1
|
Gouveia AS, Codeço CT, Ferreira FADS, Cortés JJC, Luz SLB. Diflubenzuron larvicide auto-dissemination: A modeling study. Acta Trop 2024:107325. [PMID: 39032848 DOI: 10.1016/j.actatropica.2024.107325] [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: 03/25/2024] [Revised: 06/11/2024] [Accepted: 07/13/2024] [Indexed: 07/23/2024]
Abstract
Proposing substitutes for Pyriproxyfen (PPF) in the auto-dissemination strategy is essential to ensure the continuity of the strategy in the field, especially in the case of the emergence of populations resistant to this larvicide. One possible substitute among the compounds already in use in Brazil is the larvicide Diflubenzuron (DFB). The equation that defines the proportion of oviposition sites (habitats) contaminated by the auto-dissemination strategy was modified to account for the number of visits required to reach the necessary concentration of DFB for contamination, considering scenarios with varying numbers of oviposition sites and mosquito densities. The dissemination was evaluated in oviposition sites of 2L, 1.5L, 1L, 0.5L, 0.2L, and 0.1L. The minimum concentration of active ingredient (a.i) of DFB required for a commercial product to contaminate at least 50% of oviposition sites was also investigated, along with the impact of other vector control methods, such as the removal/destruction of oviposition sites and the use of insecticides to kill adult 'females, on the auto-dissemination approach. The use of pure DFB compounds enabled contamination efficiency of more than 50% in oviposition sites with a volume of less than 2L in scenarios with fewer oviposition sites. On the other hand, with the use of the commonly used concentration of the product, similar efficacy was only achieved in oviposition sites of 0.1L and 0.2L in medium and high infestation scenarios. Strategies that reduce the number of available oviposition sites work synergistically with the auto-dissemination strategy, making it possible to use less concentrated products and contaminated sites of larger volume. The strategy proved to be resilient in situations of insecticide application according to the concentration of DFB used, abundance of females, and low number of oviposition sites. Increasing the number of dissemination traps on the field also contributes to better results, especially for oviposition sites of 0.5L and 1L. The results of the model obtained under the stipulated conditions provide further support for the potential use of DFB as a substitute for PPF in the auto-dissemination strategy.
Collapse
Affiliation(s)
- Ayrton Sena Gouveia
- Núcleo PReV Amazônia - Instituto Leônidas e Maria Deane - Fiocruz Amazônia; Programa de Computação Científica da Fiocruz - Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil; Programa de Pós-Graduação em Biologia Parasitária, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
| | - Cláudia Torres Codeço
- Programa de Computação Científica da Fiocruz - Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil
| | | | | | | |
Collapse
|
2
|
Müller JN, Galardo AKR, Corrêa APSDA, Macoris MDLDG, de Melo-Santos MAV, Nakazawa MM, Martins AJ, Lima JBP. Impact of SumiLarv ® 2MR on Aedes aegypti larvae: a multicenter study in Brazil. Parasit Vectors 2024; 17:88. [PMID: 38409019 PMCID: PMC10895835 DOI: 10.1186/s13071-023-06064-w] [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: 07/18/2023] [Accepted: 11/20/2023] [Indexed: 02/28/2024] Open
Abstract
BACKGROUND Aedes aegypti is associated with dengue, Zika, and chikungunya transmission. These arboviruses are responsible for national outbreaks with severe public health implications. Vector control is one of the tools used to prevent mosquito proliferation, and SumiLarv® 2MR is an alternative commercial product based on pyriproxyfen for larval/pupal control. In this study, the residual effectiveness of SumiLarv® 2MR in different regions of Brazil was evaluated in simulated field conditions. METHODS We conducted a multicenter study across four Brazilian states-Amapá, Pernambuco, Rio de Janeiro, and São Paulo-given the importance to the country's climatic variances in the north, northeast, and southeast regions and their influence on product efficiency. The populations of Ae. aegypti from each location were held in an insectary. Third-instar larvae (L3) were added every 2 weeks to water containers with SumiLarv® 2MR discs in 250-, 500- and 1000-l containers in Amapá and Rio de Janeiro, and 100-l containers in Pernambuco and São Paulo, using concentrations of 0.04, 0.08, and 0.16 mg/l. RESULTS Adult emergence inhibition over 420 days was observed in all tests conducted at a concentration of 0.16 mg/l; inhibition for 308-420 days was observed for 0.08 mg/l, and 224-420 days for 0.04 mg/l. CONCLUSIONS Sumilarv® 2MR residual activity demonstrated in this study suggests that this new pyriproxyfen formulation is a promising alternative for Aedes control, regardless of climatic variations and ideal concentration, since the SumiLarv® 2MR showed adult emergence inhibition of over 80% and residual activity greater than 6 months, a period longer than that recommended by the Ministry of Health of Brazil between product re-application in larval breeding sites.
Collapse
Affiliation(s)
- Josiane Nogueira Müller
- Laboratory of Biology, Control and Surveillance of Vector Insects-LBCVIV FIOCRUZ/RJ, Rio de Janeiro, Brazil.
- Laboratory of Medical Entomology, Institute of Scientific and Technological Research of the State of Amapá-IEPA, Macapá, Brazil.
- Programa de Pós-graduação em Medicina Tropical, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
| | - Allan Kardec Ribeiro Galardo
- Laboratory of Medical Entomology, Institute of Scientific and Technological Research of the State of Amapá-IEPA, Macapá, Brazil
| | - Ana Paula Sales de Andrade Corrêa
- Laboratory of Biology, Control and Surveillance of Vector Insects-LBCVIV FIOCRUZ/RJ, Rio de Janeiro, Brazil
- Laboratory of Medical Entomology, Institute of Scientific and Technological Research of the State of Amapá-IEPA, Macapá, Brazil
- Programa de Pós-graduação em Medicina Tropical, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil
| | | | | | | | - Ademir Jesus Martins
- Laboratory of Biology, Control and Surveillance of Vector Insects-LBCVIV FIOCRUZ/RJ, Rio de Janeiro, Brazil
| | - José Bento Pereira Lima
- Laboratory of Biology, Control and Surveillance of Vector Insects-LBCVIV FIOCRUZ/RJ, Rio de Janeiro, Brazil
- Programa de Pós-graduação em Medicina Tropical, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil
| |
Collapse
|
3
|
Vásquez VN, Reddy MR, Marshall JM. Environmentally appropriate vector control is facilitated by standard metrics for simulation-based evaluation. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.953212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
As anthropogenic factors contribute to the introduction and expansion of new and established vector species, the geographic incidence of mosquito-borne disease is shifting. Computer simulations, informed by field data where possible, facilitate the cost-effective evaluation of available public health interventions and are a powerful tool for informing appropriate policy action. However, a variety of measurements are used in such assessments; this can complicate direct comparisons across both vector control technologies and the models used to simulate them. The expansion of biocontrol to include genetically engineered organisms is now prompting additional metrics with no analogy to traditional measurement approaches. We propose Standard Entomological Metrics (SEMs) to facilitate the model-based appraisal of both existing and novel intervention tools and define two examples: Suppression Efficacy Score and Time to Reduction Target. We formulate twelve synthetic case studies featuring two vector control technologies over three years of observed daily temperature in Cairns, Australia. After calculating Suppression Efficacy Score and Time to Reduction Target results, we apply these example outcomes to a discussion of health policy decision-making using SEMs. We submit that SEMs such as Suppression Efficacy Score and Time to Reduction Target facilitate the wholistic and environmentally appropriate simulation-based evaluation of intervention programs and invite the community to further discussion on this topic.
Collapse
|
4
|
Barrera R. New tools for Aedes control: mass trapping. CURRENT OPINION IN INSECT SCIENCE 2022; 52:100942. [PMID: 35667560 PMCID: PMC9413017 DOI: 10.1016/j.cois.2022.100942] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/10/2022] [Accepted: 05/25/2022] [Indexed: 05/15/2023]
Abstract
Aedes aegypti, the main vector of dengue, chikungunya, and Zika viruses uses artificial containers around homes to undergo immature development, making household-level detection and control extremely difficult in large urban areas. Mass trapping is an emerging methodology to control container-Aedes species such as Aedes aegypti and Aedes albopictus because effective traps for adult stages of these mosquitoes were developed recently. There are three main approaches to mass-trapping these mosquitoes: 1) Pull (attract/kill), 2) push (repel)-pull (attract/kill), and 3) pull (attract/contaminate/infect)-push (fly away). Effective mass-trapping depends on trap quality (capture efficiency, sturdiness, frequency of servicing), trap density and areal coverage, community involvement, and safety. Recent studies showed that Ae. aegypti populations can be sustainably controlled by mass trapping, although more area-wide studies showing effectiveness at preventing disease are needed for all trapping systems. Cost-effectiveness studies are needed for all emerging Aedes control approaches.
Collapse
Affiliation(s)
- Roberto Barrera
- Entomology and Ecology Team, Dengue Branch, DBVD, NCEZID, Centers for Disease Control and Prevention (CDC), 1324 Calle Cañada, San Juan 00920, Puerto Rico.
| |
Collapse
|
5
|
Small-scale field assessment against the dengue vector Aedes aegypti using the auto-dissemination approach in an urban area of Vientiane, Lao PDR. PLoS One 2022; 17:e0270987. [PMID: 35776762 PMCID: PMC9249186 DOI: 10.1371/journal.pone.0270987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 06/21/2022] [Indexed: 11/19/2022] Open
Abstract
Background In Lao PDR, dengue fever is the most important vector borne disease and vector control remains the principal method to fight against Aedes aegypti the primary transmitter mosquito species. Vector control management programs need new strategies in addition to conventional larviciding and adulticiding interventions in the country. In this study, we examined the In2Care® Mosquito Trap’s efficacy using insecticide auto-dissemination strategy. The insecticide pyriproxyfen, present in powder form inside the trap station, contaminates the body of gravid female mosquitoes visiting the traps and is later on disseminated via the mosquitoes in breeding sites surrounding the traps. We tested the attractiveness of the Traps, their efficacy to reduce the larval and adult abundance, and the impact on emergence rates. Specifically, we tested if the servicing interval of the In2Care® Mosquito Trap could be extended to 12 weeks. Methods Two black plastic ovitrap buckets and two BG® sentinel traps were placed in the premises of the Science campus of Vientiane Capital located in an urban area to measure weekly the larval and adult relative abundance of Aedes mosquitoes from 2017 to 2019. Twenty-five In2Care® Mosquito Traps were evenly distributed in this area and two studies of 12 weeks were implemented during January and April 2018 and, July to October 2018 (dry and rainy season, respectively). Every 2 weeks, water samples from 5 In2Care® Traps were randomly selected and tested at the laboratory with Ae. aegypti larvae to measure the larval and pupal mortality. The relative abundance of Aedes mosquitoes in the BG traps® with the presence of In2Care® Traps in 2018, was compared with the surveillance results obtained in 2017 and 2019 without In2Care® Traps. Every week, water samples from the ovitrap buckets were tested for Emergence Inhibition (EI). Results The In2Care® Traps were very attractive to gravid Ae. aegypti mosquitoes specifically during the rainy seasons with 96% of the traps colonized with larvae/pupae within four weeks. The bioassays showed 100% mortality in the water samples from the traps during the twelve weeks studies showing the good efficacy over time of the pyriproxyfen without additional servicing in the 12 week period. In addition, the larvicide was successfully disseminated into the ovitrap buckets placed in the treated area where 100% of EI during all weeks of intervention was measured. There was no significant effect of the treatment on adult abundance reduction in the treated area, probably due to recolonization of adult mosquitoes surrounding the field experiment. Conclusions The observed potential of the In2Care® Mosquito Trap using the auto-dissemination strategy could lead to the use of this new tool in combination with conventional control methods against Dengue vectors in urban tropical areas. Large scale field trials should be implemented in Lao PDR to prove its efficacy for Public Health programs.
Collapse
|
6
|
Barrera R, Acevedo V, Amador M. Surveillance and Control of Culex quinquefasciatus Using Autocidal Gravid Ovitraps. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2022; 38:19-23. [PMID: 35276724 DOI: 10.2987/21-7046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We monitored trap captures of Culex quinquefasciatus using an interrupted time-series study to determine if autocidal gravid ovitraps (AGO traps) were useful to control the population of this mosquito species in a community in southern Puerto Rico. Data for this report came from a previous study in which we used mass trapping to control Aedes aegypti, resulting in a significant 79% reduction in numbers of this species. The AGO traps used to monitor and control Ae. aegypti also captured numerous Cx. quinquefasciatus. Culex quinquefasciatus was monitored in surveillance AGO traps from October 2011 to February 2013, followed by a mosquito control intervention from February 2013 to June 2014. Optimal captures of this mosquito occurred on the 2nd wk after the traps were set or serviced, which happened every 8 wk. Changes in collection numbers of Cx. quinquefasciatus were positively correlated with rainfall and showed oscillations every 8 wk, as revealed by sample autocorrelation analyses. Culex quinquefasciatus was attracted to and captured by AGO traps, so mass trapping caused a significant but moderate reduction of the local population (31.2%) in comparison with previous results for Ae. aegypti, possibly resulting from female mosquitoes flying in from outside of the study area and decreased attraction to the traps past the 2nd wk of trap servicing. Because Ae. aegypti and Cx. quinquefasciatus are frequently established in urban areas, mass trapping to control the former has some impact on Cx. quinquefasciatus. Control of the latter could be improved by locating and treating its aquatic habitats within and around the community.
Collapse
Affiliation(s)
- Roberto Barrera
- Entomology and Ecology Team, Dengue Branch, DVBD, Centers for Disease Control and Prevention, 1324 Calle Canada, San Juan, PR 00920
| | - Veronica Acevedo
- Entomology and Ecology Team, Dengue Branch, DVBD, Centers for Disease Control and Prevention, 1324 Calle Canada, San Juan, PR 00920
| | - Manuel Amador
- Entomology and Ecology Team, Dengue Branch, DVBD, Centers for Disease Control and Prevention, 1324 Calle Canada, San Juan, PR 00920
| |
Collapse
|
7
|
Sánchez-Díaz E, Gleiser RM, Lopez LR, Guzman C, Contigiani MS, Spinsanti L, Gardenal CN, Gorla DE. Oviposition dynamics of Aedes aegypti in Central Argentina. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:43-55. [PMID: 34618943 DOI: 10.1111/mve.12550] [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: 03/15/2021] [Revised: 05/26/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) is the vector of multiple arboviruses. To evaluate the association between environmental factors and the oviposition activity of Ae. aegypti in Argentina, data on the presence and abundance of eggs were collected using ovitraps, between September of 2018 and May of 2019, in the cities of Villa María, Río Cuarto and Salsipuedes (Córdoba province, Argentina). We analysed the relationships between oviposition and five environmental factors: Temperature, precipitation, vegetation cover, human population density and distance to sites with a potential high density of larval habitats, like cemeteries and trash dumps. Environmental factors' data were collected using satellite image products. The oviposition activity was randomly distributed in three cities. Using generalized linear mixed models, we show that the house where each ovitrap was placed was a source of variability in oviposition, suggesting the relevance of microsite factors and the importance of domestic control actions. Ae. aegypti oviposition was positively correlated with night-time temperature of the previous 3 weeks, and in a context-dependent manner, it was positively correlated with human population density, vegetation cover and precipitation. The consistency and magnitude of these relationships varied between cities, indicating that oviposition is related to a complex system of environmental variables.
Collapse
Affiliation(s)
- E Sánchez-Díaz
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba - CONICET, IMBIV, Córdoba, Argentina
| | - R M Gleiser
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba - CONICET, IMBIV, Córdoba, Argentina
- Instituto Multidisciplinario de Biología Vegetal, Centro de Relevamiento y Evaluación de Recursos Agrícolas y Naturales (CREAN), Universidad Nacional de Córdoba - CONICET, IMBIV, Córdoba, Argentina
- Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Diversidad Biológica y Ecología, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - L R Lopez
- Ministerio de Salud Córdoba, Córdoba, Argentina
| | - C Guzman
- Ministerio de Salud Córdoba, Córdoba, Argentina
| | - M S Contigiani
- Facultad de Ciencias Médicas, Instituto de Virología "Dr. José María Vanella" (In.Vi.V.), Universidad Nacional de Córdoba, Córdoba, Argentina
| | - L Spinsanti
- Facultad de Ciencias Médicas, Instituto de Virología "Dr. José María Vanella" (In.Vi.V.), Universidad Nacional de Córdoba, Córdoba, Argentina
| | - C N Gardenal
- Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Eco-Epidemiología Espacial de Enfermedades Transmitidas por Vectores, Universidad Nacional de Córdoba - CONICET, Córdoba, Argentina
| | - D E Gorla
- Instituto de Diversidad y Ecología Animal (IDEA), Laboratorio de Eco-Epidemiología Espacial de Enfermedades Transmitidas por Vectores, Universidad Nacional de Córdoba - CONICET, Córdoba, Argentina
| |
Collapse
|
8
|
Buckner EA, Williams KF, Ramirez S, Darrisaw C, Carrillo JM, Latham MD, Lesser CR. A Field Efficacy Evaluation of In2Care Mosquito Traps in Comparison with Routine Integrated Vector Management at Reducing Aedes aegypti. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2021; 37:242-249. [PMID: 34817613 DOI: 10.2987/21-7038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Aedes aegypti is the predominant vector of dengue, chikungunya, and Zika viruses. This mosquito is difficult to control with conventional methods due to its container-inhabiting behavior and resistance to insecticides. Autodissemination of pyriproxyfen (PPF), a potent larvicide, has shown promise as an additional tool to control Aedes species in small-scale field trials. However, few large-scale field evaluations have been conducted. We undertook a 6-month-long large-scale field study to compare the effectiveness and operational feasibility of using In2Care Mosquito Traps (In2Care Traps, commercially available Aedes traps with PPF and Beauveria bassiana) compared to an integrated vector management (IVM) strategy consisting of source reduction, larviciding, and adulticiding for controlling Ae. aegypti eggs, larvae, and adults. We found that while the difference between treatments was only statistically significant for eggs and larvae (P < 0.05 for eggs and larvae and P > 0.05 for adults), the use of In2Care Traps alone resulted in 60%, 57%, and 57% fewer eggs, larvae, and adults, respectively, collected from that site compared to the IVM site. However, In2Care Trap deployment and maintenance were more time consuming and labor intensive than the IVM strategy. Thus, using In2Care Traps alone as a control method for large areas (e.g., >20 ha) may be less practical for control programs with the capacity to conduct ground and aerial larviciding and adulticiding. Based on our study results, we conclude that In2Care Traps are effective at suppressing Ae. aegypti and have the most potential for use in areas without sophisticated control programs and within IVM programs to target hotspots with high population levels and/or risk of Aedes-borne pathogen transmission.
Collapse
|
9
|
The role and challenges of cluster randomised trials for global health. LANCET GLOBAL HEALTH 2021; 9:e701-e710. [PMID: 33865475 DOI: 10.1016/s2214-109x(20)30541-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 12/07/2020] [Accepted: 12/10/2020] [Indexed: 12/13/2022]
Abstract
Evaluating whether an intervention works when trialled in groups of individuals can pose complex challenges for clinical research. Cluster randomised controlled trials involve the random allocation of groups or clusters of individuals to receive an intervention, and they are commonly used in global health research. In this paper, we describe the potential reasons for the increasing popularity of cluster trials in low-income and middle-income countries. We also draw on key areas of global health research for an assessment of common trial planning practices, and we address their methodological shortcomings and pitfalls. Lastly, we discuss alternative approaches for population-level intervention trials that could be useful for research undertaken in low-income and middle-income countries for situations in which the use of cluster randomisation might not be appropriate.
Collapse
|
10
|
Parthasarathy R, Palli SR. Stage-specific action of juvenile hormone analogs. JOURNAL OF PESTICIDE SCIENCE 2021; 46:16-22. [PMID: 33746542 PMCID: PMC7953018 DOI: 10.1584/jpestics.d20-084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
The discovery of juvenile hormones (JH) and their synthetic analogs (JHA) generated excitement and hope that these compounds will replace first- and second-generation insecticides that have not so desirable environmental and human safety profiles. However, JHAs used commercially during the past four decades did not meet these expectations. The recent availability of advanced molecular and histological methods and the discovery of key players involved in JH action provided some insights into the functioning of JHA in a stage and species-specific manner. In this review, we will summarize recent findings and stage-specific action of JHA, focusing on three commercially used JHA, methoprene, hydroprene and pyriproxyfen and economically important pests, the red flour beetle, Tribolium castaneum, and the tobacco budworm, Heliothis virescens, and disease vector, the yellow fever mosquito, Aedes aegypti.
Collapse
Affiliation(s)
- Ramaseshadri Parthasarathy
- Department of Entomology, University of Kentucky, College of Agriculture, Food and Environment, Lexington, KY, USA
| | - Subba Reddy Palli
- Department of Entomology, University of Kentucky, College of Agriculture, Food and Environment, Lexington, KY, USA
| |
Collapse
|