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Bickersmith SA, Jurczynski JD, Sallum MAM, Chaves LSM, Bergo ES, Rodriguez GAD, Morante CA, Rios CT, Saavedra MP, Alava F, Gamboa D, Vinetz JM, Conn JE. Mutations Linked to Insecticide Resistance Not Detected in the Ace-1 or VGSC Genes in Nyssorhynchus darlingi from Multiple Localities in Amazonian Brazil and Peru. Genes (Basel) 2023; 14:1892. [PMID: 37895241 PMCID: PMC10606710 DOI: 10.3390/genes14101892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
Indoor residual spray (IRS), mainly employing pyrethroid insecticides, is the most common intervention for preventing malaria transmission in many regions of Latin America; the use of long-lasting insecticidal nets (LLINs) has been more limited. Knockdown resistance (kdr) is a well-characterized target-site resistance mechanism associated with pyrethroid and DDT resistance. Most mutations detected in acetylcholinesterase-1 (Ace-1) and voltage-gated sodium channel (VGSC) genes are non-synonymous, resulting in a change in amino acid, leading to the non-binding of the insecticide. In the present study, we analyzed target-site resistance in Nyssorhynchus darlingi, the primary malaria vector in the Amazon, in multiple malaria endemic localities. We screened 988 wild-caught specimens of Ny. darlingi from three localities in Amazonian Peru and four in Amazonian Brazil. Collections were conducted between 2014 and 2021. The criteria were Amazonian localities with a recent history as malaria hotspots, primary transmission by Ny. darlingi, and the use of both IRS and LLINs as interventions. Fragments of Ace-1 (456 bp) and VGSC (228 bp) were amplified, sequenced, and aligned with Ny. darlingi sequences available in GenBank. We detected only synonymous mutations in the frequently reported Ace-1 codon 280 known to confer resistance to organophosphates and carbamates, but detected three non-synonymous mutations in other regions of the gene. Similarly, no mutations linked to insecticide resistance were detected in the frequently reported codon (995) at the S6 segment of domain II of VGSC. The lack of genotypic detection of insecticide resistance mutations by sequencing the Ace-1 and VGSC genes from multiple Ny. darlingi populations in Brazil and Peru could be associated with low-intensity resistance, or possibly the main resistance mechanism is metabolic.
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Affiliation(s)
- Sara A. Bickersmith
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA; (S.A.B.); (J.D.J.)
| | - John D. Jurczynski
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA; (S.A.B.); (J.D.J.)
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Maria Anice Mureb Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo 01246-904, Brazil; (M.A.M.S.); (L.S.M.C.)
| | - Leonardo S. M. Chaves
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo 01246-904, Brazil; (M.A.M.S.); (L.S.M.C.)
| | - Eduardo S. Bergo
- Secretaria de Estado da Saúde de São Paulo, Instituto Pasteur, São Paulo 01027-000, Brazil;
| | - Gloria A. D. Rodriguez
- Laboratorio de Referencia Regional de Loreto, Gerencia Regional de Salud de Loreto (GERESA), Loreto 16001, Peru; (G.A.D.R.); (C.A.M.); (C.T.R.)
| | - Clara A. Morante
- Laboratorio de Referencia Regional de Loreto, Gerencia Regional de Salud de Loreto (GERESA), Loreto 16001, Peru; (G.A.D.R.); (C.A.M.); (C.T.R.)
| | - Carlos T. Rios
- Laboratorio de Referencia Regional de Loreto, Gerencia Regional de Salud de Loreto (GERESA), Loreto 16001, Peru; (G.A.D.R.); (C.A.M.); (C.T.R.)
| | - Marlon P. Saavedra
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias e Ingeniería, Universidad Peruana Cayetano Heredia, Lima 15102, Peru; (M.P.S.); (D.G.); (J.M.V.)
| | - Freddy Alava
- Gerencia Regional de Salud de Loreto (GERESA), Loreto 16001, Peru;
| | - Dionicia Gamboa
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias e Ingeniería, Universidad Peruana Cayetano Heredia, Lima 15102, Peru; (M.P.S.); (D.G.); (J.M.V.)
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima 15102, Peru
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias e Ingeniería, Universidad Peruana Cayetano Heredia, Lima 15102, Peru
| | - Joseph M. Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias e Ingeniería, Universidad Peruana Cayetano Heredia, Lima 15102, Peru; (M.P.S.); (D.G.); (J.M.V.)
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima 15102, Peru
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jan E. Conn
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA; (S.A.B.); (J.D.J.)
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY 12222, USA
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Ridha MR, Marlinae L, Zubaidah T, Fadillah NA, Widjaja J, Rosadi D, Rahayu N, Ningsih M, Desimal I, Sofyandi A. Control methods for invasive mosquitoes of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Indonesia. Vet World 2023; 16:1952-1963. [PMID: 37859959 PMCID: PMC10583872 DOI: 10.14202/vetworld.2023.1952-1963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/30/2023] [Indexed: 10/21/2023] Open
Abstract
The two invasive mosquito species in Indonesia are Aedes aegypti and Ae. albopictus. These mosquitoes are a serious nuisance to humans and are also the primary vectors of several foreign pathogens, such as dengue, Zika, and chikungunya viruses. Efforts must be made to reduce the possibility of mosquito bites and the potential for disease transmission. Given the invasion of these two Aedes species, this approach should be considered as part of an integrated strategy to manage them. This review discusses existing and developing control techniques for invasive Ae. aegypti and Ae. albopictus, with an emphasis on those that have been and are being used in Indonesia. Environmental, mechanical, biological (e.g., Bacillus thuringiensis and Wolbachia), and chemical (e.g., insect growth regulators and pyrethroids) approaches are discussed in this review, considering their effectiveness, sustainability, and control methods.
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Affiliation(s)
- Muhammad Rasyid Ridha
- Vector-borne and Zoonotic Diseases Research Group, Research Center for Public Health and Nutrition, Cibinong Science Center, National Research and Innovation Agency, Jl. Raya Jakarta-Bogor KM.46, Bogor, West Java, 16915, Indonesia
| | - Lenie Marlinae
- Department of Environmental Health, Public Health Study Program, Medical Faculty, Universitas Labung Mangkurat, Jl. A. Yani, Km. 36 Banjarbaru, South Kalimantan, Indonesia
| | - Tien Zubaidah
- Environmental Health Program, Banjarmasin Health Polytechnic, Jl. H. Mistar Cokrokusumo No.1A, Kemuning, Banjar Baru, South Kalimantan, 70714, Indonesia
| | - Noor Ahda Fadillah
- Department of Epidemiology, Public Health Study Program, Medical Faculty, Universitas Labung Mangkurat, Jl. A. Yani, Km. 36 Banjarbaru, South Kalimantan, Indonesia
| | - Junus Widjaja
- Vector-borne and Zoonotic Diseases Research Group, Research Center for Public Health and Nutrition, Cibinong Science Center, National Research and Innovation Agency, Jl. Raya Jakarta-Bogor KM.46, Bogor, West Java, 16915, Indonesia
| | - Dian Rosadi
- Department of Epidemiology, Public Health Study Program, Medical Faculty, Universitas Labung Mangkurat, Jl. A. Yani, Km. 36 Banjarbaru, South Kalimantan, Indonesia
| | - Nita Rahayu
- Vector-borne and Zoonotic Diseases Research Group, Research Center for Public Health and Nutrition, Cibinong Science Center, National Research and Innovation Agency, Jl. Raya Jakarta-Bogor KM.46, Bogor, West Java, 16915, Indonesia
| | - Murtiana Ningsih
- Public Health Study Program, Sports Sciences and Public Health Faculty, Universitas Pendidikan Mataram, Jl. Pemuda No. 59 A Mataram West Nusa Tenggara, Indonesia
| | - Iwan Desimal
- Public Health Study Program, Sports Sciences and Public Health Faculty, Universitas Pendidikan Mataram, Jl. Pemuda No. 59 A Mataram West Nusa Tenggara, Indonesia
| | - Arif Sofyandi
- Public Health Study Program, Sports Sciences and Public Health Faculty, Universitas Pendidikan Mataram, Jl. Pemuda No. 59 A Mataram West Nusa Tenggara, Indonesia
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Njoroge MM, Hiscox A, Saddler A, Takken W, van Loon JJA, Fillinger U. Less is more: repellent-treated fabric strips as a substitute for full screening of open eave gaps for indoor and outdoor protection from malaria mosquito bites. Parasit Vectors 2022; 15:259. [PMID: 35858931 PMCID: PMC9297553 DOI: 10.1186/s13071-022-05384-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 07/06/2022] [Indexed: 11/10/2022] Open
Abstract
Background Providing protection from malaria vector bites, both indoors and outdoors, is crucial to curbing malaria parasite transmission. Screening of house entry points, especially with incorporated insecticides, confers significant protection but remains a costly and labour-intensive application. Use of spatial repellents has shown promise in creating areas of protection in peri-domestic areas. Methods This study aimed at comparing the protection provided by transfluthrin-treated and untreated complete screens over open eave gaps with incomplete transfluthrin-treated eave strips as a potential replacement for a full screen. Human landing catches were implemented independently inside and outside an experimental hut under controlled semi-field conditions, with insectary-reared Anopheles arabiensis mosquitoes. Results The odds of a female mosquito finding a human volunteer indoors and attempting to bite were similar whether the eaves were completely open or there was an untreated fabric strip fixed around the eaves. However, when the eave gap was completely screened without insecticide, the odds of receiving a bite indoors were reduced by 70% (OR 0.30, 95% CI 0.20–0.47). Adding transfluthrin to the full screen, further increased the protection indoors, with the odds of receiving a bite reduced by 92% (0.08, 95% CI 0.04–0.16) compared to the untreated screen. Importantly, the same protection was conferred when only a narrow transfluthrin-treated fabric strip was loosely fixed around the eave gap (OR 0.07, 95% CI 0.04–0.13). The impact of the transfluthrin treatment on outdoor biting was correlated with evening temperatures during the experiments. At lower evening temperatures, a transfluthrin-treated, complete screen provided moderate and variable protection from bites (OR 0.62, 95% CI 0.37–1.03), whilst at higher evening temperatures the odds of receiving a bite outdoors was over four times lower in the presence of transfluthrin, on either a full screen (OR 0.22 95% 0.12–0.38) or a fabric strip (OR 0.25, 95% 0.15–0.42), than when no treatment was present. Conclusion The findings suggest that transfluthrin-treated fabric strips can provide a substitute for complete eave screens. They are a simple, easy-to-handle tool for protecting people from malaria mosquito bites indoors and potentially around the house in climatic areas where evening and night-time temperatures are relatively high.
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Affiliation(s)
- Margaret Mendi Njoroge
- International Centre of Insect Physiology and Ecology (icipe), Human Health Theme, P.O. Box 30772-00100, Nairobi, Kenya. .,Wageningen University & Research, Laboratory of Entomology, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
| | - Alexandra Hiscox
- Wageningen University & Research, Laboratory of Entomology, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.,ARCTEC, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Adam Saddler
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 833, Basel, Switzerland.,Ifakara Health Institute, P.O. Box 74, Bagamoyo, Tanzania.,Malaria Atlas Project, Telethon Kids Institute, 15 Hospital Ave, Nedlands, Perth, WA, 6009, Australia
| | - Willem Takken
- Wageningen University & Research, Laboratory of Entomology, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
| | - Joop J A van Loon
- Wageningen University & Research, Laboratory of Entomology, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
| | - Ulrike Fillinger
- International Centre of Insect Physiology and Ecology (icipe), Human Health Theme, P.O. Box 30772-00100, Nairobi, Kenya
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Elmardi KA, Adam I, Malik EM, Kafy HT, Abdin MS, Kleinschmidt I, Kremers S. Impact of malaria control interventions on malaria infection and anaemia in areas with irrigated schemes: a cross-sectional population-based study in Sudan. BMC Infect Dis 2021; 21:1248. [PMID: 34906083 PMCID: PMC8670187 DOI: 10.1186/s12879-021-06929-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/01/2021] [Indexed: 11/29/2022] Open
Abstract
Background While the overall burden of malaria is still high, the global technical strategy for malaria advocates for two sets of interventions: vector control-based prevention and diagnosis and prompt effective treatment of malaria cases. This study aimed to assess the performance of malaria interventions on malaria infection and anaemia in irrigated areas in Sudan. Methods Based on the Sudan 2016 national malaria indicator survey, data for two states (Gezira and Sennar), characterized by large-irrigated schemes, were analysed. Four community-level malaria interventions were used as contextual variables: utilization of malaria diagnosis, utilization of Artemisinin-based combination therapy (ACT), utilization of long-lasting insecticidal nets (LLINs) and coverage with indoor residual spraying (IRS). Association between these interventions and two outcomes: malaria infection and anaemia, was assessed separately. Malaria infection was assessed in all age groups while anaemia was assessed in children under 5 years. Multilevel multiple logistic regression analysis were conducted. Results Among 4478 individuals involved in this study distributed over 47 clusters, the overall malaria infection rate was 3.0% and 56.5% of the children under 5 years (total = 322) were anaemic. Except for IRS coverage (69.6%), the average utilization of interventions was relatively low: 52.3% for utilization of diagnosis, 33.0% for utilization of ACTs and 18.6% for LLINs utilization. The multi-level multiple logistic regression model showed that only IRS coverage was associated with malaria infection (Odds ratio 0.83 per 10% coverage, 95%Confidence Interval (95%CI) 0.74–0.94, p = 0.003) indicating that a higher level of IRS coverage was associated with less malaria infection. Anaemia was not associated with any intervention (all p values larger than 0.1). Conclusions Malaria transmission in Gezira and Sennar areas is low. IRS, with insecticide to which vectors are susceptible, is an effective malaria control intervention in irrigated schemes. Community utilization of other interventions was not associated with malaria infection in this study. This may be due to the low utilization of these interventions. However, individual use of LLINs provide personal protection. This study failed to establish an association between anaemia and malaria control interventions in low transmission areas. The higher level of malaria infection in urban areas is a cause for concern.
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Affiliation(s)
- Khalid Abdelmutalab Elmardi
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan. .,Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands.
| | - Ishag Adam
- Department of Obstetrics and Gynecology, Unaizah College of Medicine and Medical Sciences, Qassim University, Unaizah, Saudi Arabia
| | | | - Hmooda Toto Kafy
- Directorate General of Primary Health Care, Federal Ministry of Health, Khartoum, Sudan
| | - Mogahid Sheikheldien Abdin
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan
| | - Immo Kleinschmidt
- MRC International Statistics and Epidemiology Group, Departments of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Stef Kremers
- Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
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Orish VN, Maalman RSE, Donkor OY, Ceruantes BYH, Osei E, Amu H, Appiah PK, Konlan KD, Mumuni H, Kim E, Kim S, Jung H, Ofori-Amoah J, Kofie P, Adjuik M, Alhassan RK, Donkor ES, Zottor FB, Kweku M, Amuna P, Kim SY, Gyapong JO. Assessing health-seeking behaviour and malaria prevention practices among communities in four districts of the Volta Region of Ghana. Malar J 2021; 20:450. [PMID: 34838027 PMCID: PMC8626995 DOI: 10.1186/s12936-021-03986-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 11/16/2021] [Indexed: 11/22/2022] Open
Abstract
Background Malaria is a preventable disease that causes huge morbidity and mortality in malaria-endemic areas, especially among children and pregnant women. The malaria control programme focuses on the prevention of mosquito bites using insecticide-treated nets (ITNs) and mosquito aerosol sprays and coils, as well as prevention of severe disease among those infected through prompt and adequate treatment. The success of the malaria control programme in Ghana is dependent on the malaria prevention practices of people in the community. Therefore, this study evaluated the malaria prevention practices of participants in four districts of the Volta Region of Ghana. Methods This was a cross-sectional study conducted in Ketu South, Nkwanta South, Hohoe Municipality and Ho West districts of the Volta Region of Ghana. Questionnaire were administered to adults who consented to each household visited. Questions were asked on the socio-demographics and malaria prevention practices of the households. Data analysis was done using SPSS version 23 with frequency distribution done for all the variables. Pearson chi-square was used to determine the significant association between socio-demographics and malaria prevention practices, and Multivariate nominal logistic regression analysis was used to model the relationship between dichotomous dependent variables (ITN ownership and usage) and independent variables. Results Out of the 2493 participants; 2234 (89.6%) owned ITN and 1528 (68.4%) used ITN a night before this study, 768 (30.8%) used mosquito aerosol spray and 368 (15%) used mosquito coil. More females significantly owned ITN than males (1293, 92.4%, p ≤ 0.001). Participants from Ketu South had 1.5 times higher odds of owning an ITN compared to Ho West whose odds are not different from Nkwanta South or Hohoe (AOR, 1.56 [95% 1.09–2.22]; p = 0.01). In terms of ITN usage, participants in Nkwanta South were less likely to use ITN compared to the other districts; AOR, 0.434 [95% CI 0.31–0.62, p < 0.001]. Also, of the 668 participants that had a fever within the past 3 days, 268 (40.1%) visited a patent medicine store and 156 (23.4%) visited health facilities. Conclusion There is high ownership of ITNs, but relatively low utilization among the community members. Education on malaria prevention practices should be intensified and continuous among the population of the Volta Region to ensure the success of malaria control in the region.
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Affiliation(s)
- Verner N Orish
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | | | - Otchere Y Donkor
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | | | - Eric Osei
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana.,Department of Public Health Graduate School, Yonsei University, Seoul, Republic of Korea
| | - Hubert Amu
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Prince Kubi Appiah
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana.,Department of Public Health Graduate School, Yonsei University, Seoul, Republic of Korea
| | - Kennedy Diema Konlan
- Department of Public Health Graduate School, Yonsei University, Seoul, Republic of Korea.,School of Nursing and Midwifery, University of Health and Allied Sciences, Ho, Ghana
| | - Hadiru Mumuni
- School of Nursing and Midwifery, University of Health and Allied Sciences, Ho, Ghana
| | - Eunji Kim
- Korea Foundation for International Healthcare Ghana Office, Accra, Ghana
| | - Siwoo Kim
- Asian Institute for Bioethics and Health Law, College of Medicine, Yonsei University, Seoul, Republic of Korea
| | - Hajun Jung
- Asian Institute for Bioethics and Health Law, College of Medicine, Yonsei University, Seoul, Republic of Korea
| | - Jones Ofori-Amoah
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | - Philip Kofie
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Martin Adjuik
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Robert Kaba Alhassan
- Directorate of International Affairs, University of Health and Allied Sciences, Ho, Ghana
| | | | | | - Margaret Kweku
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Paul Amuna
- School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - So Yoo Kim
- Asian Institute for Bioethics and Health Law, College of Medicine, Yonsei University, Seoul, Republic of Korea
| | - John Owusu Gyapong
- Office of the Vice-Chancellor, University of Health and Allied Sciences, Ho, Ghana
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Oladoyinbo TO, Adeogun AO, Babalola AS, Babatunde M, Ladipo OT, Olarinde TI, Oyedemi ID. Factors Affecting Willingness to Use Indoor Residual Spraying Among Pregnant Women Attending Antenatal Care in Hyperendemic State of West Africa: A Random Survey. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:2368-2375. [PMID: 34327539 DOI: 10.1093/jme/tjab132] [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: 04/13/2021] [Indexed: 06/13/2023]
Abstract
This study assessed the perception of pregnant women on indoor residual spraying (IRS), documented acceptability, and factors that significantly dictate willingness to use IRS among the pregnant women attending antenatal clinic in Ibadan Nigeria. A structured questionnaire was used to obtain relevant information from 500 pregnant women. Descriptive and principal component analysis (PCA) were done at 5% level of significance. Majority of the pregnant women had between good and fair knowledge of IRS. Less than 70% of the respondents were willing to allow IRS in their homes. Our PCA revealed that major factors responsible for acceptance and willingness to use IRS were associated with perceived benefits, advantages, and disadvantages of IRS rather than overall knowledge of IRS among the respondents. The analysis revealed that these factors were responsible for at least 80% of the reasons for a pregnant woman to willingly accept IRS or not. The factors that positively influenced willingness to use IRS include its benefit in controlling mosquitoes and other insects, reducing malaria incidence, and prolonged effects of IRS which is an added advantage over continuous purchase of aerosols. One major factor that may negatively affect the acceptance of IRS is the fact that you may have to pack out of the house and wait for more than 3 d before entering. This current study has identified some specific factors that seem to promote and/or reduce willingness to accept IRS as a malaria control intervention among pregnant women in South Western Nigeria.
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Affiliation(s)
| | - Adedapo Olufemi Adeogun
- Public Health and Epidemiology Department, Nigerian Insitute of Medical Research, Yaba Lagos, Nigeria
- Department of Biological Sciences, Lead City University, Ibadan Oyo State, Nigeria
| | - Ayodele Samuel Babalola
- Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
| | | | - Olabode Taiwo Ladipo
- Ministry of Health, Oyo State, Nigeria
- Malaria Elimination Programme, Oyo State, Nigeria
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Ngwej LM, Mashat EM, Mukeng CK, Mundongo HT, Malonga FK, Kashala JCK, Bangs MJ. Variable residual activity of K-Othrine® PolyZone and Actellic® 300 CS in semi-field and natural conditions in the Democratic Republic of the Congo. Malar J 2021; 20:358. [PMID: 34461898 PMCID: PMC8406736 DOI: 10.1186/s12936-021-03892-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/22/2021] [Indexed: 11/10/2022] Open
Abstract
Background Indoor Residual Spray (IRS) against vector mosquitoes is a primary means for combating malaria transmission. To combat increased patterns of resistance to chemicals against mosquito vectors, alternative candidate insecticide formulations should be screened. With mortality as the primary endpoint, the persistence of residual efficacy of a polymer-enhanced pyrethroid suspension concentrate containing deltamethrin (K-Othrine® PolyZone—KOPZ) applied at 25 mg active ingredient (ai)/m2 was compared with a microencapsulated organophosphate suspension formulation of pirimiphos-methyl (Actellic® 300CS—ACS) applied at 1 g ai/m2. Methods Following standard spray application, periodic contact bioassays were conducted for at least 38 weeks on four types of wall surfaces (unbaked clay, baked clay, cement, and painted cement) sprayed with either KOPZ or ACS in simulated semi-field conditions. Similarly, two types of existing walls in occupied houses (painted cement and baked clay) were sprayed and examined. A colonized strain of female Anopheles arabiensis mosquitoes were exposed to treated or untreated surfaces (controls) for 30 min. For each wall surface test period, 40 treatment mosquitoes (4 cones × 10) in semi-field and 90 (9 cones × 10) in ‘natural’ house conditions were used per wall. 30 mosquitoes (3 cones × 10) on a matching unsprayed surface served as the control. Insecticide, wall material, and sprayed location on wall (in houses) were compared by final mortality at 24 h. Results Insecticide, wall material, and sprayed location on wall surface produced significant difference for mean final mortality over time. In semi-field conditions, KOPZ produced a 72% mean mortality over a 38-week period, while ACS gave 65% (p < 0.001). Painted cement wall performed better than other wall surfaces throughout the study period (73% mean mortality). In the two occupied houses, KOPZ provided a mean mortality of 88%, significantly higher than ACS (p < 0.001). KOPZ provided an effective residual life (≥ 80% mortality) between 7.3 and 14 weeks on experimental walls and between 18.3 and 47.2 weeks in houses, while ACS persisted between 3 and 7.6 weeks under semi-field conditions and between 7.1 and 17.3 weeks in houses. Household painted cement walls provided a longer effective residual activity compared to baked clay for both formulations. Greater mortality was recorded at the top and middle sections of sprayed wall compared to the bottom portion near the floor. Conclusion KOPZ provided longer residual activity on all surfaces compared to ACS. Painted cement walls provided better residual longevity for both insecticides compared to other surfaces. Insecticides also performed better in an occupied house environment compared to semi-field constructed walls. This study illustrates the importance of collecting field-based observations to determine appropriate product active ingredient formulations and timing for recurring IRS cycles.
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Affiliation(s)
- Leonard M Ngwej
- China Molybdenum/International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of Congo. .,School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo.
| | - Emmanuel M Mashat
- China Molybdenum/International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of Congo
| | - Clarence K Mukeng
- School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Henri T Mundongo
- School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Françoise K Malonga
- School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Jean-Christophe K Kashala
- Faculty of Veterinary Medicine, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Michael J Bangs
- China Molybdenum/International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of Congo.,Public Health & Malaria Control Department, PT Freeport Indonesia, International SOS, Jl. Kertajasa, Kuala Kencana, Papua, 99920, Indonesia.,Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand
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8
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Namias A, Jobe NB, Paaijmans KP, Huijben S. The need for practical insecticide-resistance guidelines to effectively inform mosquito-borne disease control programs. eLife 2021; 10:e65655. [PMID: 34355693 PMCID: PMC8346280 DOI: 10.7554/elife.65655] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
Monitoring local mosquito populations for insecticide resistance is critical for effective vector-borne disease control. However, widely used phenotypic assays, which are designed to monitor the emergence and spread of insecticide resistance (technical resistance), do not translate well to the efficacy of vector control products to suppress mosquito numbers in the field (practical resistance). This is because standard testing conditions such as environmental conditions, exposure dose, and type of substrate differ dramatically from those experienced by mosquitoes under field conditions. In addition, field mosquitoes have considerably different physiological characteristics such as age and blood-feeding status. Beyond this, indirect impacts of insecticide resistance and/or exposure on mosquito longevity, pathogen development, host-seeking behavior, and blood-feeding success impact disease transmission. Given the limited number of active ingredients currently available and the observed discordance between resistance and disease transmission, we conclude that additional testing guidelines are needed to determine practical resistance-the efficacy of vector control tools under relevant local conditions- in order to obtain programmatic impact.
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Affiliation(s)
- Alice Namias
- Département de Biologie, Ecole Normale Supérieure, PSL Research University, Paris, France
- Institut des Sciences de l'Evolution de Montpellier (ISEM), Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Ndey Bassin Jobe
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Life Sciences C, Tempe, United States
| | - Krijn Petrus Paaijmans
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Life Sciences C, Tempe, United States
- The Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Biodesign Institute, Tempe, United States
- ISGlobal, Carrer del Rosselló, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Distrito da Manhiça, Mozambique
| | - Silvie Huijben
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Life Sciences C, Tempe, United States
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9
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Marti-Soler H, Máquina M, Opiyo M, Alafo C, Sherrard-Smith E, Malheia A, Cuamba N, Sacoor C, Rabinovich R, Aide P, Saúte F, Paaijmans K. Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique. PLoS One 2021; 16:e0248604. [PMID: 34351936 PMCID: PMC8341595 DOI: 10.1371/journal.pone.0248604] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 07/06/2021] [Indexed: 11/22/2022] Open
Abstract
Indoor residual spraying (IRS) is one of the main malaria vector control strategies in Mozambique alongside the distribution of insecticide treated nets. As part of the national insecticide resistance management strategy, Mozambique introduced SumiShield™ 50WG, a third generation IRS product, in 2018. Its residual efficacy was assessed in southern Mozambique during the 2018-2019 malaria season. Using a susceptible Anopheles arabiensis strain, residual efficacy was assessed on two different wall surfaces, cement and mud-plastered walls, using standard WHO (World Health Organization) cone bioassay tests at three different heights. Female mosquitoes of two age groups (2-5 and 13-26 day old) were exposed for 30 minutes, after which mortality was observed 24h, 48h, 72h, and 96h and 120h post-exposure to assess (delayed) mortality. Lethal times (LT) 90, LT50 and LT10 were estimated using Bayesian models. Mortality 24h post exposure was consistently below 80%, the current WHO threshold value for effective IRS, in both young and old mosquitoes, regardless of wall surface type. Considering delayed mortality, residual efficacies (mosquito mortality equal or greater than 80%) ranged from 1.5 to ≥12.5 months, with the duration depending on mortality time post exposure, wall type and mosquito age. Looking at mortality 72h after exposure, residual efficacy was between 6.5 and 9.5 months, depending on wall type and mosquito age. The LT50 and LT10 (i.e. 90% of the mosquitoes survive exposure to the insecticides) values were consistently higher for older mosquitoes (except for LT10 values for 48h and 72h post-exposure mortality) and ranged from 0.9 to 5.8 months and 0.2 to 7.8 months for LT50 and LT10, respectively. The present study highlights the need for assessing mosquito mortality beyond the currently recommended 24h post exposure. Failure to do so may lead to underestimation of the residual efficacy of IRS products, as delayed mortality will lead to a further reduction in mosquito vector populations and potentially negatively impact disease transmission. Monitoring residual efficacy on relevant wall surfaces, including old mosquitoes that are ultimately responsible for malaria transmission, and assessing delayed mortalities are critical to provide accurate and actionable data to guide vector control programmes.
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Affiliation(s)
| | - Mara Máquina
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Mercy Opiyo
- Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Celso Alafo
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- Goodbye Malaria, Tchau Tchau Malaria Foundation, Mozambique
| | - Ellie Sherrard-Smith
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | - Arlindo Malheia
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Nelson Cuamba
- Programa Nacional de Controlo da Malária, Ministério da Saúde, Maputo, Mozambique
- PMI VectorLink Project, Abt Associates Inc., Maputo, Mozambique
| | - Charfudin Sacoor
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Regina Rabinovich
- Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- Instituto Nacional da Saúde, Ministério da Saúde, Maputo, Mozambique
| | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Krijn Paaijmans
- Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- The Biodesign Center for Immunotherapy, Vaccines, and Virotherapy, Arizona State University, Tempe, Arizona, United States of America
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10
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Ebrahimnejad P, Nikookar SH, Fazeli-Dinan M, Payman Ziapour S, Farmoudeh A, Babaei A, Enayati A. Preparation, characterisation and comparative toxicity of nanopermethrin against Anopheles stephensi and Culex pipiens. Trop Med Int Health 2021; 26:982-992. [PMID: 33837621 DOI: 10.1111/tmi.13587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVES To assess the effectiveness of nanopermethrin as a potential new formulation for pest and vector control. METHODS Permethrin nanoparticles were prepared by the ionic gelation method and its structure and the formulations were designed using Box-Behnken statistical technique. The effect of independent variables (Chitosan/Permethrin ratio, tripolyphosphate quantity, sonication time) on the properties of nanoparticles was investigated to determine the optimal formulation. RESULTS The size of the nanoparticles ranged from 135.27 ± 5.88 to 539.5 ± 24.01 nm and the insecticide entrapment efficiency per cent (EE%) ranged from 7.72 ± 1.36 to 63.59 ± 3.17%. Anopheles stephensi larvae were then bioassayed with the nanopermethrin and compared with the results of the bioassay with the mother molecule of permethrin using a standard WHO-recommended mosquito larval bioassay kit. LC50 with permethrin and nanopermethrin on larvae of An. stephensi were 0.125 and 0.026 ppm showing a 4.8 times difference. The LC50 for permethrin and nanopermethrin on Culex pipiens were 0.003 and 0.00032 ppm, respectively, showing a 9.4-fold difference. CONCLUSION Nanopermethrin is much more potent than its mother molecule against larvae of An. stephensi and Cx. pipiens.
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Affiliation(s)
- Pedram Ebrahimnejad
- Department of Pharmaceutics, School of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran.,Pharmaceutical Science Research Center, Hemoglobinopathy Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Hassan Nikookar
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Addiction Institute and School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahmoud Fazeli-Dinan
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Addiction Institute and School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Payman Ziapour
- Department of Parasitology, Zoonosis Research Center, Pasteur Institute of Iran, Amol, Iran
| | - Ali Farmoudeh
- Department of Pharmaceutics, School of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran.,Pharmaceutical Science Research Center, Hemoglobinopathy Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Amirhossein Babaei
- Department of Pharmaceutics, School of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran.,Pharmaceutical Science Research Center, Hemoglobinopathy Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmadali Enayati
- School of Public Health and Health Sciences Research Center, Medical Entomology Department, Mazandaran University of Medical Sciences, Sari, Iran
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11
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Sikalima J, Schue JL, Hill SE, Mulenga M, Handema R, Daka V, Chileshe J, Kasongo W, Chaponda M, Bukasa Kabuya JB, Moss WJ, Ippolito MM. House Structure Is Associated with Malaria among Febrile Patients in a High-Transmission Region of Zambia. Am J Trop Med Hyg 2021; 104:2131-2138. [PMID: 33844650 DOI: 10.4269/ajtmh.20-1378] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/10/2021] [Indexed: 11/07/2022] Open
Abstract
Since the late nineteenth century, the importance of house structure as a determinant of malaria risk has been recognized. Few studies to date have examined the association of housing and malaria in clinical populations. We conducted a cross-sectional study of febrile patients (n = 282) at two rural health clinics in a high malaria-transmission area of northern Zambia. Participants underwent testing for Plasmodium falciparum infection by PCR. Demographic and other risk factors including house structure, indoor residual spraying (IRS), bed net use, education level, and household income were collected. Data were fitted to logistic regression models for relational and mediation analyses. Residing in a house with a thatch roof was associated with higher odds of malaria than residing in a house with corrugated metal (odds ratio: 2.6; 95% CI: 1.0-6.3, P = 0.04). Lower income and educational attainment were also associated with greater odds of malaria. Living under a thatch roof accounted for 24% (95% CI: 14-82) of the effect of household income on malaria risk, and income accounted for 11% (95% CI: 8-19) of the effect of education. Neither IRS nor bed net use was associated with malaria risk despite large, local investments in these vector control interventions. The findings testify to malaria as a disease of rural poverty and contribute further evidence to the utility of housing improvements in vector control programs.
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Affiliation(s)
- Jay Sikalima
- 1Tropical Diseases Research Centre, Ndola, Zambia
| | - Jessica L Schue
- 2Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,3Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Sarah E Hill
- 4Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Modest Mulenga
- 5Department of Public Health, Michael Chilufya Sata School of Medicine, Copperbelt University, Kitwe, Zambia
| | - Ray Handema
- 1Tropical Diseases Research Centre, Ndola, Zambia
| | - Victor Daka
- 5Department of Public Health, Michael Chilufya Sata School of Medicine, Copperbelt University, Kitwe, Zambia
| | | | | | | | | | - William J Moss
- 3Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Matthew M Ippolito
- 3Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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12
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Rufalco-Moutinho P, Moura Kadri S, Peres Alonso D, Moreno M, Carrasco-Escobar G, Prussing C, Gamboa D, Vinetz JM, Mureb Sallum MA, Conn JE, Martins Ribolla PE. Ecology and larval population dynamics of the primary malaria vector Nyssorhynchus darlingi in a high transmission setting dominated by fish farming in western Amazonian Brazil. PLoS One 2021; 16:e0246215. [PMID: 33831004 PMCID: PMC8031405 DOI: 10.1371/journal.pone.0246215] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 03/23/2021] [Indexed: 11/21/2022] Open
Abstract
Vale do Rio Juruá in western Acre, Brazil, is a persistent malaria transmission hotspot partly due to fish farming development that was encouraged to improve local standards of living. Fish ponds can be productive breeding sites for Amazonian malaria vector species, including Nyssorhynchus darlingi, which, combined with high human density and mobility, add to the local malaria burden.This study reports entomological profile of immature and adult Ny. darlingi at three sites in Mâncio Lima, Acre, during the rainy and dry season (February to September, 2017). From 63 fishponds, 10,859 larvae were collected, including 5,512 first-instar Anophelinae larvae and 4,927 second, third and fourth-instars, of which 8.5% (n = 420) were Ny. darlingi. This species was most abundant in not-abandoned fishponds and in the presence of emerging aquatic vegetation. Seasonal analysis of immatures in urban landscapes found no significant difference in the numbers of Ny. darlingi, corresponding to equivalent population density during the rainy to dry transition period. However, in the rural landscape, significantly higher numbers of Ny. darlingi larvae were collected in August (IRR = 5.80, p = 0.037) and September (IRR = 6.62, p = 0.023) (dry season), compared to February (rainy season), suggesting important role of fishponds for vector population maintenance during the seasonal transition in this landscape type. Adult sampling detected mainly Ny. darlingi (~93%), with similar outdoor feeding behavior, but different abundance according to landscape profile: urban site 1 showed higher peaks of human biting rate in May (46 bites/person/hour), than February (4) and September (15), while rural site 3 shows similar HBR during the same sampling period (22, 24 and 21, respectively). This study contributes to a better understanding of the larvae biology of the main malaria vector in the Vale do Rio Juruá region and, ultimately will support vector control efforts.
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Affiliation(s)
- Paulo Rufalco-Moutinho
- Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- * E-mail:
| | - Samir Moura Kadri
- Instituto de Biotecnologia, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Diego Peres Alonso
- Instituto de Biotecnologia, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Marta Moreno
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Gabriel Carrasco-Escobar
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Catharine Prussing
- Department of Biomedical Sciences, School of Public Health, State University of New York-Albany, Albany, NY, United States of America
- New York State Department of Health, Wadsworth Center, Albany, NY, United States of America
| | - Dionicia Gamboa
- Facultad de Ciencias y Filosofía, Departamento de Ciencias Celulares y Moleculares, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicinal Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M. Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicinal Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Peru
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, CT, United States of America
| | - Maria Anice Mureb Sallum
- Faculdade de Saúde Pública, Departamento de Epidemiologia, Universidade de São Paulo, São Paulo, Brazil
| | - Jan E. Conn
- Department of Biomedical Sciences, School of Public Health, State University of New York-Albany, Albany, NY, United States of America
- New York State Department of Health, Wadsworth Center, Albany, NY, United States of America
| | - Paulo Eduardo Martins Ribolla
- Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- Instituto de Biotecnologia, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
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13
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Gonçalves R, de Souza CF, Rontani RB, Pereira A, Farnes KB, Gorsich EE, Silva RA, Brazil RP, Hamilton JGC, Courtenay O. Community deployment of a synthetic pheromone of the sand fly Lutzomyia longipalpis co-located with insecticide reduces vector abundance in treated and neighbouring untreated houses: Implications for control of Leishmania infantum. PLoS Negl Trop Dis 2021; 15:e0009080. [PMID: 33534804 PMCID: PMC7886189 DOI: 10.1371/journal.pntd.0009080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 02/16/2021] [Accepted: 12/17/2020] [Indexed: 01/29/2023] Open
Abstract
Background The rising incidence of visceral leishmaniasis due to Leishmania infantum requires novel methods to control transmission by the sand fly vector. Indoor residual spraying of insecticide (IRS) against these largely exophilic / exophagic vectors may not be the most effective method. A synthetic copy of the male sex-aggregation pheromone of the key vector species Lutzomyia longipalpis in the Americas, was co-located with residual pyrethroid insecticide, and tested for its effects on vector abundance, hence potential transmission, in a Brazilian community study. Methods Houses within eight defined semi-urban blocks in an endemic municipality in Brazil were randomised to synthetic pheromone + insecticide or to placebo treatments. A similar number of houses located >100m from each block were placebo treated and considered as “True Controls” (thus, analysed as three trial arms). Insecticide was sprayed on a 2.6m2 surface area of the property boundary or outbuilding wall, co-located within one metre of 50mg synthetic pheromone in controlled-release dispensers. Vector numbers captured in nearby CDC light traps were recorded at monthly intervals over 3 months post intervention. Recruited sentinel houses under True Control and pheromone + insecticide treatments were similarly monitored at 7–9 day intervals. The intervention effects were estimated by mixed effects negative binomial models compared to the True Control group. Results Dose-response field assays using 50mg of the synthetic pheromone captured a mean 4.8 (95% C.L.: 3.91, 5.80) to 6.3 (95% C.L.: 3.24, 12.11) times more vectors (female Lu. longipalpis) than using 10mg of synthetic pheromone. The intervention reduced household female vector abundance by 59% (C.L.: 48.7, 66.7%) (IRR = 0.41) estimated by the cross-sectional community study, and by 70% (C.L.: 56.7%, 78.8%) estimated by the longitudinal sentinel study. Similar reductions in male Lu. longipalpis were observed. Beneficial spill-over intervention effects were also observed at nearby untreated households with a mean reduction of 24% (95% C.L.: 0.050%, 39.8%) in female vectors. The spill-over effect in untreated houses was 44% (95% C.L.: 29.7%, 56.1%) as effective as the intervention in pheromone-treated houses. Ownership of chickens increased the intervention effects in both treated and untreated houses, attributed to the suspected synergistic attraction of the synthetic pheromone and chicken kairomones. The variation in IRR between study blocks was not associated with inter-household distances, household densities, or coverage (proportion of total households treated). Conclusions The study confirms the entomological efficacy of the lure-and-kill method to reduce the abundance of this important sand fly vector in treated and untreated homesteads. The outcomes were achieved by low coverage and using only 1–2% of the quantity of insecticide as normally required for IRS, indicating the potential cost-effectiveness of this method. Implications for programmatic deployment of this vector control method are discussed. The predominant sand fly vector of the intracellular parasite Leishmania infantum, that causes human and canine visceral leishmaniasis in the Americas, is Lutzomyia longipalpis. Vector control tools to reduce transmission are needed. A sex-aggregation pheromone released by male Lu. longipalpis attracts female conspecifics which facilitates blood-feeding and transmission. This study, conducted in Brazil, quantifies the effects of community deployment of a synthetic version of the sex-aggregation pheromone, in a controlled-release dispenser, and co-located with lethal insecticide applied to a small area of the household compound or outbuilding wall. 50mg synthetic pheromone dispensers were used since they attracted substantially more vectors than 10mg dispensers. Deploying this novel lure-and-kill method to houses in eight replicate study blocks in two suburban endemic areas, demonstrated that it reduces vector numbers at both pheromone + insecticide treated houses, and neighbouring untreated houses. The presence of chickens (a known additional attraction to blood-seeking female Lu. longipalpis) increased the beneficial effects of the intervention. The method used only 1–2% of the quantity of insecticide necessary for IRS for an average sized house. The results demonstrate the efficacy and potential cost-effectiveness of this novel lure-and-kill control method.
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Affiliation(s)
- Raquel Gonçalves
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Cristian F. de Souza
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Reila B. Rontani
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Alisson Pereira
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Katie B. Farnes
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Erin E. Gorsich
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Rafaella A. Silva
- Núcleo de Medicina Tropical, Universidade de Brasilia, Brasília, Federal District, Brazil
- Ministério da Saúde, Departamento de Imunização e Doenças Transmissíveis, Secretaria de Vigilância em Saúde, Brasília, Federal District, Brazil
| | - Reginaldo P. Brazil
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - James G. C. Hamilton
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Bailrigg, Lancaster, Lancashire, United Kingdom
- * E-mail: (JH); (OC)
| | - Orin Courtenay
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
- * E-mail: (JH); (OC)
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14
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de Araújo Barbosa V, de Souza CF, Pereira A, Gatherer D, Brazil RP, Bray DP, Hamilton JG. Insecticide-impregnated netting: A surface treatment for killing Lutzomyia longipalpis (Diptera: Psychodidae), the vector of Leishmania infantum. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2021; 1:None. [PMID: 35005688 PMCID: PMC8716342 DOI: 10.1016/j.crpvbd.2021.100044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/01/2021] [Accepted: 07/19/2021] [Indexed: 12/04/2022]
Abstract
The sand fly Lutzomyia longipalpis is the main vector of Leishmania infantum in Brazil. Synthetic male-produced sex/aggregation pheromone co-located with micro-encapsulated λ-cyhalothrin in chicken sheds can significantly reduce canine infection and sand fly densities in a lure-and-kill strategy. In this study, we determined if insecticide-impregnated netting (IN) could replace insecticide residual spraying (IRS). We compared numbers of Lu. longipalpis attracted and killed in experimental and real chicken sheds baited with pheromone and treated with a 1 m2 area of either insecticide spray or netting. First, we compared both treatments in experimental sheds to control mortality established from light trap captures. We then compared the long-term killing effect of insecticide spray and netting, without renewal, in experimental sheds over a period of 16 weeks. Finally, a longitudinal intervention study in real chicken sheds compared the numbers and proportions of Lu. longipalpis collected and killed before and after application of both treatments. In Experiment 1, a higher proportion of males and females captured in IRS- and IN-treated sheds were dead at 24 h compared to controls (P < 0.05). No difference was found in the proportion of females killed in sheds treated with IN or IRS (P = 0.15). A slightly higher proportion of males were killed by IRS (100%) compared to IN (98.6%; P < 0.05). In Experiment 2, IN- and IRS-treated traps were equally effective at killing females (P = 0.21) and males (P = 0.08). However, IRS killed a significantly higher proportion of females and males after 8 (P < 0.05) and 16 (P < 0.05) weeks. In Experiment 3, there was no significant difference between treatments in the proportion of females killed before (P = 0.88) or after (P = 0.29) or males killed before (P = 0.76) or after (P = 0.73) intervention. Overall, initially the IN was as effective as IRS at killing female and male Lu. longipalpis in both experimental and real chicken sheds. However, the relative lethal effect of the IN deteriorated over time when stored under prevailing environmental conditions. Chicken sheds treated with netting or spray insecticide killed Lutzomyia longipalpis. Same effect was seen in experimental and real chicken sheds. Netting was as effective as spraying insecticide initially. Sprayed insecticide killed a higher proportion of both sexes after 8 and 16 weeks. The relative lethal effect of the netting deteriorated over time.
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15
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Rocha EM, Katak RDM, Campos de Oliveira J, Araujo MDS, Carlos BC, Galizi R, Tripet F, Marinotti O, Souza-Neto JA. Vector-Focused Approaches to Curb Malaria Transmission in the Brazilian Amazon: An Overview of Current and Future Challenges and Strategies. Trop Med Infect Dis 2020; 5:E161. [PMID: 33092228 PMCID: PMC7709627 DOI: 10.3390/tropicalmed5040161] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/10/2020] [Accepted: 10/13/2020] [Indexed: 01/05/2023] Open
Abstract
In Brazil, malaria transmission is mostly confined to the Amazon, where substantial progress has been made towards disease control in the past decade. Vector control has been historically considered a fundamental part of the main malaria control programs implemented in Brazil. However, the conventional vector-control tools have been insufficient to control or eliminate local vector populations due to the complexity of the Amazonian rainforest environment and ecological features of malaria vector species in the Amazon, especially Anopheles darlingi. Malaria elimination in Brazil and worldwide eradication will require a combination of conventional and new approaches that takes into account the regional specificities of vector populations and malaria transmission dynamics. Here we present an overview on both conventional and novel promising vector-focused tools to curb malaria transmission in the Brazilian Amazon. If well designed and employed, vector-based approaches may improve the implementation of malaria-control programs, particularly in remote or difficult-to-access areas and in regions where existing interventions have been unable to eliminate disease transmission. However, much effort still has to be put into research expanding the knowledge of neotropical malaria vectors to set the steppingstones for the optimization of conventional and development of innovative vector-control tools.
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Affiliation(s)
- Elerson Matos Rocha
- Programa de Pós-Graduação em Biotecnologia, Universidade Federal do Amazonas—PPGBIOTEC/UFAM, Manaus 69067-005, Brazil; (E.M.R.); (R.d.M.K.); (J.C.d.O.)
| | - Ricardo de Melo Katak
- Programa de Pós-Graduação em Biotecnologia, Universidade Federal do Amazonas—PPGBIOTEC/UFAM, Manaus 69067-005, Brazil; (E.M.R.); (R.d.M.K.); (J.C.d.O.)
| | - Juan Campos de Oliveira
- Programa de Pós-Graduação em Biotecnologia, Universidade Federal do Amazonas—PPGBIOTEC/UFAM, Manaus 69067-005, Brazil; (E.M.R.); (R.d.M.K.); (J.C.d.O.)
| | - Maisa da Silva Araujo
- Laboratory of Medical Entomology, Oswaldo Cruz Foundation, FIOCRUZ RONDONIA, Porto Velho, RO 76812-245, Brazil;
| | - Bianca Cechetto Carlos
- Department of Bioprocesses and Biotechnology, School of Agricultural Sciences, São Paulo State University (UNESP), Botucatu 18610-034, Brazil;
- Central Multiuser Laboratory, School of Agricultural Sciences, São Paulo State University (UNESP), Botucatu 18610-034, Brazil
| | - Roberto Galizi
- Centre of Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire ST5 5GB, UK; (R.G.); (F.T.)
| | - Frederic Tripet
- Centre of Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire ST5 5GB, UK; (R.G.); (F.T.)
| | | | - Jayme A. Souza-Neto
- Department of Bioprocesses and Biotechnology, School of Agricultural Sciences, São Paulo State University (UNESP), Botucatu 18610-034, Brazil;
- Central Multiuser Laboratory, School of Agricultural Sciences, São Paulo State University (UNESP), Botucatu 18610-034, Brazil
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