paris, 75015, France
| | - Nicolas Pocquet
- Institut Pasteur de Nouvelle-Calédonie, URE-Entomologie Médicale, Nouméa, 98845, New Caledonia
| |
Collapse
|
22
|
Hameed M, Liu K, Anwar MN, Wahaab A, Safdar A, Di D, Boruah P, Xu J, Wang X, Li B, Zhu H, Nawaz M, Shao D, Qiu Y, Wei J, Ma Z. The emerged genotype I of Japanese encephalitis virus shows an infectivity similar to genotype III in Culex pipiens mosquitoes from China. PLoS Negl Trop Dis 2019; 13:e0007716. [PMID: 31557156 PMCID: PMC6762057 DOI: 10.1371/journal.pntd.0007716] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/16/2019] [Indexed: 12/14/2022] Open
Abstract
Japanese Encephalitis virus (JEV) is a zoonotic flavivirus that represents the most significant etiology of childhood viral neurological infections throughout the Asia. During the last 20 years, JEV genotype dominance has shifted from genotype III (GIII) to genotype I (GI). To date, the exact mechanism of this displacement is still not known. Culex (Cx.) mosquitoes are the most common species in China and play an essential role in maintaining JEV enzootic transmission cycle. In this study, we used Cx. pipiens mosquitoes from China as an in vivo mosquito model to explore if mosquitoes played a potential role in JEV genotype shift. We exposed female Cx. pipiens mosquitoes orally to either GI or GIII JEV strains. Midgut, whole mosquitoes, secondary organs, and salivary glands of JEV-infected mosquitoes were collected at 7 and 14 days of post infection (dpi) and subjected to measure the infection rate, replication kinetics, dissemination rate and transmission potential of the infected JEV strains in Cx. pipiens mosquitoes by 50% tissue culture infective dose assay. We found that Cx. pipiens mosquito was competent vector for both GI and GIII JEV infection, with similar infection rates and growth kinetics. After the establishment of infection, Cx. pipiens mosquitoes disseminated both JEV genotypes to secondary organs at similar rates of dissemination. A few GI-infected mosquito salivary glands (16.2%) were positive for GI virus, whereas GIII virus was undetectable in GIII-infected mosquito salivary glands at 7 dpi. However, 29.4% (5/17) and 36.3% (8/22) were positive for GI- and GIII-infected mosquito salivary glands at 14 dpi, respectively, showing an increase in JEV positive rate. No statistical difference in the transmission rate between GI- and GIII-infected mosquitoes was detected. Our experiment data demonstrated that GI and GIII viruses have similar infectivity in Cx. pipiens mosquitoes, suggesting that Cx. pipiens mosquitoes from China may not play a critical role in JEV genotype shift. Although the current data were obtained solely from Cx. pipiens mosquitoes, it is likely that the conclusion drawn could be extrapolated to the role of mosquitoes in JEV genotype shift.
Collapse
Affiliation(s)
- Muddassar Hameed
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Muhammad Naveed Anwar
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Abdul Wahaab
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Anum Safdar
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Di Di
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Prerona Boruah
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Jinpeng Xu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Xin Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Huaimin Zhu
- Department of Pathogen biology, Second Military Medical University, Shanghai, PR China
| | - Mohsin Nawaz
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Donghua Shao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| |
Collapse
|
23
|
Keven JB, Walker ED, Venta PJ. A Microsatellite Multiplex Assay for Profiling Pig DNA in Mosquito Bloodmeals. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:907-914. [PMID: 30768665 PMCID: PMC6595529 DOI: 10.1093/jme/tjz013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Indexed: 06/09/2023]
Abstract
Genetic profiling has been used to link mosquito bloodmeals to the individual humans, but this analysis has not been done for other mammalian bloodmeals. In this study, we describe a microsatellite-based method for identifying individual pigs in mosquito bloodmeals based on their unique multilocus genotypes. Eleven tetranucleotide microsatellites and a sex-specific marker were selected based on Smith-Waterman DNA sequence alignment scores from the reference genome and primers were designed with features that reduce primer dimers, promote complete adenylation, and enable fluorescent labeling of amplicons. A multiplex polymerase chain reaction (PCR) assay was optimized and validated by analyzing DNA of individual pigs from several nuclear families and breeds before it was used to analyze genomic DNA of pig-derived mosquito bloodmeals from villages of Papua New Guinea. Population analysis of the nuclear families showed high expected and observed heterozygosity. The probability of observing two unrelated or sibling individuals sharing the same genotype at a single microsatellite locus or a combination of loci was vanishingly low. Samples had unique genotypes and gender was accurately predicted. Analysis of 129 pig bloodmeals identified 19 unique genotypes, which varied greatly in frequency in the mosquito bloodmeal samples. The high allelic diversity of the microsatellite loci and low probability of false attribution of identity show that this genotyping method reliably distinguishes distantly and closely related pigs and can be used to identify individual pigs from genotyped mosquito bloodmeals.
Collapse
Affiliation(s)
- John B Keven
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Edward D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI
| | - Patrick J Venta
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI
| |
Collapse
|
24
|
Japanese Encephalitis Virus in Australia: From Known Known to Known Unknown. Trop Med Infect Dis 2019; 4:tropicalmed4010038. [PMID: 30791674 PMCID: PMC6473502 DOI: 10.3390/tropicalmed4010038] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/18/2019] [Accepted: 02/19/2019] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a major cause of neurological disease in Asia. It is a zoonotic flavivirus transmitted between water birds and/or pigs by Culex mosquitoes; humans are dead-end hosts. In 1995, JEV emerged for the first time in northern Australia causing an unprecedented outbreak in the Torres Strait. In this article, we revisit the history of JEV in Australia and describe investigations of JEV transmission cycles in the Australian context. Public health responses to the incipient outbreak included vaccination and sentinel pig surveillance programs. Virus isolation and vector competence experiments incriminated Culex annulirostris as the likely regional vector. The role this species plays in transmission cycles depends on the availability of domestic pigs as a blood source. Experimental evidence suggests that native animals are relatively poor amplifying hosts of JEV. The persistence and predominantly annual virus activity between 1995 and 2005 suggested that JEV had become endemic in the Torres Strait. However, active surveillance was discontinued at the end of 2005, so the status of JEV in northern Australia is unknown. Novel mosquito-based surveillance systems provide a means to investigate whether JEV still occurs in the Torres Strait or is no longer a risk to Australia.
Collapse
|
25
|
Samy AM, Alkishe AA, Thomas SM, Wang L, Zhang W. Mapping the potential distributions of etiological agent, vectors, and reservoirs of Japanese Encephalitis in Asia and Australia. Acta Trop 2018; 188:108-117. [PMID: 30118701 DOI: 10.1016/j.actatropica.2018.08.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/11/2018] [Accepted: 08/12/2018] [Indexed: 12/15/2022]
Abstract
Japanese encephalitis virus (JEV) is a substantial cause of viral encephalitis, morbidity, and mortality in South-East Asia and the Western Pacific. World Health Organization recognized Japanese Encephalitis (JE) as a public health priority in demands to initiate active vaccination programs. Recently, the geographic distribution of JEV has apparently expanded into other areas in the Pacific islands and northern Australia; however, major gaps exist in knowledge in regard to its current distribution. Here, we mapped the potential distribution of mosquito vectors of JEV (Culex tritaeniorhynchus, Cx. pseudovishnui, Cx. vishnui, Cx. fuscocephala, Cx. gelidus), and reservoirs (Egretta garzetta, E. intermedia, Nycticorax nycticorax) based on ecological niche modeling approach. Ecological niche models predicted all species to occur across Central, South and South East Asia; however, Cx. tritaeniorhynchus, E. garzetta, E. intermedia, and N. nycticorax had broader potential distributions extending west to parts of the Arabian Peninsula. All predictions were robust and significantly better than random (P < 0.001). We also tested the JEV prediction based on 4335 additional independent human case records collected by the Chinese Information System for Disease Control and Prevention (CISDCP); 4075 cases were successfully predicted by the model (P < 0.001). Finally, we tested the ecological niche similarity among JEV, vector, and reservoir species and could not reject any of the null hypotheses of niche similarity in all combination pairs.
Collapse
|
26
|
Colmant AMG, Hall-Mendelin S, Ritchie SA, Bielefeldt-Ohmann H, Harrison JJ, Newton ND, O’Brien CA, Cazier C, Johansen CA, Hobson-Peters J, Hall RA, van den Hurk AF. The recently identified flavivirus Bamaga virus is transmitted horizontally by Culex mosquitoes and interferes with West Nile virus replication in vitro and transmission in vivo. PLoS Negl Trop Dis 2018; 12:e0006886. [PMID: 30356234 PMCID: PMC6200184 DOI: 10.1371/journal.pntd.0006886] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 09/29/2018] [Indexed: 11/19/2022] Open
Abstract
Arthropod-borne flaviviruses such as yellow fever (YFV), Zika and dengue viruses continue to cause significant human disease globally. These viruses are transmitted by mosquitoes when a female imbibes an infected blood-meal from a viremic vertebrate host and expectorates the virus into a subsequent host. Bamaga virus (BgV) is a flavivirus recently discovered in Culex sitiens subgroup mosquitoes collected from Cape York Peninsula, Australia. This virus phylogenetically clusters with the YFV group, but is potentially restricted in most vertebrates. However, high levels of replication in an opossum cell line (OK) indicate a potential association with marsupials. To ascertain whether BgV could be horizontally transmitted by mosquitoes, the vector competence of two members of the Cx. sitiens subgroup, Cx. annulirostris and Cx. sitiens, for BgV was investigated. Eleven to thirteen days after imbibing an infectious blood-meal, infection rates were 11.3% and 18.8% for Cx. annulirostris and Cx. sitiens, respectively. Cx. annulirostris transmitted the virus at low levels (5.6% had BgV-positive saliva overall); Cx. sitiens did not transmit the virus. When mosquitoes were injected intrathoracially with BgV, the infection and transmission rates were 100% and 82%, respectively, for both species. These results provided evidence for the first time that BgV can be transmitted horizontally by Cx. annulirostris, the primary vector of pathogenic zoonotic flaviviruses in Australia. We also assessed whether BgV could interfere with replication in vitro, and infection and transmission in vivo of super-infecting pathogenic Culex-associated flaviviruses. BgV significantly reduced growth of Murray Valley encephalitis and West Nile (WNV) viruses in vitro. While prior infection with BgV by injection did not inhibit WNV super-infection of Cx. annulirostris, significantly fewer BgV-infected mosquitoes could transmit WNV than mock-injected mosquitoes. Overall, these data contribute to our understanding of flavivirus ecology, modes of transmission by Australian mosquitoes and mechanisms for super-infection interference. Mosquito-borne flaviviruses include medically significant members such as the dengue viruses, yellow fever virus and Zika virus. These viruses regularly cause outbreaks globally, notably in tropical regions. The ability of mosquitoes to transmit these viruses to vertebrate hosts plays a major role in determining the scale of these outbreaks. It is essential to assess the risk of emergence of flaviviruses in a given region by investigating the vector competence of local mosquitoes for these viruses. Bamaga virus was recently discovered in Australia in Culex mosquitoes and shown to be related to yellow fever virus. In this article, we investigated the potential for Bamaga virus to emerge as an arthropod-borne viral pathogen by assessing the vector competence of Cx. annulirostris and Cx. sitiens mosquitoes for this virus. We showed that Bamaga virus could be detected in the saliva of Cx. annulirostris after an infectious blood-meal, demonstrating that the virus could be horizontally transmitted. In addition, we showed that Bamaga virus could interfere with the replication in vitro and transmission in vivo of the pathogenic flavivirus West Nile virus. These data provide further insight on how interactions between viruses in their vector can influence the efficiency of pathogen transmission.
Collapse
Affiliation(s)
- Agathe M. G. Colmant
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Sonja Hall-Mendelin
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, Coopers Plains, QLD, Australia
| | - Scott A. Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Helle Bielefeldt-Ohmann
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
- School of Veterinary Science, The University of Queensland, Gatton Campus, QLD, Gatton Australia
| | - Jessica J. Harrison
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Natalee D. Newton
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Caitlin A. O’Brien
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Chris Cazier
- Technical Services, Biosciences Division, Faculty of Health, Queensland University of Technology, Gardens Point Campus, Brisbane, Qld, Australia
| | - Cheryl A. Johansen
- PathWest Laboratory Medicine WA, Nedlands, Western Australia, Australia
- School of Biomedical Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Jody Hobson-Peters
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Roy A. Hall
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
- * E-mail: (RAH); (AFVDH)
| | - Andrew F. van den Hurk
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, Coopers Plains, QLD, Australia
- * E-mail: (RAH); (AFVDH)
| |
Collapse
|
27
|
Ramírez AL, Hall-Mendelin S, Doggett SL, Hewitson GR, McMahon JL, Ritchie SA, van den Hurk AF. Mosquito excreta: A sample type with many potential applications for the investigation of Ross River virus and West Nile virus ecology. PLoS Negl Trop Dis 2018; 12:e0006771. [PMID: 30169512 PMCID: PMC6136815 DOI: 10.1371/journal.pntd.0006771] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/13/2018] [Accepted: 08/20/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Emerging and re-emerging arthropod-borne viruses (arboviruses) cause human and animal disease globally. Field and laboratory investigation of mosquito-borne arboviruses requires analysis of mosquito samples, either individually, in pools, or a body component, or secretion such as saliva. We assessed the applicability of mosquito excreta as a sample type that could be utilized during studies of Ross River and West Nile viruses, which could be applied to the study of other arboviruses. METHODOLOGY/PRINCIPAL FINDINGS Mosquitoes were fed separate blood meals spiked with Ross River virus and West Nile virus. Excreta was collected daily by swabbing the bottom of containers containing batches and individual mosquitoes at different time points. The samples were analyzed by real-time RT-PCR or cell culture enzyme immunoassay. Viral RNA in excreta from batches of mosquitoes was detected continuously from day 2 to day 15 post feeding. Viral RNA was detected in excreta from at least one individual mosquito at all timepoints, with 64% and 27% of samples positive for RRV and WNV, respectively. Excretion of viral RNA was correlated with viral dissemination in the mosquito. The proportion of positive excreta samples was higher than the proportion of positive saliva samples, suggesting that excreta offers an attractive sample for analysis and could be used as an indicator of potential transmission. Importantly, only low levels of infectious virus were detected by cell culture, suggesting a relatively low risk to personnel handling mosquito excreta. CONCLUSIONS/SIGNIFICANCE Mosquito excreta is easily collected and provides a simple and efficient method for assessing viral dissemination, with applications ranging from vector competence experiments to complementing sugar-based arbovirus surveillance in the field, or potentially as a sample system for virus discovery.
Collapse
Affiliation(s)
- Ana L. Ramírez
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Sonja Hall-Mendelin
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland, Australia
| | - Stephen L. Doggett
- Department of Medical Entomology, NSW Health Pathology-ICPMR, Westmead Hospital, Westmead, New South Wales, Australia
| | - Glen R. Hewitson
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland, Australia
| | - Jamie L. McMahon
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland, Australia
| | - Scott A. Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Andrew F. van den Hurk
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland, Australia
| |
Collapse
|
28
|
Oliveira AR, Strathe E, Etcheverry L, Cohnstaedt LW, McVey DS, Piaggio J, Cernicchiaro N. Assessment of data on vector and host competence for Japanese encephalitis virus: A systematic review of the literature. Prev Vet Med 2018; 154:71-89. [DOI: 10.1016/j.prevetmed.2018.03.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 12/15/2022]
|
29
|
More S, Bicout D, Bøtner A, Butterworth A, Calistri P, De Koeijer A, Depner K, Edwards S, Garin-Bastuji B, Good M, Gortazar Schmidt C, Michel V, Miranda MA, Nielsen SS, Raj M, Sihvonen L, Spoolder H, Thulke HH, Velarde A, Willeberg P, Winckler C, Bau A, Beltran-Beck B, Carnesecchi E, Casier P, Czwienczek E, Dhollander S, Georgiadis M, Gogin A, Pasinato L, Richardson J, Riolo F, Rossi G, Watts M, Lima E, Stegeman JA. Vector-borne diseases. EFSA J 2017; 15:e04793. [PMID: 32625493 PMCID: PMC7009857 DOI: 10.2903/j.efsa.2017.4793] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
After a request from the European Commission, EFSA's Panel on Animal Health and Welfare summarised the main characteristics of 36 vector‐borne diseases (VBDs) in https://efsa.maps.arcgis.com/apps/PublicGallery/index.html?appid=dfbeac92aea944599ed1eb754aa5e6d1. The risk of introduction in the EU through movement of livestock or pets was assessed for each of the 36 VBDs individually, using a semiquantitative Method to INTegrate all relevant RISK aspects (MINTRISK model), which was further modified to a European scale into the http://www3.lei.wur.nl/mintrisk/ModelMgt.aspx. Only eight of the 36 VBD‐agents had an overall rate of introduction in the EU (being the combination of the rate of entry, vector transmission and establishment) which was estimated to be above 0.001 introductions per year. These were Crimean‐Congo haemorrhagic fever virus, bluetongue virus, West Nile virus, Schmallenberg virus, Hepatozoon canis, Leishmania infantum, Bunyamwera virus and Highlands J. virus. For these eight diseases, the annual extent of spread was assessed, assuming the implementation of available, authorised prevention and control measures in the EU. Further, the probability of overwintering was assessed, as well as the possible impact of the VBDs on public health, animal health and farm production. For the other 28 VBD‐agents for which the rate of introduction was estimated to be very low, no further assessments were made. Due to the uncertainty related to some parameters used for the risk assessment or the instable or unpredictability disease situation in some of the source regions, it is recommended to update the assessment when new information becomes available. Since this risk assessment was carried out for large regions in the EU for many VBD‐agents, it should be considered as a first screening. If a more detailed risk assessment for a specific VBD is wished for on a national or subnational level, the EFSA‐VBD‐RISK‐model is freely available for this purpose.
Collapse
|
30
|
Mansfield KL, Hernández-Triana LM, Banyard AC, Fooks AR, Johnson N. Japanese encephalitis virus infection, diagnosis and control in domestic animals. Vet Microbiol 2017; 201:85-92. [PMID: 28284628 DOI: 10.1016/j.vetmic.2017.01.014] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 01/12/2017] [Accepted: 01/13/2017] [Indexed: 11/16/2022]
Abstract
Japanese encephalitis virus (JEV) is a significant cause of neurological disease in humans throughout Asia causing an estimated 70,000 human cases each year with approximately 10,000 fatalities. The virus contains a positive sense RNA genome within a host-derived membrane and is classified within the family Flaviviridae. Like many flaviviruses, it is transmitted by mosquitoes, particularly those of the genus Culex in a natural cycle involving birds and some livestock species. Spill-over into domestic animals results in a spectrum of disease ranging from asymptomatic infection in some species to acute neurological signs in others. The impact of JEV infection is particularly apparent in pigs. Although infection in adult swine does not result in symptomatic disease, it is considered a significant reproductive problem causing abortion, still-birth and birth defects. Infected piglets can display fatal neurological disease. Equines are also infected, resulting in non-specific signs including pyrexia, but occasionally leading to overt neurological disease that in extreme cases can lead to death. Veterinary vaccination is available for both pigs and horses. This review of JEV disease in livestock considers the current diagnostic techniques available for detection of the virus. Options for disease control and prevention within the veterinary sector are discussed. Such measures are critical in breaking the link to zoonotic transmission into the human population where humans are dead-end hosts.
Collapse
Affiliation(s)
- Karen L Mansfield
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom; Department of Clinical Infection, Microbiology and Immunology, Institute for Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, United Kingdom
| | - Luis M Hernández-Triana
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Ashley C Banyard
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Anthony R Fooks
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom; Department of Clinical Infection, Microbiology and Immunology, Institute for Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, United Kingdom
| | - Nicholas Johnson
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom; Faculty of Health and Medicine, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
| |
Collapse
|
31
|
European Aedes albopictus and Culex pipiens Are Competent Vectors for Japanese Encephalitis Virus. PLoS Negl Trop Dis 2017; 11:e0005294. [PMID: 28085881 PMCID: PMC5268654 DOI: 10.1371/journal.pntd.0005294] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 01/26/2017] [Accepted: 01/02/2017] [Indexed: 11/19/2022] Open
Abstract
Background Japanese encephalitis virus (JEV) is the causative agent of Japanese encephalitis, the leading cause of viral encephalitis in Asia. JEV transmission cycle involves mosquitoes and vertebrate hosts. The detection of JEV RNA in a pool of Culex pipiens caught in 2010 in Italy raised the concern of a putative emergence of the virus in Europe. We aimed to study the vector competence of European mosquito populations, such as Cx. pipiens and Aedes albopictus for JEV genotypes 3 and 5. Findings After oral feeding on an infectious blood meal, mosquitoes were dissected at various times post-virus exposure. We found that the peak for JEV infection and transmission was between 11 and 13 days post-virus exposure. We observed a faster dissemination of both JEV genotypes in Ae. albopictus mosquitoes, when compared with Cx. pipiens mosquitoes. We also dissected salivary glands and collected saliva from infected mosquitoes and showed that Ae. albopictus mosquitoes transmitted JEV earlier than Cx. pipiens. The virus collected from Ae. albopictus and Cx. pipiens saliva was competent at causing pathogenesis in a mouse model for JEV infection. Using this model, we found that mosquito saliva or salivary glands did not enhance the severity of the disease. Conclusions In this study, we demonstrated that European populations of Ae. albopictus and Cx. pipiens were efficient vectors for JEV transmission. Susceptible vertebrate species that develop high viremia are an obligatory part of the JEV transmission cycle. This study highlights the need to investigate the susceptibility of potential JEV reservoir hosts in Europe, notably amongst swine populations and local water birds. Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis in Asia. JEV is maintained in a cycle involving mosquitoes and vertebrate hosts, mainly pigs and wading birds. Humans can be infected when bitten by an infected mosquito. Culex tritaeniorhynchus is the main vector of the disease in tropical and subtropical areas. The recent detection of JEV in birds and mosquitoes collected in Northern Italy has led us to evaluate the putative emergence of this arboviral disease in Europe. For this purpose, we have tested the competence of European populations of Cx. pipiens and Aedes albopictus to transmit this virus in a laboratory setting. We showed that these local mosquitoes could be infected and were capable of transmitting a pathogenic virus to mice. It is thus urgent to evaluate the risks of JEV emergence in European regions displaying a favorable environment for mosquito vectors, susceptible pigs and wading birds.
Collapse
|
32
|
Differential Infectivities among Different Japanese Encephalitis Virus Genotypes in Culex quinquefasciatus Mosquitoes. PLoS Negl Trop Dis 2016; 10:e0005038. [PMID: 27706157 PMCID: PMC5051684 DOI: 10.1371/journal.pntd.0005038] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 09/13/2016] [Indexed: 12/29/2022] Open
Abstract
During the last 20 years, the epidemiology of Japanese encephalitis virus (JEV) has changed significantly in its endemic regions due to the gradual displacement of the previously dominant genotype III (GIII) with clade b of GI (GI-b). Whilst there is only limited genetic difference distinguishing the two GI clades (GI-a and GI-b), GI-b has shown a significantly wider and more rapid dispersal pattern in several regions in Asia than the GI-a clade, which remains restricted in its geographic distribution since its emergence. Although previously published molecular epidemiological evidence has shown distinct phylodynamic patterns, characterization of the two GI clades has only been limited to in vitro studies. In this study, Culex quinquefasciatus, a known competent JEV mosquito vector species, was orally challenged with three JEV strains each representing GI-a, GI-b, and GIII, respectively. Infection and dissemination were determined based on the detection of infectious viruses in homogenized mosquitoes. Detection of JEV RNA in mosquito saliva at 14 days post infection indicated that Cx. quinquefasciatus can be a competent vector species for both GI and GIII strains. Significantly higher infection rates in mosquitoes exposed to the GI-b and GIII strains than the GI-a strain suggest infectivity in arthropod vectors may lead to the selective advantage of previously and currently dominant genotypes. It could thus play a role in enzootic transmission cycles for the maintenance of JEV if this virus were ever to be introduced into North America. Japanese encephalitis virus (JEV) is a zoonotic flavivirus, which is primarily transmitted by Culex species mosquitoes and a leading cause of pediatric encephalitis in Asia. JEV is also an important public health threat to countries outside the endemic region because collections of Cx. quinquefasciatus from around the world have demonstrated competence for the transmission of JEV and are capable of establishing enzootic transmission cycles between viremic avian and swine species. In the last two decades, the dominantly circulating genotype of JEV in endemic regions has experienced a significant shift (genotype III to Genotype I). It is unclear if the newly dominant circulating G1-b genotype can still be vectored by Cx. quinquefasciatus. In this study, Cx. quinquefasciatus collected from North America was demonstrated to be competent for the transmission of the newly dominant genotype. Different infectivities observed between the endemic strains and non-endemic strain provides the mechanistic knowledge of the selection and emergence of endemic genotypes after continuous viral evolution.
Collapse
|
33
|
Meyer Steiger DB, Ritchie SA, Laurance SGW. Mosquito communities and disease risk influenced by land use change and seasonality in the Australian tropics. Parasit Vectors 2016; 9:387. [PMID: 27388293 PMCID: PMC4936001 DOI: 10.1186/s13071-016-1675-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/29/2016] [Indexed: 11/10/2022] Open
Abstract
Background Anthropogenic land use changes have contributed considerably to the rise of emerging and re-emerging mosquito-borne diseases. These diseases appear to be increasing as a result of the novel juxtapositions of habitats and species that can result in new interchanges of vectors, diseases and hosts. We studied whether the mosquito community structure varied between habitats and seasons and whether known disease vectors displayed habitat preferences in tropical Australia. Methods Using CDC model 512 traps, adult mosquitoes were sampled across an anthropogenic disturbance gradient of grassland, rainforest edge and rainforest interior habitats, in both the wet and dry seasons. Nonmetric multidimensional scaling (NMS) ordinations were applied to examine major gradients in the composition of mosquito and vector communities. Results We captured ~13,000 mosquitoes from 288 trap nights across four study sites. A community analysis identified 29 species from 7 genera. Even though mosquito abundance and richness were similar between the three habitats, the community composition varied significantly in response to habitat type. The mosquito community in rainforest interiors was distinctly different to the community in grasslands, whereas forest edges acted as an ecotone with shared communities from both forest interiors and grasslands. We found two community patterns that will influence disease risk at out study sites, first, that disease vectoring mosquito species occurred all year round. Secondly, that anthropogenic grasslands adjacent to rainforests may increase the probability of novel disease transmission through changes to the vector community on rainforest edges, as most disease transmitting species predominantly occurred in grasslands. Conclusion Our results indicate that the strong influence of anthropogenic land use change on mosquito communities could have potential implications for pathogen transmission to humans and wildlife. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1675-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Dagmar B Meyer Steiger
- Centre for Tropical Environmental and Sustainability Studies (TESS) and College of Marine and Environmental Sciences, James Cook University, 4870, Cairns, Queensland, Australia.
| | - Scott A Ritchie
- School of Public Health, Tropical Medicine and Rehabilitative Sciences, James Cook University, 4870, Cairns, Queensland, Australia
| | - Susan G W Laurance
- Centre for Tropical Environmental and Sustainability Studies (TESS) and College of Marine and Environmental Sciences, James Cook University, 4870, Cairns, Queensland, Australia
| |
Collapse
|
34
|
Steiger DBM, Ritchie SA, Laurance SGW. Land Use Influences Mosquito Communities and Disease Risk on Remote Tropical Islands: A Case Study Using a Novel Sampling Technique. Am J Trop Med Hyg 2015; 94:314-21. [PMID: 26711512 DOI: 10.4269/ajtmh.15-0161] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 11/08/2015] [Indexed: 11/07/2022] Open
Abstract
Land use changes, such as deforestation and urbanization, can influence interactions between vectors, hosts, and pathogens. The consequences may result in the appearance and rise of mosquito-borne diseases, especially in remote tropical regions. Tropical regions can be the hotspots for the emergence of diseases due to high biological diversity and complex species interactions. Furthermore, frontier areas are often haphazardly surveyed as a result of inadequate or expensive sampling techniques, which limit early detection and medical intervention. We trialed a novel sampling technique of nonpowered traps and a carbon dioxide attractant derived from yeast and sugar to explore how land use influences mosquito communities on four remote, tropical islands in the Australian Torres Strait. Using this technique, we collected > 11,000 mosquitoes from urban and sylvan habitats. We found that human land use significantly affected mosquito communities. Mosquito abundances and diversity were higher in sylvan habitats compared with urban areas, resulting in significantly different community compositions between the two habitats. An important outcome of our study was determining that there were greater numbers of disease-vectoring species associated with human habitations. On the basis of these findings, we believe that our novel sampling technique is a realistic tool for assessing mosquito communities in remote regions.
Collapse
Affiliation(s)
- Dagmar B Meyer Steiger
- Centre for Tropical Environmental and Sustainability Studies, James Cook University, Cairns, Queensland, Australia; College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia; School of Public Health, Tropical Medicine and Rehabilitative Sciences, James Cook University, Cairns, Queensland, Australia
| | - Scott Alex Ritchie
- Centre for Tropical Environmental and Sustainability Studies, James Cook University, Cairns, Queensland, Australia; College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia; School of Public Health, Tropical Medicine and Rehabilitative Sciences, James Cook University, Cairns, Queensland, Australia
| | - Susan G W Laurance
- Centre for Tropical Environmental and Sustainability Studies, James Cook University, Cairns, Queensland, Australia; College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia; School of Public Health, Tropical Medicine and Rehabilitative Sciences, James Cook University, Cairns, Queensland, Australia
| |
Collapse
|
35
|
Mackenzie-Impoinvil L, Impoinvil DE, Galbraith SE, Dillon RJ, Ranson H, Johnson N, Fooks AR, Solomon T, Baylis M. Evaluation of a temperate climate mosquito, Ochlerotatus detritus (=Aedes detritus), as a potential vector of Japanese encephalitis virus. MEDICAL AND VETERINARY ENTOMOLOGY 2015; 29:1-9. [PMID: 25087926 DOI: 10.1111/mve.12083] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 05/10/2014] [Accepted: 05/28/2014] [Indexed: 06/03/2023]
Abstract
The U.K. has not yet experienced a confirmed outbreak of mosquito-borne virus transmission to people or livestock despite numerous autochthonous epizootic and human outbreaks of mosquito-borne diseases on the European mainland. Indeed, whether or not British mosquitoes are competent to transmit arboviruses has not been established. Therefore, the competence of a local (temperate) British mosquito species, Ochlerotatus detritus (=Aedes detritus) (Diptera: Culicidae) for transmission of a member of the genus Flavivirus, Japanese encephalitis virus (JEV) as a model for mosquito-borne virus transmission was assessed. The JEV competence in a laboratory strain of Culex quinquefasciatus (Diptera: Culicidae), a previously incriminated JEV vector, was also evaluated as a positive control. Ochlerotatus detritus adults were reared from field-collected juvenile stages. In oral infection bioassays, adult females developed disseminated infections and were able to transmit virus as determined by the isolation of virus in saliva secretions. When pooled at 7-21 days post-infection, 13% and 25% of O. detritus were able to transmit JEV when held at 23 °C and 28 °C, respectively. Similar results were obtained for C. quinquefasciatus. To our knowledge, this study is the first to demonstrate that a British mosquito species, O. detritus, is a potential vector of an exotic flavivirus.
Collapse
Affiliation(s)
- L Mackenzie-Impoinvil
- Brain Infections Group, Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, U.K
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Derraik JG, Slaney D. Notes on Zika virus--an emerging pathogen now present in the South Pacific. Aust N Z J Public Health 2015; 39:5-7. [PMID: 25559142 DOI: 10.1111/1753-6405.12302] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
37
|
Nicholson J, Ritchie SA, van den Hurk AF. Aedes albopictus (Diptera: Culicidae) as a potential vector of endemic and exotic arboviruses in Australia. JOURNAL OF MEDICAL ENTOMOLOGY 2014; 51:661-669. [PMID: 24897860 DOI: 10.1603/me13204] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In 2005, established populations of Aedes albopictus (Skuse) were discovered in the Torres Strait, the region that separates Papua New Guinea from northern Australia. This increased the potential for this species to be introduced to mainland Australia. Because it is an arbovirus vector elsewhere, we undertook laboratory-based infection and transmission experiments to determine the potential for Ae. albopictus from the Torres Strait to become infected with and transmit the four major Australian endemic arboviruses--Murray Valley encephalitis virus, West Nile virus Kunjin strain (WNV(KUN)), Ross River virus (RRV), and Barmah Forest virus--as well as the exotic Japanese encephalitis virus. Ae. albopictus is susceptible to infection with all viruses, with infection rates ranging between 8% for WNV(KUN) and 71% for RRV. Transmission rates of approximately 25% were observed for RRV and Barmah Forest virus, but these were < 17% for Murray Valley encephalitis virus, WNV(KUN), and Japanese encephalitis virus. Given its relative vector competence for alphaviruses, we also examined the replication kinetics and extrinsic incubation periods required for transmission of RRV and chikungunya virus. Despite lower body titers, more mosquitoes reared and maintained at 28 degrees C became infected with and transmitted the virus than those reared and maintained at 22 degrees C. The minimum time between Ae. albopictus consuming an infected bloodmeal and transmitting chikungunya virus was 2 d at 28 degrees C and 4 d at 22 degrees C, and for RRV, it was 4 d, irrespective of the temperature. Given its opportunistic feeding habits and aggressive biting behavior, the establishment of Ae. albopictus on the Australian mainland could have a considerable impact on alphavirus transmission.
Collapse
|
38
|
Jansen CC, Hemmerter S, van den Hurk AF, Whelan PI, Beebe NW. Morphological versus molecular identification ofCulex annulirostris Skuse andCulex palpalis Taylor: key members of theCulex sitiens(Diptera: Culicidae) subgroup in Australasia. ACTA ACUST UNITED AC 2013. [DOI: 10.1111/aen.12045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Cassie C Jansen
- CSIRO Ecosystem Sciences; Brisbane Qld 4102 Australia
- School of Biological Sciences; University of Queensland; Brisbane Qld 4072 Australia
| | | | - Andrew F van den Hurk
- Public Health Virology Laboratory; Forensic and Scientific Services; Department of Health; Brisbane Qld 4108 Australia
| | - Peter I Whelan
- Centre for Disease Control; Department of Health and Families; Darwin NT 0811 Australia
| | - Nigel W Beebe
- CSIRO Ecosystem Sciences; Brisbane Qld 4102 Australia
- School of Biological Sciences; University of Queensland; Brisbane Qld 4072 Australia
| |
Collapse
|
39
|
Van Den Hurk AF, Craig SB, Tulsiani SM, Jansen CC. Emerging tropical diseases in Australia. Part 4. Mosquitoborne diseases. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2013; 104:623-40. [DOI: 10.1179/136485910x12851868779984] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
40
|
Russell RC. A review of the status and significance of the species within the Culex pipiens group in Australia. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2012; 28:24-27. [PMID: 23401942 DOI: 10.2987/8756-971x-28.4s.24] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The mosquito known in the northern hemisphere as Culex pipiens (a.k.a. Culex pipiens pipiens or Culex pipiens form pipiens) is not known from Australia. However, there are four species of the Culex pipiens group: two indigenous, Culex australicus and Culex globocoxitus, and two introduced, Culex quinquefasciatus and what is known locally as Culex molestus (? = Culex pipiens molestus or Culex pipiens form molestus), all four being members of the pipiens subgroup (= 'pipiens complex'). The species status of the indigenous Cx. australicus and Cx. globocoxitus in Australia appears to be accepted as legitimate; however, the true identity of the mosquito called 'Cx. molestus' in Australia remains contentious, even as its local profile has been increasing over the past 40 years. This paper provides an overview of the taxonomic and biologic knowledge of these species, and their public health significance as vectors of arboviruses in Australia.
Collapse
Affiliation(s)
- Richard C Russell
- University of Sydney, Department of Medical Entomology, Westmead Hospital, Westmead, NSW 2145, Australia
| |
Collapse
|
41
|
Hall-Mendelin S, Jansen CC, Cheah WY, Montgomery BL, Hall RA, Ritchie SA, Van den Hurk AF. Culex annulirostris (Diptera: Culicidae) host feeding patterns and Japanese encephalitis virus ecology in northern Australia. JOURNAL OF MEDICAL ENTOMOLOGY 2012; 49:371-377. [PMID: 22493857 DOI: 10.1603/me11148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Japanese encephalitis virus (JEV) transmission in northern Australia has, in the past, been facilitated by Culex annulirostris Skuse feeding on domestic pigs, the primary amplifying hosts of the virus. To further characterize mosquito feeding behavior in northern Australia, 1,128 bloodmeals from Cx. annulirostris were analyzed using a double-antibody enzyme-linked immunosorbent assay. Overall, Cx. annulirostris obtained > 94% of blood meals from mammals, comprising marsupials (37%), pigs (20%), dogs (16%), and cows (11%), although the proportion feeding on each of these host types varied between study locations. Where JEV activity was detected, feeding rates on pigs were relatively high. At the location that yielded the first Australian mainland isolate of JEV from mosquitoes, feral pigs (in the absence of domestic pigs) accounted for 82% of bloodmeals identified, representing the first occasion that feeding on feral pigs has been associated with JEV transmission in Australia. Interestingly, < 3% of Cx. annulirostris had fed on pigs at locations on Badu Island where JEV was detected in multiple pools of mosquitoes in a concurrent study. This suggests that either alternative hosts, such as birds, which comprised 21% of blood meals identified, or infected mosquitoes immigrating from areas where domestic pigs are housed, may have contributed to transmission at this location. Because Cx. annulirostris is both an opportunistic feeder and the primary JEV vector in the region, environmental characteristics and host presence can determine JEV transmission dynamics in northern Australia.
Collapse
Affiliation(s)
- Sonja Hall-Mendelin
- Public Health Virology, Queensland Health Forensic and Scientific Services, Coopers Plains, Queensland 4108, Australia
| | | | | | | | | | | | | |
Collapse
|
42
|
Kramer LD, Chin P, Cane RP, Kauffman EB, Mackereth G. Vector competence of New Zealand mosquitoes for selected arboviruses. Am J Trop Med Hyg 2011; 85:182-9. [PMID: 21734146 DOI: 10.4269/ajtmh.2011.11-0078] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
New Zealand (NZ) historically has been free of arboviral activity with the exception of Whataroa virus (Togaviridae: Alphavirus), which is established in bird populations and is transmitted by local mosquitoes. This naive situation is threatened by global warming, invasive mosquitoes, and tourism. To determine the threat of selected medically important arboviruses to NZ, vector competence assays were conducted using field collected endemic and introduced mosquito species. Four alphaviruses (Togaviridae): Barmah Forest virus, Chikungunya virus, Ross River virus, and Sindbis virus, and five flaviviruses (Flaviviridae): Dengue virus 2, Japanese encephalitis virus, Murray Valley encephalitis virus, West Nile virus, and Yellow fever virus were evaluated. Results indicate some NZ mosquito species are highly competent vectors of selected arboviruses, particularly alphaviruses, and may pose a threat were one of these arboviruses introduced at a time when the vector was prevalent and the climatic conditions favorable for virus transmission.
Collapse
Affiliation(s)
- Laura D Kramer
- Wadsworth Center, New York State Department of Health, Albany, New York, USA.
| | | | | | | | | |
Collapse
|
43
|
Exploiting mosquito sugar feeding to detect mosquito-borne pathogens. Proc Natl Acad Sci U S A 2010; 107:11255-9. [PMID: 20534559 DOI: 10.1073/pnas.1002040107] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current surveillance methods that involve detection of virus in mosquito populations or sero-conversion in vertebrate hosts are laborious, expensive, and logistically problematic. We report a unique arbovirus surveillance system to detect arboviruses that exploits the process whereby mosquitoes expectorate virus in their saliva during sugar feeding. In this system, infected mosquitoes captured by CO(2)-baited updraft box traps are allowed to feed on honey-soaked nucleic acid preservation cards within the trap. The cards are then analyzed for expectorated virus using real-time reverse transcription-PCR. In field trials, this system detected the presence of Ross River and Barmah Forest viruses in multiple traps deployed at two locations in Australia. Viral RNA was preserved for at least seven days on the cards, allowing for long-term placement of traps and continuous collection of data documenting virus presence in mosquito populations. Furthermore no mosquito handling or processing was required and cards were conveniently shipped to the laboratory overnight. The simplicity and efficacy of this approach has the potential to transform current approaches to vector-borne disease surveillance by streamlining the monitoring of pathogens in vector populations.
Collapse
|
44
|
Frances SP, MacKenzie DO, Rowcliffe KL, Corcoran SK. Comparative field evaluation of repellent formulations containing deet and IR3535 against mosquitoes in Queensland, Australia. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2009; 25:511-513. [PMID: 20099600 DOI: 10.2987/moco-09-5938.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Field trials comparing repellent formulations containing IR3535 (ethyl butylacetylaminopropionate) and deet (N,N-diethyl-3-methylbenzamide) against mosquitoes in Queensland, Australia, were conducted. Two repellents were compared: Avon Bug Guard, containing 7.5% IR3535; and Australian Defense Force (ADF) deet, containing 35% deet in a gel. Two tests were conducted, one in February-March 2006, and the second in February 2007. In the 1st test, the predominant mosquito species collected were Mansonia uniformis (58.9% of collection) and Culex annulirostris (33.4%), and in the 2nd test, the predominant species was Aedes vigilax (85.7% of collection). In the 1st test, Avon Bug Guard provided >95% protection against all mosquitoes for only 1 h, and ADF deet provided the same level of protection for 5 h. In the 2nd field test, Avon Bug Guard provided only 85% protection against all mosquitoes 1 h after repellent application, while ADF deet provided 5 h of protection. The study showed that ADF deet provided significantly better protection against mosquitoes than Avon Bug Guard (IR3535).
Collapse
Affiliation(s)
- S P Frances
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, Queensland 4051, Australia, USA
| | | | | | | |
Collapse
|
45
|
Johansen CA, Power SL, Broom AK. Determination of mosquito (Diptera: Culicidae) bloodmeal sources in Western Australia: implications for arbovirus transmission. JOURNAL OF MEDICAL ENTOMOLOGY 2009; 46:1167-1175. [PMID: 19769051 DOI: 10.1603/033.046.0527] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A double-antibody enzyme-linked immunosorbent assay was used to determine the bloodmeal sources of adult mosquitoes (Diptera: Culicidae) collected in encephalitis vector surveillance mosquito traps in Western Australia between May 1993 and August 2004. In total, 2,606 blood-fed mosquitoes, representing 29 mosquito species, were tested, and 81.7% reacted with one or more of the primary antibodies. Aedes camptorhynchus (Thomson) and Culex annulirostris Skuse were the most common species tested, making up 47.2% (1,234) and 35.6% (930), respectively. These species obtained bloodmeals from a variety of vertebrate hosts but particularly marsupials and cows. In contrast, Culex pullus Theobald (72.7%; 24/33), Culiseta atra (Lee) (70.0%; 7/10), Culex globocoxitus Dobrotworsky (54.5%; 12/22), and Culex quinquefasciatus Say (39.3%; 22/56) often obtained bloodmeals from birds. Although Ae. camptorhynchus and Cx. annulirostris are well established vectors of arboviruses, other mosquitoes also may have a role in enzootic and/ or epizootic transmission.
Collapse
Affiliation(s)
- C A Johansen
- Discipline of Microbiology and Immunology, School of Biomedical, Biomolecular, and Chemical Sciences, The University of Western Australia, Nedlands, Western Australia 6009, Australia.
| | | | | |
Collapse
|
46
|
Johnson PH, Hall-Mendelin S, Whelan PI, Frances SP, Jansen CC, Mackenzie DO, Northill JA, van den Hurk AF. Vector competence of AustralianCulex gelidusTheobald (Diptera: Culicidae) for endemic and exotic arboviruses. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1440-6055.2009.00711.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
47
|
van den Hurk AF, Ritchie SA, Mackenzie JS. Ecology and geographical expansion of Japanese encephalitis virus. ANNUAL REVIEW OF ENTOMOLOGY 2009; 54:17-35. [PMID: 19067628 DOI: 10.1146/annurev.ento.54.110807.090510] [Citation(s) in RCA: 314] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Japanese encephalitis virus (JEV) (Flavivirus: Flaviviridae) is a leading cause of encephalitis in eastern and southern Asia. The virus is maintained in a zoonotic cycle between ardeid wading birds and/or pigs and Culex mosquitoes. The primary mosquito vector of JEV is Culex tritaeniorhynchus, although species such as Cx. gelidus, Cx. fuscocephala, and Cx. annulirostris are important secondary or regional vectors. Control of JEV is achieved through human and/or swine vaccination, changes in animal husbandry, mosquito control, or a combination of these strategies. This review outlines the ecology of JEV and examines the recent expansion of its geographical range, before assessing its ability to emerge in new regions, using the hypothetical establishment in the United States as a case study.
Collapse
Affiliation(s)
- Andrew F van den Hurk
- Virology, Queensland Health Forensic and Scientific Services, Archerfield, Queensland 4108, Australia.
| | | | | |
Collapse
|
48
|
Ritchie SA, Zborowski P, Banks D, Walsh I, Davis J. Efficacy of novel updraft traps for collection of mosquitoes in Cairns, Australia. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2008; 24:520-527. [PMID: 19181059 DOI: 10.2987/5698.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We conducted trials in Cairns, Australia, to examine if novel updraft light traps collected significantly more mosquitoes than the Centers for Disease Control and Prevention (CDC) model 512 miniature light trap. Two new updraft traps, the Northern Australia Quarantine Strategy (NAQS) Mozzie Trap and a CDC updraft trap, both collected significantly more mosquitoes than the standard CDC light trap, with a mean CDC Trap Index (trap collections relative to paired standard CDC light trap collections) of 3.3 and 2.3, respectively. These traps both had large horizontal suction areas that increased the probability that attracted mosquitoes entered the trap updraft. However, if the CO2 source was located within the updraft of the CDC updraft trap, mosquito collections decreased considerably, indicating that placement of the bait is critical to trap performance. Creating an updraft by simply inverting the CDC trap body did not increase collections. The Mosquito Magnet X trap also did not collect significantly more mosquitoes than the CDC trap. Two CDC light traps sharing a 600 ml CO2/min gas line collected ca. 50% more mosquitoes than a single CDC trap baited with 600 ml CO2/min, suggesting that a single gas source could be used on a trap line consisting of multiple trap units. These studies suggest that the optimal trap design should incorporate a CO2 release system that lures mosquitoes to a large updraft within a bowl-shaped trap intake.
Collapse
Affiliation(s)
- Scott A Ritchie
- Tropical Population Health Unit, Queensland Health, P.O. Box 1103, Cairns, Queensland 4870, Australia
| | | | | | | | | |
Collapse
|
49
|
Ritchie SA, van den Hurk AF, Zborowski P, Kerlin TJ, Banks D, Walker JA, Lee JM, Montgomery BL, Smith GA, Pyke AT, Smith IL. Operational trials of remote mosquito trap systems for Japanese encephalitis virus surveillance in the Torres Strait, Australia. Vector Borne Zoonotic Dis 2008; 7:497-506. [PMID: 18021024 DOI: 10.1089/vbz.2006.0643] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Japanese encephalitis virus (JEV) appears nearly annually in the Torres Strait in far northern Queensland, Australia, and is a threat to invade the Australian mainland. Surveillance has involved the use of sentinel pigs that develop detectable viremias and antibody titers to JEV. However, pigs are amplifying hosts for JEV, and thus pose a health risk to the public and to pig handlers who bleed the pigs. A remote mosquito trap system would not have these risks. We report on trials using a remote mosquito trap system for the surveillance of JEV in the Torres Strait. The Mosquito Magnet (MM) Pro, MM Liberty Plus, and a novel updraft trap, the NAQS Mozzie Trap, were run at Badu and Moa islands in the Torres Strait and at Bamaga in the northern Cape York Peninsula from 2002-2005. TaqMan real-time polymerase chain reaction (PCR) was used to detect JEV nucleic acid in weekly mosquito collections. Sentinel pigs located at Badu were also bled and the serum processed by reverse transcriptase (RT)-PCR for JEV antigen and enzyme-linked immunosorbent assay (ELISA) for anti-JEV antibodies. JEV was detected in mosquito collections each year but not in each trap. No JEV was detected in trapped mosquitoes before detection in sentinel pigs. The mosquito trap system cost ca. AU$10,000 per site, about AU$5,000 less than a pig-based system. However, trap failures caused by mosquito-clogged motors, electrical faults, and blocked gas lines reduced the efficacy of some mosquito traps. Nonetheless, a remote mosquito trap system, employing stand alone traps and PCR for viral antigen detection, can be a safe, economical way to detect arbovirus activity in remote areas.
Collapse
Affiliation(s)
- Scott A Ritchie
- Tropical Population Health Unit, Queensland Health, School of Public Health and Tropical Medicine, James Cook University, Cairns, Queensland, Australia.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
McGinn D, Frances SP, Sweeney AW, Brown MD, Cooper RD. Evaluation of Bistar 80SC (bifenthrin) as a tent treatment for protection against mosquitoes in Northern Territory, Australia. JOURNAL OF MEDICAL ENTOMOLOGY 2008; 45:1087-1091. [PMID: 19058633 DOI: 10.1603/0022-2585(2008)45[1087:eobsba]2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A field trial to assess the efficacy of Bistar 80 SC as a barrier treatment of Australian military tents was conducted over 10 d at Mount Bundey Military Training Area, Northern Territory, Australia, in March 2003. Four pairs of standard eight-person tents were erected, with a single tent in each pair treated with 0.1% Bistar 80 SC as a course spray, and the remainder left as untreated control tents. Carbon dioxide-baited traps were operated in each tent nightly, and biting collections conducted over 8 nights. There was a mean increase in protection of 81% for mosquitoes entering treated tents and 90.4% increase in protection against biting of predominantly Culex annulirostris Skuse. In addition, bifenthrin applied to the military tents enhances the protection of occupants against bites from this important arbovirus vector.
Collapse
Affiliation(s)
- D McGinn
- Griffith University, School of Public Health, Queensland, 4074, Australia
| | | | | | | | | |
Collapse
|