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1.
Acta Trop ; 259: 107376, 2024 Nov.
Article de Anglais | MEDLINE | ID: mdl-39218380

RÉSUMÉ

BACKGROUND: The emergence of insecticide resistance and its spread through populations of malaria vectors has decreased the number of insecticides available for control. Insecticide resistance has been observed in vector populations across sub-Saharan Africa in malaria endemic areas. Therefore, new compounds with different modes of action are needed that can be used in the management of resistance. The current study assessed the bioefficacy of the new indoor residual spray formulation, VECTRON™ T500 against Klypson 500 WG and water against laboratory reared and wild populations of Anopheles gambiae s.l.. The comparative experimental hut trial was implemented between June 2022 and December 2022 to determine the efficacy of VECTRON™ T500, containing the active ingredient (ai) broflanilide as a 50 % wettable powder (WP). The efficacy of VECTRON™ T500 was compared with a positive control, Klypson 500 WG, a wettable granule (WG) formulation that contains 50 % clothianidin. Cement and mud walls were sprayed with VECTRON™ T500, Klypson 500 WG with water sprayed as a negative control. The two insecticides and negative control were evaluated monthly for six months against laboratory and the field-derived An. gambiae s.l. using the standard WHO cone bioassays. Each wall had two cones on each day of testing. VECTRON™ T500 was sprayed on both surface types at a rate of 100mg ai/m2 whilst Klypson 500 WG was applied at a rate of 300 mg ai/m2. For both wall surface types, the vector from the laboratory-reared and the wild populations exhibited a low knockdown effect to both VECTRON™ T500 and Klypson 500 WG. A total of 3,840 mosquitoes were used of which 2,880 (75 %) were susceptible colony of An. gambiae s.s. and 960 (25 %) were wild An. gambiae s.l.. The VECTRON™ T500 induced a mortality of 97.8 %-98.1 % in the laboratory population and 83.2-95.0 % wild population mosquitoes on cement and mud-walled huts respectively while Klypson 500 WG ranged from 89.6-99.0 % for wild and 99.0-99.3 % for the laboratory population mosquitoes on cement and mud walls respectively. The knockdown due to VECTRON™ T500 was 7.08 % in the sixth month, while for Klypson 500 WG was 16.04-17.50 %. The monthly wall cone bioassay mortality with VECTRON™ T500 remained over 80 % for 6 months post-spraying for both laboratory and wild populations. The findings of this study have shown VECTRON™ T500 to have extended efficacy against malaria vector mosquitoes when applied to cement and mud walls. The evaluated new IRS formulation, VECTRON™ T500, performed equally with the positive control, Klypson 500 WG, regarding its impact on vector mortality.


Sujet(s)
Anopheles , Insecticides , Lutte contre les moustiques , Vecteurs moustiques , Animaux , Anopheles/effets des médicaments et des substances chimiques , Insecticides/pharmacologie , Insecticides/administration et posologie , Lutte contre les moustiques/méthodes , Vecteurs moustiques/effets des médicaments et des substances chimiques , Femelle , Paludisme/prévention et contrôle , Paludisme/transmission , Logement , Résistance aux insecticides
2.
Rev Bras Parasitol Vet ; 33(3): e009524, 2024.
Article de Anglais | MEDLINE | ID: mdl-39292068

RÉSUMÉ

An evaluation was made of the larvicidal efficacy of lotilaner (Credeli®) in the treatment of dogs naturally infested with Dermatobia hominis larvae. A total of 12 dogs presenting at least three live D. hominis larvae were medicated. The animals were medicated orally with a single dose of no less than 20 mg/kg lotilaner. After drug administration, the animals remained at their homes, and observations were made to verify the larvicidal effect 6 hours after treatment. Live larvae were considered any parasite that exhibited motility after removal. For each animal was using the formula: 100 x [(total of live larvae before treatment - total live larvae after treatment) /total of live larvae before treatment] as criteria for evaluating lotilaner efficacy. A total of 98 larvae were counted in 12 dogs, with an average of 8.1 larvae per animal. The effectiveness of lotilaner was 80.6%. Nineteen larvae were found alive, albeit presenting hypomobility and lethargic behavior. However, note that the evaluation was performed just six hours after administration of the drug. Lotilaner administered orally in a single dose of 20 mg/kg showed 80.6% efficacy six hours after treating dogs naturally infested with D. hominis.


Sujet(s)
Diptera , Maladies des chiens , Myiases , Animaux , Chiens , Maladies des chiens/traitement médicamenteux , Maladies des chiens/parasitologie , Myiases/médecine vétérinaire , Myiases/traitement médicamenteux , Myiases/diagnostic , Myiases/parasitologie , Diptera/effets des médicaments et des substances chimiques , Larve/effets des médicaments et des substances chimiques , Résultat thérapeutique , Mâle , Femelle , Insecticides/administration et posologie , Oxazoles , Thiophènes
3.
PLoS One ; 19(8): e0308293, 2024.
Article de Anglais | MEDLINE | ID: mdl-39146278

RÉSUMÉ

Treatment of livestock with endectocides such as ivermectin is viewed as a complementary vector control approach to address residual transmission of malaria. However, efficacy of this treatment may vary between animal species. Hence, our purpose was to investigate the effects of ivermectin treatments of common livestock species on life history traits of the opportunistic malaria vector Anopheles coluzzii. Sheep, goats and pigs were treated using injectable veterinary ivermectin formulation at the species-specific doses (recommended dose for all species and high dose in pig). Mosquito batches were exposed to treated and control (not injected) animals at different days after treatment. Daily mosquito mortality was recorded and fecundity assessed through the count of gravid females and the number of eggs they developed. The recommended dose of ivermectin induced a significant decrease in mosquito survival for up to 7 days after injection (DAI), with a decrease of 89.7%, 66.7%, and 48.4% in treated pigs, goats and sheep, respectively, compared to control animals. In treated pigs, the triple therapeutic dose decreased mosquito survival of 68.97% relatively to controls up to 14 DAI. The average number in gravid females Anopheles that survived after feeding on treated animals were reduced when blood-meals were taken on sheep (2.57% and 42.03% at 2 and 7 DAI), or on goats (decrease of the 28.28% and 73.64% respectively at 2 and 7 DAI). This study shows that ivermectin treatments to animals negatively impacts An. coluzzii life history traits and could reduce vector densities in areas where livestock live near humans. However, due to short-term efficacy of single dose treatments, repeated treatments and potentially increased dosages would be required to span the transmission season. The use of long-acting ivermectin formulations is discussed as a mean for extending efficacy while remaining cost effective.


Sujet(s)
Anopheles , Ivermectine , Paludisme , Vecteurs moustiques , Animaux , Ivermectine/pharmacologie , Ivermectine/administration et posologie , Anopheles/effets des médicaments et des substances chimiques , Anopheles/physiologie , Femelle , Vecteurs moustiques/effets des médicaments et des substances chimiques , Vecteurs moustiques/physiologie , Paludisme/transmission , Paludisme/prévention et contrôle , Ovis , Suidae , Bétail , Capra , Insecticides/pharmacologie , Insecticides/administration et posologie , Lutte contre les moustiques/méthodes
4.
Malar J ; 23(1): 252, 2024 Aug 23.
Article de Anglais | MEDLINE | ID: mdl-39175014

RÉSUMÉ

BACKGROUND: Indoor residual spraying (IRS) is one of the most effective malaria control tools. However, its application has become limited to specific contexts due to the increased costs of IRS products and implementation programmes. Selective spraying-selective spray targeted to particular areas/surfaces of dwellings-has been proposed to maintain the malaria control and resistance-management benefits of IRS while decreasing the costs of the intervention. METHODS: A literature search was conducted to find (1) studies that assessed the resting behaviour of Anopheles mosquitoes and (2) studies that evaluated the impact of selective spraying on entomological and malaria outcomes. Additional articles were identified through hand searches of all references cited in articles identified through the initial search. A cost model was developed from PMI VectorLink IRS country programmes, and comparative cost analysis reports to describe the overall cost benefits of selective IRS. RESULTS: In some studies, there appeared to be a clear resting preference for certain Anopheles species in terms of the height at which they rested. However, for other species, and particularly the major African malaria vectors, a clear resting pattern was not detected. Furthermore, resting behaviour was not measured in a standardized way. For the selective spray studies that were assessed, there was a wide range of spray configurations, which complicates the comparison of methods. Many of these spray techniques were effective and resulted in reported 25-68% cost savings and reduced use of insecticide. The reported cost savings in the literature do not always consider all of the IRS implementation costs. Using the IRS cost model, these savings ranged from 17 to 29% for programs that targeted Anopheles spp. and 18-41% for programmes that targeted Aedes aegypti. CONCLUSIONS: Resting behaviour is generally measured in a simplistic way; noting the resting spot of mosquitoes in the morning. This is likely an oversimplification, and there is a need for better monitoring of resting mosquitoes. This may improve the target surface for selective spray techniques, which could reduce the cost of IRS while maintaining its effectiveness. Reporting of cost savings should be calculated considering the entire implementation costs, and a cost model was provided for future calculations.


Sujet(s)
Anopheles , Insecticides , Paludisme , Lutte contre les moustiques , Lutte contre les moustiques/méthodes , Lutte contre les moustiques/économie , Animaux , Paludisme/prévention et contrôle , Anopheles/effets des médicaments et des substances chimiques , Anopheles/physiologie , Insecticides/administration et posologie , Insecticides/économie , Humains , Vecteurs moustiques/effets des médicaments et des substances chimiques
5.
Res Vet Sci ; 179: 105397, 2024 Nov.
Article de Anglais | MEDLINE | ID: mdl-39216347

RÉSUMÉ

The effectiveness of a visceral leishmaniasis (VL) control strategy based on the application of 4 % deltamethrin impregnated collars (DIC) exclusively in seropositive dogs was assessed between 2018 and 2019, through a prospective study. The effectiveness of DIC-collaring was evaluated by comparing the incidence rate of anti-leishmanial antibodies among dogs from two endemic districts in Brazil. In one of the areas, the conventional control measure which is based on the non-compulsory euthanasia of LV seropositive dogs, was practiced by the official healthy service as a regular procedure, whereas strategic collaring, conceived in this study, was carried out in the other. Results of serological tests applied to serum samples collected from all domiciled dogs were evaluated in three consecutive times, spaced by around 200 days. Incidence rates of VL seroreactivity were compared between districts in the same period of time as well as within the same district, in consecutive periods. Based on the results, the risk of infection in the population under conventional control measure was up to four times higher than the risk of infection where DIC-collaring was used. The strategic use of collar proposed here emerged as a promising measure for VL control in dogs from endemic areas. Strategic collaring does not rely on the euthanasia of infected animals, an extremely controversial procedure, and instead of being used in all dogs, as collaring is normally recommended; only seropositive dogs are intervened. Strategic use of DIC has the potential to drastically reduce costs, if compared to mass collaring canine population.


Sujet(s)
Maladies des chiens , Insecticides , Leishmaniose viscérale , Nitriles , Pyréthrines , Animaux , Chiens , Leishmaniose viscérale/médecine vétérinaire , Leishmaniose viscérale/prévention et contrôle , Leishmaniose viscérale/épidémiologie , Pyréthrines/administration et posologie , Pyréthrines/pharmacologie , Maladies des chiens/prévention et contrôle , Maladies des chiens/épidémiologie , Maladies des chiens/parasitologie , Nitriles/administration et posologie , Nitriles/pharmacologie , Brésil/épidémiologie , Insecticides/administration et posologie , Incidence , Études prospectives , Anticorps antiprotozoaires/sang , Mâle , Femelle
6.
Vet Parasitol Reg Stud Reports ; 53: 101076, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-39025552

RÉSUMÉ

Furuncular myiasis due to Dermatobia hominis is the second most common skin diseases in dogs that live in tropical climates in Central and South America, causing discomfort and injuring in the connective tissue of the affected dog. Therefore, the objective of the study was to evaluate the effectiveness of Afoxolaner (Nexgard®) in the treatment of canine furuncular myiasis. Twenty-five dogs naturally infested with D. hominis were selected and received a single oral dose of 2.5 mg/kg body weight of Afoxolaner (NexGard®). Larval infestations were classified as light (< 2 larvae), moderate (2 to 5 larvae) and severe (> 5 larvae), according to the number of larvae found in the wound. Twenty-four hours post-treatment, infested lesions were inspected, and all larvae were mechanically removed from the lesion site. All removed larvae were identified as D. hominis larvae and were found dead within 24 h after treatment, demonstrating 100% larvicidal efficacy of Afoxolaner against D. hominis larvae.


Sujet(s)
Diptera , Maladies des chiens , Larve , Myiases , Naphtalènes , Animaux , Myiases/médecine vétérinaire , Myiases/traitement médicamenteux , Myiases/parasitologie , Chiens , Diptera/effets des médicaments et des substances chimiques , Maladies des chiens/traitement médicamenteux , Maladies des chiens/parasitologie , Larve/effets des médicaments et des substances chimiques , Naphtalènes/usage thérapeutique , Naphtalènes/administration et posologie , Naphtalènes/pharmacologie , Mâle , Femelle , Isoxazoles/administration et posologie , Isoxazoles/usage thérapeutique , Insecticides/usage thérapeutique , Insecticides/administration et posologie , Insecticides/pharmacologie , Résultat thérapeutique
8.
Parasit Vectors ; 17(1): 254, 2024 Jun 11.
Article de Anglais | MEDLINE | ID: mdl-38863023

RÉSUMÉ

BACKGROUND: Aedes aegypti is the primary mosquito vector for several arboviruses, such as dengue, chikungunya and Zika viruses, which cause frequent outbreaks of human disease in tropical and subtropical regions. Control of these outbreaks relies on vector control, commonly in the form of insecticide sprays that target adult female mosquitoes. However, the spatial coverage and frequency of sprays needed to optimize effectiveness are unclear. In this study, we characterize the effect of ultra-low-volume (ULV) indoor spraying of pyrethroid insecticides on Ae. aegypti abundance within households. We also evaluate the effects of spray events during recent time periods or in neighboring households. Improved understanding of the duration and distance of the impact of a spray intervention on Ae. aegypti populations can inform vector control interventions, in addition to modeling efforts that contrast vector control strategies. METHODS: This project analyzes data from two large-scale experiments that involved six cycles of indoor pyrethroid spray applications in 2 years in the Amazonian city of Iquitos, Peru. We developed spatial multi-level models to disentangle the reduction in Ae. aegypti abundance that resulted from (i) recent ULV treatment within households and (ii) ULV treatment of adjacent or nearby households. We compared fits of models across a range of candidate weighting schemes for the spray effect, based on different temporal and spatial decay functions to understand lagged ULV effects. RESULTS: Our results suggested that the reduction of Ae. aegypti in a household was mainly due to spray events occurring within the same household, with no additional effect of sprays that occurred in neighboring households. Effectiveness of a spray intervention should be measured based on time since the most recent spray event, as we found no cumulative effect of sequential sprays. Based on our model, we estimated the spray effect is reduced by 50% approximately 28 days after the spray event. CONCLUSIONS: The reduction of Ae. aegypti in a household was mainly determined by the number of days since the last spray intervention in that same household, highlighting the importance of spray coverage in high-risk areas with a spray frequency determined by local viral transmission dynamics.


Sujet(s)
Aedes , Caractéristiques familiales , Insecticides , Lutte contre les moustiques , Vecteurs moustiques , Pyréthrines , Analyse spatio-temporelle , Animaux , Aedes/effets des médicaments et des substances chimiques , Insecticides/pharmacologie , Insecticides/administration et posologie , Lutte contre les moustiques/méthodes , Vecteurs moustiques/effets des médicaments et des substances chimiques , Pyréthrines/pharmacologie , Femelle , Pérou , Humains , Densité de population , Dengue/prévention et contrôle , Dengue/transmission
9.
Parasit Vectors ; 17(1): 274, 2024 Jun 27.
Article de Anglais | MEDLINE | ID: mdl-38937791

RÉSUMÉ

BACKGROUND: Indoor residual spraying (IRS) has been implemented to prevent malaria in Zambia for several decades, but its effectiveness has not been evaluated long term and in Vubwi District yet. This study aimed to assess the association between IRS and the malaria burden in Zambia and Vubwi District and to explore the factors associated with refusing IRS. METHODS: A retrospective study was used to analyze the association between IRS and malaria incidence in Zambia in 2001-2020 and in Vubwi District in 2014-2020 by Spearman correlation analysis. A case-control study was used to explore the factors associated with IRS refusals by households in Vubwi District in 2021. A logistic regression model was performed to identify factors associated with IRS refusals. RESULTS: The malaria incidence reached its peak (391/1000) in 2001 and dropped to the lowest (154/1000) in 2019. The annual percentage change in 2001-2003, 2003-2008, 2008-2014, 2014-2018 and 2018-2020 was - 6.54%, - 13.24%, 5.04%, - 10.28% and 18.61%, respectively. A significantly negative correlation between the percentage of population protected by the IRS against the total population in Zambia (coverage) and the average malaria incidence in the whole population was observed in 2005-2020 (r = - 0.685, P = 0.003) and 2005-2019 (r = - 0.818, P < 0.001). Among 264 participants (59 in the refuser group and 205 in the acceptor group), participants with specific occupations (self-employed: OR 0.089, 95% CI 0.022-0.364; gold panning: OR 0.113, 95% CI 0.022-0.574; housewives: OR 0.129, 95% CI 0.026-0.628 and farmers: OR 0.135, 95% CI 0.030-0.608 compared to employees) and no malaria case among household members (OR 0.167; 95% CI 0.071-0.394) had a lower risk of refusing IRS implementation, while those with a secondary education level (OR 3.690, 95% CI 1.245-10.989) had a higher risk of refusing IRS implementation compared to those who had never been to school. CONCLUSIONS: Increasing coverage with IRS was associated with decreasing incidence of malaria in Zambia, though this was not observed in Vubwi District, possibly because of the special geographical location of Vubwi District. Interpersonal communication and targeted health education should be implemented at full scale to ensure household awareness and gain community trust.


Sujet(s)
Insecticides , Paludisme , Lutte contre les moustiques , Zambie/épidémiologie , Humains , Études cas-témoins , Paludisme/épidémiologie , Paludisme/prévention et contrôle , Paludisme/transmission , Lutte contre les moustiques/méthodes , Incidence , Études rétrospectives , Insecticides/administration et posologie , Femelle , Mâle , Animaux , Adulte , Enfant d'âge préscolaire , Enfant , Adolescent
10.
Parasit Vectors ; 17(1): 208, 2024 May 08.
Article de Anglais | MEDLINE | ID: mdl-38720313

RÉSUMÉ

BACKGROUND: Triatoma infestans, Triatoma brasiliensis, Triatoma pseudomaculata and Rhodnius prolixus are vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Chickens serve as an important blood food source for triatomines. This study aimed to assess the insecticidal activity of fluralaner (Exzolt®) administered to chickens against triatomines (R. prolixus, T. infestans, T. brasiliensis and T. pseudomaculata). METHODS: Twelve non-breed chickens (Gallus gallus domesticus) were randomized based on weight into three groups: negative control (n = 4); a single dose of 0.5 mg/kg fluralaner (Exzolt®) (n = 4); two doses of 0.5 mg/kg fluralaner (Exzolt®) (n = 4). Nymphs of 3rd, 4th and 5th instars of R. prolixus, T. infestans, T. brasiliensis and T. pseudomaculata (all n = 10) were allowed to feed on chickens before treatment, and at intervals of 1, 7, 14, 21, 28, 35 and 56 days after treatment, with insect mortality determined. RESULTS: Treatment with two doses of fluralaner showed higher insecticidal efficacy against R. prolixus, T. infestans and T. brasiliensis compared to the single-dose treatment. Similar insecticidal efficacy was observed for T. pseudomaculata for one and two doses of fluralaner. Insecticidal activity of fluralaner (Exzolt®) against triatomine bugs was noted up to 21 and 28 days after treatment with one and two doses of fluralaner, respectively. CONCLUSIONS: The results demonstrate that treatment of chickens with fluralaner (Exzolt®) induces insecticidal activity against triatomines for up to 28 days post-treatment, suggesting its potential use as a control strategy for Chagas disease in endemic areas.


Sujet(s)
Poulets , Insecticides , Isoxazoles , Animaux , Poulets/parasitologie , Isoxazoles/pharmacologie , Isoxazoles/administration et posologie , Insecticides/pharmacologie , Insecticides/administration et posologie , Vecteurs insectes/effets des médicaments et des substances chimiques , Maladie de Chagas/transmission , Maladie de Chagas/traitement médicamenteux , Maladie de Chagas/médecine vétérinaire , Triatominae , Nymphe/effets des médicaments et des substances chimiques , Maladies de la volaille/parasitologie , Maladies de la volaille/prévention et contrôle , Triatoma/effets des médicaments et des substances chimiques
11.
BMC Ecol Evol ; 24(1): 60, 2024 May 11.
Article de Anglais | MEDLINE | ID: mdl-38734594

RÉSUMÉ

BACKGROUND: Foraging behavior in insects is optimised for locating scattered resources in a complex environment. This behavior can be exploited for use in pest control. Inhibition of feeding can protect crops whereas stimulation can increase the uptake of insecticides. For example, the success of a bait spray, depends on either contact or ingestion, and thus on the insect finding it. METHODS: To develop an effective bait spray against the invasive pest, Drosophila suzukii, we investigated aspects of foraging behavior that influence the likelihood that the pest interacts with the baits, in summer and winter morphotypes. We video-recorded the flies' approach behavior towards four stimuli in a two-choice experiment on strawberry leaflets. To determine the most effective bait positioning, we also assessed where on plants the pest naturally forages, using a potted raspberry plant under natural environmental conditions. We also studied starvation resistance at 20 °C and 12 °C for both morphs. RESULTS: We found that summer morph flies spent similar time on all baits (agar, combi-protec, yeast) whereas winter morphs spent more time on yeast than the other baits. Both morphs showed a preference to feed at the top of our plant's canopy. Colder temperatures enhanced survival under starvation conditions in both morphs, and mortality was reduced by food treatment. CONCLUSIONS: These findings on feeding behavior support informed decisions on the type and placement of a bait to increase pest control.


Sujet(s)
Drosophila , Comportement alimentaire , Lutte contre les insectes , Animaux , Drosophila/physiologie , Lutte contre les insectes/méthodes , Comportement alimentaire/physiologie , Insecticides/pharmacologie , Insecticides/administration et posologie , Rubus , Fragaria , Femelle , Saisons
12.
J Econ Entomol ; 117(4): 1628-1635, 2024 Aug 12.
Article de Anglais | MEDLINE | ID: mdl-38753642

RÉSUMÉ

The western drywood termite, Incisitermes minor (Hagen), causes significant economic damage to wood structures in the United States of America, especially California. When infestation is not widespread, localized insecticide injections may be useful for remedial control. However, the extensive gallery structure of drywood termites and their tendency to aggregate at specific parts of the galleries can impact the efficacy of localized insecticide injection. Chemicals that attract termites from a distance may improve the localized insecticide injection by increasing the number of termites contacting the insecticide residues. Two volatile terpenes, α-pinene and ß-pinene, commonly found in many coniferous timber trees, were applied to artificial termite galleries to determine if termites were attracted from their original aggregation site. Furthermore, we examined if adding these pinenes would improve the overall efficacy of some insecticide products for drywood termite control. Behavioral assay results showed that the treatment with pinenes increased the likelihood that drywood termites would leave their original aggregation site and contact the treated part of the gallery. When tested with the pesticide products applied in a small area away from the termite aggregation, ß-pinene significantly accelerated the time course of mortality for the aqueous fipronil. The efficacy of disodium octaborate tetrahydrate dust was not influenced by the addition of pinenes. Implications for drywood termite management and future research directions are discussed.


Sujet(s)
Monoterpènes bicycliques , Lutte contre les insectes , Insecticides , Isoptera , Animaux , Insecticides/administration et posologie , Composés bicycliques pontés/administration et posologie , Monoterpènes/administration et posologie
13.
Plant Dis ; 108(9): 2750-2759, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-38654535

RÉSUMÉ

One strategy to reduce huanglongbing (HLB) is controlling its insect vector, the Asian citrus psyllid (ACP) Diaphorina citri, by preventive insecticide sprays. The recommendation is to spray insecticide in all rows (conventional spray [CONV]), but some growers empirically spray in alternate rows (ALT) to increase the spray frequency without increasing the operating cost. Therefore, this work compared the effect of ALT with CONV on the ACP population and HLB incidence. The spray deposition (amount of metallic copper per leaf area), coverage (percentage of water-sensitive paper area covered by spray), and efficacy (ACP mortality) of each treatment were also evaluated on both sides of the trees. Two field trials were performed: Trial #1 compared ALT every 7 days (ALT7) with CONV every 14 days (CONV14), and trial #2 compared different spray frequencies of ALT with CONV every 7 days (CONV7). In trial #1, no differences were observed in the ACP population or HLB progress between ALT7 and CONV14 after 5 years. In trial #2, ALT7 presented the highest percentage of ACP and cumulative HLB incidence than CONV7 and ALT every 3 to 4 days, after 2 years. Hence, when the frequency of ALT was half the frequency of CONV, similar results were observed. Spray deposition, coverage, and efficacy were similar between tree sides in CONV, but they were uneven in ALT, resulting in higher values on the tree side that directly received the spray. Insecticide spray should be performed with the frequency enough to keep new shoots protected during their growth.


Sujet(s)
Citrus sinensis , Hemiptera , Insecticides , Maladies des plantes , Animaux , Insecticides/pharmacologie , Insecticides/administration et posologie , Hemiptera/effets des médicaments et des substances chimiques , Maladies des plantes/prévention et contrôle , Maladies des plantes/microbiologie , Lutte contre les insectes/méthodes , Citrus/microbiologie
14.
Parasit Vectors ; 17(1): 197, 2024 Apr 29.
Article de Anglais | MEDLINE | ID: mdl-38685048

RÉSUMÉ

BACKGROUND: Tungiasis is a neglected tropical disease caused by the adult female sand flea (Tunga penetrans). Dogs are considered important reservoirs of T. penetrans in Brazil. The aim of this study was to determine the monthly insecticidal efficacy of a single oral administration of fluralaner at a dose of 10-18 mg/kg (Bravecto® 1-Month, also registered as Defenza® in some countries; MSD Animal Health) in dogs naturally infested with T. penetrans. METHODS: This clinical trial was conducted in a rural community located in Ilhéus, Bahia, Brazil. A total of 64 dogs were selected and distributed in a completely randomized design between a treated group (TG) that received one single dose of Bravecto® 1-Month (Defenza®) and a negative control group (CG) that received no treatment. Each group was composed of 32 dogs. The evaluations took place on days 0, 7 ± 2, 14 ± 2, 21 ± 2, 28 ± 2, 35 ± 2, and 42 ± 2 post treatment, in which the dogs were inspected to evaluate the infestation stage and classify lesions associated with tungiasis. The primary efficacy was determined from the percentage of treated dogs free of fleas (stage II and III lesions) after administration of the formulation at each evaluation time. Secondary efficacy was based on the number of active lesions (stages II and III) in each group at each evaluation time. The clinical condition of the animals was defined based on the Severity Score for Acute Dog Tungiasis (SCADT), which is related to the number and severity of lesions. RESULTS: The primary efficacy of the product was greater than 95.0% from days 7 to 21 and reached 100.0% between days 28 and 42, with a significant association between treatment and infestation decline (P < 0.025) between days 7 and 42. Secondary drug efficacy was greater than 99.9% from days 7 to 21, reaching 100.0% between days 28 and 42 (P < 0.05). The treated dogs also scored lower on the SCADT than the control animals did during the entire clinical evaluation period (P < 0.05). CONCLUSIONS: A single administration of Bravecto® 1-Month (Defenza®) was effective in eliminating Tunga penetrans infestations, as well as in preventing parasitism for at least 42 days after treatment.


Sujet(s)
Maladies des chiens , Insecticides , Isoxazoles , Tunga , Tungose , Animaux , Chiens , Brésil , Isoxazoles/administration et posologie , Isoxazoles/usage thérapeutique , Maladies des chiens/traitement médicamenteux , Maladies des chiens/parasitologie , Femelle , Insecticides/administration et posologie , Insecticides/usage thérapeutique , Tunga/effets des médicaments et des substances chimiques , Tungose/traitement médicamenteux , Tungose/médecine vétérinaire , Tungose/parasitologie , Administration par voie orale , Mâle , Méthode en double aveugle , Résultat thérapeutique
15.
Am J Trop Med Hyg ; 110(4_Suppl): 94-100, 2024 04 02.
Article de Anglais | MEDLINE | ID: mdl-38118168

RÉSUMÉ

In the final stages of malaria elimination, interventions to reduce malaria transmission are often centered around a confirmed case of malaria, as cases tend to cluster together at very low levels of transmission. The WHO commissioned a systematic review of the literature and synthesis of evidence for reactive indoor residual spraying (IRS) to develop official recommendations for countries. Several electronic databases were searched in November 2020. A total of 455 records were identified and screened; 20 full-text articles were assessed for eligibility. Two cluster-randomized trials met the inclusion criteria for epidemiological outcomes. Risk of bias was assessed using standard criteria. Because one study was a superiority trial in which the comparator included reactive case detection or mass drug administration and the other was a noninferiority trial in which the comparator was proactive, focal IRS, results could not be pooled. In the superiority trial, reactive IRS reduced malaria prevalence by 68% (risk ratio [RR]: 0.32; 95% CI: 0.13-0.80; certainty of evidence: HIGH) compared with no reactive IRS. No difference was observed for clinical malaria (RR: 0.65; 95% CI: 0.38-1.11; certainty of evidence: MODERATE). In the noninferiority study, the mean difference in incidence between reactive IRS and proactive IRS was 0.10 additional case per 1,000 person-years, which was within the prespecified noninferiority bound (95% CI: -0.38 to 0.58; certainty of evidence: MODERATE). The evidence indicates that reactive IRS may be a cost-effective tool for the prevention of malaria in elimination settings. As only two cluster-randomized controlled trials from sub-Saharan Africa were found, additional high-quality studies should be encouraged.


Sujet(s)
Insecticides , Paludisme , Lutte contre les moustiques , Humains , Lutte contre les moustiques/méthodes , Insecticides/administration et posologie , Paludisme/prévention et contrôle , Paludisme/transmission , Paludisme/épidémiologie , Animaux , Essais contrôlés randomisés comme sujet
16.
Pestic Biochem Physiol ; 191: 105363, 2023 Apr.
Article de Anglais | MEDLINE | ID: mdl-36963934

RÉSUMÉ

Spodoptera frugiperda is an economically important agricultural pest and poses a serious threat to food security globally. Its management is gravely challenged by its high polyphagous nature, strong migratory ability, and massive fecundity. Chlorantraniliprole (CHL) is widely utilized in controlling S. frugiperda, its intensive application and over-reliance pose adverse health risks, development of resistance, toxicity to beneficial insects, natural enemies, and environmental contamination. To address S. frugiperda resistance to CHL and its inherent challenges, this study explores the synergistic effects of camptothecin (CPT) with CHL in its management. The binary mixed adversely induced the larvae weight and mortality when compared to single-treated. CHL + CPT (1:20 mg/L) had the highest larvae mortality of (73.80 %) with a high antagonistic factor (0.90), while (1:10 mg/L) with (66.10%) mortality exhibited a high synergistic factor (1.43). Further, CHL + CPT (1:10 mg/L) considerably altered the midgut epithelial cell, peritrophic membrane, microvilli, basement membrane, and regenerative cells. For biochemical analysis, CHL + CPT (1:10 mg/L) significantly decreased glutathione-S-transferase (1-chloro-2,4-dinitrobenzene CDNB) and cytochrome P450 (7-ethoxycoumarin O-deethylation) activities in the midgut in a dose and time dependent manner. Based on RNA-Seq analysis, a total of 4,373 differentially expressed genes (DEGs) were identified from the three treatments. CPT vs CK (Control) had 1694 (968 up-, 726 down-regulated), CHL vs CK with 1771 (978 up-, 793 down-regulated), and CHL + CPT vs CK had 908 (394 up-, 514 down-regulated) DEGs. The enrichment analysis disclosed significant pathways such as metabolism of xenobiotics by cytochrome P450, glutathione metabolism, TOLL and IMD (Immune Deficiency) signaling pathway, longevity regulating pathway. This study provides basis to expatiate on the molecular toxicological mechanism of CHL + CPT in management of fall armyworm.


Sujet(s)
Camptothécine , Insecticides , Larve , Spodoptera , Synergie des médicaments , Spodoptera/anatomie et histologie , Spodoptera/effets des médicaments et des substances chimiques , Spodoptera/croissance et développement , Spodoptera/physiologie , Camptothécine/administration et posologie , Camptothécine/pharmacologie , Camptothécine/toxicité , Larve/anatomie et histologie , Larve/effets des médicaments et des substances chimiques , Sécurité alimentaire , Insecticides/administration et posologie , Insecticides/pharmacologie , Insecticides/toxicité , Animaux , Métabolisme secondaire , Poids/effets des médicaments et des substances chimiques , Glutathione transferase/métabolisme , Cytochrome P-450 enzyme system/métabolisme , Inhibiteurs des enzymes du cytochrome P-450/administration et posologie , Inhibiteurs des enzymes du cytochrome P-450/pharmacologie , Inhibiteurs des enzymes du cytochrome P-450/toxicité , Analyse de profil d'expression de gènes , Gene Ontology , RNA-Seq , Reproductibilité des résultats
17.
Actas dermo-sifiliogr. (Ed. impr.) ; 114(2): 132-140, feb. 2023. ilus, tab
Article de Espagnol | IBECS | ID: ibc-215418

RÉSUMÉ

La escabiosis es una de las enfermedades transmisibles más prevalentes en el mundo, actualmente en auge en nuestro entorno. Existen diferentes causas que explican la problemática de esta epidemia: una incorrecta aplicación o pauta del tratamiento; la disminución de la sensibilidad o la resistencia al tratamiento tópico y las carencias en el conocimiento del parásito y su transmisibilidad. Por este motivo es necesario un nuevo enfoque en el tratamiento de esta enfermedad que contemple los problemas y la evidencia actual. Si hay una persistencia de la clínica tras un correcto tratamiento es importante corroborar el fracaso terapéutico y estandarizar la actitud. Por último, ante un caso recalcitrante cabría plantear la posibilidad de priorizar el tratamiento oral, aumentar su dosis, realizar tratamientos combinados o plantear su uso fuera de ficha técnica en poblaciones especiales. La aparición de nuevos tratamientos, como el spinosad o, sobre todo, la moxidectina, aportan esperanza en el control de esta enfermedad (AU)


Scabies, which is among the most prevalent diseases worldwide, is becoming more frequent in Spain. The problems of this epidemic can be explained by several factors: improper application or prescription of treatments, resistance or reduced sensitivity to topical treatments, and poor understanding of the parasite and contagion. We require a new evidence-based approach to therapy that takes these problems into consideration. If symptoms persist after proper treatment, it is important to identify the reason for failure and standardize our approach. In refractory cases, the prescriber should prioritize oral medication, indicate a higher dose, combine treatments, or evaluate the use of off-label treatments in certain populations. The availability of new medications —such as spinosad or, especially, moxidectin— offer hope for bringing this disease under control (AU)


Sujet(s)
Humains , Animaux , Antiparasitaires/administration et posologie , Insecticides/administration et posologie , Gale/diagnostic , Gale/traitement médicamenteux , Administration par voie orale , Administration par voie topique , Ivermectine/administration et posologie , Perméthrine/administration et posologie , Gale/épidémiologie , Épidémies
18.
Actas dermo-sifiliogr. (Ed. impr.) ; 114(2): t132-t140, feb. 2023. ilus, tab
Article de Anglais | IBECS | ID: ibc-215419

RÉSUMÉ

Scabies, which is among the most prevalent diseases worldwide, is becoming more frequent in Spain. The problems of this epidemic can be explained by several factors: improper application or prescription of treatments, resistance or reduced sensitivity to topical treatments, and poor understanding of the parasite and contagion. We require a new evidence-based approach to therapy that takes these problems into consideration. If symptoms persist after proper treatment, it is important to identify the reason for failure and standardize our approach. In refractory cases, the prescriber should prioritize oral medication, indicate a higher dose, combine treatments, or evaluate the use of off-label treatments in certain populations. The availability of new medications —such as spinosad or, especially, moxidectin— offer hope for bringing this disease under control (AU)


La escabiosis es una de las enfermedades transmisibles más prevalentes en el mundo, actualmente en auge en nuestro entorno. Existen diferentes causas que explican la problemática de esta epidemia: una incorrecta aplicación o pauta del tratamiento; la disminución de la sensibilidad o la resistencia al tratamiento tópico y las carencias en el conocimiento del parásito y su transmisibilidad. Por este motivo es necesario un nuevo enfoque en el tratamiento de esta enfermedad que contemple los problemas y la evidencia actual. Si hay una persistencia de la clínica tras un correcto tratamiento es importante corroborar el fracaso terapéutico y estandarizar la actitud. Por último, ante un caso recalcitrante cabría plantear la posibilidad de priorizar el tratamiento oral, aumentar su dosis, realizar tratamientos combinados o plantear su uso fuera de ficha técnica en poblaciones especiales. La aparición de nuevos tratamientos, como el spinosad o, sobre todo, la moxidectina, aportan esperanza en el control de esta enfermedad (AU)


Sujet(s)
Humains , Animaux , Antiparasitaires/administration et posologie , Insecticides/administration et posologie , Gale/diagnostic , Gale/traitement médicamenteux , Administration par voie orale , Administration par voie topique , Ivermectine/administration et posologie , Perméthrine/administration et posologie , Gale/épidémiologie , Épidémies
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