Simposio: Vigilancia y control de vectores
SIMPOSIO
Vigilancia y control de vectores
COORDINA: Ima Aparecida Braga & Lorenzo Verger
Problemáticas actuales y nuevas estrategias de vigilancia y prevención de enfermedades vectoriales
Las enfermedades transmitidas por vectores constituyen una seria amenaza para la salud pública en Latinoamérica, una región donde factores ambientales, climáticos y sociales crean condiciones propicias para su persistencia y expansión. A desafíos históricos como el control del dengue y la malaria, se suman amenazas emergentes, entre ellas la creciente incidencia del virus de Oropuche, la expansión de la resistencia a insecticidas en diversas especies y la escasa efectividad de los métodos tradicionales de control. Estos cambios exigen una renovación en los enfoques de vigilancia y control, incorporando tecnologías más precisas y estrategias adaptadas a contextos locales. Este simposio ofrece una visión actualizada sobre investigaciones recientes y metodologías innovadoras para enfrentar con mayor eficacia la complejidad del control vectorial en la región.
Challenges for the surveillance and control of Culicoides
Lima, J B P1, Bertazzo, K3, Coelho L A L2, Amorim Q S1, Lemos, P S2, FrutuosoL C V2.
1Instituto Oswaldo Cruz/Fiocruz, Brazil
2Coordenação-Geral de Vigilância de Arboviroses – CGARB, MS, Brazil
3Secretaria de Estado de Saúde do Espírito Santo, Espírito Santo, Brazil.
Oropouche fever (OF) is a febrile syndrome caused by an arbovirus of the species Orthobunyavirus oropoucheense. The primary vector of this arbovirus is the insect species Culicoides paraensis (Ceratopogonidae: Diptera), commonly known as maruim, which thrives in humid or semi-aquatic environments rich in organic matter and is often associated with fruit-bearing plants such as banana, cocoa, and coffee plants. Maruins are widely distributed in Brazil and are easily found in rural, wild, peri-urban, and even urban environments. Several outbreaks of OF have been reported nationwide, but there are currently no recommendations for insecticide use to control Culicoides sp. To evaluate the effectiveness of pyrethroid and neonicotinoid insecticides for controlling adults of C. paraensis. The tests were conducted with samples of C. paraensis collected in the municipality of Alfredo Chaves, ES, between February and May 2025. Collections were conducted during the day using two methods: protected human landing catch and CDC CO2-associated traps. In the laboratory, five pyrethroids (alphacypermethrin, deltamethrin, permethrin, prallethrin, and transfluthrin) and two neonicotinoids (imidacloprid and clothianidin) were tested, all recommended for public health use. The World Health Organization methodologies for bottle bioassays for prallethrin, clothianidin and imidacloprid (at the respective concentrations: 30 µg/mL, 20 µg/mL and 260 µg/mL) and bioassays with tubes and impregnated papers for permethrin and transfluthrin (at concentrations of 0.4% and 0.15%, respectively) were used (WHO, 2022; Kim et al., 2023). A total of 2,769 C. paraensis specimens were used in the bioassays: 1,867 for the bottle tests and 902 for the impregnated paper tests. In the bottle bioassays, all specimens demonstrated susceptibility to insecticides, particularly permethrin, whose tests showed higher mortality (100%) in the shortest exposure time. In the impregnated paper tests, the insects demonstrated complete susceptibility to transfluthrin and partial susceptibility to permethrin, with some specimens recovering hours after exposure. These results represent a significant advance in national policy for the prevention and control of Culicoides and will serve as a basis for more comprehensive studies focused on vector control of C. paraensis.
Keywords: Oropouche, inseticide, Culicoides, Control
Droplet Dynamics in Motion: Science and Precision in Aerial Mosquito Control, A Realistic and Effective Solution in Latin America?
Lizarraga, GS1
1Clarke Mosquito Control
E-mail address: Glizarraga@clarke.com
Understanding droplet dynamics is the key to the next major step in advancing the understanding and evolution of mosquito control. The way droplets behave after being released—their size, speed, trajectory, evaporation rate, and ability to reach a mosquito that is flying, resting, or moving unpredictably—these variables define the effectiveness of aerial applications, both for adult control and, in special cases, for larvae.
Vector control in Latin America increasingly relies on science- and precision-based applications. Environmental factors such as temperature, relative humidity, wind, and application height directly influence droplet survival and effective deposition. Adapting operations to these local variables is essential to achieving effective field control.
Exploring essential aspects of technical knowledge regarding cloud dispersion and parameters associated with droplet size measurements, such as VMD, DV10, and DV90, is crucial. These indicators allow us to characterize how droplets are distributed in an application, but there are other factors to consider.
Understanding these values is vital for control managers to properly select and calibrate equipment, adjust formulations, and evaluate whether the generated spray cloud is effective depending on whether the target is larvae or adults, or whether we are dealing with an urban vector or a nuisance mosquito that also needs control. These concepts should not remain in the laboratory; they must be a basic part of the operational knowledge of anyone involved in mosquito control programs.
Currently, drones are being used for general control, especially for larval control in hard-to-reach areas, scattered water bodies, and some complex urban environments. Unlike traditional aircraft (whose use remains valuable but limited), drones enable more targeted, safer, and flexible interventions. In addition to their use in control efforts, drones offer the possibility of mapping specific areas, and their low logistical impact has facilitated their growing adoption in integrated vector control programs.
Mastering droplet dynamics in motion is the key to transforming aerial mosquito control in Latin America. With technologies like drones, properly calibrated aerial applications, and operational knowledge of common parameters such as VMD, DV10, and DV90, the future of vector control will be based on science applied to the field.
Now, imagine if we had all the resources in the world: are we truly prepared? Can any field technician interpret how a droplet behaves in flight? Are we ready to lead an aerial program if we were asked to start tomorrow?
This talk will not only answer these questions but will also show why understanding droplets will be the first step toward an exploratory view of vector control—precise, effective, and adapted to the challenges of our region.
Keywords: vector control, droplet, dengue, mosquito
Challenges and Strategies in Anopheles Larval Control: Global Overview and the Reality in Amapá, Brazil.
SARAIVA, José Ferreira1, 2, GALARDO, Allan Kardec Ribeiro2
1 Department Natural Sciences, State University of Amapá – UEAP. Macapá, Amapá, Brazil.
2 Department Biodiversity, Institute of Scientific and Technological Research of the State of Amapá – IEPA. Macapá, Amapá, Brazil.
E-mail address: jfsento@gmail.com
Controlling the immature stages of the malaria vector Anopheles is among the greatest challenges in public health, demanding constant innovation amid diverse breeding habitats and rising resistance to conventional methods. Early strategies—drainage and physical elimination of breeding sites—gave way to chemical larvicides, whose initial success waned due to resistance and environmental damage. Biological control with Bacillus thuringiensis israelensis (Bti) offered high specificity and safety, yet its large-scale use has been limited by cost and the need for frequent applications. Biotechnology has since spurred more sustainable options, from insect-growth regulators to cutting-edge genetic control strategies that release CRISPR/Cas9-edited or otherwise modified mosquitoes to suppress local populations. Integrating microbial agents, smart traps, and especially drone-based larvicide delivery has widened the reach and effectiveness of interventions in remote or hard-to-access areas. In the Amazon, the Lourenço gold-mining zone in Amapá exemplifies persistent challenges: ongoing mining generates myriad pools of standing water ideal for vector proliferation. Here, integrated, locally tailored strategies—combined with continuous monitoring and community engagement—are essential for sustainable larval control. Overall, the current landscape underscores the need for innovative solutions that unite technology, scientific insight, and social participation to curb malaria transmission effectively and durably in Amapá and other endemic regions worldwide.
Keywords: public health, gold mining, artificial breeding sites, biotechnology.
Evaluation of transfluthrin space repellent as a complementary malaria control measure in Colombia.
Martha L. Quiñones¹, Daniel Velazco¹, Tania Vivas¹, Carlos Panza²
¹ Department of Public Health, Faculty of Medicine, National University of Colombia
² Department of Statistics, Faculty of Sciences, National University of Colombia
E-mail address: mlquinonesp@unal.edu.co
The main vector control measures for malaria are the use of pyrethroid insecticide-treated mosquito nets (Long lasting insecticidal nets – LLINs) and indoor residual spraying. LLINs are effective when mosquito vectors are most active late at night when people are using mosquito nets. However, malaria vector mosquitoes in Latin America are active in the early evening and even in the afternoon (6 p.m.), biting outside the home when people may be socializing with neighbors or friends, outside the protection provided by mosquito nets. Several studies in Africa have shown promising results in reducing mosquito density when using the space repellent transfluthrin-impregnated jute strips placed outside homes, under chairs, or even in sandals.
This study aimed to determine the effect of volatile transfluthrin impregnated in jute strips and mats on reducing human-vector contact in the peridomicile area of homes in Guapi, Cauca, Colombia.
Mosquitoes were collected in the peridomicile area of homes between 6 p.m. and 10 p.m., both before and after the installation of jute strips and mats impregnated with 0.38% transfluthrin. Five homes were treated by placing transfluthrin-treated strips and mats outside, while the other five acted as controls with untreated strips. After treatment, sampling was carried out for three weeks in one replicate and for 12 weeks in the second.
The following mosquito species were found: malaria vectors Anopheles albimanus (12%) and Anopheles neivai (2%); dengue vectors Aedes aegypti (4.7%) and Aedes albopictus (18.6%); and Culex quinquefasciatus (57%), the latter of which occurred in high densities and caused health nuisances due to their bites. The geometric mean number mosquitoes/person/night found before and after treatment were 2,7 and 0,2 respectively for Anopheles; 4,4 and 0,8 for Aedes, and 5,5 and 1,4 for Culex mosquitoes, in the treated houses. In the control houses, in contrast, the numbers did not show a significant difference before and after treatment of the treated houses.
A reduction of between 80% and 90% was observed for all mosquito species, even up to 13 weeks after the transfluthrin-impregnated bands and mats were installed. The reduction for Anopheles mosquitoes was between 90% and 97%, and for Ae. aegypti and Ae. albopictus, it was between 81% and 83%.
Using bands and mats impregnated with the pyrethroid transfluthrin outside homes in malaria endemic areas can protect against mosquito bites. However, further studies are needed in Latin America before this new tool can be used in control programs, covering larger areas, in different zones and with different vectors.
Keywords: malaria, dengue, spatial repellent, transfluthrin.
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Viernes 24
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