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Al-Eryani SM, Irish SR, Carter TE, Lenhart A, Aljasari A, Montoya LF, Awash AA, Mohammed E, Ali S, Esmail MA, Hussain A, Amran JG, Kayad S, Nouredayem M, Adam MA, Azkoul L, Assada M, Baheshm YA, Eltahir W, Hutin YJ. Public health impact of the spread of Anopheles stephensi in the WHO Eastern Mediterranean Region countries in Horn of Africa and Yemen: need for integrated vector surveillance and control. Malar J 2023; 22:187. [PMID: 37337209 PMCID: PMC10278259 DOI: 10.1186/s12936-023-04545-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/30/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND Anopheles stephensi is an efficient vector of both Plasmodium falciparum and Plasmodium vivax in South Asia and the Middle East. The spread of An. stephensi to countries within the Horn of Africa threatens progress in malaria control in this region as well as the rest of sub-Saharan Africa. METHODS The available malaria data and the timeline for the detection of An. stephensi was reviewed to analyse the role of An. stephensi in malaria transmission in Horn of Africa of the Eastern Mediterranean Region (EMR) in Djibouti, Somalia, Sudan and Yemen. RESULTS Malaria incidence in Horn of Africa of EMR and Yemen, increased from 41.6 in 2015 to 61.5 cases per 1000 in 2020. The four countries from this region, Djibouti, Somalia, Sudan and Yemen had reported the detection of An. stephensi as of 2021. In Djibouti City, following its detection in 2012, the estimated incidence increased from 2.5 cases per 1000 in 2013 to 97.6 cases per 1000 in 2020. However, its contribution to malaria transmission in other major cities and in other countries, is unclear because of other factors, quality of the urban malaria data, human mobility, uncertainty about the actual arrival time of An. stephensi and poor entomological surveillance. CONCLUSIONS While An. stephensi may explain a resurgence of malaria in Djibouti, further investigations are needed to understand its interpretation trends in urban malaria across the greater region. More investment for multisectoral approach and integrated surveillance and control should target all vectors particularly malaria and dengue vectors to guide interventions in urban areas.
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Affiliation(s)
- Samira M Al-Eryani
- Department of Universal Health Coverage/Communicable Diseases Prevention and Control, Eastern Mediterranean Regional Office, World Health Organization, Cairo, Egypt.
| | - Seth R Irish
- World Health Organization, Headquarters, 1211, Geneva, Switzerland
| | | | - Audrey Lenhart
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Adel Aljasari
- World Health Organization, Country Office, Sana'a, Yemen
| | | | - Abdullah A Awash
- World Health Organization, Country Office, Sub-Office, Aden, Yemen
| | | | - Said Ali
- National Malaria Control Programme, Ministry of Health Development, Hargeisa, Somaliland
| | - Mohammed A Esmail
- National Malaria Control Programme, Ministry of Public Health & Population, Sana'a, Yemen
| | | | - Jamal G Amran
- World Health Organization, Country Office, Mogadishu, Somalia
| | - Samatar Kayad
- National Malaria Control Programme, Ministry of Health, Djibouti, Djibouti
| | | | - Mariam A Adam
- World Health Organization, Country Office, Khartoum, Sudan
| | - Lina Azkoul
- Department of Universal Health Coverage/Communicable Diseases Prevention and Control, Eastern Mediterranean Regional Office, World Health Organization, Cairo, Egypt
| | - Methaq Assada
- National Malaria Control Programme, Ministry of Public Health & Population, Sana'a, Yemen
| | - Yasser A Baheshm
- National Malaria Control Programme, Ministry of Public Health & Population, Aden, Yemen
| | - Walid Eltahir
- Directorate of the Integrated Vector Management (IVM), Federal Ministry of Health, Khartoum, Sudan
| | - Yvan J Hutin
- Department of Universal Health Coverage/Communicable Diseases Prevention and Control, Eastern Mediterranean Regional Office, World Health Organization, Cairo, Egypt
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Mosquera KD, Nilsson LKJ, de Oliveira MR, Rocha EM, Marinotti O, Håkansson S, Tadei WP, de Souza AQL, Terenius O. Comparative assessment of the bacterial communities associated with Anopheles darlingi immature stages and their breeding sites in the Brazilian Amazon. Parasit Vectors 2023; 16:156. [PMID: 37127597 PMCID: PMC10150499 DOI: 10.1186/s13071-023-05749-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/19/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND The neotropical anopheline mosquito Anopheles darlingi is a major malaria vector in the Americas. Studies on mosquito-associated microbiota have shown that symbiotic bacteria play a major role in host biology. Mosquitoes acquire and transmit microorganisms over their life cycle. Specifically, the microbiota of immature forms is largely acquired from their aquatic environment. Therefore, our study aimed to describe the microbial communities associated with An. darlingi immature forms and their breeding sites in the Coari municipality, Brazilian Amazon. METHODS Larvae, pupae, and breeding water were collected in two different geographical locations. Samples were submitted for DNA extraction and high-throughput 16S rRNA gene sequencing was conducted. Microbial ecology analyses were performed to explore and compare the bacterial profiles of An. darlingi and their aquatic habitats. RESULTS We found lower richness and diversity in An. darlingi microbiota than in water samples, which suggests that larvae are colonized by a subset of the bacterial community present in their breeding sites. Moreover, the bacterial community composition of the immature mosquitoes and their breeding water differed according to their collection sites, i.e., the microbiota associated with An. darlingi reflected that in the aquatic habitats where they developed. The three most abundant bacterial classes across the An. darlingi samples were Betaproteobacteria, Clostridia, and Gammaproteobacteria, while across the water samples they were Gammaproteobacteria, Bacilli, and Alphaproteobacteria. CONCLUSIONS Our findings reinforce the current evidence that the environment strongly shapes the composition and diversity of mosquito microbiota. A better understanding of mosquito-microbe interactions will contribute to identifying microbial candidates impacting host fitness and disease transmission.
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Affiliation(s)
- Katherine D Mosquera
- Department of Cell and Molecular Biology, Biomedical Centre (BMC), Uppsala University, Uppsala, Sweden
| | - Louise K J Nilsson
- Department of Cell and Molecular Biology, Biomedical Centre (BMC), Uppsala University, Uppsala, Sweden
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Marta Rodrigues de Oliveira
- Programa de Pós-graduação em Biodiversidade e Biotecnologia (PPG-BIONORTE), Universidade do Estado do Amazonas, Manaus, Brazil
- Department of Entomology and Acarology, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo, Piracicaba, Brazil
| | - Elerson Matos Rocha
- School of Agricultural Sciences, Department of Bioprocesses and Biotechnology, Central Multi User Laboratory, São Paulo State University (UNESP), Botucatu, Brazil
| | | | - Sebastian Håkansson
- Division of Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
| | - Wanderli P Tadei
- Laboratório de Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil
| | - Antonia Queiroz Lima de Souza
- Department of Entomology and Acarology, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo, Piracicaba, Brazil
- Faculdade de Ciências Agrárias, Universidade Federal do Amazonas, Manaus, Brazil
| | - Olle Terenius
- Department of Cell and Molecular Biology, Biomedical Centre (BMC), Uppsala University, Uppsala, Sweden.
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
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Mosquera KD, Martínez Villegas LE, Rocha Fernandes G, Rocha David M, Maciel-de-Freitas R, A Moreira L, Lorenzo MG. Egg-laying by female Aedes aegypti shapes the bacterial communities of breeding sites. BMC Biol 2023; 21:97. [PMID: 37101136 PMCID: PMC10134544 DOI: 10.1186/s12915-023-01605-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 04/18/2023] [Indexed: 04/28/2023] Open
Abstract
BACKGROUND Aedes aegypti, the main arboviral mosquito vector, is attracted to human dwellings and makes use of human-generated breeding sites. Past research has shown that bacterial communities associated with such sites undergo compositional shifts as larvae develop and that exposure to different bacteria during larval stages can have an impact on mosquito development and life-history traits. Based on these facts, we hypothesized that female Ae. aegypti shape the bacteria communities of breeding sites during oviposition as a form of niche construction to favor offspring fitness. RESULTS To test this hypothesis, we first verified that gravid females can act as mechanical vectors of bacteria. We then elaborated an experimental scheme to test the impact of oviposition on breeding site microbiota. Five different groups of experimental breeding sites were set up with a sterile aqueous solution of larval food, and subsequently exposed to (1) the environment alone, (2) surface-sterilized eggs, (3) unsterilized eggs, (4) a non-egg laying female, or (5) oviposition by a gravid female. The microbiota of these differently treated sites was assessed by amplicon-oriented DNA sequencing once the larvae from the sites with eggs had completed development and formed pupae. Microbial ecology analyses revealed significant differences between the five treatments in terms of diversity. In particular, between-treatment shifts in abundance profiles were detected, showing that females induce a significant decrease in microbial alpha diversity through oviposition. In addition, indicator species analysis pinpointed bacterial taxa with significant predicting values and fidelity coefficients for the samples in which single females laid eggs. Furthermore, we provide evidence regarding how one of these indicator taxa, Elizabethkingia, exerts a positive effect on the development and fitness of mosquito larvae. CONCLUSIONS Ovipositing females impact the composition of the microbial community associated with a breeding site, promoting certain bacterial taxa over those prevailing in the environment. Among these bacteria, we found known mosquito symbionts and showed that they can improve offspring fitness if present in the water where eggs are laid. We deem this oviposition-mediated bacterial community shaping as a form of niche construction initiated by the gravid female.
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Affiliation(s)
- Katherine D Mosquera
- Vector Behavior and Pathogen Interaction Group, René Rachou Institute-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Luis Eduardo Martínez Villegas
- Department of Entomology, The Ohio State University, 2001 Fyffe Rd., Room 232 Howlett Hall, Columbus, OH, 43210, USA
- Mosquito Vectors: Endosymbionts and Pathogen-Vector Interactions Group, René Rachou Institute-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | | | - Mariana Rocha David
- Laboratory of Hematozoa Transmitting Mosquitoes, Oswaldo Cruz Institute-FIOCRUZ, Rio de Janeiro, Brazil
| | - Rafael Maciel-de-Freitas
- Laboratory of Hematozoa Transmitting Mosquitoes, Oswaldo Cruz Institute-FIOCRUZ, Rio de Janeiro, Brazil
| | - Luciano A Moreira
- Mosquito Vectors: Endosymbionts and Pathogen-Vector Interactions Group, René Rachou Institute-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Marcelo G Lorenzo
- Vector Behavior and Pathogen Interaction Group, René Rachou Institute-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil.
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Ouédraogo WM, Toé KH, Sombié A, Viana M, Bougouma C, Sanon A, Weetman D, McCall PJ, Kanuka H, Badolo A. Impact of physicochemical parameters of Aedes aegypti breeding habitats on mosquito productivity and the size of emerged adult mosquitoes in Ouagadougou City, Burkina Faso. Parasit Vectors 2022; 15:478. [PMID: 36539816 PMCID: PMC9768987 DOI: 10.1186/s13071-022-05558-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 10/14/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Outbreaks of dengue fever caused by viruses transmitted by Aedes aegypti mosquitoes are repeated occurrences in West Africa. In recent years, Burkina Faso has experienced major dengue outbreaks, most notably in 2016 and 2017 when 80% of cases were recorded in Ouagadougou City (Central Health Region). In order to better understand the ecology of this vector and to provide information for use in developing control measures, a study on the characteristics of Aedes container breeding sites and the productivity of such sites, as measured by the abundance of immature stages and resultant adult body size, was undertaken in three health districts (Baskuy, Bogodogo and Nongremassom) of Ouagadougou. METHODS Adult mosquitoes were collected indoors and outdoors in 643 households during the rainy season from August to October 2018. The presence of water containers was systematically recorded and the containers examined for the presence or absence of larvae. Characteristics of the container breeding sites, including size of the container and temperature, pH and conductivity of the water contained within, were recorded as well as the volume of water. Traditional Stegomyia indices were calculated as quantitative indicators of the risk of dengue outbreaks; generalised mixed models were fitted to larval and pupal densities, and the contribution of each covariate to the model was evaluated by the Z-value and associated P-value. RESULTS A total of 1061 container breeding sites were inspected, of which 760 contained immature stages of Ae. aegypti ('positive' containers). The most frequent container breeding sites found in each health district were tyres and both medium (buckets/cans/pots) and large (bins/barrels/drums) containers; these containers were also the most productive larval habitats and the types that most frequently tested positive. Of the Stegomyia indices, the Breteau, House and Container indices exceeded WHO dengue risk thresholds. Generalised linear mixed models showed that larval and pupal abundances were associated with container type, physicochemical characteristics of the water and collection month, but there were significant differences among container types and among health districts. Aedes aegypti body size was positively associated with type and diameter of the container, as well as with electrical conductivity of the water, and negatively associated with pH and temperature of the water and with the level of exposure of the container to sunlight. CONCLUSION This study provides data on putative determinants of the productivity of habitats regarding Ae. aegypti immature stages. These data are useful to better understand Ae. aegypti proliferation. The results suggest that identifying and targeting the most productive container breeding sites could contribute to dengue vector control strategies in Burkina Faso.
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Affiliation(s)
- Wendegoudi Mathias Ouédraogo
- Laboratoire d’Entomologie Fondamentale et Appliquée, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso ,grid.491199.dProgramme National de Lutte Contre Les Maladies Tropicales Négligées, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Kobié Hyacinthe Toé
- Laboratoire d’Entomologie Fondamentale et Appliquée, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso ,grid.507461.10000 0004 0413 3193Institut National de Santé Publique, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Aboubacar Sombié
- Laboratoire d’Entomologie Fondamentale et Appliquée, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso
| | - Mafalda Viana
- grid.8756.c0000 0001 2193 314XSchool of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Clarisse Bougouma
- grid.491199.dProgramme National de Lutte Contre Les Maladies Tropicales Négligées, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Antoine Sanon
- Laboratoire d’Entomologie Fondamentale et Appliquée, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso
| | - David Weetman
- grid.48004.380000 0004 1936 9764Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Philip J. McCall
- grid.48004.380000 0004 1936 9764Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Hirotaka Kanuka
- grid.411898.d0000 0001 0661 2073Department of Tropical Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Athanase Badolo
- Laboratoire d’Entomologie Fondamentale et Appliquée, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso
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NTONGA AKONO P, MBONGUE RS, FOKO DADJI GA, TSILA HG, OFFONO ENAMA L, NOPOWO TAKAP F, EKOKO WE, MBIDA MBIDA JA. [ Anopheles gambiae s.l. larval habitats and resistance mechanisms in Kribi, Cameroon]. Med Trop Sante Int 2022; 2:mtsi.v2i4.2022.284. [PMID: 36815176 PMCID: PMC9940278 DOI: 10.48327/mtsi.v2i4.2022.284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 10/10/2022] [Indexed: 02/24/2023]
Abstract
Background The effectiveness of Long-Lasting Insecticidal Nets (LLINs) and indoor residual spraying (IRS) in controlling malaria vectors is hampered by the resistance of anopheles to insecticides. A good knowledge of the breeding sites and of the resistance profile of the vectors could facilitate the development of an appropriate control strategy. This study looks at the larval ecology and the susceptibility profile of An. gambiae s.l. to insecticides in urban and rural areas in Kribi, South Region of Cameroon. Methods Mosquito breeding sites were categorized and geo-referenced. For each site, larvae were collected and reared and physicochemical parameters were measured in situ. The susceptibility of anopheles to dichlorodiphenyltrichloroethane (DDT), deltamethrin and permethrin, after pre-exposure to piperonyl butoxide (PBO) or not, was evaluated on the reared larvae. The Kdr mutation was detected using the Hot Oligonucleotide Ligation Assay (HOLA). Results Natural breeding sites of An. gambiae s.l. were tyre tracks (12%, n=10), unbuilt wells (5%, n=4), pools of residual water (57%, n=48), foot and hoof prints, gullies, streams and the banks of the Kienké River (15%, n=13). Artificial breeding sites were abandoned dugouts (11%, n=9). Breeding sites in urban areas were characterized by higher mean values of temperature, conductivity, salinity and turbidity compared to the breeding sites in the rural area. The breeding sites of An. gambiae s.l. in urban Kribi were found to be sunnier than those in rural Kribi. A total of 4320 adults were used for testing, 1 440 mosquitoes from rural Kribi, 1 440 from urban Kribi and 1 440 specimens from the laboratory Kisumu strain. For DDT and deltamethrin, susceptibility tests showed that mortality was lower in a situation of no pre-exposure to PBO than in a situation of pre-exposure to PBO in the two study areas. The frequency of the resistant allele (R) was high for the Kdr West mutation in both urban (0.94) and rural areas in Kribi (0.93). Conclusion An. gambiae s.l. colonizes a wide range of breeding sites and develops metabolic and mutation resistance to recommended insecticides. The search of alternative molecules for vector control is a necessity.
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Affiliation(s)
- Patrick NTONGA AKONO
- Faculté des sciences, Laboratoire de biologie et physiologie des organismes animaux, Université de Douala, B.P. 24 157 Douala, Cameroun,*
| | - Roméo Serge MBONGUE
- Faculté des sciences, Laboratoire de biologie et physiologie des organismes animaux, Université de Douala, B.P. 24 157 Douala, Cameroun
| | - Gisèle Aurélie FOKO DADJI
- École Normale Supérieure de Yaoundé, Laboratoire de Zoologie, Université de Yaoundé I, B.P. 812 Yaoundé, Cameroun
| | - Henri Gabriel TSILA
- Faculté des sciences, Unité de biologie et écologie appliquée, Université de Dschang, B.P. 067 Dschang, Cameroun
| | - Léger OFFONO ENAMA
- Faculté des sciences, Laboratoire de biologie et physiologie des organismes animaux, Université de Douala, B.P. 24 157 Douala, Cameroun
| | - Francis NOPOWO TAKAP
- Faculté des sciences, Laboratoire de biologie et physiologie des organismes animaux, Université de Douala, B.P. 24 157 Douala, Cameroun
| | - Wolfgang Eyisap EKOKO
- Institut de recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroun
| | - Jean Arthur MBIDA MBIDA
- Faculté des sciences, Laboratoire de biologie et physiologie des organismes animaux, Université de Douala, B.P. 24 157 Douala, Cameroun
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González MA, Delacour-Estrella S, Bengoa M, Barceló C, Bueno-Marí R, Eritja R, Ruiz-Arrondo I. A Survey on Native and Invasive Mosquitoes and Other Biting Dipterans in Northern Spain. Acta Parasitol 2022; 67:867-77. [PMID: 35298775 DOI: 10.1007/s11686-022-00529-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 02/21/2022] [Indexed: 11/01/2022]
Abstract
PURPOSE Haematophagous Diptera, such as mosquitoes (Culicidae), biting midges (Ceratopogonidae), and black flies (Simuliidae), are important insects for public and animal health due to their capacity to bite and transmit pathogens. Outdoor recreation areas are usually affected by biting species and provide suitable habitats to both adult and immature stages. This study aimed to determine the species diversity and larval sites of these Diptera groups in two golf courses. METHODS A multi-method collection approach using ultraviolet-CDC traps, human landing catches, collection in breeding sites, and ovitraps was implemented during summer 2020 in northern Spain. Insects were determined by morphological features accompanied by DNA barcoding. RESULTS A total of ten native mosquito species were recorded either as adults or as larval stages. The invasive species Aedes japonicus was collected only at egg or pupa stage in ovitraps. Culex pipiens s.l. and Culex torrentium were both common mosquito species accounting for 47.9% of the total larval site collections and their larvae might be found in a wide range of natural and artificial sites. Culiseta longiareolata specimens were also prominent (30.1% of the total) and occurred exclusively in man-made water-filled containers. A total of 13 Culicoides species were identified, 10 of which were captured by ultraviolet-CDC traps, particularly members of the Obsoletus complex (Culicoides obsoletus/Culicoides scoticus, 74.9%) and seven species by emergence traps, being the two most abundant C. kibunensis (44.8%) and C. festivipennis (34.9%). Simulium cryophilum was also collected hovering around the operator under field sampling. CONCLUSION A comprehensive representation of the blood-sucking Diptera fauna and their larval sites was obtained by the multi-method approach in two Spanish golf courses.
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Wijerathna T, Gunathilaka N. Diurnal adult resting sites and breeding habitats of phlebotomine sand flies in cutaneous leishmaniasis endemic areas of Kurunegala District, Sri Lanka. Parasit Vectors 2020; 13:284. [PMID: 32503610 PMCID: PMC7275303 DOI: 10.1186/s13071-020-04154-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 05/28/2020] [Indexed: 12/11/2022] Open
Abstract
Background Sand flies are responsible for the transmission of several disease pathogens including Leishmania. Sand flies breed in habitats with high levels of humidity and organic matter. They are nocturnal in nature and peak activity ranges from dusk to dawn. The scientific evidence on breeding ecology and diurnal resting sites of sand fly fauna are important aspects of planning and implementing vector control activities. However, such fundamental information is grossly inadequate in Sri Lanka to support the control efforts in the country. Therefore, the present study addresses some of the important aspects of sand fly breeding ecology and diurnal resting sites. Methods Potential resting sites were thoroughly observed, and sand flies were collected using a battery-operated aspirator and sticky papers when appropriate from three selected Medical Officer of Health (MOH) areas (Polpithigama, Maho and Galgamuwa) in Kurunegala district, Sri Lanka. Soil samples were collected from each potential breeding site. Half of each soil sample was incubated for 45 days. The other half was screened for immature stages. Adult sand flies collected from field and emerged adults at the insectary under confined incubation were identified using morphological characteristics. Results Pepper bushes and termite mounds were the most notable resting sites while, betel bushes, cattle huts, piles of coconut shells, latrines, manna bushes and tree holes were also positive for sand fly adults. Only two species, Phlebotomus argentipes and Sergentomyia punjabensis, were reported. Soil samples were collected from a total of 432 sites and 7 of them were positive for immature stages. Predominant breeding habitats identified during the present study were mud flats and moist soils of rice paddies, the soil below decaying hay, drying irrigational tank bottom moist soil, and the floors of cattle huts. Conclusion This study demonstrates that the potential adult resting sites and breeding habitats are abundant in the Polpithigama, Maho and Galgamuwa MOH areas. Therefore, vector control activities targeting both adult and immature stages of sand flies are recommended.![]()
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Affiliation(s)
- Tharaka Wijerathna
- Department of Parasitology, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
| | - Nayana Gunathilaka
- Department of Parasitology, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka.
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Shukla A, Rajalakshmi A, Subash K, Jayakumar S, Arul N, Srivastava PK, Eapen A, Krishnan J. Seasonal variations of dengue vector mosquitoes in rural settings of Thiruvarur district in Tamil Nadu, India. J Vector Borne Dis 2020; 57:63-70. [PMID: 33818458 DOI: 10.4103/0972-9062.308803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND & OBJECTIVES Mosquitoes are vectors of several important vector-borne diseases (VBDs) like malaria, dengue, chikungunya, Japanese encephalitis (JE) and lymphatic filariasis (LF). Globally, these VBDs are of major public health concern including India. The information on vector mosquitoes from Thiruvarur district in Tamil Nadu state remains largely either unknown or undocumented. The present study was, therefore, undertaken to find out the seasonal variation in mosquitoes with special reference to dengue vectors in rural areas of Thiruvarur district, Tamil Nadu, India. METHODS Surveillance of immature vector mosquitoes was undertaken from March 2018 to February 2019. The emerged adults were identified to find out the composition of mosquito species prevalent in the district. The seasonal variations of the mosquitoes especially dengue vectors were analysed for summer (March-July) spring (August-November) and winter (December-February) seasons in all the blocks of Thiruvarur district. RESULTS A total of 4879 mosquitoes emerged from the immature collection and the species identification revealed the prevalence of both vector and non-vector species. Five important mosquito vectors collected were -Aedes albopictus, Ae. aegypti, Culex tritaeniorhynchus, Cx. gelidus, and Cx. quinquefasciatus. Other mosquito species collected were Lutzia fuscana, Anopheles barbirostris, An. subpictus, and Armigeres (Armigeres) subalbatus. During the spring season, the dengue vectors showed high indices of breateau index (BI), ranging from 16 to 120; besides, container index (CI) ranging from14.29 to 68.57 and pupal index (PI) from 53.33 to 295 among the study blocks. The major breeding sites were discarded plastic containers, discarded tyres, open sintex tanks (water storage tanks), cement tanks, discarded fibre box, pleated plastic sheets, tree holes, bamboo cut stumps, coconut spathe, and coconut shells. INTERPRETATION & CONCLUSION The immature vector surveillance revealed seasonal variations in the entomological indices of Aedes breeding potential. The high indices observed indicate high Aedes breeding density and, therefore, a higher risk for dengue/chikungunya outbreaks in rural areas of Thiruvarur district. The present finding warrants intensive surveillance and follow up vector control measures to avert outbreaks and prevent vector-borne diseases. Health education and the community participation in awareness camps prior to monsoon and societal commitment will help in strengthening source reduction, anti-larval operations and anti-adult measures to tackle vector-borne diseases especially dengue.
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Affiliation(s)
- Arpita Shukla
- Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
| | - A Rajalakshmi
- Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
| | - K Subash
- Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
| | - S Jayakumar
- Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Puducherry, Tamil Nadu, India
| | - N Arul
- Department of Zoology, Bharathiar University, Tamil Nadu, India
| | - Pradeep Kumar Srivastava
- Visiting Faculty, Department of Epidemiology and Public Health, Central University of Tamil Nadu, Thiruvarur; Division of Entomology & Vector Control, National Vector Borne Disease Control Programme, Delhi; Director, Absolute Human Care Foundation, New Delhi, India
| | - Alex Eapen
- ICMR-National Institute of Malaria Research Field Unit, Chennai, India
| | - Jayalakshmi Krishnan
- Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
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9
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Wanji S, Tayong DB, Ebai R, Opoku V, Kien CA, Ndongmo WPC, Njouendou AJ, Ghani RN, Ritter M, Debrah YA, Layland LE, Enyong PA, Hoerauf A. Update on the biology and ecology of Culicoides species in the South-West region of Cameroon with implications on the transmission of Mansonella perstans. Parasit Vectors 2019; 12:166. [PMID: 30975194 PMCID: PMC6460808 DOI: 10.1186/s13071-019-3432-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 04/04/2019] [Indexed: 11/17/2022] Open
Abstract
Background Culicoides (Diptera; Ceratoponidae) are tiny, stout, blood-sucking flies with a near worldwide distribution. When present, they are often considered a biting nuisance but in addition, they are involved in the transmission of pathogens to humans, domestic and wild animals. Data on Culicoides species in the South-West region of Cameroon dates back to the 1950s. Over the decades, ecological transformation due to agriculture and deforestation may have affected the population dynamics of Culicoides and therefore our study provides an update of their bio-ecology in the region. Furthermore, the role of various Culicoides species in the transmission of parasitic filariae of the genus Mansonella remains inconclusive in this region. This study was designed to address these unknown issues and expand on current scientific knowledge. Results Eight species of Culicoides (C. bedfordi, C. inornatipennis, C. fulvithorax, C. grahamii, C. imicola, C. milnei, C. neavei and C. kumbaensis) were collected using light traps and human baits. Culicoides grahamii was the most abundant species, followed closely by C. milnei. Three species (C. milnei, C. grahamii and C. inornatipennis) were common in all observed larval development sites. Only four species (C. inornatipennis, C. fulvithorax, C. grahamii and C. milnei) were collected on humans. Anthropophilic species were more abundant (P < 0.001) in the evening (4–7 pm) when compared to the morning collections (6–9 am). After overnight fly collections using a drop trap with a human microfilaremic donor, C. milnei emerged as the potential host for transmitting Mansonella perstans. Substantial heterogeneity was observed between the trap visiting cycles of the various species (P < 0.001). The biting cycle of the main vector, C. milnei, showed two peaks (10–11 pm and 4–5 am), the highest being 10–11 pm. Conclusions The Culicoides fauna of the South-West region of Cameroon has not changed significantly since the 1950s. Culicoides milnei was demonstrated to be the major vector of M. perstans in this part of Cameroon. It is essentially a nocturnal species which peaks in abundance between 10 and 11 pm. Electronic supplementary material The online version of this article (10.1186/s13071-019-3432-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Samuel Wanji
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon. .,Research Foundation for Tropical Diseases and the Environment (REFOTDE), P.O. Box 474, Buea, Cameroon.
| | - Dizzle Bita Tayong
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon.,Research Foundation for Tropical Diseases and the Environment (REFOTDE), P.O. Box 474, Buea, Cameroon
| | - Rene Ebai
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Vera Opoku
- Kumasi Centre for Collaborative Research (KCCR), Kumasi, Ghana
| | - Chi Anizette Kien
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Winston Patrick Chounna Ndongmo
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon.,Research Foundation for Tropical Diseases and the Environment (REFOTDE), P.O. Box 474, Buea, Cameroon
| | - Abdel Jelil Njouendou
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon.,Research Foundation for Tropical Diseases and the Environment (REFOTDE), P.O. Box 474, Buea, Cameroon
| | - Raymond Nsaidzedze Ghani
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Manuel Ritter
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Yaw Alex Debrah
- Kumasi Centre for Collaborative Research (KCCR), Kumasi, Ghana
| | - Laura E Layland
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.,German Centre for Infection Research (DZIF), Partner Site, Bonn-Cologne, Bonn, Germany
| | - Peter A Enyong
- Parasite and Vector Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon.,Research Foundation for Tropical Diseases and the Environment (REFOTDE), P.O. Box 474, Buea, Cameroon
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.,German Centre for Infection Research (DZIF), Partner Site, Bonn-Cologne, Bonn, Germany
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10
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Giantsis IA, Chaskopoulou A. Broadening the tools for studying sand fly breeding habitats: A novel molecular approach for the detection of phlebotomine larval DNA in soil substrates. Acta Trop 2019; 190:123-128. [PMID: 30444972 DOI: 10.1016/j.actatropica.2018.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/06/2018] [Accepted: 11/09/2018] [Indexed: 12/01/2022]
Abstract
Phlebotomine sand flies constitute a group of haematophagous insects of great medical and veterinary importance. Despite the significant knowledge on the biology and behavior of adult sand flies in the wild, there is little information available on the ecology of their larval stages due to difficulties of detecting them in the soil. So far, investigations on sand fly breeding sites have been based on methods to catch emerging adults or on microscopic examination of the soil for the presence of immatures, neither of which is very precise or efficient for studying immatures in the field. Thus, there is a need for a better method to detect, identify and quantify immatures in soil samples. To address this issue we developed a novel molecular genetic approach for the detection of sand fly larval DNA within soil samples. Different numbers of live larvae of Phlebotomus papatasi and P. tobbi (alone or in combination), were mixed with soil and analyzed to identify and quantify the sand flies. By modifying already existing soil DNA extraction protocols in combination with a real-time PCR using species-specific primers, we successfully detected as little as one larva/40 ml of soil. We could also distinguish the two species of sand flies. This method should be very useful for increasing our knowledge of sand fly larval ecology in the field, and thus help develop more efficient, targeted control strategies against Phlebotomus sand flies.
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Affiliation(s)
- I A Giantsis
- European Biological Control Laboratory, USDA-ARS, Thessaloniki, Greece
| | - A Chaskopoulou
- European Biological Control Laboratory, USDA-ARS, Thessaloniki, Greece.
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11
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Abstract
Background & objectives : Increase of vector-borne diseases (VBDs) in India has posed a question on the situation in Lakshadweep Islands, where VBDs are reported from time-to-time. The present investigation was aimed to assess the faunastic situation of the prevailing vectors along with their breeding sites in different islands of the Lakshadweep. Methods : Extensive surveys were carried out from November 2017 to January 2018 (post-monsoon season) randomly in the nine inhabited islands of Lakshadweep for conducting faunastic studies on mosquitoes and to know the basic binomics like breeding and resting preference of mosquitoes. The study islands included, Kavaratti, Agatti, Chetlat, Bitra, Amini, Kadmath, Andrott, Kalpeni and Kiltan. Both immature and adult collections were carried out by standard/appropriate sampling techniques. The obtained data were calculated and analysed in terms of different entomological indices. Results : A total of 3356 mosquitoes were collected during the study period which comprised of 16 species from nine genera. Out of the 16 species, six belonged to mosquito vectors. The collection included malaria vector, Anopheles stephensi; Japanese encephalitis vector, Culex tritaeniorhynchus; Bancroftian filariasis vector, Cx. quinquefasciatus; Brugian filariasis vector, Mansonia uniformis; and dengue and chikungunya vectors, Stegomya albopicta and St. aegypti. Stegomya albopicta was the most predominant species observed constituting 54% of the catch, followed by Cx. quinquefasciatus, An. stephensi, Cx. tritaeniorhynchus, and St. aegypti constituting 10.5, 6, 3 and 1.2%, respectively. Apart from vector species many non-vectors such as Heizmannia chandi, An. subpictus, An. varuna, Cx. sitiens, Cx. minutissimus, Cx. rubithoracis, Fredwardsius vittatus, Lutzia fuscana, Malaya genurostris and Armigeres subalbatus were also present in the study area. In Kavaratti Island, the capital of Lakshadweep, a non-vector species of sandfly, Sergentomyia (Parrotomyia) babu was observed during the indoor resting collection. The major breeding sites which supported various mosquito species included, discarded plastic containers, tree holes, open sintex tanks (water storage tanks), unused wells, discarded tyres, discarded iron pots, unused and damaged boats, cement tanks, pleated plastic sheets, coral holes, pits and irrigation canals, discarded washing machines, and Colocasia plant leaf axils. Breteau index ranged between 65.3 and 110, CI ranged between 63.64 and 72.41; and HI ranged between 38.46 and 70 among the various islands. Interpretation & conclusion : Entomological indices such as house index (HI), breteau index (BI) and pupal index (PI) were high in all the nine islands and exceeded the threshold levels specified by WHO, indicating high risk for dengue virus transmission in case of outbreaks. Occurrence of vector as well as non-vector species indicates that the global change in climate is causing notable changes in terms of breeding of vector and non-vector species in the islands. With the reported cases of VBDs and the presence of vectors species in Lakshadweep Islands, a stringent control measure needs to be implemented at the Lakshadweep Islands.
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Affiliation(s)
- Jayalakshmi Krishnan
- Department of Life Sciences; Department of Epidemiology and Public Health, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
| | - L Mathiarasan
- Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
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12
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Bitsindou P, Bantsimba-Ndziona MJ, Lenga A. [Current Distribution and Bioecological Characterizations of Aedes aegypti and Aedes albopictus in Brazzaville]. Bull Soc Pathol Exot 2018; 111:301-308. [PMID: 30950593 DOI: 10.3166/bspe-2019-0056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Aedes aegypti is a mosquito that has been known in Congo for decades. It has always been involved in the transmission of some arboviruses. Ae. albopictus is an invasive species native from Asia. Its presence was reported in Congo in 2009. The proliferation of Ae. albopictus, especially in Brazzaville, in association with Ae. aegypti, have increased the risk of arbovirus transmission. The distribution and bio-ecology of these two species remain poorly studied. We undertook entomological investigations to determine the bio-ecological factors that may influence the abundance and distribution of the two species in two districts of Brazzaville. Collection of immature stages was carried out during the survey of breeding sites. In addition, adults were captured twice a day (morning and evening) during 8 collection sessions in dwellings. The results show that both species have the same distribution and share the same ecological sites. Their activity is essentially diurnal with nocturnal intrusion. They are more exophagous than endophagous. Domestic and peri-domestic sites, especially tires and water storage containers, are the most productive breeding sites. The biting activity has two peaks: one at the end of morning and the other at the end of afternoon. Both species have been observed in all areas visited and the larval index values are above WHO standards indicating a high epidemic risk. Aedes albopictus is the predominant species.
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Affiliation(s)
- P Bitsindou
- Point focal pour la lutte intégrée contre les vecteurs (ministère de la Santé et de la Population), Brazzaville, Congo
| | - M J Bantsimba-Ndziona
- Laboratoire de bioécologie des Vertébrés et Invertébrés (LBEVI), faculté des sciences et techniques, BP 69, Brazzaville, Congo
| | - A Lenga
- Laboratoire de bioécologie des Vertébrés et Invertébrés (LBEVI), faculté des sciences et techniques, BP 69, Brazzaville, Congo
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Emidi B, Kisinza WN, Mmbando BP, Malima R, Mosha FW. Effect of physicochemical parameters on Anopheles and Culex mosquito larvae abundance in different breeding sites in a rural setting of Muheza, Tanzania. Parasit Vectors 2017. [PMID: 28645303 PMCID: PMC5482952 DOI: 10.1186/s13071-017-2238-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Basiliana Emidi
- Kilimanjaro Christian Medical University College, P.O. Box 2240, Moshi, Tanzania. .,National Institute for Medical Research, Headquarters, P.O. Box 9653, Dar es Salaam, Tanzania.
| | - William N Kisinza
- National Institute for Medical Research, Amani Centre, P.O. Box 81, Muheza, Tanzania
| | - Bruno P Mmbando
- National Institute for Medical Research, Tanga Centre, P.O. Box 5004, Tanga, Tanzania
| | - Robert Malima
- National Institute for Medical Research, Amani Centre, P.O. Box 81, Muheza, Tanzania
| | - Franklin W Mosha
- Kilimanjaro Christian Medical University College, P.O. Box 2240, Moshi, Tanzania
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Malik A, Yasar A, Tabinda AB, Zaheer IE, Malik K, Batool A, Mahfooz Y. Assessing spatio-temporal trend of vector breeding and dengue fever incidence in association with meteorological conditions. Environ Monit Assess 2017; 189:189. [PMID: 28353206 DOI: 10.1007/s10661-017-5902-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 03/16/2017] [Indexed: 06/06/2023]
Abstract
Th aim of this study is to investigate spatio-temporal trends of dengue vector breeding and epidemic (disease incidence) influenced by climatic factors. The spatio-temporal (low-, medium-, and high-intensity periods) evaluation of entomological and epidemiological investigations along with climatic factors like rainfall (RF), temperature (Tmax), relative humidity (RH), and larval indexing was conducted to develop correlations in the area of Lahore, Pakistan. The vector abundance and disease transmission trend was geo-tagged for spatial insight. The sufficient rainfall events and optimum temperature and relative humidity supported dengue vector breeding with high larval indices for water-related containers (27-37%). Among temporal analysis, the high-intensity period exponentially projected disease incidence followed by post-rainfall impacts. The high larval incidence that was observed in early high-intensity periods effected the dengue incidence. The disease incidence had a strong association with RF (r = 0.940, α = 0.01). The vector larva occurrence (r = 0.017, α = 0.05) influenced the disease incidence. Similarly, RH (r = 0.674, α = 0.05) and average Tmax (r = 0.307, α = 0.05) also induced impact on the disease incidence. In this study, the vulnerability to dengue fever highly correlates with meteorological factors during high-intensity period. It provides area-specific understanding of vector behavior, key containers, and seasonal patterns of dengue vector breeding and disease transmission which is essential for preparing an effective prevention plan against the vector.
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Affiliation(s)
- Afifa Malik
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan.
| | - Abdullah Yasar
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Amtul Bari Tabinda
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Ihsan Elahi Zaheer
- Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, Faisalabad, 38000, Pakistan
| | - Khalida Malik
- Department of Statistics, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Adeeba Batool
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
| | - Yusra Mahfooz
- Sustainable Development Study Center, Government College University, Katchery Road, Lahore, 54000, Pakistan
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15
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Louis VR, Montenegro Quiñonez CA, Kusumawathie P, Palihawadana P, Janaki S, Tozan Y, Wijemuni R, Wilder-Smith A, Tissera HA. Characteristics of and factors associated with dengue vector breeding sites in the City of Colombo, Sri Lanka. Pathog Glob Health 2017; 110:79-86. [PMID: 27241954 PMCID: PMC4894263 DOI: 10.1080/20477724.2016.1175158] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Introduction Dengue has emerged as a major public health problem in Sri Lanka. Vector control at community level is a frequent and widespread strategy for dengue control. The aim of the study was to assess Aedes mosquito breeding sites and the prevention practices of community members in a heavily urbanized part of Colombo. Methods A cross-sectional entomological survey was conducted from April to June 2013 in 1469 premises located in a subdistrict of the City of Colombo. Types of breeding sites and, where found, their infestation with larvae or pupae were recorded. Furthermore, a questionnaire was administered to the occupants of these premises to record current practices of dengue vector control. Results The surveyed premises consisted of 1341 residential premises and 110 non-residential premises (11 schools, 99 work or public sites), 5 open lands, and 13 non-specified. In these 1469 premises, 15447 potential breeding sites suitable to host larvae of pupae were found; of these sites18.0% contained water. Among the 2775 potential breeding sites that contained water, 452 (16.3%) were positive for larvae and/or pupae. Schools were associated with the proportionally highest number of breeding sites; 85 out of 133 (63.9%) breeding sites were positive for larvae and/or pupae in schools compared with 338 out of 2288 (14.8%) in residential premises. The odds ratio (OR) for schools and work or public sites for being infested with larvae and/or pupae was 2.77 (95% CI 1.58, 4.86), when compared to residential premises. Occupants of 80.8% of the residential premises, 54.5% of the schools and 67.7% of the work or public sites reported using preventive measures. The main prevention practices were coverage of containers and elimination of mosquito breeding places. Occupants of residential premises were much more likely to practice preventive measures than were those of non-residential premises (OR 2.23; 1.49, 3.36). Conclusion Schools and working sites were associated with the highest numbers of breeding sites and lacked preventive measures for vector control. In addition to pursuing vector control measures at residential level, public health strategies should be expanded in schools and work places.
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Affiliation(s)
- Valérie R Louis
- a Institute of Public Health, Heidelberg University , Heidelberg , Germany
| | | | - Pad Kusumawathie
- b Regional Malaria Office , Ministry of Health , Kandy , Sri Lanka
| | | | - Sakoo Janaki
- d National Dengue Control Unit , Ministry of Health , Colombo , Sri Lanka
| | - Yesim Tozan
- a Institute of Public Health, Heidelberg University , Heidelberg , Germany.,e College of Global Public Health, New York University , New York , NY , USA
| | - Ruwan Wijemuni
- f Department of Public Health , Colombo Municipal Council , Colombo , Sri Lanka
| | - Annelies Wilder-Smith
- a Institute of Public Health, Heidelberg University , Heidelberg , Germany.,g Lee Kong Chian School of Medicine , Nanyang Technological University , Singapore.,h Department of Public Health and Clinical Medicine, Epidemiology and Global Health , Umeå University , Umeå , Sweden
| | - Hasitha A Tissera
- c Epidemiology Unit , Ministry of Health , Colombo , Sri Lanka.,d National Dengue Control Unit , Ministry of Health , Colombo , Sri Lanka
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Ferrolho J, Maia C, Gomes J, Alves-Pires C, Cristóvão J, Campino L, Afonso M. Rotation of the external genitalia in male Phlebotomine sand flies (Diptera, Psychodidae) in laboratory conditions and in captured specimens in Algarve, Portugal. Acta Trop 2015; 150:1-3. [PMID: 26099682 DOI: 10.1016/j.actatropica.2015.06.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 06/16/2015] [Indexed: 10/23/2022]
Abstract
Protozoal parasites are the causative agents of many insect-borne infectious diseases worldwide with impact on human and animal health. Leishmaniasis is caused by Leishmania spp. and transmitted by female Phlebotomine sand flies. In Portugal, two species of Phlebotomus (Larroussius), namely Phlebotomus perniciosus and Phlebotomus ariasi are the proven vectors of Leishmania infantum. Phlebotomine females and males rest and breed in the same sites; and these locations can be predicted according to the male external genitalia maturation. Therefore, this study aimed to determine the timing of complete rotation of the male external genitalia in laboratory conditions and to characterize the external genitalia rotation in field captured males to predict the male and female sand fly breeding and resting sites. This knowledge can be applied in the design and implementation of integrated sand fly control strategies targeting these sites.
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Ceretti-Junior W, de Oliveira Christe R, Rizzo M, Strobel RC, de Matos Junior MO, de Mello MHSH, Fernandes A, Medeiros-Sousa AR, de Carvalho GC, Marrelli MT. Species Composition and Ecological Aspects of Immature Mosquitoes (Diptera: Culicidae) in Bromeliads in Urban Parks in the City of São Paulo, Brazil. J Arthropod Borne Dis 2015; 10:102-12. [PMID: 27047978 PMCID: PMC4813398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 12/06/2014] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Bromeliads can be epiphytic, terrestrial or saxicolous and use strategies to allow water to be retained in their leaf axils, where various arthropods can be found. These include mosquitoes, whose larvae are the most abundant and commonly found organisms in the leaf axils. The objective of this study was to look for immature forms of mosquitoes (the larval and pupal stages) in bromeliads in municipal parks in São Paulo and to discuss the ecological and epidemiological importance of these insects. METHODS From October 2010 to July 2013, immature mosquitoes were collected from bromeliads in 65 municipal parks in the city of São Paulo, Brazil, using suction samplers. The immature forms were maintained until adult forms emerged, and these were then identified morphologically. RESULTS Two thousand forty-two immature-stage specimens belonging to the genera Aedes, Culex, Trichoprosopon, Toxorhynchites, Limatus and Wyeomyia were found in bromeliads in 15 of the 65 parks visited. Aedes albopictus was the most abundant species (660 specimens collected), followed by Culex quinquefasciatus (548 specimens) and Cx. (Microculex) imitator (444). The taxa with the most widespread distribution were Ae. aegypti and Toxorhynchites spp, followed by Ae. albopictus and Cx. quinquefasciatus. CONCLUSION Bromeliads in urban parks are refuges for populations of native species of Culicidae and breeding sites for exotic species that are generally of epidemiological interest. Hence, administrators and surveillance and mosquito-control agencies must constantly monitor these microenvironments as the presence of these species endangers the health of park users and employees as well as people living near the parks.
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Affiliation(s)
- Walter Ceretti-Junior
- Department of Epidemiology, School of Public Health, University of São Paulo, São Paulo, Brazil
| | - Rafael de Oliveira Christe
- Department of Epidemiology, School of Public Health, University of São Paulo, São Paulo, Brazil,Tropical Medicine Institute, University of São Paulo, São Paulo, Brazil
| | - Marco Rizzo
- Office of Parks and Green Areas, Department of the Environment and Green Areas, São Paulo City Hall, São Paulo, SP, Brazil
| | - Regina Claudia Strobel
- Office of Parks and Green Areas, Department of the Environment and Green Areas, São Paulo City Hall, São Paulo, SP, Brazil
| | - Marco Otavio de Matos Junior
- Laboratory for Research into and Identification of Synanthropic Fauna, Zoonosis Control Center, Health Surveillance Coordination Unit, Municipal Health Department, São Paulo City Hall, São Paulo, SP, Brazil
| | - Maria Helena Silva Homem de Mello
- Laboratory for Research into and Identification of Synanthropic Fauna, Zoonosis Control Center, Health Surveillance Coordination Unit, Municipal Health Department, São Paulo City Hall, São Paulo, SP, Brazil
| | - Aristides Fernandes
- Department of Epidemiology, School of Public Health, University of São Paulo, São Paulo, Brazil
| | | | | | - Mauro Toledo Marrelli
- Department of Epidemiology, School of Public Health, University of São Paulo, São Paulo, Brazil,Tropical Medicine Institute, University of São Paulo, São Paulo, Brazil,Corresponding author: Dr Mauro Toledo Marrelli, E-mail:
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Dieng H, Saifur RGM, Ahmad AH, Salmah MRC, Aziz AT, Satho T, Miake F, Jaal Z, Abubakar S, Morales RE. Unusual developing sites of dengue vectors and potential epidemiological implications. Asian Pac J Trop Biomed 2015; 2:228-32. [PMID: 23569903 DOI: 10.1016/s2221-1691(12)60047-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/01/2011] [Accepted: 09/24/2011] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE To identify the unusual breeding sites of two dengue vectors, i.e. Aedes albopictus (Ae. albopictus) and Aedes aegypti (Ae. aegypti). METHODS During the second half of 2010, we performed an occasional survey in rural (Teluk Tempoyak) and urban (Gelugor) areas of Penang Island, Malaysia, to identify cryptic breeding sites. RESULTS In the rural area, we found heterogeneous immature stages of Ae. albopictus in the water bowl of an encaged bird. We also observed Ae. aegypti eggs deposited in the flush tank of a toilet in the urban area. CONCLUSIONS It can be concluded that both breeding patterns can increase contact with hosts (humans and birds) and presumably population densities of Ae. albopictus and Ae. aegypti, thereby potentially boosting the risks for spread and transmission of arboviral diseases.
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Affiliation(s)
- Hamady Dieng
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
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Dabo A, Diarra AZ, Machault V, Touré O, Niambélé DS, Kanté A, Ongoiba A, Doumbo O. Urban schistosomiasis and associated determinant factors among school children in Bamako, Mali, West Africa. Infect Dis Poverty 2015; 4:4. [PMID: 25973199 PMCID: PMC4429506 DOI: 10.1186/2049-9957-4-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 12/25/2014] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Schistosomiasis is classically described as a rural disease that occurs in areas with poor sanitary conditions. However, over recent decades, there has been an expansion of schistosomiasis foci towards urban areas faced with a rapid and disordered urbanization. In Bamako, Mali, the impact of environmental change on vector-borne diseases such as schistosomiasis is not well known. This study sought to identify the presence of schistosomiasis transmission hotspots in Bamako. Using this perspective, we aimed to describe the risk factors of the endemization and maintenance of schistosomiasis. MATERIALS AND METHODS A cross-sectional study was carried out in the six municipalities (communes) in Bamako. Environmental information was obtained from earth observation satellites in order to maximize ecological contrasts. Twenty-nine blocks of 200 m x 200 m were identified. We selected a school inside or nearest to each block for urine and stool samples examination. The study cohort was school children aged between eight and 15 years. The Kato-Katz technique and filtration were used for Schistosoma mansoni and S. haematobium ova research in stools and urine, respectively. The schools and snail breeding sites were georeferenced. Four malacological surveys were conducted between October 2011 and February 2012. Bivariate analysis was used to identify independent predictors of being infected with schistosomiasis. RESULTS The prevalence rate of S. haematobium was 14.7% (n = 1,761) and that of S. mansoni 1.5% (n = 1,491). Overall, the urinary form was endemic in 76.6% of schools. The infection significantly varied between the municipalities (p < 0.001). It was also more prevalent on the left side of the Niger River than the right side (17.4% vs. 9.5% respectively; p < 0.001). The vicinity to snail breeding sites (OR = 3.677; 95% IC [2.765-4.889]; p < 10 (-3) ) and parents' occupations (OR = 7.647; 95% IC [2.406-24.305]; p < 0.001) were the most important risk factors associated with S. haematobium infection exposure. Biomphalaria pfeifferi, Bulinus truncatus, and B. globosus were the intermediate hosts captured. The schistosome natural infection rates (SNIRs), which were low or nil in October and November, rose to 2.8% in January and 8.3% in February for B. pfeifferi and B. truncatus, respectively. CONCLUSION Our findings show that there is a high transmission risk for schistosomiasis in Bamako. Appropriate integrated control measures need to be introduced to control the transmission of this disease in the study area.
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Affiliation(s)
- Abdoulaye Dabo
- />Department of Epidemiology of Infectious Diseases, Faculty of Medicine, Pharmacy and Dentistry, University of Techniques and Technologies of Bamako, Box 1805, Bamako, UMI 3189 Mali
| | - Adama Z Diarra
- />Department of Epidemiology of Infectious Diseases, Faculty of Medicine, Pharmacy and Dentistry, University of Techniques and Technologies of Bamako, Box 1805, Bamako, UMI 3189 Mali
| | - Vanessa Machault
- />Unité d’entomologie médicale, Equipe 7, Maladies émergentes et moustiques, Institut de Médecine Tropicale du Service de Santé des Armées, Allée du Médecin Colonel Jamot, Parc du Pharo, BP60109, 13262 Marseille Cedex 07, France
| | - Ousmane Touré
- />Department of Epidemiology of Infectious Diseases, Faculty of Medicine, Pharmacy and Dentistry, University of Techniques and Technologies of Bamako, Box 1805, Bamako, UMI 3189 Mali
| | - Diarra Sira Niambélé
- />Department of Epidemiology of Infectious Diseases, Faculty of Medicine, Pharmacy and Dentistry, University of Techniques and Technologies of Bamako, Box 1805, Bamako, UMI 3189 Mali
| | - Abdoulaye Kanté
- />Department of Epidemiology of Infectious Diseases, Faculty of Medicine, Pharmacy and Dentistry, University of Techniques and Technologies of Bamako, Box 1805, Bamako, UMI 3189 Mali
| | - Abdoulaye Ongoiba
- />Department of Epidemiology of Infectious Diseases, Faculty of Medicine, Pharmacy and Dentistry, University of Techniques and Technologies of Bamako, Box 1805, Bamako, UMI 3189 Mali
| | - Ogobara Doumbo
- />Department of Epidemiology of Infectious Diseases, Faculty of Medicine, Pharmacy and Dentistry, University of Techniques and Technologies of Bamako, Box 1805, Bamako, UMI 3189 Mali
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Souza T, Figueiredo F, Almeida A, Benigno C, Pontes C, Souza M. Natural breeding sites of phlebotomine sand flies (Diptera: Psychodidae) on Marambaia Island, Rio de Janeiro State, Brazil. Acta Trop 2014; 136:104-7. [PMID: 24742903 DOI: 10.1016/j.actatropica.2014.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 04/05/2014] [Indexed: 10/25/2022]
Abstract
Immature phlebotomine sand flies develop in soils with essential and ideal characteristics for their life cycle, such as organic matter, humidity, temperature and low levels of light. Information regarding the potential breeding places of these dipterans is fundamental to understand the epidemiology and ecology of leishmaniasis, in addition to its importance to control them. In the present study, we aimed to find natural breeding sites of sand flies on Marambaia Island with the aid of emergence traps and direct search of immature forms using the flotation technique with saturated sugar solution in organic substrates of the region. Both methods were effective, with a total of 42 specimens of six different species - including some species that participate in the transmission cycle of American Tegumentary Leishmaniasis - collected by the emergence traps, and five immature forms obtained by floatation technique. However, further studies are still necessary, mainly with respect to the ecology and biology of immature sandfly stages, so that control measures focused on breeding sites can produce positive sustainable results in natural environments.
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