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Marcombe S, Doeurk B, Thammavong P, Veseli T, Heafield C, Mills MA, Kako S, Prado MF, Thomson S, Millett S, Hill T, Kentsley I, Davies S, Pathiraja G, Daniels B, Browne L, Nyamukanga M, Harvey J, Rubinstein L, Townsend C, Allen Z, Davey-Spence C, Hupi A, Jones AK, Boyer S. Metabolic Resistance and Not Voltage-Gated Sodium Channel Gene Mutation Is Associated with Pyrethroid Resistance of Aedes albopictus (Skuse, 1894) from Cambodia. INSECTS 2024; 15:358. [PMID: 38786914 PMCID: PMC11122440 DOI: 10.3390/insects15050358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
(1) Background: In Cambodia, Aedes albopictus is an important vector of the dengue virus. Vector control using insecticides is a major strategy implemented in managing mosquito-borne diseases. Resistance, however, threatens to undermine the use of insecticides. In this study, we present the levels of insecticide resistance of Ae. albopictus in Cambodia and the mechanisms involved. (2) Methods: Two Ae. albopictus populations were collected from the capital, Phnom Penh city, and from rural Pailin province. Adults were tested with diagnostic doses of malathion (0.8%), deltamethrin (0.03%), permethrin (0.25%), and DDT (4%) using WHO tube assays. Synergist assays using piperonyl butoxide (PBO) were implemented before the pyrethroid assays to detect the potential involvement of metabolic resistance mechanisms. Adult female mosquitoes collected from Phnom Penh and Pailin were tested for voltage-gated sodium channel (VGSC) kdr (knockdown resistance) mutations commonly found in Aedes sp.-resistant populations throughout Asia (S989P, V1016G, and F1534C), as well as for other mutations (V410L, L982W, A1007G, I1011M, T1520I, and D1763Y). (3) Results: The two populations showed resistance against all the insecticides tested (<90% mortality). The use of PBO (an inhibitor of P450s) strongly restored the efficacy of deltamethrin and permethrin against the two resistant populations. Sequences of regions of the vgsc gene showed a lack of kdr mutations known to be associated with pyrethroid resistance. However, four novel non-synonymous mutations (L412P/S, C983S, Q1554STOP, and R1718L) and twenty-nine synonymous mutations were detected. It remains to be determined whether these mutations contribute to pyrethroid resistance. (4) Conclusions: Pyrethroid resistance is occurring in two Ae. albopictus populations originating from urban and rural areas of Cambodia. The resistance is likely due to metabolic resistance specifically involving P450s monooxygenases. The levels of resistance against different insecticide classes are a cause for concern in Cambodia. Alternative tools and insecticides for controlling dengue vectors should be used to minimize disease prevalence in the country.
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Affiliation(s)
- Sébastien Marcombe
- Medical Entomology and Vector-borne Diseases Laboratory, Institut Pasteur du Laos, Ministry of Health, Vientiane P.O. Box 3560, Laos; (S.M.); (P.T.)
- Vector Control Consulting—South East Asia Sole Co., Ltd., Vientiane P.O. Box 3463, Laos
| | - Bros Doeurk
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh P.O. Box 983, Cambodia; (B.D.); (S.B.)
| | - Phoutmany Thammavong
- Medical Entomology and Vector-borne Diseases Laboratory, Institut Pasteur du Laos, Ministry of Health, Vientiane P.O. Box 3560, Laos; (S.M.); (P.T.)
| | - Tuba Veseli
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Derby DE65 5NX, UK
| | - Christian Heafield
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Oxford OX14 2RN, UK
| | - Molly-Ann Mills
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK
| | - Sedra Kako
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Marcelly Ferreira Prado
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Oxford University Hospitals, Churchill Hospital, Genetics Laboratories, Old Rd, Headington, Oxford OX3 7LE, UK
| | - Shakira Thomson
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Burnham-On-Sea TA8 1AZ, UK
| | - Saffron Millett
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Timothy Hill
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Imogen Kentsley
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Brighton BN8 4HR, UK
| | - Shereena Davies
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Shrewsbury SY1 4YP, UK
| | - Geethika Pathiraja
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Wallingford OX10 7EA, UK
| | - Ben Daniels
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Syngenta, Jealott’s Hill International Research Centre, Bracknell RG42 6EY, Berkshire, UK
| | - Lucianna Browne
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Reading RG31 4SE, UK
| | - Miranda Nyamukanga
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Wythenshawe Hospital, Southmoor Rd, Wythenshawe M23 9LT, Manchester, UK
| | - Jess Harvey
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Oxford Nanopore Technologies plc, Unit 3, Genesis Building, Library Avenue, Harwell, Didcot OX11 0SG, Oxfordshire, UK
| | - Lyranne Rubinstein
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, 69009 Lyon, France
| | - Chloe Townsend
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Zack Allen
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Christopher Davey-Spence
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Adina Hupi
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
- Independent Researcher, Oxford OX3 8HP, UK
| | - Andrew K. Jones
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, UK; (T.V.); (C.H.); (M.-A.M.); (S.K.); (M.F.P.); (S.T.); (S.M.); (T.H.); (I.K.); (S.D.); (G.P.); (B.D.); (L.B.); (M.N.); (J.H.); (L.R.); (C.T.); (Z.A.); (C.D.-S.); (A.H.)
| | - Sebastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh P.O. Box 983, Cambodia; (B.D.); (S.B.)
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Paixão FRS, Falvo ML, Huarte-Bonnet C, Santana M, García JJ, Fernandes ÉKK, Pedrini N. Pathogenicity of microsclerotia from Metarhizium robertsii against Aedes aegypti larvae and antimicrobial peptides expression by mosquitoes during fungal-host interaction. Acta Trop 2024; 249:107061. [PMID: 37918505 DOI: 10.1016/j.actatropica.2023.107061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/23/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023]
Abstract
Aedes aegypti is a vector of various disease-causing arboviruses. Chemical insecticide-based methods for mosquito control have increased resistance in different parts of the world. Thus, alternative control agents such as the entomopathogenic fungi are excellent candidates to control mosquitoes as part of an ecofriendly strategy. There is evidence of the potential of entomopathogenic fungal conidia and blastospores for biological control of eggs, larval and adult stages, as well as the pathogenicity of fungal microsclerotia against adults and eggs. However, there are no studies on the pathogenicity of microsclerotia against either aquatic insects or insects that develop part of their life cycle in the water, such as the A. aegypti larvae. In this study, we assayed the production of microsclerotia and their pathogenicity against A. aegypti larvae of two isolates of Metarhizium robertsii, i.e., CEP 423 isolated in La Plata, Argentina, and the model ARSEF 2575. Both isolates significantly reduced the survival of A. aegypti exposed to their microsclerotia. The fungus-larva interaction resulted in a delayed response in the host. This was evidenced by the expression of some humoral immune system genes such as defensins and cecropin on the 9th day post-infection, when the fungal infection was consolidated as a successful process that culminates in larvae mortality. In conclusion, M. robertsii microsclerotia are promising propagules to be applied as biological control agents against mosquitoes since they produce pathogenic conidia against A. aegypti larvae.
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Affiliation(s)
- Flávia R S Paixão
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), calles 60 y 120, 1900 La Plata, Argentina
| | - Marianel L Falvo
- Centro de Estudios Parasitológicos y de Vectores (CEPAVE), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), calles 60 y 122, 1900 La Plata, Argentina
| | - Carla Huarte-Bonnet
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), calles 60 y 120, 1900 La Plata, Argentina
| | - Marianela Santana
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), calles 60 y 120, 1900 La Plata, Argentina
| | - Juan J García
- Centro de Estudios Parasitológicos y de Vectores (CEPAVE), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), calles 60 y 122, 1900 La Plata, Argentina
| | - Éverton K K Fernandes
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, 74690-900, Goiânia, Goiás, Brazil
| | - Nicolás Pedrini
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), calles 60 y 120, 1900 La Plata, Argentina.
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Kasai S, Itokawa K, Uemura N, Takaoka A, Furutani S, Maekawa Y, Kobayashi D, Imanishi-Kobayashi N, Amoa-Bosompem M, Murota K, Higa Y, Kawada H, Minakawa N, Cuong TC, Yen NT, Phong TV, Keo S, Kang K, Miura K, Ng LC, Teng HJ, Dadzie S, Subekti S, Mulyatno KC, Sawabe K, Tomita T, Komagata O. Discovery of super-insecticide-resistant dengue mosquitoes in Asia: Threats of concomitant knockdown resistance mutations. SCIENCE ADVANCES 2022; 8:eabq7345. [PMID: 36542722 PMCID: PMC9770935 DOI: 10.1126/sciadv.abq7345] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/04/2022] [Indexed: 05/29/2023]
Abstract
Aedes aegypti (Linnaeus, 1762) is the main mosquito vector for dengue and other arboviral infectious diseases. Control of this important vector highly relies on the use of insecticides, especially pyrethroids. The high frequency (>78%) of the L982W substitution was detected at the target site of the pyrethroid insecticide, the voltage-gated sodium channel (Vgsc) of A. aegypti collected from Vietnam and Cambodia. Alleles having concomitant mutations L982W + F1534C and V1016G + F1534C were also confirmed in both countries, and their frequency was high (>90%) in Phnom Penh, Cambodia. Strains having these alleles exhibited substantially higher levels of pyrethroid resistance than any other field population ever reported. The L982W substitution has never been detected in any country of the Indochina Peninsula except Vietnam and Cambodia, but it may be spreading to other areas of Asia, which can cause an unprecedentedly serious threat to the control of dengue fever as well as other Aedes-borne infectious diseases.
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Affiliation(s)
- Shinji Kasai
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Kentaro Itokawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Nozomi Uemura
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Aki Takaoka
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Shogo Furutani
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Yoshihide Maekawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Daisuke Kobayashi
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | | | - Michael Amoa-Bosompem
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Katsunori Murota
- Kagoshima Research Station, National Institute of Animal Health, National Agriculture and Food Research Organization, Kagoshima 891-0105, Japan
| | - Yukiko Higa
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Hitoshi Kawada
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
| | - Noboru Minakawa
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
| | - Tran Chi Cuong
- Medical Entomology and Zoology Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Nguyen Thi Yen
- Medical Entomology and Zoology Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Tran Vu Phong
- Medical Entomology and Zoology Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Sath Keo
- Faculty of Veterinary Medicine, Royal University of Agriculture, P.O. Box 2696, Phnom Penh, Cambodia
| | - Kroesna Kang
- Faculty of Veterinary Medicine, Royal University of Agriculture, P.O. Box 2696, Phnom Penh, Cambodia
| | - Kozue Miura
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore 138667, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Hwa-Jen Teng
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei City 10050, Taiwan
| | - Samuel Dadzie
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon,, Ghana
| | - Sri Subekti
- Entomology Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60115, Indonesia
| | - Kris Cahyo Mulyatno
- Entomology Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60115, Indonesia
| | - Kyoko Sawabe
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Takashi Tomita
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Osamu Komagata
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
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Bonnin L, Tran A, Herbreteau V, Marcombe S, Boyer S, Mangeas M, Menkes C. Predicting the Effects of Climate Change on Dengue Vector Densities in Southeast Asia through Process-Based Modeling. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:127002. [PMID: 36473499 PMCID: PMC9726451 DOI: 10.1289/ehp11068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Aedes aegypti and Ae. albopictus mosquitoes are major vectors for several human diseases of global importance, such as dengue and yellow fever. Their life cycles and hosted arboviruses are climate sensitive and thus expected to be impacted by climate change. Most studies investigating climate change impacts on Aedes at global or continental scales focused on their future global distribution changes, whereas a single study focused on its effects on Ae. aegypti densities regionally. OBJECTIVES A process-based approach was used to model densities of Ae. aegypti and Ae. albopictus and their potential evolution with climate change using a panel of nine CMIP6 climate models and climate scenarios ranging from strong to low mitigation measures at the Southeast Asian scale and for the next 80 y. METHODS The process-based model described, through a system of ordinary differential equations, the variations of mosquito densities in 10 compartments, corresponding to 10 different stages of mosquito life cycle, in response to temperature and precipitation variations. Local field data were used to validate model outputs. RESULTS We show that both species densities will globally increase due to future temperature increases. In Southeast Asia by the end of the century, Ae. aegypti densities are expected to increase from 25% with climate mitigation measures to 46% without; Ae. albopictus densities are expected to increase from 13%-21%, respectively. However, we find spatially contrasted responses at the seasonal scales with a significant decrease in Ae. albopictus densities in lowlands during summer in the future. DISCUSSION These results contrast with previous results, which brings new insight on the future impacts of climate change on Aedes densities. Major sources of uncertainties, such as mosquito model parametrization and climate model uncertainties, were addressed to explore the limits of such modeling. https://doi.org/10.1289/EHP11068.
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Affiliation(s)
- Lucas Bonnin
- ENTROPIE (UMR 9220), IRD, Université de la Réunion, CNRS, Ifremer, Université de Nouvelle Calédonie, Nouméa, Nouvelle-Calédonie
| | - Annelise Tran
- CIRAD, UMR TETIS, Sainte-Clotilde, Reunion Island, France
- TETIS, Université Montpellier, AgroParisTech, CIRAD, CNRS, INRAE, Montpellier, France
- CIRAD, UMR ASTRE, Sainte-Clotilde, Reunion Island, France
- ASTRE, Université Montpellier, CIRAD, INRAE, Montpellier, France
| | - Vincent Herbreteau
- ESPACE-DEV, IRD, Université Antilles, Université Guyane, Université Montpellier, Université de la Réunion, Montpellier, France
- ESPACE-DEV, IRD, Université Antilles, Université Guyane, Université Montpellier, Université de la Réunion, Phnom Penh, Cambodia
| | - Sébastien Marcombe
- Medical Entomology and Vector-Borne Disease Laboratory, Institut Pasteur du Laos, Vientiane, Lao PDR
| | - Sébastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Morgan Mangeas
- ENTROPIE (UMR 9220), IRD, Université de la Réunion, CNRS, Ifremer, Université de Nouvelle Calédonie, Nouméa, Nouvelle-Calédonie
| | - Christophe Menkes
- ENTROPIE (UMR 9220), IRD, Université de la Réunion, CNRS, Ifremer, Université de Nouvelle Calédonie, Nouméa, Nouvelle-Calédonie
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de Oliveira Barbosa Bitencourt R, de Souza Faria F, Marchesini P, Reis Dos Santos-Mallet J, Guedes Camargo M, Rita Elias Pinheiro Bittencourt V, Guedes Pontes E, Baptista Pereira D, Siqueira de Almeida Chaves D, da Costa Angelo I. Entomopathogenic fungi and Schinus molle essential oil: The combination of two eco-friendly agents against Aedes aegypti larvae. J Invertebr Pathol 2022; 194:107827. [PMID: 36108793 DOI: 10.1016/j.jip.2022.107827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 08/22/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022]
Abstract
Aedes aegypti transmits arbovirus, which is a public health concern. Certain filamentous fungi have the potential to control the disease. Here, the effects of Metarhizium anisopliae s.l. CG 153, Beauveria bassiana s.l. CG 206 and Schinus molle L. were investigated against Aedes aegypti larvae. In addition, the effect of essential oil on fungal development was analyzed. Fungal germination was assessed after combination with essential oil at 0.0025 %, 0.0075 %, 0.005 %, or 0.01 %; all of the oil concentrations affected germination except 0.0025 % (v/v). Larvae were exposed to 0.0025 %, 0.0075 %, 0.005 %, or 0.01 % of the essential oil or Tween 80 at 0.01 %; however, only the essential oil at 0.0025 % achieved similar results as the control. Larvae were exposed to fungi at 107 conidia mL-1 alone or in combination with the essential oil at 0.0025 %. Regardless of the combination, M. anisopliae reduced the median survival time of mosquitoes more than B. bassiana. The cumulative survival of mosquitoes exposed to M. anisopliae alone or in combination with essential oil was 7.5 % and 2 %, respectively, and for B. bassiana, it was 75 % and 71 %, respectively. M. anisopliae + essential oil had a synergistic effect against larvae, whereas B. bassiana + essential oil was antagonistic. Scanning and transmission electron microscopy, and histopathology confirmed that the interaction of M. anisopliae was through the gut and hemocoel. In contrast, the mosquito's gut was the main route for invasion by B. bassiana. Results from gas chromatography studies demonstrated sabinene and bicyclogermacrene as the main compounds of S. molle, and the in-silico investigation found evidence that both compounds affect a wide range of biological activity. For the first time, we demonstrated the potential of S. molle and its interaction with both fungal strains against A. aegypti larvae. Moreover, for the first time, we reported that S. molle might be responsible for significant changes in larval physiology. This study provides new insights into host-pathogen interplay and contributes to a better understanding of pathogenesis in mosquitoes, which have significant consequences for biological control strategies.
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Affiliation(s)
| | - Fernanda de Souza Faria
- Graduate Program in Veterinary Sciences, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil
| | - Paula Marchesini
- Graduate Program in Veterinary Sciences, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil
| | - Jacenir Reis Dos Santos-Mallet
- Oswaldo Cruz Foundation, IOC-FIOCRUZ-RJ, Rio de Janeiro, RJ and FIOCRUZ-PI, Teresina, Piaui, Brazil; Iguaçu University-UNIG, Nova Iguaçu, RJ, Brazil
| | - Mariana Guedes Camargo
- Department of Animal Parasitology, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil
| | | | - Emerson Guedes Pontes
- Department of Chemistry, Institute of Exact Sciences, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil
| | - Debora Baptista Pereira
- Graduate Program in Chemistry, Department of Chemistry, Institute of Exact Sciences, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil
| | - Douglas Siqueira de Almeida Chaves
- Department of Pharmaceutical Sciences, Institute of Biological Sciences and Health, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil
| | - Isabele da Costa Angelo
- Department of Epidemiology and Public Health, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil.
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Saleh M, Wahid I, Daud A, Mallongi A, Russeng SS. The Potential Test of the Mosquito Oviposition Preference Using Similar Subtracts: Colonized Water and Aides Larvae Extract. Open Access Maced J Med Sci 2022. [DOI: 10.3889/oamjms.2022.8184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The research on ovitrap using attractants have been extensively developed, but studies on the use of similar substrates in the form of colonized water and Aedes larvae extract as attractants have not been widely published. Adding an attractant to the ovitrap can stimulate the sense of smell for mosquitoes to come to the place to lay their eggs. The use of ovitrap has recently begun to be developed because it is environmentally friendly. The purpose of this study is to determine the attractants potential of colonized water and larvae extract as the oviposition preferences for of Aedes Sp. to lay eggs in the ovitrap. The type of this research is a true experimental design, the design of The Posttest-Only Control Group Design. Observations are made in the laboratory for nine repetitions. Observational data show that the average number of eggs in ovitraps that uses the colonized water and larvae extract is higher than that of conventional/control water. The results of the Kruskal-Wallis test indicate that there is a significant difference in the average number of eggs in the colonized water attractant, larval extract and conventional water (Asymp. Sig < 0.05). The conclusion is obtained that similar substrate attractants in the form of larvae extract and Aedes colonization water have the potential to be Aedes sp oviposition preferences compared to conventional water. However, it is still necessary to conduct a field study so that it can be used as an environmentally friendly method of the surveillance and control of the vector transmitting Dengue Hemorrhagic Fever.
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Ang JXD, Nevard K, Ireland R, Purusothaman DK, Verkuijl SAN, Shackleford L, Gonzalez E, Anderson MAE, Alphey L. Considerations for homology-based DNA repair in mosquitoes: Impact of sequence heterology and donor template source. PLoS Genet 2022; 18:e1010060. [PMID: 35180218 PMCID: PMC8893643 DOI: 10.1371/journal.pgen.1010060] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 03/03/2022] [Accepted: 01/28/2022] [Indexed: 12/23/2022] Open
Abstract
The increasing prevalence of insecticide resistance and the ongoing global burden of vector-borne diseases have encouraged new efforts in mosquito control. For Aedes aegypti, the most important arboviral vector, integration rates achieved in Cas9-based knock-ins so far have been rather low, highlighting the need to understand gene conversion patterns and other factors that influence homology-directed repair (HDR) events in this species. In this study, we report the effects of sequence mismatches or donor template forms on integration rates. We found that modest sequence differences between construct homology arms [DNA sequence in the donor template which resembles the region flanking the target cut] and genomic target comprising 1.2% nucleotide dissimilarity (heterology) significantly reduced integration rates. While most integrations (59–88%) from plasmid templates were the result of canonical [on target, perfect repair] HDR events, no canonical events were identified from other donor types (i.e. ssDNA, biotinylated ds/ssDNA). Sequencing of the transgene flanking region in 69 individuals with canonical integrations revealed 60% of conversion tracts to be unidirectional and extend up to 220 bp proximal to the break, though in three individuals bidirectional conversion of up to 725 bp was observed. The field of genetic control of mosquito vectors has progressed rapidly in recent years, especially in Cas9-based control systems, due to its robustness to elicit a species-specific and dispersive control of mosquito population. To generate a Cas9-based integration, Cas9 and sgRNA are used to cleave a chromosomal locus while a plasmid DNA donor, containing a genetic cargo flanked by sequences homologous to the chromosomal locus, is supplied as a repair template. This results in the cargo being copied into the genome through HDR. This form of integration, however, is currently one of the major bottlenecks for researchers as it involves a laborious process of microinjecting mosquito embryos and has rather low integration rates. In this study, we assessed the effects of homologous sequence mismatches and various donor template forms (i.e. plasmid, ssDNA, biotinylated ds/ssDNA) on HDR. We found that sequence mismatches and non-plasmid donors reduced the efficiency and integrity of integration, respectively. By analysing the direction and length of homologous sequence that was copied into the genome concurrently with the cargo, we inferred the mechanism responsible for the integrations observed in our study. These findings will be useful to guide future construct designs for optimal HDR rates in mosquitoes.
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Affiliation(s)
| | | | | | | | - Sebald A. N. Verkuijl
- The Pirbright Institute, Pirbright, Woking, United Kingdom
- Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | | | | | - Luke Alphey
- The Pirbright Institute, Pirbright, Woking, United Kingdom
- * E-mail: (MAEA); (LA)
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Boyer S, Maquart PO, Chhuoy K, Suor K, Chhum M, Heng K, Leng S, Fontenille D, Marcombe S. Monitoring insecticide resistance of adult and larval Aedes aegypti (Diptera: Culicidae) in Phnom Penh, Cambodia. Parasit Vectors 2022; 15:44. [PMID: 35101104 PMCID: PMC8805314 DOI: 10.1186/s13071-022-05156-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/08/2022] [Indexed: 01/01/2023] Open
Abstract
Background Dengue fever is a major public health concern in Cambodia, with thousands of cases every year in urban, suburban and rural areas of the country. The main vector of dengue fever in Cambodia is Aedes aegypti. The organophosphate larvicide temephos and adulticides belonging to the pyrethroid family have been widely used for decades by public health authorities to fight dengue vectors, but resistance of Ae. aegypti to these insecticides has been previously described for Cambodia. Methods In order to adapt the vector control strategy presently used in Cambodia, we tested 14 adulticides belonging to the carbamate, organochlorine, organophosphate, and pyrethroid insecticide families and three larvicides [temephos, spinosad and Bacillus thuringiensis ser. israelensis (Bti)] belonging to three different insecticide families (organophosphates, spinosyns and entomopathogenic bacteria). The standard procedures used here to test the adults and larvae of an Ae. aegypti population from Phnom Penh followed World Health Organization guidelines. Results For adults, high mortality rates were observed with carbamate, organophosphate and organochlorine (with the exception of dichlorodiphenyltrichloroethane) insecticides (i.e. between 87.6 and 100%), while low mortality rates were observed with all of the tested pyrethroid insecticides (i.e. between 1 and 35%). For larvae, no resistance against Bti was detected [resistance ratio (RR90 < 1.6)], but moderate resistance was observed for temephos and spinosad (RR90 < 5.6). Conclusions The results of this study indicate that (i) Bti should be considered a serious alternative to temephos for the control of Ae. aegypti larvae; and (ii) the carbamate adulticides propoxur and bendiocarb should be employed instead of the widely used pyrethroid insecticides for the control of adult Ae. aegypti on land under mosaic farming and crop rotation in Cambodia, as the insects were found to be resistant to the latter types of insecticide. Research focusing on insecticide resistance and innovative and effective vector control strategies should be undertaken as a public health priority in Cambodia. Graphical abstract ![]()
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Bigio J, Braack L, Chea T, Set S, Suon S, Echaubard P, Hustedt J, Debackere M, Ramirez B, Prasetyo DB, Bunleng S, Wharton-Smith A, Hii J. Entomological outcomes of cluster-randomised, community-driven dengue vector-suppression interventions in Kampong Cham province, Cambodia. PLoS Negl Trop Dis 2022; 16:e0010028. [PMID: 35077452 PMCID: PMC8789142 DOI: 10.1371/journal.pntd.0010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/24/2021] [Indexed: 11/18/2022] Open
Abstract
Cambodia has one of the highest dengue infection rates in Southeast Asia. Here we report quantitative entomological results of a large-scale cluster-randomised trial assessing the impact on vector populations of a package of vector control interventions including larvivorous guppy fish in household water containers, mosquito trapping with gravid-ovitraps, solid waste management, breeding-container coverage through community education and engagement for behavioural change, particularly through the participation of school children. These activities resulted in major reductions in Container Index, House Index, Breteau Index, Pupal Index and Adult Index (all p-values 0.002 or lower) in the Intervention Arm compared with the Control Arm in a series of household surveys conducted over a follow-up period of more than one year, although the project was not able to measure the longer-term sustainability of the interventions. Despite comparative reductions in Adult Index between the study arms, the Adult Index was higher in the Intervention Arm in the final household survey than in the first household survey. This package of biophysical and community engagement interventions was highly effective in reducing entomological indices for dengue compared with the control group, but caution is required in extrapolating the reduction in household Adult Index to a reduction in the overall population of adult Aedes mosquitoes, and in interpreting the relationship between a reduction in entomological indices and a reduction in the number of dengue cases. The package of interventions should be trialled in other locations.
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Affiliation(s)
- Jacob Bigio
- Research Institute of the McGill University Health Centre, Montreal, Canada
- McGill International TB Centre, Montreal, Canada
| | - Leo Braack
- Malaria Consortium, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- UP Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Thy Chea
- Malaria Consortium, Phnom Penh, Cambodia
| | - Srun Set
- Malaria Consortium, Phnom Penh, Cambodia
| | - Sokha Suon
- Malaria Consortium, Phnom Penh, Cambodia
| | | | - John Hustedt
- Malaria Consortium, Phnom Penh, Cambodia
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Bernadette Ramirez
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
| | | | - Sam Bunleng
- National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Alexandra Wharton-Smith
- Department for Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jeffrey Hii
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Australia
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Rohaizat Hassan M, Atika Azit N, Mohd Fadzil S, Abd Ghani SR, Ahmad N, Mohammed Nawi A. Insecticide resistance of Dengue vectors in South East Asia: a systematic review. Afr Health Sci 2021; 21:1124-1140. [PMID: 35222575 PMCID: PMC8843301 DOI: 10.4314/ahs.v21i3.21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The insecticides used widely has led to resistance in the vector and impose a challenge to vector control operation. OBJECTIVES This review aims to analyse the distribution of insecticide resistance of dengue vectors in South East Asia and to describe the mechanism of insecticide resistance. METHODS Literature search for articles published on 2015 to 2019 from PubMed, Scopus and ProQuest was performed. Total of 37 studies included in the final review from the initial 420 studies. RESULTS Pyrethroid resistance was concentrated on the west coast of Peninsular Malaysia and Northern Thailand and scattered at Java Island, Indonesia while organophosphate resistance was seen across the Java Island (Indonesia), West Sumatera and North Peninsular Malaysia. Organochlorine resistance was seen in Sabah, Malaysia and scattered distribution in Nusa Tenggara, Indonesia. V1016G, S989P, F1269C gene mutation in Aedes Aegypti were associated with Pyrethroid resistance in Singapore and Indonesia. In Malaysia, over-expressed with monooxygenase P450 genes (CYP9J27, CYP6CB1, CYP9J26 and CYP9M4) Glutathione S-transferases, carboxylesterases commonly associated with pyrethroids resistance in Aedes Aegypti and CYP612 overexpressed in Aedes Albopictus. The genetic mutation in A302S in Aedes Albopictus was associated with organochlorine resistance in Malaysia. CONCLUSIONS Rotation of insecticide, integration with synergist and routine assessment of resistance profile are recommended strategies in insecticide resistance management.
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Gan SJ, Leong YQ, Bin Barhanuddin MFH, Wong ST, Wong SF, Mak JW, Ahmad RB. Dengue fever and insecticide resistance in Aedes mosquitoes in Southeast Asia: a review. Parasit Vectors 2021; 14:315. [PMID: 34112220 PMCID: PMC8194039 DOI: 10.1186/s13071-021-04785-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 05/11/2021] [Indexed: 12/26/2022] Open
Abstract
Dengue fever is the most important mosquito-borne viral disease in Southeast Asia. Insecticides remain the most effective vector control approach for Aedes mosquitoes. Four main classes of insecticides are widely used for mosquito control: organochlorines, organophosphates, pyrethroids and carbamates. Here, we review the distribution of dengue fever from 2000 to 2020 and its associated mortality in Southeast Asian countries, and we gather evidence on the trend of insecticide resistance and its distribution in these countries since 2000, summarising the mechanisms involved. The prevalence of resistance to these insecticides is increasing in Southeast Asia, and the mechanisms of resistance are reported to be associated with target site mutations, metabolic detoxification, reduced penetration of insecticides via the mosquito cuticle and behavioural changes of mosquitoes. Continuous monitoring of the status of resistance and searching for alternative control measures will be critical for minimising any unpredicted outbreaks and improving public health. This review also provides improved insights into the specific use of insecticides for effective control of mosquitoes in these dengue endemic countries. ![]()
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Affiliation(s)
- Soon Jian Gan
- International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Yong Qi Leong
- International Medical University, 57000, Kuala Lumpur, Malaysia.,Monash University Malaysia, 47500, Subang Jaya, Selangor, Malaysia
| | | | - Siew Tung Wong
- International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Shew Fung Wong
- International Medical University, 57000, Kuala Lumpur, Malaysia. .,Institute for Research, Development and Innovation (IRDI), International Medical University, 57000, Kuala Lumpur, Malaysia.
| | - Joon Wah Mak
- International Medical University, 57000, Kuala Lumpur, Malaysia.,Institute for Research, Development and Innovation (IRDI), International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Rohani Binti Ahmad
- Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
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Management of insecticides for use in disease vector control: Lessons from six countries in Asia and the Middle East. PLoS Negl Trop Dis 2021; 15:e0009358. [PMID: 33930033 PMCID: PMC8115796 DOI: 10.1371/journal.pntd.0009358] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 05/12/2021] [Accepted: 03/31/2021] [Indexed: 01/22/2023] Open
Abstract
Interventions to control the vectors of human diseases, notably malaria, leishmaniasis and dengue, have relied mainly on the action of chemical insecticides. However, concerns have been raised regarding the management of insecticides in vector-borne disease-endemic countries. Our study aimed to analyze how vector control insecticides are managed in selected countries to extract lessons learned. A qualitative analysis of the situation of vector control insecticides management was conducted in six countries. Multi-stakeholder meetings and key informer interviews were conducted on aspects covering the pesticide lifecycle. Findings were compared and synthesized to extract lessons learned. Centrally executed guidelines and standards on the management of insecticides offered direction and control in most malaria programs, but were largely lacking from decentralized dengue programs, where practices of procurement, application, safety, storage, and disposal were variable between districts. Decentralized programs were better at facilitating participation of stakeholders and local communities and securing financing from local budgets. However, little coordination existed between malaria, visceral leishmaniasis and dengue programs within countries. Entomological capacity was concentrated in malaria programs at central level, while dengue and visceral leishmaniasis programs were missing out on expertise. Monitoring systems for insecticide resistance in malaria vectors were rarely used for dengue or visceral leishmaniasis vectors. Strategies for insecticide resistance management, where present, did not extend across programs or sectors in most countries. Dengue programs in most countries continued to rely on space spraying which, considering the realities on the ground, call for revision of international guidelines. Vector control programs in the selected countries were confronted with critical shortcomings in the procurement, application, safety measures, storage, and disposal of vector control insecticides, with implications for the efficiency, effectiveness, and safety of vector control. Further international support is needed to assist countries in situation analysis, action planning and development of national guidelines on vector control insecticide management. Vector-borne diseases such as dengue, malaria and leishmaniasis are transmitted by insect vectors. Transmission can be interrupted through vector control. Chemical insecticides are the mainstay for controlling these insect vectors. However, the use of chemicals also introduces risks to health and the environment and may lead to insecticide resistance. Hence, proper management of those insecticides is critical. To find out how the insecticides used for vector control are being managed, the authors conducted investigations in six countries in Asia and the Middle East. They found that the practices of insecticide procurement, application, storage, and disposal depended on how a program is organized. Dengue programs were operated in a decentralized manner and, consequently, lacked coordination through guidelines and standards on best practices. Also, coordination between malaria, visceral leishmaniasis and dengue programs within countries was minimal, and expertise needed to guide decisions on vector control and to monitor insecticide resistance was in short supply. The identified shortcomings in how vector control insecticides are managed likely affected the efficiency, effectiveness, and safety of vector control operations.
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Cattel J, Haberkorn C, Laporte F, Gaude T, Cumer T, Renaud J, Sutherland IW, Hertz JC, Bonneville J, Arnaud V, Fustec B, Boyer S, Marcombe S, David J. A genomic amplification affecting a carboxylesterase gene cluster confers organophosphate resistance in the mosquito Aedes aegypti: From genomic characterization to high-throughput field detection. Evol Appl 2021; 14:1009-1022. [PMID: 33897817 PMCID: PMC8061265 DOI: 10.1111/eva.13177] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 01/06/2023] Open
Abstract
By altering gene expression and creating paralogs, genomic amplifications represent a key component of short-term adaptive processes. In insects, the use of insecticides can select gene amplifications causing an increased expression of detoxification enzymes, supporting the usefulness of these DNA markers for monitoring the dynamics of resistance alleles in the field. In this context, the present study aims to characterize a genomic amplification event associated with resistance to organophosphate insecticides in the mosquito Aedes aegypti and to develop a molecular assay to monitor the associated resistance alleles in the field. An experimental evolution experiment using a composite population from Laos supported the association between the over-transcription of multiple contiguous carboxylesterase genes on chromosome 2 and resistance to multiple organophosphate insecticides. Combining whole genome sequencing and qPCR on specific genes confirmed the presence of a ~100-Kb amplification spanning at least five carboxylesterase genes at this locus with the co-existence of multiple structural duplication haplotypes. Field data confirmed their circulation in South-East Asia and revealed high copy number polymorphism among and within populations suggesting a trade-off between this resistance mechanism and associated fitness costs. A dual-color multiplex TaqMan assay allowing the rapid detection and copy number quantification of this amplification event in Ae. aegypti was developed and validated on field populations. The routine use of this novel assay will improve the tracking of resistance alleles in this major arbovirus vector.
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Affiliation(s)
- Julien Cattel
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
- Present address:
Symbiosis Technologies for Insect Control (SymbioTIC)Plateforme de Recherche CyroiSte ClotildeFrance
| | - Chloé Haberkorn
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
| | - Fréderic Laporte
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
| | - Thierry Gaude
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
| | - Tristan Cumer
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
| | - Julien Renaud
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
| | - Ian W. Sutherland
- United States Navy Entomology. Center of ExcellenceNAS JacksonvilleJacksonvilleFLUSA
| | | | - Jean‐Marc Bonneville
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
| | - Victor Arnaud
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
| | - Bénédicte Fustec
- Department of MicrobiologyKhon Kaen UniversityKhon KaenThailand
- Institut de Recherche pour le DéveloppementUMR IRD 224‐CNRS 5290‐Université MontpellierMontpellier Cedex 5France
| | - Sébastien Boyer
- Medical and Veterinary EntomologyInstitut Pasteur du CambodgePhnom PenhCambodia
| | - Sébastien Marcombe
- Medical Entomology and Vector‐Borne Disease LaboratoryInstitut Pasteur du LaosVientianeLaos
| | - Jean‐Philippe David
- Laboratoire d'Ecologie Alpine (LECA)UMR 5553 CNRS – Université Grenoble‐AlpesGrenobleFrance
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de Oliveira Barbosa Bitencourt R, Reis dos Santos Mallet J, Mesquita E, Silva Gôlo P, Fiorotti J, Rita Elias Pinheiro Bittencourt V, Guedes Pontes E, da Costa Angelo I. Larvicidal activity, route of interaction and ultrastructural changes in Aedes aegypti exposed to entomopathogenic fungi. Acta Trop 2021; 213:105732. [PMID: 33188750 DOI: 10.1016/j.actatropica.2020.105732] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/29/2022]
Abstract
Blastospores or conidia (formulated or not) of entomopathogenic fungi were assessed against Aedes aegypti larvae. Larvae (L2) were exposed to 105, 106, 107, and 108 propagules mL-1 water suspension. Mineral oil at 0.1%, 0.5%, or 1.0% (v/v) was employed to observe the effect on larval survival. The 0.1% mineral oil did not affect larval survival. Accordingly, 107 propagules mL-1 and 0.1% mineral oil were used to prepare all fungal emulsions. The fungal suspension or formulation was prepared as follows: 107 propagules mL-1 on 0.03% TweenⓇ 80 (v/v) aqueous solution or 107 propagules mL-1 on 0.03% TweenⓇ 80 plus 0.1% mineral oil; larval survival rates were evaluated for 7 days, and median survival time (S50) was also determined. The presence of fungi in larvae was examined both histologically and by scanning electron microscopy 24 h or 48 h after exposure. To evaluate the larval growth, larvae were exposed to 107 propagules mL-1 for 48 hours and their length measured using a digital caliper. Here, propagules had similar results in reducing the larvae survival rate and time. The treatment with Beauveria bassiana s.l. at 108 propagules mL-1 or with Metarhizium anisopliae s.l. at 108 blastopores mL-1 reduced the larval survival time to two days. M. anisopliae s.l. at 108 conidia mL-1 reduced the survival time to three days. The survival time of larvae submitted to the other treatments ranged from 6 days to over 7 days. M. anisopliae s.l. or B. bassiana s.l. oil-in-water emulsions at 107 propagules mL-1 yielded better results than the water suspensions, the larvae survival rate was 2 days for both propagules in oil-in-water emulsion. Larvae exposed to blastospores from both isolates or M. anisopliae conidia were longer than in the other treatments. Scanning electron microscopy and histology analyzes found fungi predominantly in the gut, mouthparts, and perispiracular lobes of larvae. Formulated fungus yielded better results than the aqueous suspensions for control of mosquito larvae. Thus, for the first time, the effect of mineral oil on the fungal interaction on A. aegypti larvae was observed as well as the effect of entomopathogenic fungi in the growth of larvae, supporting the search for strategies to control this arthropod.
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Zhou G, Lo E, Githeko AK, Afrane YA, Yan G. Long-lasting microbial larvicides for controlling insecticide resistant and outdoor transmitting vectors: a cost-effective supplement for malaria interventions. Infect Dis Poverty 2020; 9:162. [PMID: 33243294 PMCID: PMC7691065 DOI: 10.1186/s40249-020-00767-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 10/19/2020] [Indexed: 01/19/2023] Open
Abstract
The issues of pyrethroid resistance and outdoor malaria parasite transmission have prompted the WHO to call for the development and adoption of viable alternative vector control methods. Larval source management is one of the core malaria vector interventions recommended by the Ministry of Health in many African countries, but it is rarely implemented due to concerns on its cost-effectiveness. New long-lasting microbial larvicide can be a promising cost-effective supplement to current vector control and elimination methods because microbial larvicide uses killing mechanisms different from pyrethroids and other chemical insecticides. It has been shown to be effective in reducing the overall vector abundance and thus both indoor and outdoor transmission. In our opinion, the long-lasting formulation can potentially reduce the cost of larvicide field application, and should be evaluated for its cost-effectiveness, resistance development, and impact on non-target organisms when integrating with other malaria vector control measures. In this opinion, we highlight that long-lasting microbial larvicide can be a potential cost-effective product that complements current front-line long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) programs for malaria control and elimination. Microbial larviciding targets immature mosquitoes, reduces both indoor and outdoor transmission and is not affected by vector resistance to synthetic insecticides. This control method is a shift from the conventional LLINs and IRS programs that mainly target indoor-biting and resting adult mosquitoes.
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Affiliation(s)
- Guofa Zhou
- Program in Public Health, University of California, Irvine, CA 92697 USA
| | - Eugenia Lo
- Program in Public Health, University of California, Irvine, CA 92697 USA
- Department of Biological Sciences, University of North Carolina, Charlotte, NC 28223 USA
| | - Andrew K. Githeko
- Central for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Yaw A. Afrane
- Department of Medical Microbiology, University of Ghana, Accra, Ghana
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA 92697 USA
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16
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Bitencourt RDOB, Salcedo-Porras N, Umaña-Diaz C, da Costa Angelo I, Lowenberger C. Antifungal immune responses in mosquitoes (Diptera: Culicidae): A review. J Invertebr Pathol 2020; 178:107505. [PMID: 33238166 DOI: 10.1016/j.jip.2020.107505] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/27/2020] [Accepted: 11/17/2020] [Indexed: 02/08/2023]
Abstract
Mosquitoes transmit many parasites and pathogens to humans that cause significant morbidity and mortality. As such, we are constantly looking for new methods to reduce mosquito populations, including the use of effective biological controls. Entomopathogenic fungi are excellent candidate biocontrol agents to control mosquitoes. Understanding the complex ecological, environmental, and molecular interactions between hosts and pathogens are essential to create novel, effective and safe biocontrol agents. Understanding how mosquitoes recognize and eliminate pathogens such as entomopathogenic fungi may allow us to create insect-order specific biocontrol agents to reduce pest populations. Here we summarize the current knowledge of fungal infection, colonization, development, and replication within mosquitoes and the innate immune responses of the mosquitoes towards the fungal pathogens, emphasizing those features required for an effective mosquito biocontrol agent.
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Affiliation(s)
- Ricardo de Oliveira Barbosa Bitencourt
- Program in Veterinary Science, Institute of Veterinary Science, Rural Federal University of Rio de Janeiro, Seropédica, RJ, Brazil; Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada.
| | - Nicolas Salcedo-Porras
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada
| | - Claudia Umaña-Diaz
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada
| | - Isabele da Costa Angelo
- Department of Epidemiology and Public Health, Veterinary Institute, Rural Federal University of Rio de Janeiro, Seropédica, RJ, Brazil
| | - Carl Lowenberger
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada.
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Cataldo NP, Lea CS, Kelley T, Richards SL. Assessment of Resistance to Organophosphates and Pyrethroids in Aedes aegypti (Diptera: Culicidae): Do Synergists Affect Mortality? JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1992-1996. [PMID: 32484559 DOI: 10.1093/jme/tjaa101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Indexed: 06/11/2023]
Abstract
Aedes aegypti (L.) is the primary vector of Zika, dengue, yellow fever, and chikungunya viruses. Insecticides used in mosquito control can help prevent the spread of vector-borne diseases. However, it is essential to determine insecticide resistance (IR) status before control measures are undertaken. Only the most effective insecticides should be used to avoid ineffective control and/or promotion of IR. Pyrethroids and organophosphates are the most commonly used insecticides for mosquito control. Here, the efficacy of two active ingredients (AIs; permethrin [pyrethroid], chlorpyrifos [organophosphate]), two formulated products (FPs; Biomist [AI: permethrin]) and (Mosquitomist [AI: chlorpyrifos]), and three synergists (piperonyl butoxide, diethyl maleate, S-S-S-tributyl phosphorotrithioate) was evaluated in two Ae. aegypti colonies (pyrethroid resistant and susceptible). Mosquitomist was most effective against the pyrethroid-resistant colony (100% mortality at diagnostic time). Pre-exposure to synergists did not increase the efficacy of AIs against the pyrethroid-resistant colony. Further research is needed to discover how synergists may affect the efficacy of insecticides when used on pyrethroid-resistant mosquitoes.
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Affiliation(s)
- Natalie P Cataldo
- Environmental Health Sciences Program, Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC
| | - C Suzanne Lea
- Department of Public Health, Brody School of Medicine, East Carolina University, Greenville, NC
| | - Timothy Kelley
- Environmental Health Sciences Program, Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC
| | - Stephanie L Richards
- Environmental Health Sciences Program, Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC
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18
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Echaubard P, Thy C, Sokha S, Srun S, Nieto-Sanchez C, Grietens KP, Juban NR, Mier-Alpano J, Deacosta S, Sami M, Braack L, Ramirez B, Hii J. Fostering social innovation and building adaptive capacity for dengue control in Cambodia: a case study. Infect Dis Poverty 2020; 9:126. [PMID: 32883345 PMCID: PMC7469325 DOI: 10.1186/s40249-020-00734-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/31/2020] [Indexed: 11/15/2022] Open
Abstract
Background The social-ecological systems theory, with its unique conception of resilience (social-ecological systems & resilience, SESR), provides an operational framework that currently best meets the need for integration and adaptive governance as encouraged by the Sustainable Development Goals. SESR accounts for the complex dynamics of social-ecological systems and operationalizes transdisciplinarity by focusing on community engagement, value co-creation, decentralized leadership and social innovation. Targeting Social Innovation (SI) in the context of implementation research for vector-borne diseases (VBD) control offers a low-cost strategy to contribute to lasting and contextualized community engagement in disease control and health development in low and middle income countries of the global south. In this article we describe the processes of community engagement and transdisciplinary collaboration underpinning community-based dengue management in rural primary schools and households in two districts in Cambodia. Methods Multiple student-led and community-based interventions have been implemented focusing on empowering education, communication for behavioral change and participatory epidemiology mapping in order to engage Cambodian communities in dengue control. We describe in particular the significance of the participatory processes that have contributed to the design of SI products that emerged following iterative consultations with community stakeholders to address the dengue problem. Results The SI products that emerged following our interaction with community members are 1) adult mosquito traps made locally from solid waste collections, 2) revised dengue curriculum with hands-on activities for transformative learning, 3) guppy distribution systems led by community members, 4) co-design of dengue prevention communication material by students and community members, 5) community mapping. Conclusions The initiative described in this article put in motion processes of community engagement towards creating ownership of dengue control interventions tools by community stakeholders, including school children. While the project is ongoing, the project’s interventions so far implemented have contributed to the emergence of culturally relevant SI products and provided initial clues regarding 1) the conditions allowing SI to emerge, 2) specific mechanisms by which it happens and 3) how external parties can facilitate SI emergence. Overall there seems to be a strong argument to be made in supporting SI as a desirable outcome of project implementation towards building adaptive capacity and resilience and to use the protocol supporting this project implementation as an operational guiding document for other VBD adaptive management in the region.
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Affiliation(s)
- Pierre Echaubard
- SOAS University London, Thornhaugh Street, London, WC1H 0XG, UK.
| | - Chea Thy
- Malaria Consortium, Phnom Penh, Cambodia.
| | - Soun Sokha
- Malaria Consortium, Phnom Penh, Cambodia
| | - Set Srun
- Malaria Consortium, Phnom Penh, Cambodia
| | | | | | - Noel R Juban
- Social Innovation and Health Initiatives, University of the Philipines, Manilla, Philippines
| | - Jana Mier-Alpano
- Social Innovation and Health Initiatives, University of the Philipines, Manilla, Philippines
| | - Sucelle Deacosta
- Social Innovation and Health Initiatives, University of the Philipines, Manilla, Philippines
| | | | - Leo Braack
- Malaria Consortium, Phnom Penh, Cambodia
| | - Bernadette Ramirez
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, Geneva, Switzerland
| | - Jeffrey Hii
- Australian Institute of Tropical Health & Medicine, James Cook University of North Queesland, Townsville, QLD, Australia
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Saeung M, Ngoen-Klan R, Thanispong K, Muenworn V, Bangs MJ, Chareonviriyaphap T. Susceptibility of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) to Temephos in Thailand and Surrounding Countries. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1207-1220. [PMID: 32159772 DOI: 10.1093/jme/tjaa035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Indexed: 06/10/2023]
Abstract
Aedes-borne virus disease control relies on insecticides to interrupt transmission. Temephos remains a key chemical for control of immature stage Aedes in Thailand and much of Southeast Asia. However, repeated use of insecticides may result in selection for resistance in vector populations, thus compromising operational intervention. Herein, the phenotypic response to temephos by Aedes aegypti (L.) and Aedes albopictus (Skuse) collected in Thailand and surrounding countries is presented. Data from 345 collection sites are included: 283 from literature review (244 sites with Ae. aegypti, 21 with Ae. albopictus, and 18 having both species sampled), plus 62 locations with Ae. aegypti in Thailand conducted between 2014 and 2018. Susceptibility assays followed WHO guidelines using the recommended discriminating dose of temephos (0.012 mg/liter) against late third to early fourth instar Ae. aegypti. Findings revealed 34 locations with susceptible Ae. aegypti, 13 with suspected resistance, and 15 indicating resistance. Published data between 1999 and 2019 in Thailand found Ae. aegypti resistant in 73 of 206 collection sites, whereas 3 locations from 11 sampled with low-level resistant in Ae. albopictus. From surrounding countries conducting temephos assays (Cambodia, Lao PDR, Myanmar, Malaysia, and Singapore), resistance is present in Ae. aegypti and Ae. albopictus from 27 of 56 and 19 of 28 locations, respectively. Routine insecticide susceptibility monitoring should be an operational requirement in vector control programs. Given the wide distribution and apparent increase in temephos-resistance, alternative larvicidal compounds must be considered if chemical control is to remain a viable vector control strategy.
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Affiliation(s)
- Manop Saeung
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - Ratchadawan Ngoen-Klan
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - Kanutcharee Thanispong
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - Vithee Muenworn
- Department of Entomology and Plant Pathology, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
| | - Michael J Bangs
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- Public Health & Malaria Control Department, PT Freeport Indonesia/International SOS, Kuala Kencana, Papua, Indonesia
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20
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Christofferson RC, Parker DM, Overgaard HJ, Hii J, Devine G, Wilcox BA, Nam VS, Abubakar S, Boyer S, Boonnak K, Whitehead SS, Huy R, Rithea L, Sochantha T, Wellems TE, Valenzuela JG, Manning JE. Current vector research challenges in the greater Mekong subregion for dengue, Malaria, and Other Vector-Borne Diseases: A report from a multisectoral workshop March 2019. PLoS Negl Trop Dis 2020; 14:e0008302. [PMID: 32730249 PMCID: PMC7392215 DOI: 10.1371/journal.pntd.0008302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Rebecca C. Christofferson
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Daniel M. Parker
- University of California, Irvine, California, United States of America
| | | | | | - Gregor Devine
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Bruce A. Wilcox
- ASEAN Institute for Health Development, Mahidol University, Nakhon Pathom, Thailand
| | - Vu Sinh Nam
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Sazaly Abubakar
- Tropical Infectious Diseases Research and Education Center, Kuala Lumpur, Malaysia
| | | | - Kobporn Boonnak
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Stephen S. Whitehead
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Rekol Huy
- National Center for Parasitology Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Leang Rithea
- National Center for Parasitology Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Tho Sochantha
- National Center for Parasitology Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Thomas E. Wellems
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Jesus G. Valenzuela
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Jessica E. Manning
- US National Institute of Allergy and Infectious Diseases, Phnom Penh, Cambodia
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21
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High diversity of mosquito vectors in Cambodian primary schools and consequences for arbovirus transmission. PLoS One 2020; 15:e0233669. [PMID: 32502226 PMCID: PMC7274438 DOI: 10.1371/journal.pone.0233669] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 05/12/2020] [Indexed: 11/19/2022] Open
Abstract
Only few data exist in Cambodia on mosquito diversity and their potential role as vectors. Many arboviruses, such as dengue and Japanese encephalitis, are endemic and mostly affect children in the country. This research sets out to evaluate vector relative abundance and diversity in primary schools in Cambodia in an attempt to explain the apparent burden of dengue fever, severe dengue (DEN), Japanese encephalitis (JE), other arboviral diseases and malaria among children, 15 years and under, attending selected primary schools through vector surveys. Entomological surveys were implemented in primary schools in two provinces of Cambodia to assess the potential risk of exposure of schoolchildren to mosquito vector species. Light traps and BG traps were used to collect adult mosquitoes in 24 schools during the rainy and dry seasons of 2017 and 2018 in Kampong Cham and Tboung Khmum provinces. A total of 61 species were described, including Aedes, Culex and Anopheles species. The relative abundance and biodiversity of mosquito species were dependent on the month and school. Of the 37,725 mosquitoes caught during the study, three species accounted for three-quarters of the relative abundance: Culex vishnui, Anopheles indefinitus and Culex quinquefasciatus. More importantly, nearly 90% of the mosquitoes caught in the schools were identified as potential vectors of pathogens including Japanese encephalitis, dengue, and malaria parasites. Our results showed that schools in Cambodia represent a risk for vector-borne disease transmission and highlight the importance of implementing vector control in schools in Cambodia to decrease the risk of transmission.
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22
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Distribution of insecticide resistance and mechanisms involved in the arbovirus vector Aedes aegypti in Laos and implication for vector control. PLoS Negl Trop Dis 2019; 13:e0007852. [PMID: 31830027 PMCID: PMC6932826 DOI: 10.1371/journal.pntd.0007852] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 12/26/2019] [Accepted: 10/16/2019] [Indexed: 12/13/2022] Open
Abstract
Background The yellow fever mosquito Aedes aegypti is the major vector of dengue, yellow fever, Zika, and Chikungunya viruses. Worldwide vector control is largely based on insecticide treatments but, unfortunately, vector control programs are facing operational challenges due to mosquitoes becoming resistant to commonly used insecticides. In Southeast Asia, resistance of Ae. aegypti to chemical insecticides has been documented in several countries but no data regarding insecticide resistance has been reported in Laos. To fill this gap, we assessed the insecticide resistance of 11 Ae. aegypti populations to larvicides and adulticides used in public health operations in the country. We also investigated the underlying molecular mechanisms associated with resistance, including target site mutations and detoxification enzymes putatively involved in metabolic resistance. Methods and results Bioassays on adults and larvae collected in five provinces revealed various levels of resistance to organophosphates (malathion and temephos), organochlorine (DDT) and pyrethroids (permethrin and deltamethrin). Synergist bioassays showed a significant increased susceptibility of mosquitoes to insecticides after exposure to detoxification enzyme inhibitors. Biochemical assays confirmed these results by showing significant elevated activities of cytochrome P450 monooxygenases (P450), glutathione S-transferases (GST) and carboxylesterases (CCE) in adults. Two kdr mutations, V1016G and F1534C, were detected by qPCR at low and high frequency, respectively, in all populations tested. A significant negative association between the two kdr mutations was detected. No significant association between kdr mutations frequency (for both 1534C and 1016G) and survival rate to DDT or permethrin (P > 0.05) was detected. Gene Copy Number Variations (CNV) were detected for particular detoxification enzymes. At the population level, the presence of CNV affecting the carboxylesterase CCEAE3A and the two cytochrome P450 CYP6BB2 and CYP6P12 were significantly correlated to insecticide resistance. Conclusions These results suggest that both kdr mutations and metabolic resistance mechanisms are present in Laos but their impact on phenotypic resistance may differ in proportion at the population or individual level. Molecular analyses suggest that CNV affecting CCEAE3A previously associated with temephos resistance is also associated with malathion resistance while CNV affecting CYP6BB2 and CYP6P12 are associated with pyrethroid and possibly DDT resistance. The presence of high levels of insecticide resistance in the main arbovirus vector in Laos is worrying and may have important implications for dengue vector control in the country. Aedes aegypti is the major vector of dengue in Laos and the control of this vector rely mainly on insecticide treatments. Compared to the neighboring countries, where resistance has been detected, there was no data on the distribution, the levels, and the mechanisms involved in the resistance in Laos. Laboratory bioassays showed that resistance to the currently used larvicides (temephos) and adulticides (pyrethroids) was present at different levels and distributed throughout the country. This may have important implications for dengue vector control in Laos. The mechanisms underlying the resistance were determined to be both metabolic and target site mutations (kdr) supporting results found in other countries. Several key detoxification enzyme genes were identified as potential candidates for metabolic resistance. This study provides a baseline on insecticide resistance in Laos and will help the Public Health authorities in designing more adapted vector control strategies.
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Shafique M, Lopes S, Doum D, Keo V, Sokha L, Sam B, Vibol C, Alexander N, Bradley J, Liverani M, Hii J, Rithea L, Aryal S, Hustedt J. Implementation of guppy fish (Poecilia reticulata), and a novel larvicide (Pyriproxyfen) product (Sumilarv 2MR) for dengue control in Cambodia: A qualitative study of acceptability, sustainability and community engagement. PLoS Negl Trop Dis 2019; 13:e0007907. [PMID: 31738759 PMCID: PMC6886868 DOI: 10.1371/journal.pntd.0007907] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 12/02/2019] [Accepted: 11/05/2019] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND In Cambodia dengue vector control activities are focused on larviciding with temephos and pyrethroid based adulticide sprays to which Aedes have been shown to be increasingly resistant. A cluster randomized trial assessed the impact of using biological control tools (guppy fish, pyriproxyfen (PPF), and Communication for Behavioral Impact (COMBI) activities in combination), which would be used in a value comparison to traditional chemical control tools. Given these new intervention methods, a qualitative assessment was designed in order to represent the quality of understanding, acceptance, and implementation by participants. METHODOLOGY/PRINCIPAL FINDINGS A total of 103 participants in 12 Focus Group Discussions (FGDs) and nine In-Depth Interviews (IDIs) were included in the study. The majority of participants in intervention villages (50 out of 80) preferred guppy fish over other vector control methods due to ease of use and rearing, quick reproduction and propensity to eat larvae. A substantial number of participants (11 out of 40) in intervention villages with PPF favored it due to long-lasting effectiveness, lack of smell and easy maintenance. Participants showed high demand for both interventions and were willing to pay between 100-500 riel (0.03-0.13 USD). Nearly all participants perceived that the interventions resulted in a reduction in Aedes mosquitos (both adults and immatures) and dengue cases. The presence of larvae in the water despite the use of PPF was a source of concern for some participants, although this was overcome in some cases with proper health education through health volunteers. Interpersonal communication through health volunteers was the most favorite method of transmitting prevention messages. CONCLUSIONS/SIGNIFICANCE The community led COMBI strategy resulted in high acceptance and perceived effectiveness of the interventions in target villages. Health volunteers are an effective and accepted channel of communication to engage communities, disseminate information and promote behavioral change at the household and community level. If shown effective through corresponding entomological surveys, the interventions should be continued and further strengthened to ensure they are accessible, available and affordable.
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Affiliation(s)
| | - Sergio Lopes
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Dyna Doum
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Vanney Keo
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Ly Sokha
- National Dengue Control Program, National Center of Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - BunLeng Sam
- National Dengue Control Program, National Center of Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Chan Vibol
- Malaria and other Vector-borne and Parasitic diseases, World Health Organization, Phnom Penh, Cambodia
| | - Neal Alexander
- MRC Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - John Bradley
- MRC Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Marco Liverani
- Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jeffrey Hii
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Leang Rithea
- National Dengue Control Program, National Center of Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Siddhi Aryal
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - John Hustedt
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
- Malaria and other Vector-borne and Parasitic diseases, World Health Organization, Phnom Penh, Cambodia
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Fiaz M, Martínez LC, Plata-Rueda A, Gonçalves WG, de Souza DLL, Cossolin JFS, Carvalho PEGR, Martins GF, Serrão JE. Pyriproxyfen, a juvenile hormone analog, damages midgut cells and interferes with behaviors of Aedes aegypti larvae. PeerJ 2019; 7:e7489. [PMID: 31534837 PMCID: PMC6731771 DOI: 10.7717/peerj.7489] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 07/16/2019] [Indexed: 01/12/2023] Open
Abstract
Juvenile hormone analogs (JHA) are known to interfere with growth and biosynthesis of insects with potential for insecticide action. However, there has been comparatively few data on morphological effects of JHA on insect organs. To determine pyriproxyfen effects on Aedes aegypti larvae, we conducted toxicity, behavioral bioassays and assessed ultrastructural effects of pyriproxyfen on midgut cells. A. aegypti larvae were exposed in aqueous solution of pyriproxyfen LC50 concentrations and evaluated for 24 h. This study fulfilled the toxic prevalence of pyriproxyfen to A. aegypti larvae (LC50 = 8.2 mg L-1). Behavioral observations confirmed that pyriproxyfen treatment significantly changes swimming behavior of larvae, limiting its displacement and speed. The pyriproxyfen causes remarkable histopathological and cytotoxic alterations in the midgut of larvae. Histopathological study reveals presence of cytoplasmic vacuolization and damage to brush border of the digestive cells. The main salient lesions of cytotoxic effects are occurrence of cell debris released into the midgut lumen, cytoplasm rich in lipid droplets, autophagosomes, disorganized microvilli and deformed mitochondria. Data suggest that pyriproxyfen can be used to help to control and eradicate this insect vector.
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Affiliation(s)
- Muhammad Fiaz
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Luis Carlos Martínez
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Angelica Plata-Rueda
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | | | | | | | | | | | - José Eduardo Serrão
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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