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Yuen NKY, Bielefeldt-Ohmann H, Coyle MP, Henning J. Exposure dynamics of Ross River virus in horses - Horses as potential sentinels (a One Health approach). Epidemiol Infect 2024; 152:e67. [PMID: 38606586 PMCID: PMC11062785 DOI: 10.1017/s0950268824000554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/06/2024] [Accepted: 03/24/2024] [Indexed: 04/13/2024] Open
Abstract
Ross River virus (RRV), the most medically and economically important arbovirus in Australia, has been the most prevalent arbovirus infections in humans for many years. Infected humans and horses often suffer similar clinical symptoms. We conducted a prospective longitudinal study over a 3.5-year period to investigate the exposure dynamics of RRV in three foal cohorts (n = 32) born in a subtropical region of South East Queensland, Australia, between 2020 and 2022. RRV-specific seroconversion was detected in 56% (n = 18) of foals with a median time to seroconversion, after waning of maternal antibodies, of 429 days (95% CI: 294-582). The median age at seroconversion was 69 weeks (95% CI: 53-57). Seroconversion events were only detected between December and March (Southern Hemisphere summer) over the entire study period. Cox proportion hazards regression analyses revealed that seroconversions were significantly (p < 0.05) associated with air temperature in the month of seroconversion. Time-lags in meteorological variables were not significantly (p > 0.05) associated with seroconversion, except for relative humidity (p = 0.036 at 2-month time-lag). This is in contrast to research results of RRV infection in humans, which peaked between March and May (Autumn) and with a 0-3 month time-lag for various meteorological risk factors. Therefore, horses may be suitable sentinels for monitoring active arbovirus circulation and could be used for early arbovirus outbreak detection in human populations.
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Affiliation(s)
- Nicholas K. Y. Yuen
- School of Veterinary Science, Faculty of Science, The University of Queensland, Gatton, Queensland, Australia
| | - Helle Bielefeldt-Ohmann
- School of Chemistry and Molecular Biosciences, Faculty of Science, The University of Queensland, St Lucia, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, Queensland, Australia
| | - Mitchell P. Coyle
- Equine Unit, Office of the Director Gatton Campus, Faculty of Science, The University of Queensland, Gatton, Queensland, Australia
| | - Joerg Henning
- School of Veterinary Science, Faculty of Science, The University of Queensland, Gatton, Queensland, Australia
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2
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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.
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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
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3
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Sikazwe C, Neave MJ, Michie A, Mileto P, Wang J, Cooper N, Levy A, Imrie A, Baird RW, Currie BJ, Speers D, Mackenzie JS, Smith DW, Williams DT. Molecular detection and characterisation of the first Japanese encephalitis virus belonging to genotype IV acquired in Australia. PLoS Negl Trop Dis 2022; 16:e0010754. [PMID: 36409739 PMCID: PMC9721490 DOI: 10.1371/journal.pntd.0010754] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/05/2022] [Accepted: 10/24/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND A fatal case of Japanese encephalitis (JE) occurred in a resident of the Tiwi Islands, in the Northern Territory of Australia in February 2021, preceding the large JE outbreak in south-eastern Australia in 2022. This study reports the detection, whole genome sequencing and analysis of the virus responsible (designated JEV/Australia/NT_Tiwi Islands/2021). METHODS Reverse transcription quantitative PCR (RT-qPCR) testing was performed on post-mortem brain specimens using a range of JE virus (JEV)-specific assays. Virus isolation from brain specimens was attempted by inoculation of mosquito and mammalian cells or embryonated chicken eggs. Whole genome sequencing was undertaken using a combination of Illumina next generation sequencing methodologies, including a tiling amplicon approach. Phylogenetic and selection analyses were performed using alignments of the Tiwi Islands JEV genome and envelope (E) protein gene sequences and publicly available JEV sequences. RESULTS Virus isolation was unsuccessful and JEV RNA was detected only by RT-qPCR assays capable of detecting all JEV genotypes. Phylogenetic analysis revealed that the Tiwi Islands strain is a divergent member of genotype IV (GIV) and is closely related to the 2022 Australian outbreak virus (99.8% nucleotide identity). The Australian strains share highest levels of nucleotide identity with Indonesian viruses from 2017 and 2019 (96.7-96.8%). The most recent common ancestor of this Australian-Indonesian clade was estimated to have emerged in 2007 (95% HPD range: 1998-2014). Positive selection was detected using two methods (MEME and FEL) at several sites in the E and non-structural protein genes, including a single site in the E protein (S194N) unique to the Australian GIV strains. CONCLUSION This case represents the first detection of GIV JEV acquired in Australia, and only the second confirmed fatal human infection with a GIV JEV strain. The close phylogenetic relationship between the Tiwi Islands strain and recent Indonesian viruses is indicative of the origin of this novel GIV lineage, which we estimate has circulated in the region for several years prior to the Tiwi Islands case.
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Affiliation(s)
- Chisha Sikazwe
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - Matthew J. Neave
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
| | - Alice Michie
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - Patrick Mileto
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
| | - Jianning Wang
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
| | - Natalie Cooper
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - Avram Levy
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- School of Biomedical Sciences, University of Western Australia, Nedlands, Western Australia, Australia
| | - Allison Imrie
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- School of Biomedical Sciences, University of Western Australia, Nedlands, Western Australia, Australia
| | - Robert W. Baird
- Pathology and Infectious Diseases Departments, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Bart J. Currie
- Pathology and Infectious Diseases Departments, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - David Speers
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - John S. Mackenzie
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- Faculty of Health Sciences, Curtin University, Bentley, Western Australia, Australia
| | - David W. Smith
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- * E-mail: (DWS); (DTW)
| | - David T. Williams
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
- * E-mail: (DWS); (DTW)
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Yaro AS, Linton YM, Dao A, Diallo M, Sanogo ZL, Samake D, Ousmane Y, Kouam C, Krajacich BJ, Faiman R, Bamou R, Woo J, Chapman JW, Reynolds DR, Lehmann T. Diversity, composition, altitude, and seasonality of high-altitude windborne migrating mosquitoes in the Sahel: Implications for disease transmission. FRONTIERS IN EPIDEMIOLOGY 2022; 2:1001782. [PMID: 38455321 PMCID: PMC10910920 DOI: 10.3389/fepid.2022.1001782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/16/2022] [Indexed: 03/09/2024]
Abstract
Recent studies have reported Anopheles mosquitoes captured at high-altitude (40-290 m above ground) in the Sahel. Here, we describe this migration modality across genera and species of African Culicidae and examine its implications for disease transmission and control. As well as Anopheles, six other genera-Culex, Aedes, Mansonia, Mimomyia, Lutzia, and Eretmapodites comprised 90% of the 2,340 mosquitoes captured at altitude. Of the 50 molecularly confirmed species (N = 2,107), 33 species represented by multiple specimens were conservatively considered high-altitude windborne migrants, suggesting it is a common migration modality in mosquitoes (31-47% of the known species in Mali), and especially in Culex (45-59%). Overall species abundance varied between 2 and 710 specimens/species (in Ae. vittatus and Cx. perexiguus, respectively). At altitude, females outnumbered males 6:1, and 93% of the females have taken at least one blood meal on a vertebrate host prior to their departure. Most taxa were more common at higher sampling altitudes, indicating that total abundance and diversity are underestimated. High-altitude flight activity was concentrated between June and November coinciding with availability of surface waters and peak disease transmission by mosquitoes. These hallmarks of windborne mosquito migration bolster their role as carriers of mosquito-borne pathogens (MBPs). Screening 921 mosquitoes using pan-Plasmodium assays revealed that thoracic infection rate in these high-altitude migrants was 2.4%, providing a proof of concept that vertebrate pathogens are transported by windborne mosquitoes at altitude. Fourteen of the 33 windborne mosquito species had been reported as vectors to 25 MBPs in West Africa, which represent 32% of the MBPs known in that region and include those that inflict the heaviest burden on human and animal health, such as malaria, yellow fever, dengue, and Rift Valley fever. We highlight five arboviruses that are most likely affected by windborne mosquitoes in West Africa: Rift Valley fever, O'nyong'nyong, Ngari, Pangola, and Ndumu. We conclude that the study of windborne spread of diseases by migrating insects and the development of surveillance to map the sources, routes, and destinations of vectors and pathogens is key to understand, predict, and mitigate existing and new threats of public health.
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Affiliation(s)
- Alpha Seydou Yaro
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Yvonne-Marie Linton
- Walter Reed Biosystematics Unit, Smithsonian Institution Museum Support Center, Suitland, MD, United States
- Department of Entomology, Smithsonian Institution, National Museum of Natural History, Washington, DC, United States
- One Health Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Adama Dao
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Moussa Diallo
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Zana L. Sanogo
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Djibril Samake
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Yossi Ousmane
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Cedric Kouam
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
| | | | - Roy Faiman
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
| | - Roland Bamou
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
| | - Joshua Woo
- Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD, United States
| | - Jason W. Chapman
- Centre for Ecology and Conservation, and Environment and Sustainability Institute, University of Exeter, Penryn, United Kingdom
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Don R. Reynolds
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
- Rothamsted Research, Harpenden, United Kingdom
| | - Tovi Lehmann
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
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Paulraj PS, Rajamannar V, Renu G, Kumar A. Changing Paradigm in the epidemiology of Japanese encephalitis in India. J Vector Borne Dis 2022; 59:312-319. [PMID: 36751762 DOI: 10.4103/0972-9062.345180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Japanese encephalitis (JE) is a very serious public health problem in India and the conducive environment permit its emergence in non-endemic areas in the country. There are constant changes taking place in the pattern of current agricultural practices and vector breeding habitats which had far-reaching consequences on the epidemiology of JE and the severity of epidemic outbreaks today. Due to the continuous ecological changes taking place, vectors changed in their breeding dynamics, feeding, and resting behavior and started invading previously non-endemic areas. JE has recently spread to new territories due to land-use changes, including forest fragmentation and concentrated livestock production. Changes in the livestock population decreased the cattle pig ratio which enhanced the Japanese encephalitis virus (JEV) infection. This review brings forth the present widespread changes encountered that grossly impact the risk of infection in many places for the emergence of Japanese encephalitis and to address the implications for its control.
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Affiliation(s)
| | | | - Govindarajan Renu
- ICMR-Vector Control Research Centre, Field Station, Madurai, Tamil Nadu, India
| | - Ashwani Kumar
- ICMR Vector Control Research Centre, Puducherry, India
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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.
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Mulvey P, Duong V, Boyer S, Burgess G, Williams DT, Dussart P, Horwood PF. The Ecology and Evolution of Japanese Encephalitis Virus. Pathogens 2021; 10:1534. [PMID: 34959489 PMCID: PMC8704921 DOI: 10.3390/pathogens10121534] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by Culex mosquitoes that currently has a geographic distribution across most of Southeast Asia and the Western Pacific. Infection with JEV can cause Japanese encephalitis (JE), a severe disease with a high mortality rate, which also results in ongoing sequalae in many survivors. The natural reservoir of JEV is ardeid wading birds, such as egrets and herons, but pigs commonly play an important role as an amplifying host during outbreaks in human populations. Other domestic animals and wildlife have been detected as hosts for JEV, but their role in the ecology and epidemiology of JEV is uncertain. Safe and effective JEV vaccines are available, but unfortunately, their use remains low in most endemic countries where they are most needed. Increased surveillance and diagnosis of JE is required as climate change and social disruption are likely to facilitate further geographical expansion of Culex vectors and JE risk areas.
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Affiliation(s)
- Peter Mulvey
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
| | - Veasna Duong
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Sebastien Boyer
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Graham Burgess
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
| | - David T. Williams
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Geelong 3220, Australia;
| | - Philippe Dussart
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Paul F. Horwood
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
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8
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Spatiotemporal Analysis of West Nile Virus Epidemic in South Banat District, Serbia, 2017-2019. Animals (Basel) 2021; 11:ani11102951. [PMID: 34679972 PMCID: PMC8533022 DOI: 10.3390/ani11102951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/05/2021] [Accepted: 10/09/2021] [Indexed: 11/17/2022] Open
Abstract
West Nile virus (WNV) is an arthropod-born pathogen, which is transmitted from wild birds through mosquitoes to humans and animals. At the end of the 20th century, the first West Nile fever (WNF) outbreaks among humans in urban environments in Eastern Europe and the United States were reported. The disease continued to spread to other parts of the continents. In Serbia, the largest number of WNV-infected people was recorded in 2018. This research used spatial statistics to identify clusters of WNV infection in humans and animals in South Banat County, Serbia. The occurrence of WNV infection and risk factors were analyzed using a negative binomial regression model. Our research indicated that climatic factors were the main determinant of WNV distribution and were predictors of endemicity. Precipitation and water levels of rivers had an important influence on mosquito abundance and affected the habitats of wild birds, which are important for maintaining the virus in nature. We found that the maximum temperature of the warmest part of the year and the annual temperature range; and hydrographic variables, e.g., the presence of rivers and water streams were the best environmental predictors of WNF outbreaks in South Banat County.
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Bamou R, Mayi MPA, Djiappi-Tchamen B, Nana-Ndjangwo SM, Nchoutpouen E, Cornel AJ, Awono-Ambene P, Parola P, Tchuinkam T, Antonio-Nkondjio C. An update on the mosquito fauna and mosquito-borne diseases distribution in Cameroon. Parasit Vectors 2021; 14:527. [PMID: 34635176 PMCID: PMC8507310 DOI: 10.1186/s13071-021-04950-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
The expansion of mosquito-borne diseases such as dengue, yellow fever, and chikungunya in the past 15 years has ignited the need for active surveillance of common and neglected mosquito-borne infectious diseases. The surveillance should be designed to detect diseases and to provide relevant field-based data for developing and implementing effective control measures to prevent outbreaks before significant public health consequences can occur. Mosquitoes are important vectors of human and animal pathogens, and knowledge on their biodiversity and distribution in the Afrotropical region is needed for the development of evidence-based vector control strategies. Following a comprehensive literature search, an inventory of the diversity and distribution of mosquitoes as well as the different mosquito-borne diseases found in Cameroon was made. A total of 290 publications/reports and the mosquito catalogue website were consulted for the review. To date, about 307 species, four subspecies and one putative new species of Culicidae, comprising 60 species and one putative new species of Anopheles, 67 species and two subspecies of Culex, 77 species and one subspecies of Aedes, 31 species and one subspecies of Eretmapodites, two Mansonia, eight Coquillettidia, and 62 species with unknown medical and veterinary importance (Toxorhynchites, Uranotaenia, Mimomyia, Malaya, Hodgesia, Ficalbia, Orthopodomyia, Aedeomyia, and Culiseta and Lutzia) have been collected in Cameroon. Multiple mosquito species implicated in the transmission of pathogens within Anopheles, Culex, Aedes, Eretmapodites, Mansonia, and Coquillettidia have been reported in Cameroon. Furthermore, the presence of 26 human and zoonotic arboviral diseases, one helminthic disease, and two protozoal diseases has been reported. Information on the bionomics, taxonomy, and distribution of mosquito species will be useful for the development of integrated vector management programmes for the surveillance and elimination of mosquito-borne diseases in Cameroon. ![]()
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Affiliation(s)
- Roland Bamou
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon. .,Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon. .,Aix Marseille Univ, IRD, SSA, AP-HM, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France. .,IHU Méditerranée Infection, Marseille, France.
| | - Marie Paul Audrey Mayi
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - Borel Djiappi-Tchamen
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon.,Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Stella Mariette Nana-Ndjangwo
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon.,Laboratoire de Parasitologie et d'écologie, Université de Yaoundé 1, Yaoundé, Cameroun
| | - Elysée Nchoutpouen
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Antony John Cornel
- Department of Entomology and Nematology, Mosquito Control Research Laboratory, University of California, Davis, California, USA
| | - Parfait Awono-Ambene
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Phillipe Parola
- Aix Marseille Univ, IRD, SSA, AP-HM, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,IHU Méditerranée Infection, Marseille, France
| | - Timoléon Tchuinkam
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - Christophe Antonio-Nkondjio
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon.,Vector Biology Liverpool School of Tropical Medicine, Liverpool, UK
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Thongjued K, Chotigeat W, Bumrungsri S, Thanakiatkrai P, Kitpipit T. Direct PCR-DGGE Technique Reveals Wrinkle-Lipped Free-Tailed Bat (Chaerephon plicatus Buchanan, 1800) Predominantly Consume Planthoppers and Mosquitoes in Central Thailand. ACTA CHIROPTEROLOGICA 2021. [DOI: 10.3161/15081109acc2021.23.1.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Kantima Thongjued
- Prince of Songkla University, 15 Karnchanawanich Road, Hat Yai, Songkhla, Thailand 90112
| | - Wilaiwan Chotigeat
- Prince of Songkla University, 15 Karnchanawanich Road, Hat Yai, Songkhla, Thailand 90112
| | - Sara Bumrungsri
- Prince of Songkla University, 15 Karnchanawanich Road, Hat Yai, Songkhla, Thailand 90112
| | - Phuvadol Thanakiatkrai
- Prince of Songkla University, 15 Karnchanawanich Road, Hat Yai, Songkhla, Thailand 90112
| | - Thitika Kitpipit
- Prince of Songkla University, 15 Karnchanawanich Road, Hat Yai, Songkhla, Thailand 90112
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11
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Md Naim D, Kamal NZM, Mahboob S. Population structure and genetic diversity of Aedes aegypti and Aedes albopictus in Penang as revealed by mitochondrial DNA cytochrome oxidase I. Saudi J Biol Sci 2020; 27:953-967. [PMID: 32127775 PMCID: PMC7042630 DOI: 10.1016/j.sjbs.2020.01.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 11/24/2022] Open
Abstract
The population genetics study is crucial as it helps in understanding the epidemiological aspects of dengue and help improving a vector control measures. This research aims to investigate the population genetics structure of two common species of Aedes mosquitoes in Penang; Aedes aegypti and Aedes albopictus using Cytochrome Oxidase I (COI) mitochondrial DNA (mtDNA) marker. Molecular investigations were derived from 440 bp and 418 bp mtDNA COI on 125 and 334 larvae of Aedes aegypti and Aedes albopictus respectively, from 32 locations in Penang. All samples were employed in the BLASTn for species identification. The haplotype diversity, nucleotide diversity, neutrality test and mismatch distribution analysis were conducted in DnaSP version 5.10.1. AMOVA analysis was conducted in ARLEQUIN version 3.5 and the phylogenetic reconstructions based on maximum likelihood (ML) and neighbor-joining (NJ) methods were implemented in MEGA X. The relationships among haplotypes were further tested by creating a minimum spanning tree using Network version 4.6.1. All samples were genetically identified and clustered into six distinct species. Among the species, Ae. albopictus was the most abundant (67.2%), followed by Ae. aegypti (25.2%) and the rest were counted for Culex sp. and Toxorhynchites sp. Both Ae. aegypti and Ae. albopictus show low nucleotide diversity (π) and high haplotype diversity (h), while the neutrality test shows a negative value in most of the population for both species. There are a total of 39 and 64 haplotypes recorded for Ae. aegypti and Ae. albopictus respectively. AMOVA analysis revealed that most of the variation occurred within population for both species. Mismatch distribution analysis showed bimodal characteristic of population differentiation for Ae. aegypti but Ae. albopictus showed unimodal characteristics of population differentiation. Genetic distance based on Tamura-Nei parameter showed low genetic divergent within population and high genetic divergent among population for both species. The maximum likelihood tree showed no obvious pattern of population genetic structure for both Ae. aegypti and Ae. albopictus from Penang and a moderate to high bootstrap values has supported this conclusion. The minimum spanning network for Ae. aegypti and Ae. albopictus showed five and three dominant haplotypes respectively, which indicates a mixture of haplotypes from the regions analysed. This study revealed that there is no population genetic structure exhibited by both Ae. aegypti and Ae. albopictus in Penang. Mutation has occurred rapidly in both species and this will be challenging in controlling the populations. However, further analysis needed to confirm this statement.
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Affiliation(s)
- Darlina Md Naim
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia
| | | | - Shahid Mahboob
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
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Reisen WK, Wheeler SS. Overwintering of West Nile Virus in the United States. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1498-1507. [PMID: 31549726 DOI: 10.1093/jme/tjz070] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Indexed: 06/10/2023]
Abstract
The establishment of a tropical virus such as West Nile (WNV; Flaviviridae: Flavivirus) within the temperate latitudes of the continental United States was unexpected and perhaps contingent, in part, upon the ability of this invasive virus to persist during winter when temperatures become too cold for replication and vector mosquito gonotrophic activity. Our Forum article reviews research examining possible overwintering mechanisms that include consistent reintroduction and local persistence in vector mosquitoes and avian hosts, mostly using examples from research conducted in California. We conclude that the transmission of WNV involves so many vectors and hosts within different landscapes that multiple overwintering pathways are possible and collectively may be necessary to allow this virus to overwinter consistently within the United States.
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Affiliation(s)
- William K Reisen
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA
| | - Sarah S Wheeler
- Sacramento-Yolo Mosquito and Vector Control District, Elk Grove, CA
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The global biogeography of avian haemosporidian parasites is characterized by local diversification and intercontinental dispersal. Parasitology 2018; 146:213-219. [PMID: 30009719 DOI: 10.1017/s0031182018001130] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The biogeographic histories of parasites and pathogens are infrequently compared with those of free-living species, including their hosts. Documenting the frequency with which parasites and pathogens disperse across geographic regions contributes to understanding not only their evolution, but also the likelihood that they may become emerging infectious diseases. Haemosporidian parasites of birds (parasite genera Plasmodium, Haemoproteus and Leucocytozoon) are globally distributed, dipteran-vectored parasites. To date, over 2000 avian haemosporidian lineages have been designated by molecular barcoding methods. To achieve their current distributions, some lineages must have dispersed long distances, often over water. Here we quantify such events using the global avian haemosporidian database MalAvi and additional records primarily from the Americas. We scored lineages as belonging to one or more global biogeographic regions based on infection records. Most lineages were restricted to a single region but some were globally distributed. We also used part of the cytochrome b gene to create genus-level parasite phylogenies and scored well-supported nodes as having descendant lineages in regional sympatry or allopatry. Descendant sister lineages of Plasmodium, Haemoproteus and Leucocytozoon were distributed in allopatry in 11, 16 and 15% of investigated nodes, respectively. Although a small but significant fraction of the molecular variance in cytochrome b of all three genera could be explained by biogeographic region, global parasite dispersal likely contributed to the majority of the unexplained variance. Our results suggest that avian haemosporidian parasites have faced few geographic barriers to dispersal over their evolutionary history.
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Abstract
Colonization comprises the physical arrival of a species in a new area, but also its successful establishment within the local community. Oceanic islands, like the Hawaiian and the Galapagos archipelagos, represent excellent systems to study the mechanisms of colonization because of their historical isolation. In this chapter, we first review some of the major mechanisms by which parasites and vectors could arrive to an oceanic island, both naturally or due to human activities, and the factors that may influence their successful establishment in the insular host community. We then explore examples of natural and anthropogenic colonization of the Galapagos Islands by parasites and vectors, focusing on one or more case studies that best represent the diversity of colonization mechanisms that has shaped parasite distribution in the archipelago. Finally, we discuss future directions for research on parasite and vector colonization in Galapagos Islands.
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Affiliation(s)
- Patricia G. Parker
- Department of Biology, University of Missouri – St. Louis, St. Louis, Missouri USA
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Cella E, Gabrielli I, Zehender G, Giovanetti M, Presti AL, Lai A, Dicuonzo G, Angeletti S, Salemi M, Ciccozzi M. Phylogeny of Murray Valley encephalitis virus in Australia and Papua New Guinea. ASIAN PAC J TROP MED 2016; 9:385-389. [PMID: 27086158 DOI: 10.1016/j.apjtm.2016.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/20/2016] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To study the genetic diversity of Murray Valley encephalitis virus (MVEV) in Australia and Papua New Guinea. METHODS MVEV envelope gene sequences were aligned using Clustal X and manual editing was performed with Bioedit. ModelTest v. 3.7 was used to select the simplest evolutionary model that adequately fitted the sequence data. Maximum likelihood analysis was performed using PhyML. The phylogenetic signal of the dataset was investigated by the likelihood mapping analysis. The Bayesian phylogenetic tree was built using BEAST. RESULTS The phylogenetic trees showed two main clades. The clade Ⅰ including eight strains isolated from West Australia. The clade Ⅱ was characterized by at least four epidemic entries, three of which localized in Northern West Australia and one in Papua New Guinea. The estimated mean evolutionary rate value of the MVEV envelope gene was 0.407 × 10(-3) substitution/site/year (95% HPD: 0.623 × 10(-4)-0.780 × 10(-3)). Population dynamics defines a relative constant population until the year 2000, when a reduction occurred, probably due to a bottleneck. CONCLUSIONS This study has been useful in supporting the probable connection between climate changes and viral evolution also by the vector point of view; multidisciplinary monitoring studies are important to prevent new viral epidemics inside and outside new endemic areas.
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Affiliation(s)
- Eleonora Cella
- Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy; Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | | | | | - Marta Giovanetti
- Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy; University of Rome 'Tor Vergata', Italy
| | - Alessandra Lo Presti
- Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy
| | - Alessia Lai
- L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, Italy
| | - Giordano Dicuonzo
- Clinical Pathology and Microbiology Laboratory, University Hospital Campus Bio-Medico of Rome, Italy
| | - Silvia Angeletti
- Clinical Pathology and Microbiology Laboratory, University Hospital Campus Bio-Medico of Rome, Italy
| | - Marco Salemi
- Department of Pathology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Massimo Ciccozzi
- Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy; University Hospital Campus Bio-Medico, Rome, Italy.
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Paz S. Climate change impacts on West Nile virus transmission in a global context. Philos Trans R Soc Lond B Biol Sci 2015; 370:20130561. [PMID: 25688020 PMCID: PMC4342965 DOI: 10.1098/rstb.2013.0561] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
West Nile virus (WNV), the most widely distributed virus of the encephalitic flaviviruses, is a vector-borne pathogen of global importance. The transmission cycle exists in rural and urban areas where the virus infects birds, humans, horses and other mammals. Multiple factors impact the transmission and distribution of WNV, related to the dynamics and interactions between pathogen, vector, vertebrate hosts and environment. Hence, among other drivers, weather conditions have direct and indirect influences on vector competence (the ability to acquire, maintain and transmit the virus), on the vector population dynamic and on the virus replication rate within the mosquito, which are mostly weather dependent. The importance of climatic factors (temperature, precipitation, relative humidity and winds) as drivers in WNV epidemiology is increasing under conditions of climate change. Indeed, recent changes in climatic conditions, particularly increased ambient temperature and fluctuations in rainfall amounts, contributed to the maintenance (endemization process) of WNV in various locations in southern Europe, western Asia, the eastern Mediterranean, the Canadian Prairies, parts of the USA and Australia. As predictions show that the current trends are expected to continue, for better preparedness, any assessment of future transmission of WNV should take into consideration the impacts of climate change.
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Affiliation(s)
- Shlomit Paz
- Department of Geography and Environmental Studies, University of Haifa, Israel
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Freed LA, Cann RL. Vector movement underlies avian malaria at upper elevation in Hawaii: implications for transmission of human malaria. Parasitol Res 2013; 112:3887-95. [DOI: 10.1007/s00436-013-3578-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 08/12/2013] [Indexed: 11/28/2022]
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Thomas CJ, Cross DE, Bøgh C. Landscape movements of Anopheles gambiae malaria vector mosquitoes in rural Gambia. PLoS One 2013; 8:e68679. [PMID: 23874719 PMCID: PMC3715529 DOI: 10.1371/journal.pone.0068679] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 06/04/2013] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND For malaria control in Africa it is crucial to characterise the dispersal of its most efficient vector, Anopheles gambiae, in order to target interventions and assess their impact spatially. Our study is, we believe, the first to present a statistical model of dispersal probability against distance from breeding habitat to human settlements for this important disease vector. METHODS/PRINCIPAL FINDINGS We undertook post-hoc analyses of mosquito catches made in The Gambia to derive statistical dispersal functions for An. gambiae sensu lato collected in 48 villages at varying distances to alluvial larval habitat along the River Gambia. The proportion dispersing declined exponentially with distance, and we estimated that 90% of movements were within 1.7 km. Although a 'heavy-tailed' distribution is considered biologically more plausible due to active dispersal by mosquitoes seeking blood meals, there was no statistical basis for choosing it over a negative exponential distribution. Using a simple random walk model with daily survival and movements previously recorded in Burkina Faso, we were able to reproduce the dispersal probabilities observed in The Gambia. CONCLUSIONS/SIGNIFICANCE Our results provide an important quantification of the probability of An. gambiae s.l. dispersal in a rural African setting typical of many parts of the continent. However, dispersal will be landscape specific and in order to generalise to other spatial configurations of habitat and hosts it will be necessary to produce tractable models of mosquito movements for operational use. We show that simple random walk models have potential. Consequently, there is a pressing need for new empirical studies of An. gambiae survival and movements in different settings to drive this development.
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Affiliation(s)
- Christopher J Thomas
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Wales, United Kingdom.
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Impoinvil DE, Baylis M, Solomon T. Japanese encephalitis: on the One Health agenda. Curr Top Microbiol Immunol 2013; 365:205-47. [PMID: 22886540 DOI: 10.1007/82_2012_243] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Japanese encephalitis (JE) is one of the most well studied arthropod zoonotic diseases with human and animal research and their integration spanning 6-7 decades. JE research and policy in some Asian countries has epitomized the 'One Health' strategy of attainment of optimal health for people, animals, and the environment. However, despite significant mitigation of JE in some Asian countries primarily due to vaccination programs and infrastructural development, JE continues to be a major disease burden in the Asian region. Arthropod-borne zoonotic infections such as JE present some of the greatest challenges to animal and human health globally. Their emergence involves a complex interplay of vectors, hosts, environment, climate, and anthropogenic factors. Therefore, the integrated management of infectious agents that affect both humans and animals is perhaps the most highly coveted strategy that public health policy makers aspire to attain in the twenty-first century. This is in response to the seemingly growing challenges of controlling the burden of emerging infectious diseases such as shrinking financial budgets and resources, increasing demand for public health deliverables, demographic shifts and mobility, global trade economies, and climate and landscape changes. Thus, while JE research and policy is an excellent example of the One Health strategy in action, further work is required to address the obstinate burden of transmission.
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Affiliation(s)
- Daniel E Impoinvil
- Department of Epidemiology and Population Health, Liverpool University Climate and Infectious Diseases of Animals (LUCINDA group), University of Liverpool-Institute of Infection and Global Health, Leahurst, Neston, Cheshire, CH64 7TE, UK
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Lindahl J, Chirico J, Boqvist S, Thu HTV, Magnusson U. Occurrence of Japanese encephalitis virus mosquito vectors in relation to urban pig holdings. Am J Trop Med Hyg 2012; 87:1076-1082. [PMID: 23033401 PMCID: PMC3516078 DOI: 10.4269/ajtmh.2012.12-0315] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 08/27/2012] [Indexed: 12/12/2022] Open
Abstract
Japanese encephalitis virus (JEV) is transmitted to humans from pigs or birds by mosquitoes. In this study, the association between urban pig keeping and mosquito vectors was analyzed. A total of 7, 419 mosquitoes were collected overnight in urban households with and without pigs in Can Tho City, Vietnam. The most prevalent vectors were Culex tritaeniorhynchus (36%), Cx. gelidus (24%), and Cx. quinquefasciatus (15%), which were present in all parts of the city. Pigs were associated with increased numbers of Cx. tritaeniorhynchus. Traps close to pigs had higher numbers of Cx. tritaeniorhynchus and Cx. gelidus than traps close to humans. Increased number of persons in the household was associated with increased numbers of Cx. quinquefasciatus. We demonstrate that JEV vector species are present at urban households with and without pigs, and show that keeping pigs in an urban area increase the number of mosquitoes competent as vectors for JEV.
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Affiliation(s)
| | | | | | | | - Ulf Magnusson
- Department of Clinical Sciences, National Veterinary Institute, Department of Virology, Immunobiology and Parasitology, and Department of Biomedicine and Veterinary Public Health Swedish, University of Agricultural Sciences, Uppsala, Sweden; Department of Veterinary Medicine, Can Tho University, Can Tho, Vietnam
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Brown CR, O'Brien VA. Are Wild Birds Important in the Transport of Arthropod-borne Viruses? ACTA ACUST UNITED AC 2011. [DOI: 10.1525/om.2011.71.1.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Boyce WM, Vickers W, Morrison SA, Sillett TS, Caldwell L, Wheeler SS, Barker CM, Cummings R, Reisen WK. Surveillance for West Nile virus and vaccination of free-ranging island scrub-jays (Aphelocoma insularis) on Santa Cruz Island, California. Vector Borne Zoonotic Dis 2011; 11:1063-8. [PMID: 21438695 DOI: 10.1089/vbz.2010.0171] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transmission of West Nile virus (WNV) on mainland California poses an ongoing threat to the island scrub-jay (ISSJ, Aphelocoma insularis), a species that occurs only on Santa Cruz Island, California, and whose total population numbers <5000. Our report describes the surveillance and management efforts conducted since 2006 that are designed to understand and mitigate for the consequences of WNV introduction into the ISSJ population. We suspect that WNV would most likely be introduced to the island via the movement of infected birds from the mainland. However, antibody testing of >750 migrating and resident birds on the island from 2006 to 2009 indicated that WNV had not become established by the end of 2009. Several species of competent mosquito vectors were collected at very low abundance on the island, including the important mainland vectors Culex tarsalis and Culex quinquefasciatus. However, the island was generally cooler than areas of mainland California that experienced intense WNV transmission, and these lower temperatures may have reduced the likelihood of WNV becoming established because they do not support efficient virus replication in mosquitoes. A vaccination program was initiated in 2008 to create a rescue population of ISSJ that would be more likely to survive a catastrophic outbreak. To further that goal, we recommend managers vaccinate >100 ISSJ each year as part of ongoing research and monitoring efforts.
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Affiliation(s)
- Walter M Boyce
- Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
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Finlaison DS, Read AJ, Kirkland PD. An epizootic of bovine ephemeral fever in New South Wales in 2008 associated with long-distance dispersal of vectors. Aust Vet J 2010; 88:301-6. [PMID: 20633165 DOI: 10.1111/j.1751-0813.2010.00596.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To report the rapid transmission of bovine ephemeral fever (BEF) virus from north-western New South Wales south to the Victorian border in January 2008 and to present data that suggests an uncommon meteorological event caused this rapid southward dispersal of vectors. PROCEDURE The locations of reported clinical cases, data from sentinel herds and results from a survey of cattle in the southern affected area were examined to delineate the distribution of virus transmission. Synoptic weather charts for January 2008 were examined for meteorological conditions that may have favoured movement of vectors in a southerly direction. RESULTS Cases of BEF and exposure to BEF virus in NSW were confirmed west of the Great Dividing Range, extending from the Queensland border to Finley, on the far North Coast and around the Hunter Valley. A low-pressure system moved south across the state on 18-19 January 2008, preceding the first cases of BEF in the south of NSW by 1-2 days. CONCLUSION Heavy rainfall in December 2007 provided a suitable environment for vector breeding, resulting in the initiation of and support for continuing BEF virus transmission in north-western NSW. The movement of a low-pressure system south across central western NSW in mid-January 2008 after the commencement of BEF virus transmission in the north-west of the state provided a vehicle for rapid southward movement of infected vectors.
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Affiliation(s)
- D S Finlaison
- Virology Laboratory, Elizabeth Macarthur Agricultural Institute, Industry and Investment NSW, Narellan 2567, New South Wales, Australia.
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Abstract
Landscape epidemiology describes how the temporal dynamics of host, vector, and pathogen populations interact spatially within a permissive environment to enable transmission. The spatially defined focus, or nidus, of transmission may be characterized by vegetation as well as by climate, latitude, elevation, and geology. The ecological complexity, dimensions, and temporal stability of the nidus are determined largely by pathogen natural history and vector bionomics. Host populations, transmission efficiency, and therefore pathogen amplification vary spatially, thereby creating a heterogeneous surface that may be defined by remote sensing and statistical tools. The current review describes the evolution of landscape epidemiology as a science and exemplifies selected aspects by contrasting the ecology of two different recent disease outbreaks in North America caused by West Nile virus, an explosive, highly virulent mosquito-borne virus producing ephemeral nidi, and Borrelia burgdorferi, a slowly amplifying chronic pathogen producing semipermanent nidi.
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Affiliation(s)
- William K Reisen
- Center for Vectorborne Diseases and Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California-Davis, CA 95616, USA.
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Carver S, Spafford H, Storey A, Weinstein P. Dryland Salinity and the Ecology of Ross River Virus: The Ecological Underpinnings of the Potential for Transmission. Vector Borne Zoonotic Dis 2009; 9:611-22. [DOI: 10.1089/vbz.2008.0124] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Scott Carver
- School of Animal Biology (M085), University of Western Australia, Crawley 6009, Western Australia, Australia
- School of Population Health (M431), University of Western Australia, Crawley 6009, Western Australia, Australia
| | - Helen Spafford
- School of Animal Biology (M085), University of Western Australia, Crawley 6009, Western Australia, Australia
| | - Andrew Storey
- School of Animal Biology (M085), University of Western Australia, Crawley 6009, Western Australia, Australia
| | - Philip Weinstein
- School of Population Health (M431), University of Western Australia, Crawley 6009, Western Australia, Australia
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Multiple virus lineages sharing recent common ancestry were associated with a Large Rift Valley fever outbreak among livestock in Kenya during 2006-2007. J Virol 2008; 82:11152-66. [PMID: 18786992 DOI: 10.1128/jvi.01519-08] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rift Valley fever (RVF) virus historically has caused widespread and extensive outbreaks of severe human and livestock disease throughout Africa, Madagascar, and the Arabian Peninsula. Following unusually heavy rainfall during the late autumn of 2006, reports of human and animal illness consistent with RVF virus infection emerged across semiarid regions of the Garissa District of northeastern Kenya and southern Somalia. Following initial RVF virus laboratory confirmation, a high-throughput RVF diagnostic facility was established at the Kenyan Central Veterinary Laboratories in Kabete, Kenya, to support the real-time identification of infected livestock and to facilitate outbreak response and control activities. A total of 3,250 specimens from a variety of animal species, including domesticated livestock (cattle, sheep, goats, and camels) and wildlife collected from a total of 55 of 71 Kenyan administrative districts, were tested by molecular and serologic assays. Evidence of RVF infection was found in 9.2% of animals tested and across 23 districts of Kenya, reflecting the large number of affected livestock and the geographic extent of the outbreak. The complete S, M, and/or L genome segment sequence was obtained from a total of 31 RVF virus specimens spanning the entire known outbreak period (December-May) and geographic areas affected by RVF virus activity. Extensive genomic analyses demonstrated the concurrent circulation of multiple virus lineages, gene segment reassortment, and the common ancestry of the 2006/2007 outbreak viruses with those from the 1997-1998 east African RVF outbreak. Evidence of recent increases in genomic diversity and effective population size 2 to 4 years prior to the 2006-2007 outbreak also was found, indicating ongoing RVF virus activity and evolution during the interepizootic/epidemic period. These findings have implications for further studies of basic RVF virus ecology and the design of future surveillance/diagnostic activities, and they highlight the critical need for safe and effective vaccines and antiviral compounds to combat this significant veterinary and public health threat.
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Johnson PDR, Azuolas J, Lavender CJ, Wishart E, Stinear TP, Hayman JA, Brown L, Jenkin GA, Fyfe JAM. Mycobacterium ulcerans in mosquitoes captured during outbreak of Buruli ulcer, southeastern Australia. Emerg Infect Dis 2008; 13:1653-60. [PMID: 18217547 PMCID: PMC3375796 DOI: 10.3201/eid1311.061369] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Buruli ulcer (BU) occurs in >30 countries. The causative organism, Mycobacterium ulcerans, is acquired from the environment, but the exact mode of transmission is unknown. We investigated an outbreak of BU in a small coastal town in southeastern Australia and screened by PCR mosquitoes caught there. All cases of BU were confirmed by culture or PCR. Mosquitoes were trapped in multiple locations during a 26-month period. BU developed in 48 residents of Point Lonsdale/Queenscliff and 31 visitors from January 2001 through April 2007. We tested 11,504 mosquitoes trapped at Point Lonsdale (predominantly Aedes camptorhynchus). Forty-eight pools (5 species) were positive for insertion sequence IS2404 (maximum likelihood estimate 4.3/1,000), and we confirmed the presence of M. ulcerans in a subset of pools by detection of 3 additional PCR targets.
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Affiliation(s)
- Paul D R Johnson
- Infectious Disease Department, Austin Health, Melbourne, Victoria, Australia.
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Johansen CA, Susai V, Hall RA, Mackenzie JS, Clark DC, May FJ, Hemmerter S, Smith DW, Broom AK. Genetic and phenotypic differences between isolates of Murray Valley encephalitis virus in Western Australia, 1972–2003. Virus Genes 2007; 35:147-54. [PMID: 17393295 DOI: 10.1007/s11262-007-0091-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Accepted: 02/22/2007] [Indexed: 10/23/2022]
Abstract
Murray Valley encephalitis virus (MVEV) is a medically important mosquito-borne flavivirus found in Australia and Papua New Guinea (PNG). Partial envelope gene nucleotide sequences of 28 isolates of MVEV from Western Australia (WA) between 1972 and 2003 were aligned and compared phylogenetically with the prototype MVE-1-51 from Victoria in 1951 and isolates from northern Queensland and PNG. Monoclonal antibody-binding patterns were also investigated. Results showed that the majority of isolates of MVEV from widely disparate locations in WA were genetically and phenotypically homogeneous. Furthermore, isolates of MVEV from WA and northern Queensland were almost identical, confirming results from earlier studies. Recent isolates of MVEV from Western Province in PNG were more similar to Australian isolates of MVEV than to isolates from PNG in 1956 and 1966, providing further evidence for the movement of flaviviruses between PNG and Australia. Additional representatives of a unique variant of MVEV (OR156) from Kununurra in the northeast Kimberley region of WA were also detected. This suggests that the OR156 lineage is still intermittently active but may be restricted to a small geographic area in northern WA, possibly due to altered biological characteristics.
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Affiliation(s)
- Cheryl A Johansen
- Discipline of Microbiology and Immunology, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA, Australia, 6009.
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Reynolds DR, Chapman JW, Harrington R. The migration of insect vectors of plant and animal viruses. Adv Virus Res 2006; 67:453-517. [PMID: 17027687 DOI: 10.1016/s0065-3527(06)67012-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- D R Reynolds
- Natural Resources Institute, University of Greenwich Chatham Maritime, Kent ME4 4TB, United Kingdom
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30
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Teng HJ, Huang GC, Chen YC, Hsia WT, Lu LC, Tsai WT, Chung MJ. Mosquito surveys carried out on Green Island, Orchid Island, and Penghu Island, Taiwan, in 2003. Kaohsiung J Med Sci 2005; 21:51-6. [PMID: 15825689 DOI: 10.1016/s1607-551x(09)70277-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Field surveys of mosquitoes were carried out on Green, Orchid, and Penghu Islands in 2003 to ascertain the status of mosquito vectors. Eighteen species of mosquitoes were collected, including three species of Anopheles, four species of Aedes, eight species of Culex, two species of Armigeres, and one species of Malaya. Seventeen previously recorded species were not collected in this study but 11 species collected had not previously been recorded. Ten newly recorded species, An. maculatus, An. takasagoensis, Ae. alcasidi, Ae. lineatopennis, Ae. vexans vexans, Ar. omissus, Cx. vishnui, Cx. halifaxii, Cx. hayashii, and Cx. neomimulus, were collected on Green Island and one previously unrecorded species, Ar. subalbatus, was collected on Orchid Island. Potential vectors An. maculatus and An. sinensis, malaria vectors in Korea and Mainland China, Ae. albopictus, a vector of dengue in Taiwan and West Nile virus in the USA, Cx. vishnui and Cx. tritaeniorhynchus, Japanese encephalitis vectors in Taiwan, Ae. vexans vexans, an eastern equine encephalitis vector in the USA, and Cx. quinquefasciatus, a vector of filariasis in Taiwan and West Nile virus in the USA, were among the mosquito species collected.
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Affiliation(s)
- Hwa-Jen Teng
- Medical Entomological Laboratory, Research and Development Center, Center for Disease Control, Department of Health, Taipei, Taiwan.
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31
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Glass K. Ecological mechanisms that promote arbovirus survival: a mathematical model of Ross River virus transmission. Trans R Soc Trop Med Hyg 2005; 99:252-60. [PMID: 15708384 DOI: 10.1016/j.trstmh.2004.08.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 07/26/2004] [Accepted: 08/05/2004] [Indexed: 10/26/2022] Open
Abstract
Many assessments of host and vector competence for arboviruses focus on level and length of infectivity and ignore ecological mechanisms that contribute to virus survival. In this paper, mathematical models are used to compare local survival mechanisms for a range of scenarios, using Ross River virus as a case study. Ross River virus is an Australian arbovirus with many mosquito vectors and reservoir hosts. The mechanisms for maintaining long-term transmission of the virus vary between salt and freshwater mosquito vectors, and according to the availability of susceptible hosts. The models demonstrate that overwintering of virus in adult freshwater mosquitoes requires a large host population, while overwintering of virus in infected eggs of saltwater mosquitoes is an effective survival strategy when filial infection rates are high. The virus survives longer when both salt and freshwater mosquito species are included in the model than when only one mosquito species is present. When the marsupial host is replaced by a host with higher birth rate and shorter infectious period, the virus survived longer under all models. This suggests that birth rate can be a key factor when assessing the competence of reservoir hosts to maintain virus transmission.
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Affiliation(s)
- K Glass
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, ACT 0200, Australia.
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Reisen W, Lothrop H, Chiles R, Madon M, Cossen C, Woods L, Husted S, Kramer V, Edman J. West Nile virus in California. Emerg Infect Dis 2004; 10:1369-78. [PMID: 15496236 PMCID: PMC3320391 DOI: 10.3201/eid1008.040077] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
West Nile virus (WNV) was first isolated in California during July 2003 from a pool of Culex tarsalis collected near El Centro, Imperial County. WNV transmission then increased and spread in Imperial and Coachella Valleys, where it was tracked by isolation from pools of Cx. tarsalis, seroconversions in sentinel chickens, and seroprevalence in free-ranging birds. WNV then dispersed to the city of Riverside, Riverside County, and to the Whittier Dam area of Los Angeles County, where it was detected in dead birds and pools of Cx. pipiens quinquefasciatus. By October, WNV was detected in dead birds collected from riparian corridors in Los Angeles, west to Long Beach, and through inland valleys south from Riverside to San Diego County. WNV was reported concurrently from Arizona in mid-August and from Baja, Mexico, in mid-November. Possible mechanisms for virus introduction, amplification, and dispersal are discussed.
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Affiliation(s)
- William K Reisen
- Arbovirus Field Station Center for Vectorborne Diseases, School of Veterinary Medicine, University of California, Davis, Davis, California 95616, USA
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34
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Affiliation(s)
- Laura D Kramer
- Arbovirus Laboratories, Wadsworth Center, New York State Department of Health, Slingerlands, New York 12159, USA
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35
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Broom AK, Lindsay MDA, Harrington SA, Smith DW. Investigation of the southern limits of Murray Valley encephalitis activity in Western Australia during the 2000 wet season. Vector Borne Zoonotic Dis 2003; 2:87-95. [PMID: 12653302 DOI: 10.1089/153036602321131887] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Western Australia experienced its worst-ever outbreak of the mosquito-borne Murray Valley encephalitis (MVE) virus during the 2000 wet season. Highest-on-record rainfall throughout much of the state during the 2000 wet season gave rise to extensive mosquito breeding and increased MVE virus transmission, resulting in nine cases of encephalitis. Activity of MVE virus in Western Australia is monitored by detecting MVE virus-specific antibodies in serum from sentinel chickens, located at towns and communities throughout the north of the state. However, during 2000, all 28 flocks of chickens seroconverted to MVE virus, including a flock located >600 km further south than MVE virus activity had ever previously been recorded. Furthermore, the majority of the nine cases of encephalitis occurred outside the enzootic Kimberley region. We therefore undertook a major serosurvey of domestic chicken flocks both south and east of the previously defined regions of virus activity. The results suggest that MVE virus activity extended as far south as the Midwest and northern Goldfields during 2000. A new southern limit of activity of MVE virus is therefore proposed. The results have implications for managing outbreaks of MVE virus in Western Australia and have enabled us to locate additional sentinel flocks as part of the MVE surveillance program for future years.
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Affiliation(s)
- Annette K Broom
- Arbovirus Surveillance and Research Laboratory, Department of Microbiology, University of Western Australia, Nedlands, Western Australia, Australia.
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36
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Chapman HF, Hughes JM, Ritchie SA, Kay BH. Population structure and dispersal of the freshwater mosquitoes Culex annulirostris and Culex palpalis (Diptera: Culicidae) in Papua New Guinea and northern Australia. JOURNAL OF MEDICAL ENTOMOLOGY 2003; 40:165-169. [PMID: 12693844 DOI: 10.1603/0022-2585-40.2.165] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In 1995 and 1998, outbreaks of Japanese encephalitis (JE) virus occurred for the first time in Australia. Virus isolation from pools of mosquitoes indicated Culex annulirostris Skuse was the most likely vector. It was hypothesized that wind-blown mosquitoes introduced JE from Papua New Guinea to the Torres Strait and Cape York, northern Australia. This study used levels of genetic differentiation, as indirect evidence of dispersal of mosquitoes between the two continents. The results have demonstrated that in the region incorporating Western Province in PNG, the Torres Strait and Cape York Peninsula, Cx. annulirostris is represented by a panmictic population, indicating frequent widespread dispersal throughout the region of investigation. The closely related Cx. Palpalis Taylor was also present at some locations but the population structure of this species is uncertain. This supports the hypothesis that wind-blown Cx. annulirostris and possibly Cx. Palpalis could be a possible mechanism for introduction of JE virus into Australia.
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Affiliation(s)
- H F Chapman
- Queensland Institute of Medical Research and University of Queensland Tropical Health Program, P.O. Royal Brisbane Hospital, Queensland 4029, Australia.
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37
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Johansen CA, Farrow RA, Morrisen A, Foley P, Bellis G, Van Den Hurk AF, Montgomery B, Mackenzie JS, Ritchie SA. Collection of wind-borne haematophagous insects in the Torres Strait, Australia. MEDICAL AND VETERINARY ENTOMOLOGY 2003; 17:102-109. [PMID: 12680932 DOI: 10.1046/j.1365-2915.2003.00413.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Circumstantial evidence has implicated wind-borne mosquitoes (Diptera: Culicidae) in the introduction of Japanese encephalitis (JE) virus into Australia from the New Guinea mainland. A study was initiated on Saibai Island in the northern Torres Strait, during January and February 2000, to identify the potential source of insects collected in aerial (kytoon) and surface-level traps. Wind speed and direction were recorded to determine wind profiles during insect sampling. Northerly winds capable of carrying insects from New Guinea to Saibai Island were only present on three out of 18 nights sampled. Only three male mosquitoes, comprising two Verrallina funerea (Theobald) and one Ochlerotatus vigilax (Skuse), were collected in aerial samples, and were most likely of local origin. Culicoides midges were also collected in aerial nets and included gravid/parous C. bundyensis Lee and Reye, and one parous C. histrio Johannsen. Highest densities of arthropods (up to 1562/million m3) were on 30 January 2000 when NW winds, sustained for six hours, probably introduced midges from the New Guinea mainland. Adult mosquitoes (including three female Ve. funerea and a single female Ficalbia) and Culicoides (including two gravid C. bundyensis and one parous C. cordiger Macfie) were also collected in 2 m high mast nets during northerly surface winds. Although the results do not provide evidence that wind-blown mosquitoes introduced JE from New Guinea into Australia, they do not preclude that strong N winds associated with low pressure systems SW of the Torres Strait could have done so. However, results suggest that Culicoides were more likely than mosquitoes to reach high altitude and travel long distances during the light N winds experienced during the study.
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Affiliation(s)
- C A Johansen
- Department of Microbiology and Parasitology, The University of Queensland, St Lucia, Queensland, Australia.
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Mackenzie JS, Johansen CA, Ritchie SA, van den Hurk AF, Hall RA. Japanese encephalitis as an emerging virus: the emergence and spread of Japanese encephalitis virus in Australasia. Curr Top Microbiol Immunol 2002; 267:49-73. [PMID: 12083000 DOI: 10.1007/978-3-642-59403-8_3] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- J S Mackenzie
- Department of Microbiology and Parasitology, The University of Queensland, Brisbane, Queensland 4072, Australia
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39
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Ritchie SA, Rochester W. Wind-blown mosquitoes and introduction of Japanese encephalitis into Australia. Emerg Infect Dis 2001; 7:900-3. [PMID: 11747709 PMCID: PMC2631883 DOI: 10.3201/eid0705.017524] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Backtrack simulation analysis indicates that wind-blown mosquitoes could have traveled from New Guinea to Australia, potentially introducing Japanese encephalitis virus. Large incursions of the virus in 1995 and 1998 were linked with low-pressure systems that sustained strong northerly winds from New Guinea to the Cape York Peninsula.
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Affiliation(s)
- S A Ritchie
- Tropical Public Unit, Queensland Health, Cairns, Australia
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