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Comparisons of chemosensory gene repertoires in human and non-human feeding Anopheles mosquitoes link olfactory genes to anthropophily. iScience 2022; 25:104521. [PMID: 35754720 PMCID: PMC9213756 DOI: 10.1016/j.isci.2022.104521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 05/08/2022] [Accepted: 05/30/2022] [Indexed: 11/06/2022] Open
Abstract
We investigate the genetic basis of anthropophily (human host use) in a non-model mosquito species group, the Anopheles farauti complex from the southwest Pacific. This complex has experienced multiple transitions from anthropophily to zoophily, contrasting with well-studied systems (the global species Aedes aegypti and the African Anopheles gambiae complex) that have evolved to be specialist anthropophiles. By performing tests of selection and assessing evolutionary patterns for >200 olfactory genes from nine genomes, we identify several candidate genes associated with differences in anthropophily in this complex. Based on evolutionary patterns (phylogenetic relationships, fixed amino acid differences, and structural differences) as well as results from selection analyses, we identify numerous genes that are likely to play an important role in mosquitoes’ ability to detect humans as hosts. Our findings contribute to the understanding of the evolution of insect olfactory gene families and mosquito host preference as well as having potential applied outcomes. Genomes of Anopheles mosquitoes with differing host preferences were sequenced Evolutionary comparisons were performed on >200 insect chemosensory genes These comparisons revealed candidate genes involved in human feeding Two of the main candidates identified were co-receptor Ir8a and Or75
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Ambrose L, Ortiz‐Barrientos D, Cooper RD, Lobo NF, Burkot TR, Russell TL, Beebe NW. Gene flow between island populations of the malaria mosquito, Anopheles hinesorum, may have contributed to the spread of divergent host preference phenotypes. Evol Appl 2021; 14:2244-2257. [PMID: 34603496 PMCID: PMC8477600 DOI: 10.1111/eva.13288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/23/2021] [Accepted: 07/13/2021] [Indexed: 12/04/2022] Open
Abstract
Anopheles hinesorum is a mosquito species with variable host preference. Throughout New Guinea and northern Australia, An. hinesorum feeds on humans (it is opportunistically anthropophagic) while in the south-west Pacific's Solomon Archipelago, the species is abundant but has rarely been found biting humans (it is exclusively zoophagic in most populations). There are at least two divergent zoophagic (nonhuman biting) mitochondrial lineages of An. hinesorum in the Solomon Archipelago representing two independent dispersals. Since zoophagy is a derived (nonancestral) trait in this species, this leads to the question: has zoophagy evolved independently in these two populations? Or conversely: has nuclear gene flow or connectivity resulted in the transfer of zoophagy? Although we cannot conclusively answer this, we find close nuclear relationships between Solomon Archipelago populations indicating that recent nuclear gene flow has occurred between zoophagic populations from the divergent mitochondrial lineages. Recent work on isolated islands of the Western Province (Solomon Archipelago) has also revealed an anomalous, anthropophagic island population of An. hinesorum. We find a common shared mitochondrial haplotype between this Solomon Island population and another anthropophagic population from New Guinea. This finding suggests that there has been recent migration from New Guinea into the only known anthropophagic population from the Solomon Islands. Although currently localized to a few islands in the Western Province of the Solomon Archipelago, if anthropophagy presents a selective advantage, we may see An. hinesorum emerge as a new malaria vector in a region that is now working on malaria elimination.
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Affiliation(s)
- Luke Ambrose
- School of Biological SciencesUniversity of QueenslandBrisbaneQldAustralia
| | | | - Robert D. Cooper
- Australian Defence Force, Malaria and Infectious Disease InstituteBrisbaneQldAustralia
| | | | | | | | - Nigel W. Beebe
- School of Biological SciencesUniversity of QueenslandBrisbaneQldAustralia
- CSIROBrisbaneQldAustralia
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Craig AT, Kama N, Fafale G, Bugoro H. Citizen science as a tool for arboviral vector surveillance in a resourced-constrained setting: results of a pilot study in Honiara, Solomon Islands, 2019. BMC Public Health 2021; 21:509. [PMID: 33726697 PMCID: PMC7962342 DOI: 10.1186/s12889-021-10493-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 02/24/2021] [Indexed: 12/12/2022] Open
Abstract
Background Recent arboviral disease outbreaks highlight the value a better understanding of the spread of disease-carrying mosquitoes across spatial-temporal scales can provide. Traditional surveillance tools are limited by jurisdictional boundaries, workforce constraints, logistics, and cost; factors that in low- and middle-income countries often conspire to undermine public health protection efforts. To overcome these, we undertake a pilot study designed to explore if citizen science provides a feasible strategy for arboviral vector surveillance in small developing Pacific island contexts. Methods We recruited, trained, and equipped community volunteers to trap and type mosquitos within their household settings, and to report count data to a central authority by short-message-service. Mosquito catches were independently assessed to measure participants’ mosquito identification accuracy. Other data were collected to measure the frequency and stability of reporting, and volunteers’ experiences. Results Participants collected data for 78.3% of the study period, and agreement between the volunteer citizen scientists’ and the reviewing entomologist’s mosquito identification was 94%. Opportunity to contribute to a project of social benefit, the chance to learn new skills, and the frequency of engagement with project staff were prime motivators for participation. Unstable electricity supply (required to run the trap’s fan), insufficient personal finances (to buy electricity and phone credit), and inconvenience were identified as barriers to sustained participation. Conclusions While there are challenges to address, our findings suggest that citizen science offers an opportunity to overcome the human resource constraints that conspire to limit health authorities’ capacity to monitor arboviral vectors across populations. We note that the success of citizen science-based surveillance is dependent on the appropriate selection of equipment and participants, and the quality of engagement and support provided. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-021-10493-6.
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Affiliation(s)
- Adam T Craig
- University of New South Wales (Sydney), Sydney, New South Wales, Australia
| | - Nathan Kama
- Vector-borne Disease Unit, Solomon Islands Ministry of Health and Medical Services, Honiara, Solomon Islands
| | - George Fafale
- Environmental Health Unit, Honiara City Council, Honiara, Solomon Islands
| | - Hugo Bugoro
- Solomon Islands National University, Honiara, Solomon Islands.
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Burkot TR, Bugoro H, Apairamo A, Cooper RD, Echeverry DF, Odabasi D, Beebe NW, Makuru V, Xiao H, Davidson JR, Deason NA, Reuben H, Kazura JW, Collins FH, Lobo NF, Russell TL. Spatial-temporal heterogeneity in malaria receptivity is best estimated by vector biting rates in areas nearing elimination. Parasit Vectors 2018; 11:606. [PMID: 30482239 PMCID: PMC6260740 DOI: 10.1186/s13071-018-3201-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/14/2018] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Decisions on when vector control can be withdrawn after malaria is eliminated depend on the receptivity or potential of an area to support vector populations. To guide malaria control and elimination programmes, the potential of biting rates, sporozoite rates, entomological inoculation rates and parity rates to estimate malaria receptivity and transmission were compared within and among geographically localised villages of active transmission in the Western Province of the Solomon Islands. RESULTS Malaria transmission and transmission potential was heterogeneous in both time and space both among and within villages as defined by anopheline species composition and biting densities. Biting rates during the peak biting period (from 18:00 to 00:00 h) of the primary vector, Anopheles farauti, ranged from less than 0.3 bites per person per half night in low receptivity villages to 26 bites per person in highly receptive villages. Within villages, sites with high anopheline biting rates were significantly clustered. Sporozoite rates provided evidence for continued transmission of Plasmodium falciparum, P. vivax and P. ovale by An. farauti and for incriminating An. hinesorum, as a minor vector, but were unreliable as indicators of transmission intensity. CONCLUSIONS In the low transmission area studied, sporozoite, entomological inoculation and parity rates could not be measured with the precision required to provide guidance to malaria programmes. Receptivity and potential transmission risk may be most reliably estimated by the vector biting rate. These results support the meaningful design of operational research programmes to ensure that resources are focused on providing information that can be utilised by malaria control programmes to best understand both transmission, transmission risk and receptivity across different areas.
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Affiliation(s)
- Thomas R. Burkot
- James Cook University, Australian Institute of Tropical Health and Medicine, Cairns, QLD 4870 Australia
| | - Hugo Bugoro
- National Vector Borne Disease Control Programme, Ministry of Health and Medical Services, Honiara, Solomon Islands
- Research Department, Solomon Islands National University, Honiara, Solomon Islands
| | - Allan Apairamo
- National Vector Borne Disease Control Programme, Ministry of Health and Medical Services, Honiara, Solomon Islands
| | - Robert D. Cooper
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052 Australia
| | - Diego F. Echeverry
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Danyal Odabasi
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Nigel W. Beebe
- University of Queensland, School of Biological Sciences, QLD, St. Lucia, 4068 Australia
- CSIRO, Dutton Park, Brisbane, QLD 4102 Australia
| | - Victoria Makuru
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Honglin Xiao
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Jenna R. Davidson
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Nicholas A. Deason
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Hedrick Reuben
- Western Province Malaria Control, Gizo, Western Province Solomon Islands
| | - James W. Kazura
- Center for Global Health & Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106–4983 USA
| | - Frank H. Collins
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Neil F. Lobo
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Tanya L. Russell
- James Cook University, Australian Institute of Tropical Health and Medicine, Cairns, QLD 4870 Australia
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Russell TL, Burkot TR, Bugoro H, Apairamo A, Beebe NW, Chow WK, Cooper RD, Collins FH, Lobo NF. Larval habitats of the Anopheles farauti and Anopheles lungae complexes in the Solomon Islands. Malar J 2016; 15:164. [PMID: 26980326 PMCID: PMC4791962 DOI: 10.1186/s12936-016-1196-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 02/26/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is an urgent need for vector control tools to supplement long-lasting insecticidal nets (LLINs) and indoor residual spraying; particularly in the Solomon Islands where the primary vector, Anopheles farauti, is highly anthropophagic and feeds mainly outdoors and early in the evening. Currently, the only supplementary tool recommended by the World Health Organization is larval source management (LSM). The feasibility and potential effectiveness of LSM requires information on the distribution of anophelines, the productivity of larval habitats and the potential impacts of larval control on adult fitness. METHODS The distribution of anophelines in Central and Western Provinces in the Solomon Islands was mapped from cross-sectional larval habitat surveys. The composition and micro-distribution of larval instars within a large permanent river-mouth lagoon was examined with a longitudinal survey. Density-dependent regulation of An. farauti larvae was investigated by longitudinally following the development and survival of different densities of first instars in floating cages in a river-mouth lagoon. RESULTS Five anopheline species were molecularly identified from a range of fresh and brackish water habitats: An. farauti s.s., An. hinesorum, An. lungae, An. nataliae and An. solomonis. The most common habitats used by the primary malaria vector, An. farauti, were coastal lagoons and swamps. In the detailed study of lagoon micro-productivity, An. farauti was non-uniformly distributed with highest densities found at collections sites most proximal and distal to the mouth of the lagoon. The survival of An. farauti larvae was more than twofold lower when larvae were held at the highest experimental density (1 larva per 3.8 cm(2)) when compared with the lowest density (1 larva per 38 cm(2)). CONCLUSIONS The only documented major malaria vector collected in larval surveys in both Central and Western Provinces was An. farauti. Lagoons and swamps, the most common, largest and (potentially) most productive larval sites of this malaria vector, were "few, fixed and findable" and theoretically, therefore, amenable to successful LSM. However, the immense scale and complexity of these ecosystems in which An. farauti larvae are found raises questions regarding the ability to effectively control the larvae, as incomplete larviciding could trigger density dependent effects resulting in increased larval survivorship. While LSM has the potential to significantly contribute to malaria control of this early and outdoor biting vector, more information on the distribution of larvae within these extensive habitats is required to maximize the effectiveness of LSM.
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Affiliation(s)
- Tanya L Russell
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, 4870, Australia.
| | - Thomas R Burkot
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, 4870, Australia
| | - Hugo Bugoro
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Allan Apairamo
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Nigel W Beebe
- School of Biological Sciences, University of Queensland, St. Lucia, QLD, 4068, Australia.,CSIRO, Dutton Park, Brisbane, QLD, 4102, Australia
| | - Weng K Chow
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052, Australia
| | - Robert D Cooper
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052, Australia
| | - Frank H Collins
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Neil F Lobo
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
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Beebe NW, Russell T, Burkot TR, Cooper RD. Anopheles punctulatus group: evolution, distribution, and control. ANNUAL REVIEW OF ENTOMOLOGY 2015; 60:335-350. [PMID: 25341094 DOI: 10.1146/annurev-ento-010814-021206] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The major malaria vectors of the Southwest Pacific belong to a group of closely related mosquitoes known as the Anopheles punctulatus group. The group comprises 13 co-occurring species that either are isomorphic or carry overlapping morphological features, and today several species remain informally named. The advent of species-diagnostic molecular tools in the 1990s permitted a new raft of studies into the newly differentiated mosquitoes of this group, and these have revealed five species as the region's primary malaria vectors: An. farauti, An. hinesorum, An. farauti 4, An. koliensis, and An. punctulatus. Species' distributions are now well established across Papua New Guinea, northern Australia, and the Solomon Archipelago, but little has been documented thus far in eastern Indonesia. As each species reveals significant differences in distribution and biology, the relative paucity of knowledge of their biology or ecology in relation to malaria transmission is brought into clearer focus. Only three of the species have undergone some form of spatial or population genetics analyses, and this has revealed striking differences in their genetic signatures throughout the region. This review compiles and dissects the key findings for this important mosquito group and points to where future research should focus to maximize the output of field studies in developing relevant knowledge on these malaria vectors.
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Affiliation(s)
- Nigel W Beebe
- The University of Queensland, St. Lucia, Brisbane, Australia and CSIRO Ecosystem Sciences, Brisbane, Australia;
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Ambrose L, Riginos C, Cooper RD, Leow KS, Ong W, Beebe NW. Population structure, mitochondrial polyphyly and the repeated loss of human biting ability in anopheline mosquitoes from the southwest Pacific. Mol Ecol 2012; 21:4327-43. [PMID: 22747666 PMCID: PMC3470930 DOI: 10.1111/j.1365-294x.2012.05690.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 04/27/2012] [Accepted: 05/16/2012] [Indexed: 11/30/2022]
Abstract
Australia and New Guinea contain high levels of endemism and biodiversity, yet there have been few evaluations of population-level genetic diversity in fauna occurring throughout the Australo-Papuan region. Using extensive geographical sampling, we examined and compared the phylogenetic relationships, phylogeography and population structure of Anopheles farauti, An. hinesorum and An. irenicus throughout their ranges in the southwest Pacific using mitochondrial (mtDNA COI) and nuclear (ribosomal protein S9 and ribosomal DNA ITS2) loci. Phylogenetic analyses suggest that the ability to utilize humans as hosts has been lost repeatedly, coincident with independent colonizations of the Solomon Islands. As some of the species under investigation transmit malaria in the region, this is a medically important finding. Maximum likelihood and Bayesian phylogenetic analyses of nuclear loci also showed that the three species are monophyletic. However, putative introgression of An. hinesorum mtDNA onto a nuclear background of An. farauti was evident in populations from Queensland, Torres Strait and southern New Guinea. Haplotype networks and pairwise F(ST) values show that there is significant genetic structure within New Guinea and Australia in both An. farauti and An. hinesorum, consistent with a long-term history of low gene flow among populations.
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Affiliation(s)
- L Ambrose
- School of Biological Sciences, University of Queensland, St Lucia, Brisbane, Qld. 4072, Australia
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Bugoro H, Iro'ofa C, Mackenzie DO, Apairamo A, Hevalao W, Corcoran S, Bobogare A, Beebe NW, Russell TL, Chen CC, Cooper RD. Changes in vector species composition and current vector biology and behaviour will favour malaria elimination in Santa Isabel Province, Solomon Islands. Malar J 2011; 10:287. [PMID: 21961990 PMCID: PMC3192714 DOI: 10.1186/1475-2875-10-287] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 09/30/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In 2009, Santa Isabel Province in the Solomon Islands embarked on a malaria elimination programme. However, very little is known in the Province about the anopheline fauna, which species are vectors, their bionomics and how they may respond to intensified intervention measures. The purpose of this study was to provide baseline data on the malaria vectors and to ascertain the possibility of successfully eliminating malaria using the existing conventional vector control measures, such as indoor residual spraying (IRS) and long-lasting insecticidal nets (LLIN). METHODS Entomological surveys were undertaken during October 2009. To determine species composition and distribution larval surveys were conducted across on the whole island. For malaria transmission studies, adult anophelines were sampled using human landing catches from two villages - one coastal and one inland. RESULTS Five Anopheles species were found on Santa Isabel: Anopheles farauti, Anopheles hinesorum, Anopheles lungae, Anopheles solomonis, and Anopheles nataliae. Anopheles hinesorum was the most widespread species. Anopheles farauti was abundant, but found only on the coast. Anopheles punctulatus and Anopheles koliensis were not found. Anopheles farauti was the only species found biting in the coastal village, it was incriminated as a vector in this study; it fed early in the night but equally so indoors and outdoors, and had a low survival rate. Anopheles solomonis was the main species biting humans in the inland village, it was extremely exophagic, with low survival rates, and readily fed on pigs. CONCLUSION The disappearance of the two major vectors, An. punctulatus and An. koliensis, from Santa Isabel and the predominance of An. hinesorum, a non-vector species may facilitate malaria elimination measures. Anopheles farauti was identified as the main coastal vector with An. solomonis as a possible inland vector. The behaviour of An. solomonis is novel as it has not been previously found biting humans in any numbers. Both species appear to be short-lived, a characteristic that will limit their transmission potential. The early night feeding behaviour and a degree of outdoor biting seen in An. farauti and particularly in An. solomonis will require that their response to IRS and LLIN be closely monitored. In coastal villages, where large, favourable breeding sites allow for high numbers of An. farauti may require the addition of larval control to achieve elimination.
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Affiliation(s)
- Hugo Bugoro
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
- Institute of Tropical Medicine, National Yang-Ming University, No. 155, Sec.2, Li-Nong Street, Taipei 112, Taiwan
| | - Charlie Iro'ofa
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Donna O Mackenzie
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052, Australia
| | - Allen Apairamo
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Watson Hevalao
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Sarah Corcoran
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052, Australia
| | - Albino Bobogare
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Nigel W Beebe
- School of Biological Sciences, University of Queensland, Goddard Building, St.Lucia, Qld 4068, Australia
| | - Tanya L Russell
- The University of Queensland, School of Population Health, Australian Centre for Tropical and International Health, Pacific Malaria Initiative Support Centre, Herston, 4006, Australia
| | - Cheng-Chen Chen
- Institute of Tropical Medicine, National Yang-Ming University, No. 155, Sec.2, Li-Nong Street, Taipei 112, Taiwan
| | - Robert D Cooper
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052, Australia
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Rocha LDS, Falqueto A, Dos Santos CB, Grimaldi GJ, Cupolillo E. Possible implication of the genetic composition of the Lutzomyia longipalpis (Diptera: Psychodidae) populations in the epidemiology of the visceral leishmaniasis. JOURNAL OF MEDICAL ENTOMOLOGY 2011; 48:1016-1022. [PMID: 21936320 DOI: 10.1603/me10249] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Lutzomyia longipalpis (Diptera: Psychodidae) is the principal vector of American visceral leishmaniasis. Several studies have indicated that the Lu. longipalpis population structure is complex. It has been suggested that genetic divergence caused by genetic drift, selection, or both may affect the vectorial capacity of Lu. longipalpis. However, it remains unclear whether genetic differences among Lu. longipalpis populations are directly implicated in the transmission features of visceral leishmaniasis. We evaluated the genetic composition and the patterns of genetic differentiation among Lu. longipalpis populations collected from regions with different patterns of transmission of visceral leishmaniasis by analyzing the sequence variation in the mitochondrial cytochrome b gene. Furthermore, we investigated the temporal distribution of haplotypes and compared our results with those obtained in a previous study. Our data indicate that there are differences in the haplotype composition and that there has been significant differentiation between the analyzed populations. Our results reveal that measures used to control visceral leishmaniasis might have influenced the genetic composition of the vector population. This finding raises important questions concerning the epidemiology of visceral leishmaniasis, because these differences in the genetic structures among populations of Lu. longipalpis may have implications with respect to their efficiency as vectors for visceral leishmaniasis.
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Affiliation(s)
- Leonardo de Souza Rocha
- Laboratório de Pesquisas em Leishmanioses, Instituto Oswaldo Cruz, IOC/FIOCRUZ, Pavilhão Leônidas Deane-sala 509, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, Brazil 21045-900.
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Sinka ME, Bangs MJ, Manguin S, Chareonviriyaphap T, Patil AP, Temperley WH, Gething PW, Elyazar IRF, Kabaria CW, Harbach RE, Hay SI. The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis. Parasit Vectors 2011; 4:89. [PMID: 21612587 PMCID: PMC3127851 DOI: 10.1186/1756-3305-4-89] [Citation(s) in RCA: 317] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 05/25/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed. RESULTS Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented. CONCLUSIONS This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.
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Affiliation(s)
- Marianne E Sinka
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Michael J Bangs
- Public Health and Malaria Control Department, PT Freeport Indonesia, Kuala Kencana, Papua, Indonesia
| | - Sylvie Manguin
- Institut de Recherche pour le Développement, Lab. d'Immuno-Physiopathologie Moléculaire Comparée, UMR-MD3/Univ. Montpellier 1, Faculté de Pharmacie, 15, Ave Charles Flahault, 34093 Montpellier, France
| | | | - Anand P Patil
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - William H Temperley
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Peter W Gething
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | | | - Caroline W Kabaria
- Malaria Public Health and Epidemiology Group, Centre for Geographic Medicine, KEMRI - Univ. Oxford - Wellcome Trust Collaborative Programme, Kenyatta National Hospital Grounds, P.O. Box 43640-00100 Nairobi, Kenya
| | - Ralph E Harbach
- Department of Entomology, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Simon I Hay
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
- Malaria Public Health and Epidemiology Group, Centre for Geographic Medicine, KEMRI - Univ. Oxford - Wellcome Trust Collaborative Programme, Kenyatta National Hospital Grounds, P.O. Box 43640-00100 Nairobi, Kenya
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Bugoro H, Cooper RD, Butafa C, Iro'ofa C, Mackenzie DO, Chen CC, Russell TL. Bionomics of the malaria vector Anopheles farauti in Temotu Province, Solomon Islands: issues for malaria elimination. Malar J 2011; 10:133. [PMID: 21592366 PMCID: PMC3123245 DOI: 10.1186/1475-2875-10-133] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 05/18/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the Solomon Islands, the Malaria Eradication Programmes of the 1970s virtually eliminated the malaria vectors: Anopheles punctulatus and Anopheles koliensis, both late night biting, endophagic species. However, the vector, Anopheles farauti, changed its behaviour to bite early in the evening outdoors. Thus, An. farauti mosquitoes were able to avoid insecticide exposure and still maintain transmission. Thirty years on and the Solomon Islands are planning for intensified malaria control and localized elimination; but little is currently known about the behaviour of the vectors and how they will respond to intensified control. METHODS In the elimination area, Temotu Province, standard entomological collection methods were conducted in typical coastal villages to determine the vector, its ecology, biting density, behaviour, longevity, and vector efficacy. These vector surveys were conducted pre-intervention and post-intervention following indoor residual spraying and distribution of long-lasting insecticidal nets. RESULTS Anopheles farauti was the only anopheline in Temotu Province. In 2008 (pre-intervention), this species occurred in moderate to high densities (19.5-78.5 bites/person/night) and expressed a tendency to bite outdoors, early in the night (peak biting time 6-8 pm). Surveys post intervention showed that there was little, if any, reduction in biting densities and no reduction in the longevity of the vector population. After adjusting for human behaviour, indoor biting was reduced from 57% pre-intervention to 40% post-intervention. CONCLUSION In an effort to learn from historical mistakes and develop successful elimination programmes, there is a need for implementing complimentary vector control tools that can target exophagic and early biting vectors. Intensified indoor residual spraying and long-lasting insecticide net use has further promoted the early, outdoor feeding behaviour of An. farauti in the Solomon Islands. Consequently, the effectiveness of IRS and the personal protection provided by bed nets is compromised. To achieve elimination, any residual transmission should be targeted using integrated vector control incorporating complementary tools such as larviciding and/or zooprophylaxis.
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Affiliation(s)
- Hugo Bugoro
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
- Institute of Tropical Medicine, National Yang-Ming University, No. 155, Sec.2, Li-Nong Street, Taipei 112, Taiwan
| | - Robert D Cooper
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052, Australia
| | - Charles Butafa
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Charles Iro'ofa
- National Vector Borne Disease Control Programme, Ministry of Health, Honiara, Solomon Islands
| | - Donna O Mackenzie
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, 4052, Australia
| | - Cheng-Chen Chen
- Institute of Tropical Medicine, National Yang-Ming University, No. 155, Sec.2, Li-Nong Street, Taipei 112, Taiwan
| | - Tanya L Russell
- The University of Queensland, School of Population Health, Australian Centre for Tropical and International Health, Pacific Malaria Initiative Support Centre, Herston, 4006, Australia
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Service MW. Sequel to Kitzmiller's Anopheline names: their derivations and histories. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2010; 35:213-266. [PMID: 21175930 DOI: 10.1111/j.1948-7134.2010.00081.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The derivations of the names of 74 Anopheles species and one subgenus are explained together with accounts of the life and scientific work of people who have been honored by having a mosquito named after them. Descriptive accounts are given of geographical locations, whether towns, regions or counties, that have had anopheline species named after them.
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Affiliation(s)
- Michael W Service
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
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Malaria on isolated Melanesian islands prior to the initiation of malaria elimination activities. Malar J 2010; 9:218. [PMID: 20659316 PMCID: PMC2921077 DOI: 10.1186/1475-2875-9-218] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 07/26/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Australian Government's Pacific Malaria Initiative (PacMI) is supporting the National Malaria Program in both Solomon Islands and Vanuatu, complementing assistance from the Global Fund for AIDS, Tuberculosis and Malaria (GFATM). Two remote island groups - Tafea Province, Vanuatu and Temotu Province, Solomon Islands have been selected by the governments of both countries as possible malaria elimination areas. To provide information on the prevalence and distribution of the disease within these island groups, malariometric surveys were conducted during the wet seasons of 2008. METHODS In Tafea Province, a school-based survey was conducted which included the 2-12 y age group, while in Temotu a village based all-ages survey was conducted. An effort was made to sample villages or schools from a wide an area as possible on all islands. Diagnosis was initially based on Giemsa stained blood slides followed by molecular analysis using polymerase chain reaction (PCR). RESULTS In Tafea Province, 73% (5238/7150) of children (2-12 y) were surveyed and in Temotu Province, in the all-ages survey, 50.2% (8742/17410) of the provincial population participated in the survey. In both Vanuatu and Solomon Islands malariometric surveys of their southern-most islands in 2008 showed relatively low over-all malaria parasite prevalence (2 to 3%). Other features of malaria in these island groups were low parasitaemia, low gametocyte carriage rates, low spleen rates, low malaria associated morbidity, a high incidence of asymptomatic infections, and a predominance of Plasmodium vivax over Plasmodium falciparum. CONCLUSION For various reasons malaria rates are declining in these provinces providing a favourable situation for local malaria elimination. This will be advanced using mass distribution of bed nets and selective indoor residual spraying, the introduction of rapid diagnostic tests and artemisinin combination therapy, and intensive case detection and surveillance. It is as yet uncertain whether malaria parasites can themselves be sustainably eliminated from entire Melanesian islands, where they have previously been endemic. Key issues on the road to malaria elimination will be continued community involvement, improved field diagnostic methods and elimination of residual P. vivax parasites from the liver of asymptomatic persons.
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Kinzer MH, Chand K, Basri H, Lederman ER, Susanti AI, Elyazar I, Taleo G, Rogers WO, Bangs MJ, Maguire JD. Active case detection, treatment of falciparum malaria with combined chloroquine and sulphadoxine/pyrimethamine and vivax malaria with chloroquine and molecular markers of anti-malarial resistance in the Republic of Vanuatu. Malar J 2010; 9:89. [PMID: 20370920 PMCID: PMC2853556 DOI: 10.1186/1475-2875-9-89] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 04/06/2010] [Indexed: 11/15/2022] Open
Abstract
Background Chloroquine-resistant Plasmodium falciparum was first described in the Republic of Vanuatu in the early 1980s. In 1991, the Vanuatu Ministry of Health instituted new treatment guidelines for uncomplicated P. falciparum infection consisting of chloroquine/sulphadoxine-pyrimethamine combination therapy. Chloroquine remains the recommended treatment for Plasmodium vivax. Methods In 2005, cross-sectional blood surveys at 45 sites on Malo Island were conducted and 4,060 adults and children screened for malaria. Of those screened, 203 volunteer study subjects without malaria at the time of screening were followed for 13 weeks to observe peak seasonal incidence of infection. Another 54 subjects with malaria were followed over a 28-day period to determine efficacy of anti-malarial therapy; chloroquine alone for P. vivax and chloroquine/sulphadoxine-pyrimethamine for P. falciparum infections. Results The overall prevalence of parasitaemia by mass blood screening was 6%, equally divided between P. falciparum and P. vivax. Twenty percent and 23% of participants with patent P. vivax and P. falciparum parasitaemia, respectively, were febrile at the time of screening. In the incidence study cohort, after 2,303 person-weeks of follow-up, the incidence density of malaria was 1.3 cases per person-year with P. vivax predominating. Among individuals participating in the clinical trial, the 28-day chloroquine P. vivax cure rate was 100%. The 28-day chloroquine/sulphadoxine-pyrimethamine P. falciparum cure rate was 97%. The single treatment failure, confirmed by merozoite surface protein-2 genotyping, was classified as a day 28 late parasitological treatment failure. All P. falciparum isolates carried the Thr-76 pfcrt mutant allele and the double Asn-108 + Arg-59 dhfr mutant alleles. Dhps mutant alleles were not detected in the study sample. Conclusion Peak seasonal malaria prevalence on Malo Island reached hypoendemic levels during the study observation period. The only in vivo malaria drug efficacy trial thus far published from the Republic of Vanuatu showed chloroquine/sulphadoxine-pyrimethamine combination therapy for P. falciparum and chloroquine alone for P. vivax to be highly efficacious. Although the chloroquine-resistant pfcrt allele was present in all P. falciparum isolates, mutant alleles in the dhfr and dhps genes do not yet occur to the extent required to confer sulphadoxine-pyrimethamine resistance in this population.
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Affiliation(s)
- Michael H Kinzer
- U,S, Naval Medical Research Unit No,2, Kompleks P2P/PLP-LITBANGKES, Jl, Percetakan Negara No. 29, Jakarta Pusat 10560, Indonesia.
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Hasan AU, Suguri S, Sattabongkot J, Fujimoto C, Amakawa M, Harada M, Ohmae H. Implementation of a novel PCR based method for detecting malaria parasites from naturally infected mosquitoes in Papua New Guinea. Malar J 2009; 8:182. [PMID: 19646275 PMCID: PMC2729773 DOI: 10.1186/1475-2875-8-182] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 08/01/2009] [Indexed: 11/21/2022] Open
Abstract
Background Detection of Plasmodium species in mosquitoes is important for designing vector control studies. However, most of the PCR-based detection methods show some potential limitations. The objective of this study was to introduce an effective PCR-based method for detecting Plasmodium vivax and Plasmodium falciparum from the field-caught mosquitoes of Papua New Guinea. Methods A method has been developed to concurrently detect mitochondrial cytochrome b (Cyt b) of four human Plasmodium species using PCR (Cytb-PCR). To particularly discriminate P. falciparum from P. vivax, Plasmodium ovale and Plasmodium malariae, a polymerase chain reaction-repeated fragment length polymorphism (PCR-RFLP) has further been developed to use with this method. However, due to limited samples number of P. ovale and P. malariae; this study was mainly confined to P. vivax and P. falciparum. The efficiency of Cytb-PCR was evaluated by comparing it with two 'gold standards' enzyme linked immunosorbent assay specific for circumsporozoite protein (CS-ELISA) using artificially infected mosquitoes; and nested PCR specific for small subunit ribosomal RNA (SSUrRNA) using field caught mosquitoes collected from three areas (Kaboibus, Wingei, and Jawia) of the East Sepic Province of Papua New Guinea. Results A total of 90 mosquitoes were artificially infected with three strains of Plasmodium: P. vivax-210 (n = 30), P. vivax-247 (n = 30) and P. falciparum (n = 30). These infected mosquitoes along with another 32 unfed mosquitoes were first checked for the presence of Plasmodium infection by CS-ELISA, and later the same samples were compared with the Cytb-PCR. CS-ELISA for P. vivax-210, P. vivax-247 and P. falciparum detected positive infection in 30, 19 and 18 mosquitoes respectively; whereas Cytb-PCR detected 27, 16 and 16 infections, respectively. The comparison revealed a close agreement between the two assays (κ = 0.862, 0.842 and 0.894, respectively for Pv-210, Pv-247 and P. falciparum groups). It was found that the eight CS-ELISA-positive mosquitoes detected negative by Cytb-PCR were false-positive results. The lowest detection limit of this Cytb-PCR was 10 sporozoites. A highly concordance result was also found between nested PCR and Cytb-PCR using 107 field caught mosquitoes, and both tests concordantly detected P. falciparum in an Anopheles punctulatus mosquito collected from Kaboibus. Both tests thus suggested an overall sporozoite rate of 0.9% (1/107) in the study areas. Subsequently, PCR-RFLP efficiently discriminated P. falciparum from P. vivax for all of the Cytb-PCR positive samples. Conclusion A single step PCR based method has been introduced here that is highly sensitive, efficient and reliable for identifying P. vivax and P. falciparum from mosquitoes. The reliability of the technique was confirmed by its ability to detect Plasmodium as efficiently as those of CS-ELISA and nested PCR. Application of the assay offers the opportunity to detect vector species of Papua New Guinea and may contribute for designing further vector control programmes.
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Affiliation(s)
- Arif U Hasan
- Department of International Medical Zoology, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki, Kita, Kagawa, 761-0793 Japan.
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Hasan AU, Suguri S, Fujimoto C, Itaki RL, Harada M, Kawabata M, Bugoro H, Albino B. Genetic diversity in two sibling species of the Anopheles punctulatus group of mosquitoes on Guadalcanal in the Solomon Islands. BMC Evol Biol 2008; 8:318. [PMID: 19025663 PMCID: PMC2612007 DOI: 10.1186/1471-2148-8-318] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Accepted: 11/24/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mosquito Anopheles irenicus, a member of the Anopheles punctulatus group, is geographically restricted to Guadalcanal in the Solomon Islands. It shows remarkable morphological similarities to one of its sibling species, An. farauti sensu stricto (An. farauti s.s.), but is dissimilar in host and habitat preferences. To infer the genetic variations between these two species, we have analyzed mitochondrial cytochrome oxidase subunit II (COII) and nuclear ribosomal internal transcribed spacer 2 (ITS2) sequences from Guadalcanal and from one of its nearest neighbours, Malaita, in the Solomon Islands. RESULTS An. farauti s.s. was collected mostly from brackish water and by the human bait method on both islands, whereas An. irenicus was only collected from fresh water bodies on Guadalcanal Island. An. irenicus is distributed evenly with An. farauti s.s. (Phi SC = 0.033, 0.38%) and its range overlaps in three of the seven sampling sites. However, there is a significant population genetic structure between the species (Phi CT = 0.863, P < 0.01; Phi ST = 0.865, P < 0.01 and FST = 0.878, P < 0.01). Phylogenetic analyses suggest that An. irenicus is a monophyletic species, not a hybrid, and is closely related to the An. farauti s.s. on Guadalcanal. The time estimator suggests that An. irenicus diverged from the ancestral An. farauti s.s. on Guadalcanal within 29,000 years before present (BP). An. farauti s.s. expanded much earlier on Malaita (texp = 24,600 BP) than the populations on Guadalcanal (texp = 16,800 BP for An. farauti s.s. and 14,000 BP for An. irenicus). CONCLUSION These findings suggest that An. irenicus and An. farauti s.s. are monophyletic sister species living in sympatry, and their populations on Guadalcanal have recently expanded. Consequently, the findings further suggest that An. irenicus diverged from the ancestral An. farauti s.s. on Guadalcanal.
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Affiliation(s)
- Arif U Hasan
- Department of International Medical Zoology, Faculty of Medicine, Kagawa University, Kita, Kagawa, 761-0793, Japan.
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Phylogeography and dispersion pattern of Anopheles farauti senso stricto mosquitoes in Melanesia. Mol Phylogenet Evol 2008; 46:792-800. [PMID: 18357645 DOI: 10.1016/j.ympev.2007.09.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lum JK, Kaneko A, Taleo G, Amos M, Reiff DM. Genetic diversity and gene flow of humans, Plasmodium falciparum, and Anopheles farauti s.s. of Vanuatu: inferred malaria dispersal and implications for malaria control. Acta Trop 2007; 103:102-7. [PMID: 17662681 DOI: 10.1016/j.actatropica.2007.05.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2007] [Accepted: 05/22/2007] [Indexed: 10/23/2022]
Abstract
A comparison of the patterns of gene flow within and between islands and the genetic diversities of the three species required for malaria transmission (humans, Plasmodium falciparum, and Anopheles farauti s.s.) within the model island system of Vanuatu, shows that the active dispersal of An. farauti s.s. is responsible for within island movement of parasites. In contrast, since both P. falciparum and An. farauti s.s. populations are largely restricted to islands, movement of parasites between islands is likely due to human transport. Thus, control of vectors is crucial for controlling malaria within islands, while control of human movement is essential to control malaria transmission across the archipelago.
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Affiliation(s)
- J K Lum
- Laboratory of Evolutionary Anthropology and Health, Binghamton University, Binghamton, NY 13902-6000, USA
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FOLEY DESMONDH, BRYAN JOANH, WILKERSON RICHARDC. Species-richness of the Anopheles annulipes complex (Diptera: Culicidae) revealed by tree and model-based allozyme clustering analyses. Biol J Linn Soc Lond 2007. [DOI: 10.1111/j.1095-8312.2007.00818.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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20
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Reiff DM, Kaneko A, Taleo G, Amos M, Lum JK. Population structure and gene flow of Anopheles farauti s.s. (Diptera: Culicidae) among ten sites on five islands of Vanuatu: implications for malaria control. JOURNAL OF MEDICAL ENTOMOLOGY 2007; 44:601-7. [PMID: 17695014 DOI: 10.1603/0022-2585(2007)44[601:psagfo]2.0.co;2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The Anopheles punctulatus (Diptera: Culicidae) group is the main vector for malaria and Bancroftian filariasis in Vanuatu. Anopheles larvae were collected from 10 localities on five islands of Vanuatu during the 2004 dry season for species identification as well as for estimating population structure and gene flow within and among islands. Species identification was determined using polymerase chain reaction-restriction fragment length polymorphism analysis of the internal transcribed spacer 2 region. Population structure and gene flow were examined by sequencing a portion of the ND4/ND5 region of the mitochondrial genome. Only one species of the An. punctulatus group, An. farauti s.s., was identified, consistent with previous studies in Vanuatu. A nonrandom distribution of An. farauti s.s. lineages was observed with one cosmopolitan lineage shared by eight sites on all five islands and a preponderance of island-specific lineages (36/40), indicating the introduction of a single main lineage into Vanuatu followed by dispersal, diversification, and limited lineage exchange between islands. Network analysis suggests a possible second introduction of An. farauti s.s. into the northern islands of Gaua and Malekula. Gene flow was high on three of the five islands, whereas Tanna and Santo have significant population structure. Among islands, gene flow was limited, indicating active mosquito dispersal only over short distances and a paucity of passive human-mediated dispersal over long distances. Minimal risk of active dispersal among these islands indicates that vector control can be effectively initiated at the island level within the archipelago of Vanuatu.
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Affiliation(s)
- D M Reiff
- Laboratory of Evolutionary Anthropology and Health, Binghamton University, PO Box 6000, Binghamton, NY 13902-6000, USA.
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Torres EP, Foley DH, Bryan JH. Molecular systematics of the Philippine malaria vector Anopheles flavirostris. MEDICAL AND VETERINARY ENTOMOLOGY 2006; 20:44-52. [PMID: 16608489 DOI: 10.1111/j.1365-2915.2006.00610.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Allozyme and molecular sequence data from the malaria vector Anopheles flavirostris (Ludlow) (Diptera: Culicidae) were analysed from 34 sites throughout the Philippines, including the type locality, to test the hypothesis that this taxon is a single panmictic species. A finer-scaled allozyme study, of mainly Luzon samples, revealed no fixed genetic differences in sympatric sites and only low levels of variation. We obtained data from partial sequences for the internal transcribed spacer 2 (ITS2) (483 bp), the third domain (D3) (330 bp) of the 28S ribosomal DNA subunit and cytochrome c oxidase subunit I (COI) of mitochondrial DNA (261 bp). No sequence variation was observed for ITS2, only a one base pair difference was observed between Philippine and Indonesian D3 sequences and An. flavirostris sequences were unique, confirming their diagnostic value for this taxon. Sixteen COI haplotypes were identified, giving 25 parsimony informative sites. Neighbour-Joining, Maximum Parsimony, Maximum Likelihood and Bayesian phylogenetic analysis of COI sequences for An. flavirostris and outgroup taxa revealed strong branch support for the monophyly of An. flavirostris, thus confirming that Philippine populations of this taxon comprise a single separate species within the Minimus Subgroup of the Funestus Group. Variation in the behaviour of An. flavirostris is likely to be intraspecific rather than interspecific in origin.
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Affiliation(s)
- E P Torres
- Tropical Health Program, Australian Centre for International and Tropical Health and Nutrition, The University of Queensland, Brisbane, Australia
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Russell RC, Kay BH. Medical entomology: changes in the spectrum of mosquito-borne disease in Australia and other vector threats and risks, 1972-2004. ACTA ACUST UNITED AC 2004. [DOI: 10.1111/j.1326-6756.2004.00436.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Foley DH, Russell RC, Bryan JH. Population structure of the peridomestic mosquito Ochlerotatus notoscriptus in Australia. MEDICAL AND VETERINARY ENTOMOLOGY 2004; 18:180-190. [PMID: 15189244 DOI: 10.1111/j.0269-283x.2004.00497.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ochlerotatus notoscriptus (Skuse) (Diptera: Culicidae) is the predominant peridomestic mosquito in Australia where it is the primary vector of dog heartworm, Dirofilaria immitis (Leidy), and a potentially important vector of arboviruses (Barmah Forest, Ross River) with geographical variation of vector competence. Although widespread, Oc. notoscriptus has low dispersal ability, so it may have isolated subpopulations. The identification of gene flow barriers may assist in understanding arbovirus epidemiology and disease risk, and for developing control strategies for this species. We investigated the population structure of Oc. notoscriptus from 17 sites around Australia, using up to 31 putative allozyme loci, 11 of which were polymorphic. We investigated the effect of larval environment and adult morphology on genetic variation. At least five subpopulations were found, four in New South Wales (NSW) and one unique to Darwin. Perth samples appear to be a product of recent colonization from the Australian east coast. For NSW sites, a Mantel test revealed an isolation by distance effect and spatial autocorrelation analysis revealed an area of effective gene flow of 67 km, which is high given the limited dispersal ability of this species. No consistent difference was observed between 'urban' and 'sylvan' habitats, which suggests frequent movement between these sites. However, a finer-scaled habitat study at Darwin revealed small but significant allele frequency differences, including for Gpi. No fixed allozyme differences were detected for sex, size, integument colour or the colour of species-diagnostic pale scales on the scutum. The domestic habit of Oc. notoscriptus and assisted dispersal have helped to homogenize this species geographically but population structure is still detectable on several levels associated with geographical variation of vector competence.
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Affiliation(s)
- D H Foley
- Tropical Health Program, ACITHN, The University of Queensland, Brisbane, Australia
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Schmidt ER, Foley DH, Bugoro H, Bryan JH. A morphological study of the Anopheles punctulatus group (Diptera: Culicidae) in the Solomon Islands, with a description of Anopheles (Cellia) irenicus Schmidt, sp.n. BULLETIN OF ENTOMOLOGICAL RESEARCH 2003; 93:515-526. [PMID: 14704098 DOI: 10.1079/ber2003267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A description of Anopheles (Cellia) irenicus Schmidt, sp.n. (formerly A. farauti No. 7) is provided. This species is one of six recorded from the Solomon Islands within the A. punctulatus group, which contains the major vectors of the causative agents of malaria and lymphatic filariasis in the southwest Pacific. Morphological markers are described for adult females, fourth-instar larvae and pupae that identify most specimens of A. irenicus. Keys are presented to distinguish members of the A. punctulatus group in the Solomon Islands.
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Affiliation(s)
- E R Schmidt
- Tropical Health Program ACITHN, Medical School, University of Queensland, Brisbane 4072, Australia
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Maingon RDC, Ward RD, Hamilton JGC, Noyes HA, Souza N, Kemp SJ, Watts PC. Genetic identification of two sibling species of Lutzomyia longipalpis (Diptera: Psychodidae) that produce distinct male sex pheromones in Sobral, Ceará State, Brazil. Mol Ecol 2003; 12:1879-94. [PMID: 12803639 DOI: 10.1046/j.1365-294x.2003.01871.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Lutzomyia longipalpis, the main sandfly vector for New World visceral leishmaniasis is a complex of an as yet undefined number of sibling species. At present, there is no consensus on the status (single species vs. species complex) of Brazilian populations. We applied five microsatellite loci to test the hypothesis that L. longipalpis occurs as two sympatric cryptic species in Sobral, Ceará State, Brazil as predicted by male sex pheromone chemotypes described previously for field specimens from this site [S-9-methyl-germacrene-B (9MGB) and a cembrene compound]. Abdominal spot morphology corresponds with pheromone type at this locality (9MGB in '1 spot' males and cembrene in '2 spot' males). Genotype data from 190 wild-caught L. longipalpis specimens collected in October 1999 and April 2001 were used to estimate genetic differentiation between the two sex pheromone populations and sampling dates. No significant (P > 0.05) genetic differences were found between the 1999 and 2001 9MGB samples (theta = 0.018; RST = -0.005), and genetic differentiation was low between the cembrene collections (theta = 0.037, P < 0.05; RST = -0.043, P > 0.05). By contrast, highly divergent allelic frequencies (largely at two microsatellite loci) corresponded to significant (P > 0.05) genetic differentiation (theta = 0.221; RST = 0.215) for all comparisons between samples with different pheromones. When pheromone samples were pooled across sample date, genetic differentiation was high (theta = 0.229; P < 0.001; Nem = 0.84). The allele frequency distribution at each of the five microsatellite loci was similar for males and females from the two collection years. Two of these loci showed highly divergent allele frequencies in the two sex pheromone populations. This was reflected in the highly significant genetic differentiation obtained from the male genotypes, between populations producing different pheromones (theta = 0.229-0.268; P < 0.0001 for the 2001 and theta = 0.254-0.558; P < 0.0001 for the 1999 collections, respectively). Similar results were obtained when the females, assigned to a pheromone type, were included in the analysis. Both a Bayesian analysis of the data set and a population assignment test provided strong evidence for two distinct populations corresponding to pheromone type. Given its genotype, the probability of assigning a 9MGB male to the original 9MGB population was 100% once the two years' collections were pooled. For cembrene-producing '2 spot' males this probability although still high, was lower than for 9MGB males, at 86%. This microsatellite data together with previously reported reproductive isolation between the two Sobral populations confirm that premating barriers are important in speciation of L. longipalpis.
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Affiliation(s)
- R D C Maingon
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, ST5 5BG, UK.
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26
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Kazura JW, Bockarie MJ. Lymphatic filariasis in Papua New Guinea: interdisciplinary research on a national health problem. Trends Parasitol 2003; 19:260-3. [PMID: 12798083 DOI: 10.1016/s1471-4922(03)00110-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Bancroftian filariasis is a major public health problem in Papua New Guinea, where the level of transmission by the mosquito vector, human infection rates and clinical morbidity are among the highest in the world. Coordinated research efforts within the country, involving the disciplines of epidemiology, vector biology, immunology and genetics, have led to new insights into the ecology and pathogenesis of human lymphatic filariasis. Recent work using this knowledge base should be helpful in assessing local and global strategies aimed at eliminating Wuchereria bancrofti and in guiding research that will facilitate achievement of this goal.
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Affiliation(s)
- James W Kazura
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH 44106, USA.
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27
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Abstract
Papua New Guinea (PNG) is a patchwork of different ecological zones, inhabited by human populations of exceptional cultural and linguistic diversity. This results in complex variations in vector ecology and malaria epidemiology. Malaria is the main cause of morbidity in many health facilities in lowland areas, but it is absent in much of the highlands. All four human malaria species occur, but endemicity varies widely, with Plasmodium falciparum locally reaching holo-endemic levels that are rarely found outside sub-Saharan Africa. The high frequency of Plasmodium vivax is an important difference to most African situations. PNG is therefore a prime location for studies of interactions between different parasite species, and of the biology of local human genetic adaptation and its implications for malaria morbidity and mortality.
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Affiliation(s)
- Ivo Müller
- Papua New Guinea Institute of Medical Research, Maprik, EHP 441, Papua New Guinea
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28
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Ishikawa H, Ishii A, Nagai N, Ohmae H, Harada M, Suguri S, Leafasia J. A mathematical model for the transmission of Plasmodium vivax malaria. Parasitol Int 2003; 52:81-93. [PMID: 12543150 DOI: 10.1016/s1383-5769(02)00084-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have proposed a mathematical model for the transmission of Plasmodium vivax malaria quantitatively, which is adjusted to the infected region, Guadalcanal, in the Solomon Islands. The simulation of a transmission model will be instrumental in planning the malaria control strategy. A characteristic of the life cycle of P. vivax is that a sporozoite injected into the blood stream by a mosquito bite may sometimes stay in a hepatocyte as a hypnozoite. Therefore, we have incorporated a phenomenon of renewed infections caused by a relapse into the transmission model. Also through the simulations we have attempted to evaluate the decline in prevalence caused by the programs of selective mass drug administration (MDA) and vector control such as the distribution of permethrin-treated bednets. The simulations have indicated that the concentrated repetition of MDA at 1-week intervals would reduce the prevalence of vivax malaria swiftly in the beginning and would keep the parasite rate below 1% for a few years but the prevalence would increase thereafter. In contrast, the parasite rate would remain below 1% for a long time if a trial of 1 or 2 times MDA is accompanied with some reduction of the vectorial capacity by the enforcement of vector control. In any case, it is important to beware of relapse cases because even after the execution of MDA it takes a long time to decrease the proportion of hypnozoite carriers.
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Affiliation(s)
- Hirofumi Ishikawa
- Department of Environmental and Mathematical Sciences, Faculty of Environmental Science and Technology, Okayama University, Tsushimanaka, Okayama 700-8530, Japan.
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29
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30
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Cooper RD, Waterson DGE, Frances SP, Beebe NW, Sweeney AW. Speciation and distribution of the members of the Anopheles punctulatus (Diptera: Culicidae) group in Papua New Guinea. JOURNAL OF MEDICAL ENTOMOLOGY 2002; 39:16-27. [PMID: 11931251 DOI: 10.1603/0022-2585-39.1.16] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mosquito collections were made throughout the mainland of Papua New Guinea to identify the members of the Anopheles punctulatus group present and to determine their distribution. Identification was made using morphology, DNA hybridization, and polymerase chain reaction (PCR)-RFLP analysis. Nine members of the group were identified: An. farauti s.s. Laveran, An. farauti 2, An. koliensis Owen, and An. punctulatus Dönitz, were common and widespread; An. farauti 4 was restricted to the north of the central ranges where it was common; An. farauti 6 was found only in the highlands above 1,000 m; and An. farauti 3, An. sp. near punctulatus and An. clowi Rozeboom & Knight were uncommon and had restricted distributions. Identification of An. koliensis and An. punctulatus using proboscis morphology was found to be unreliable wherever An. farauti 4 occurred. The distribution and dispersal of the members of the An. punctulatus group is discussed in regard to climate, larval habitats, distance from the coast, elevation, and proximity to human habitation.
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Affiliation(s)
- R D Cooper
- Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, Queensland
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31
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Schmidt ER, Foley DH, Hartel GF, Williams GM, Bryan JH. Descriptions of the Anopheles (Cellia) farauti complex of sibling species (Diptera: Culicidae) in Australia. BULLETIN OF ENTOMOLOGICAL RESEARCH 2001; 91:389-411. [PMID: 11583601 DOI: 10.1079/ber2001113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Descriptions of the three sibling species of the Anopheles farauti complex in Australia, A. farauti Laveran (formerly A. farauti No. 1), A. hinesorum Schmidt sp.n. (formerly A. farauti No. 2) and A. torresiensis Schmidt sp.n. (formerly A. farauti No. 3) are provided. These species form a part of the punctulatus group, which contains the major malaria vectors in the southwest Pacific. Morphological markers are described for adult females, fourth instar larvae and pupae which identify most specimens, and are presented in keys.
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32
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Márquez LM, Lampo M, Rinaldi M, Lau P. Gene flow between natural and domestic populations of Lutzomyia longipalpis (Diptera: Psychodidae) in a restricted focus of American visceral leishmaniasis in Venezuela. JOURNAL OF MEDICAL ENTOMOLOGY 2001; 38:12-16. [PMID: 11268683 DOI: 10.1603/0022-2585-38.1.12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The epidemiology of the visceral leishmaniasis in the Americas is associated with both a natural and a domestic cycle. The existence of reproductively isolated populations of Lutzomyia longipalpis (Lutz & Neiva), and the scarcity of records of this species from natural habitats in areas where it has been associated with domestic habitats indicated that natural populations could be genetically distinct from domestic ones. Therefore, we compared the genetic structure and estimated the gene flow between L. longipalpis from domestic and peridomestic habitat and from an adjacent undisturbed natural environment along a 1.2-km transect. The analyses were performed on electrophoretic data from eight isozyme loci. The absence of fixed differences in the diagnostic loci Ak and Hk indicated that all specimens belonged to one of the two cryptic species identified in Venezuela. The average number of alleles per locus ranged from 2.0 to 2.9 and the average heterozygosity ranged from 7.8 to 13.4%. No differences were detected in the genetic structure of this species from domestic or peridomestic habitats and those trapped as far as 1.2 km from human dwellings. Nm, estimated from Wright's Fst, indicated that at least 208 individuals per generation migrated between the peridomestic habitat and a 1.2-km distant point to maintain the observed similarities in allelic frequencies. This high rate of gene flow indicated that this species has high migration rates between domestic and natural environments, and has the potential to transport for Leishmania from natural to domestic environments.
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Affiliation(s)
- L M Márquez
- Centro de Ecología Instituto Venezolano de Investigaciones Científicas, Apartado 21827, Caracas-1020, Venezuela
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33
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Beebe NW, Cooper RD, Morrison DA, Ellis JT. A phylogenetic study of the Anopheles punctulatus group of malaria vectors comparing rDNA sequence alignments derived from the mitochondrial and nuclear small ribosomal subunits. Mol Phylogenet Evol 2000; 17:430-6. [PMID: 11133197 DOI: 10.1006/mpev.2000.0853] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A phylogenetic study of the members of the Anopheles punctulatus group was performed using structural and similarity-based DNA sequence alignments of the small ribosomal subunit (SSU) from both the nuclear and the mitochondrial genomes. The mitochondrial SSU gene (12S, approximately 650 bp) proved to be highly restricted by its secondary structure and displayed little informative sequence variation. Consequently, it was considered unsuitable for a phylogenetic study of these closely related mosquito species. A structural alignment of the nuclear ribosomal DNA SSU (18S, approximately 2000 bp) proved to be more informative than similarity-based alignments. Analyses showed the A. punctulatus group to be monophyletic with two major clades; a Farauti clade containing members displaying an all-black-scaled proboscis (A. farauti 1-3 and 5-7) and the Punctulatus clade containing members displaying extensive white scaling on the apical half of the proboscis (A. farauti 4, A. punctulatus, and An. sp. near punctulatus). Anopheles koliensis was positioned basal to the Farauti clade.
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Affiliation(s)
- N W Beebe
- Molecular Parasitology Unit, University of Technology, Sydney, New South Wales, 2065, Australia
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34
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Foley DH, Bryan JH. Shared salinity tolerance invalidates a test for the malaria vector Anopheles farauti s.s. on Guadalcanal, Solomon Islands [corrected]. MEDICAL AND VETERINARY ENTOMOLOGY 2000; 14:450-452. [PMID: 11129712 DOI: 10.1046/j.1365-2915.2000.00268.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Among the Punctulatus Group of Anopheles mosquitoes (Diptera: Culicidae), first-instar larvae of the medically unimportant freshwater Anopheles farauti species No. 7 survives a seawater tolerance test (STT) that was previously thought to be diagnostic for the saltwater-tolerant malaria vector species, An. farauti Laveran s.s. Salt tolerance in these two closely related isomorphic species appears to be a shared derived character within the Farauti Complex. Failure to differentiate An. farauti s.s. from An. farauti No.7 will overestimate potential malaria vector numbers and waste limited larval control resources. Use of the STT should therefore be discontinued on Guadalcanal and other techniques such as allozyme electrophoresis used instead [corrected].
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Affiliation(s)
- D H Foley
- Tropical Health Program and the Department of Zoology and Entomology, University of Queensland, Brisbane, Australia
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35
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Foley DH, Bryan JH, Lawrence GW. The potential of ivermectin to control the malaria vector Anopheles farauti. Trans R Soc Trop Med Hyg 2000; 94:625-8. [PMID: 11198644 DOI: 10.1016/s0035-9203(00)90211-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We investigated mortality in Anopheles farauti mosquitoes, a major coastal malaria vector in the south-west Pacific, fed on a volunteer who had taken a 250 micrograms/kg dose of ivermectin. High mortality was recorded in mosquitoes feeding during the first week after treatment of the volunteer, for instance 100-80% failed to survive 3 days. A long-term residual effect of ivermectin in the blood was indicated by a small but significantly higher mortality in mosquitoes fed 6 weeks after ivermectin was taken. These effects were included in malaria transmission models that incorporated host choice and host-induced mortality parameters. For the zoophilic An. farauti, ivermectin treatment of animals resulted in a greater reduction in malaria than ivermectin treatment of humans alone, whereas for an anthropophilic vector, treatment of humans was more important. This suggests that ivermectin treatment of animals could have an important role in malaria control where An. farauti is the vector. Improvement in the health of humans and domestic animals through control of parasitic worms and mites might encourage community participation in strategies involving ivermectin.
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Affiliation(s)
- D H Foley
- Tropical Health Program, ACITHN, Australia.
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36
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Beebe NW, Cooper RD, Morrison DA, Ellis JT. Subset partitioning of the ribosomal DNA small subunit and its effects on the phylogeny of the Anopheles punctulatus group. INSECT MOLECULAR BIOLOGY 2000; 9:515-520. [PMID: 11029670 DOI: 10.1046/j.1365-2583.2000.00211.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A phylogenetic study, based on maximum parsimony, of ten species in the Anopheles punctulatus group of malaria vectors from the south-west Pacific was performed using structural and similarity-based DNA sequence alignments of the nuclear small ribosomal subunit (SSU = 18S). The structural alignment proved to be more informative than a computer generated similarity-based alignment. Analyses involving the full structural sequence alignment (2169 bp) and the helical regions (1547 bp) resolved a single tree of the same topology, while analyses using the similarity based alignment could not resolve the group. Studies on the three structural domains of the nuclear rDNA SSU identified domain 2 (769 bp) as the only region informative at the sibling-species level and resulted in the same tree as the full structural sequence and helical regions. The main conclusions of these studies were that the An. punctulatus group formed two clades: a Farauti clade containing members displaying an all black scaled proboscis (An. farauti 1-3 and 5-7) and a Punctulatus clade containing members that display some degree of white scaling on the proboscis (An. farauti 4, An. punctulatus and An. species near punctulatus). Anopheles koliensis can display either proboscis morphology and was positioned basal to the Farauti Clade. These results do not fully concord with those derived from the mitochondrial COII gene.
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Affiliation(s)
- N W Beebe
- Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, NSW, Australia.
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37
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Beebe NW, Bakote'e B, Ellis JT, Cooper RD. Differential ecology of Anopheles punctulatus and three members of the Anopheles farauti complex of mosquitoes on Guadalcanal, Solomon Islands, identified by PCR-RFLP analysis. MEDICAL AND VETERINARY ENTOMOLOGY 2000; 14:308-312. [PMID: 11016439 DOI: 10.1046/j.1365-2915.2000.00248.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
From a series of larval collections made across northern Guadalcanal during the dry season, October-November 1997, four members of the Anopheles punctulatus group of mosquitoes (Diptera: Culicidae) were identified using PCR-RFLP analysis. Anopheline larvae were found in 54/57 (95%) of the sites sampled, comprising An. farauti Laveran sensu stricto (32 sites), An. farauti species no. 2 (39 sites), An. farauti no. 7 (36 sites) and An. punctulatus Dönitz (10 sites). Anopheles punctulatus occurred only on the coastal plain, where it was associated with the more transient sites. Anopheles farauti sensu lato was more widespread throughout the survey region, with similar proportions of all three sibling species in both transient and permanent sites. Two members of the An. farauti complex, An. farauti s.s. and species no. 2, were found in brackish water. All breeding sites of An. punctulatus were cohabited by An. farauti s.l., sometimes by all three sibling species. Anopheles farauti s.s. was the only species collected on human bait, with a much higher biting rate early in the evening (57 bites/human/hour at 18.30-20.00 hours) than later (0.8 bites/human/hour at 21.00-24.00 hours).
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Affiliation(s)
- N W Beebe
- Department of Cell and Molecular Biology, University of Technology, Sydney, NSW, Australia.
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38
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Foley DH, Bryan JH. Shared salinity tolerance invalidates a test for the malaria vector Anopheles farauti s.s. on Guadalcanal, Solomon Islands. MEDICAL AND VETERINARY ENTOMOLOGY 2000; 14:102-104. [PMID: 10759320 DOI: 10.1046/j.1365-2915.2000.00219.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Among the Punctulatus Group of Anopheles mosquitoes (Diptera: Culicidae), first-instar larvae of the medically unimportant freshwater Anopheles farauti species No. 7 survives a seawater tolerance test (SST) that was previously thought to be diagnostic for the saltwater-tolerant malaria vector species, An. farauti Laveran s.s. Salt tolerance in these two closely related isomorphic species appears to be a shared derived character within the Farauti Complex. Failure to differentiate An. farauti s.s. from An. farauti No. 7 will overestimate potential malaria vector numbers and waste limited larval control resources. Use of the SST should therefore be discontinued on Guadalcanal and other techniques such as allozyme electrophoresis used instead.
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Affiliation(s)
- D H Foley
- Tropical Health Program and the Department of Zoology and Entomology, University of Queensland, Brisbane, Australia
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39
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Beebe NW, Cooper RD, Foley DH, Ellis JT. Populations of the south-west Pacific malaria vector Anopheles farauti s.s. revealed by ribosomal DNA transcribed spacer polymorphisms. Heredity (Edinb) 2000; 84 ( Pt 2):244-53. [PMID: 10762395 DOI: 10.1046/j.1365-2540.2000.00665.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malaria in the south-west Pacific is transmitted by members of the Anopheles punctulatus group which comprises 12 cryptic species with overlapping morphology. The most widely distributed species of the group is Anopheles farauti s.s. (An. farauti 1) found throughout northern Australia, Papua New Guinea, eastern Indonesia, the Solomon Islands and Vanuatu. A study of the population structure of this species using PCR-RFLP analysis on the ribosomal DNA internal transcribed spacer 1 reveals five genotypes which had distinct geographical distributions. Where these distributions overlap, genotype hybrids can be identified. Heteroduplex analysis of the ITS2 region reveals combinations of nonhomogenized ITS2 sequences and subsequently seven identifiable genotypes, reflecting the ITS1 distribution. Sequence analysis of these ITS2 polymorphisms reveals a minimum of 13 ITS2 sequence types present in heterogeneous combinations in individual mosquitoes. It appears that there are different levels of evolution occurring within the ITS1 and ITS2 regions. These data suggest that An. farauti s.s. may contain multiple loci for the rDNA gene family or that the homogenization of these regions is relatively slow and can be used in genetic studies of population distribution and structure.
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Affiliation(s)
- N W Beebe
- Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, Gore Hill 2065, Australia.
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40
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Beebe NW, Cooper RD. Systematics of malaria vectors with particular reference to the Anopheles punctulatus group. Int J Parasitol 2000; 30:1-17. [PMID: 10675739 DOI: 10.1016/s0020-7519(99)00171-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The appearance of groups and complexes of closely related cryptic or sibling species in many of the anopheline taxa has impeded studies on malaria transmission and the evaluation of control strategies which have relied on morphological characters to identify the vector species involved. The advantages of morphological identification are low cost, speed and simplicity, which allow large numbers of specimens to be processed rapidly in the field. The need for accurate identification is crucial, as time and money may be wasted in studying and controlling species of no medical importance. Various techniques such as cross-mating, chromosome studies and allozyme analysis have been developed to resolve problems of identifying sibling species, though none, as yet, can match the speed and simplicity afforded by morphology markers. The latest of these identification methods comes from advances that have been made in DNA-based technology. Although costly and requiring fairly sophisticated laboratory support, methods such as DNA probe hybridisation and PCR are the quickest and most user-friendly to date. The use of DNA has other advantages in the study of intraspecific differences and in providing characters for phylogenetic studies. This review looks at the development of DNA-based techniques for taxonomic and systematic studies of anopheline mosquitoes. The Anopheles punctulatus group of the southwest Pacific is featured as an example of how this technology has been applied and how it has progressed.
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Affiliation(s)
- N W Beebe
- Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, Westbourne Street, Gore Hill, Australia.
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41
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van den Hurk AF, Cooper RD, Beebe NW, Williams GM, Bryan JH, Ritchie SA. Seasonal abundance of Anopheles farauti (Diptera: Culicidae) sibling species in far north Queensland, Australia. JOURNAL OF MEDICAL ENTOMOLOGY 2000; 37:153-161. [PMID: 15218920 DOI: 10.1603/0022-2585-37.1.153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In the Cairns area of far north Queensland, Australia, the seasonal abundance of Anopheles farauti Laveran sibling species was studied at 6 locations, representing 3 habitat types, between August 1995 and September 1997. A total of 45,401 An. farauti s.l. was collected using CO2 + octenol baited CDC light traps, and consisted of 29,565 An. farauti No. 2, 14,214 An. farauti No. 3, and 1,622 An. farauti s.s. The relative abundance of all 3 species differed significantly by season and location. An. farauti No.2 was the dominant species except in Cairns, where An. farauti s.s. was most abundant, and at Ninds Creek, where An. farauti No. 3 predominated. The dominant species at each location was present year round, although peaks in seasonal abundance were observed. An. farauti s.s. populations were highest during the wet season (January-April). In lowland freshwater swamp habitats and 1 brackish location, An. farauti No. 2 was more abundant during the wet season. However, at the highland freshwater swamp habitat, populations of An. farauti No. 2 were highest during the late dry season and early wet season (October-December). There was a significant positive correlation of both temperature and rainfall with An. farauti s.s. and An. farauti No. 2 trap collections. There was a negative correlation between An. farauti No. 3 and temperature, indicating that this species may be more abundant during cool weather. Although there were significant relationships among weather variables and An. farauti s.l. collections, correlation values were generally low, indicating that other factors may contribute to variability among An. farauti sibling species trap collections.
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Affiliation(s)
- A F van den Hurk
- Tropical Public Health Unit, Queensland Health, Cairns, Australia
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42
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Andrews RH, Chilton NB. Multilocus enzyme electrophoresis: a valuable technique for providing answers to problems in parasite systematics. Int J Parasitol 1999; 29:213-53. [PMID: 10221624 DOI: 10.1016/s0020-7519(98)00168-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aim of this review is to highlight the effectiveness of the technique of multilocus enzyme electrophoresis in answering questions relating to the systematics of parasites and to highlight errors in the way the technique has been used and the results interpreted. We have approached this topic by answering specific questions that we have been asked by colleagues and students not necessarily familiar with the technique, the method of data analysis and its application. Although the technique has been applied to provide answers for taxonomic and population genetics studies, it remains under-utilised, perhaps because of recent advances in newer molecular technology. Rather than not acknowledge or dismiss the value of more traditional technology, we suggest that researchers examine problems in the systematics of parasites by the comparison of data derived from morphological, biochemical and molecular techniques.
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Affiliation(s)
- R H Andrews
- Department of Microbiology and Immunology, The University of Adelaide, SA, Australia.
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43
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van den Hurk AF, Ritchie SA, Ingram A, Cooper RD. The first report of Anopheles farauti sensu stricto below the nineteenth parallel at Mackay, Queensland. Med J Aust 1998; 169:89-90. [PMID: 9700344 DOI: 10.5694/j.1326-5377.1998.tb140190.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fifty-six adult female mosquitoes of the species Anopheles farauti sensu stricto--the arthropod vector for malaria--were collected from Mackay, central Queensland, at latitude 21 degrees 09'S, between August 1996 and August 1997. This is the southernmost record of this species, and may indicate that the malaria-receptive zone in Queensland needs to be expanded.
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44
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Foley DH, Bryan JH, Yeates D, Saul A. Evolution and systematics of Anopheles: insights from a molecular phylogeny of Australasian mosquitoes. Mol Phylogenet Evol 1998; 9:262-75. [PMID: 9562985 DOI: 10.1006/mpev.1997.0457] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Relationships among the genus Anopheles and its many sibling species-groups are obscure despite the importance of anophelines as the vectors of human malaria. For the first time, the interrelationships and the origin of Australasian members of the subgenus Cellia are investigated by a cladistic analysis of sequence variation within the mitochondrial cytochrome oxidase subunit II gene. Estimated divergence times between many Australasian and Oriental taxa predate the mid Miocene collision of Australasia and Southeast Asia. Phylogenetic analysis suggests that two-way exchanges with Oriental mosquitoes rather than only immigration may have been a characteristic of anopheline paleobiogeography in Australasia. The Australasian fauna is mostly included in a large clade. The medically important Punctulatus Group is monophyletic and appears derived from Oriental stock. Populations within this group from as far apart as Australia and Vanuatu were in contact in the recent past (i.e., 0.35-2.44 mya), supporting dispersal rather than vicariance explanations. Some support for the monophyly of the Myzomyia, Neomyzomyia, and Pyretophorus Series was found. However, the subgenera Anopheles and Cellia and the Neocellia Series are paraphyletic, but branch support at these taxonomic levels was poor. The COII gene shows promise for questions concerning alpha taxonomy but appears to be of limited use for resolving deeper relationships within the Anopheles.
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Affiliation(s)
- D H Foley
- Tropical Health Program ACITHN, University of Queensland, Brisbane, Australia
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van den Hurk AF, Beebe NW, Ritchie SA. Responses of mosquitoes of the Anopheles farauti complex to 1-octen-3-ol and light in combination with carbon dioxide in northern Queensland, Australia. MEDICAL AND VETERINARY ENTOMOLOGY 1997; 11:177-180. [PMID: 9226649 DOI: 10.1111/j.1365-2915.1997.tb00310.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In northern Queensland, Australia, three experiments were conducted to determine the response of mosquitoes of the Anopheles farauti complex to CDC traps baited with four attractant combinations: octenol + CO2 and light; octenol and light; CO2 and light; or CO2 and octenol without light. A CDC-modified updraft light-trap was also trialled, but did not significantly enhance collections of An.farauti sensu lato. The combination of light, octenol and CO2 caught significantly more An.farauti s.l. (both An.farauti No.1 and No.2 sibling species) when compared to CO2 and light alone. Only small numbers of the An.farauti complex were captured when CDC traps were baited with octenol alone, i.e. no light or CO2.
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Munstermann LE, Conn JE. Systematics of mosquito disease vectors (Diptera, Culicidae): impact of molecular biology and cladistic analysis. ANNUAL REVIEW OF ENTOMOLOGY 1997; 42:351-369. [PMID: 9017898 DOI: 10.1146/annurev.ento.42.1.351] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The field of medical entomology, by nature of its association with problems of human health, has been conservative in its application of molecular and computer technologies to systematic research. Recently, however, these methods have opened new interpretations for systematics of disease vectors. Medically important insects, particularly mosquitoes, are among those more thoroughly described by conventional taxonomy, and thereby provide a secure framework for testing congruencies with molecular data. In turn, molecular investigations have provided a stimulus to vector systematics in the discovery and delineation of cryptic species complexes, as well as providing new perspectives on relationships at higher taxonomic divisions. In this review, examples involving cladistic analysis, cytogenetics--in situ hybridization, isoenzymes, DNA sequencing, and restriction fragment polymorphism are drawn from the following taxa: Aedes communis; Aedes (Ochlerotatus) group G; Aedes (Stegomyia) species including A. aegypti, A. albopictus, and A. scutellaris group; Anopheles albitarsis, Anopheles dirus, Anopheles gambiae, Anopheles nuneztovari, Anopheles pseudopunctipennis, and Anopheles punctulatus groups; Culex pipiens and the Culex subgenus Melanoconion; and the tribe Sabethini.
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Affiliation(s)
- L E Munstermann
- Yale School of Medicine, Department of Epidemiology and Public Health, New Haven, Connecticut 06520-8034, USA.
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Kere NK, Arabola A, Bakote'e B, Qalo O, Burkot TR, Webber RH, Southgate BA. Permethrin-impregnated bednets are more effective than DDT house-spraying to control malaria in Solomon Islands. MEDICAL AND VETERINARY ENTOMOLOGY 1996; 10:145-148. [PMID: 8744706 DOI: 10.1111/j.1365-2915.1996.tb00720.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A field trial compared DDT house-spraying with permethrin-impregnated bednets for malaria control in Solomon Islands from 1987 to 1991. Mortality-rates of malaria vector Anopheles farauti in exit window traps were 11.6% from an untreated hut, 10.1% from a hut sprayed with DDT 2 g/m2, and 98% of those from a hut in which the occupants used bednets treated with permethrin 0.5 g/m2. Since bioassays of the DDT-sprayed walls (15 min exposure in W.H.O. standard test cones) gave 77% mortality of An.farauti, it was concluded that the insignificant impact of DDT could be explained by the exophilic behaviour of endophagic vectors, whereas the greater impact of permethrin was attributed to the more effective exposure of An.farauti females to the impregnated bednets-attracted by the occupants. The parous rate was higher indoors, except in the area with permethrin-impregnated bednets. It was therefore concluded that permethrin-impregnated bednets reduced the mean longevity of An.farauti and hence its vectorial capacity. The circumsporozoite (CS) antigen positivity rate of An.farauti in the DDT area was 0.18% outdoors, significantly less than 1.42% indoors. In the comparison area CS rates were 0.65% outdoors and 0.75% indoors. CS antigen was not detected in An.farauti from the bednet area, indicating the apparent prevention of malaria transmission. As DDT spraying was so much less effective, it was discontinued in 1993 and permethrin-impregnated bednets are now the principal malaria control method in Solomon Islands.
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Affiliation(s)
- N K Kere
- Ministry of Health and Medical Services, Solomon Islands, U.K
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Abstract
Although endemic malaria was eradicated from Australia by 1981, the vectors remain and transmission from imported cases still occurs. Climate modelling shows that global warming will enlarge the potential range of the main vector, Anopheles farauti sensu stricto; by the year 2030 it could extend along the Queensland coast to Gladstone, 800 km south of its present limit. Vigilance and a dispassionate assessment of risk are needed to meet this challenge.
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Affiliation(s)
- J H Bryan
- University of Queensland, Brisbane, QLD
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Williams TN, Maitland K, Foley DH. Malaria sporozoite rates for Anopheles farauti s.s. Laveran (Diptera: culicidae) from Vanuatu. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1995; 89:305-7. [PMID: 7668922 DOI: 10.1080/00034983.1995.11812956] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- T N Williams
- Northern District Hospital, Espiritu Santo, Vanuatu
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Cooper RD, Meza RA, Schneider I. Anopheles farauti refractoriness to malaria infection with cultured gametocytes of Plasmodium falciparum. MEDICAL AND VETERINARY ENTOMOLOGY 1994; 8:389-390. [PMID: 7841495 DOI: 10.1111/j.1365-2915.1994.tb00105.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- R D Cooper
- Army Malaria Research Unit, Liverpool Military Area, New South Wales, Australia
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