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Pereira LC, Pereira NDS, Barbosa da Silva AN, Bezerra CDF, Sousa KMD, Fagundes Neto JC, Sampaio GHF, Brito CRDN, Souza RDCM, Galvão LMDC, Câmara ACJD, Nascimento MSL, Guedes PMM. Insecticidal activity of fluralaner (Exzolt ®) administered to Gallus gallus domesticus against triatomines (Hemiptera, Reduviidae, Triatominae). Parasit Vectors 2024; 17:208. [PMID: 38720313 PMCID: PMC11080163 DOI: 10.1186/s13071-024-06276-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 04/09/2024] [Indexed: 05/12/2024] Open
Abstract
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.
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Affiliation(s)
| | - Nathalie de Sena Pereira
- Graduate Program in Biological and Health Sciences, Federal University of Vale do São Francisco, Petrolina, Brazil
| | | | | | - Kivia Millana de Sousa
- Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | | | | | | | - Lúcia Maria da Cunha Galvão
- Graduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | | | - Paulo Marcos Matta Guedes
- Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Brazil.
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Busselman RE, Curtis-Robles R, Meyers AC, Zecca IB, Auckland LD, Hodo CL, Christopher D, Saunders AB, Hamer SA. Abundant triatomines in Texas dog kennel environments: Triatomine collections, infection with Trypanosoma cruzi, and blood feeding hosts. Acta Trop 2024; 250:107087. [PMID: 38061614 DOI: 10.1016/j.actatropica.2023.107087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/26/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023]
Abstract
Triatomine insects are vectors of the protozoan parasite Trypanosoma cruzi- the causative agent of Chagas disease. Chagas disease is endemic to Latin America and the southern United States and can cause severe cardiac damage in infected mammals, ranging from chronic disease to sudden death. Identifying interactions among triatomines, T. cruzi discrete typing units (DTUs), and blood feeding hosts is necessary to understand parasite transmission dynamics and effectively protect animal and human health. Through manual insect trapping efforts, kennel staff collections, and with the help of a trained scent detection dog, we collected triatomines from 10 multi-dog kennels across central and south Texas over a one-year period (2018-2019) and tested a subset to determine their T. cruzi infection status and identify the primary bloodmeal hosts. We collected 550 triatomines, including Triatoma gerstaeckeri (n = 515), Triatoma lecticularia (n = 15), Triatoma sanguisuga (n = 6), and Triatoma indictiva (n = 2), with an additional 10 nymphs and 2 adults unable to be identified to species. The trained dog collected 42 triatomines, including nymphs, from areas not previously considered vector habitat by the kennel owners. Using qPCR, we found a T. cruzi infection prevalence of 47 % (74/157), with T. lecticularia individuals more likely to be infected with T. cruzi than other species. Infected insects harbored two T. cruzi discrete typing units: TcI (64 %), TcIV (23 %), and mixed TcI/TcIV infections (13 %). Bloodmeal host identification was successful in 50/149 triatomines, revealing the majority (74 %) fed on a dog (Canis lupus), with other host species including humans (Homo sapiens), raccoons (Procyon lotor), chickens (Gallus gallus), wild pig (Sus scrofa), black vulture (Coragyps atratus), cat (Felis catus), and curve-billed thrasher (Toxostoma curviostre). Given the frequency of interactions between dogs and infected triatomines in these kennel environments, dogs may be an apt target for future vector control and T. cruzi intervention efforts.
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Affiliation(s)
- R E Busselman
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - R Curtis-Robles
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - A C Meyers
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - I B Zecca
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - L D Auckland
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - C L Hodo
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States; Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX, United States
| | | | - A B Saunders
- Department of Small Animal Clinical Sciences, Texas A&M University, College Station, TX, United States
| | - S A Hamer
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States.
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Fiatsonu E, Deka A, Ndeffo-Mbah ML. Effectiveness of Systemic Insecticide Dog Treatment for the Control of Chagas Disease in the Tropics. BIOLOGY 2023; 12:1235. [PMID: 37759635 PMCID: PMC10525078 DOI: 10.3390/biology12091235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023]
Abstract
Chagas disease, caused by Trypanosoma cruzi and transmitted by triatomines, can lead to severe cardiac issues and mortality in many mammals. Recent studies have shown that systemic insecticide treatment of dogs is highly effective in killing triatomines. Here, we assessed the impact of dog treatment on T. cruzi transmission. We developed a mathematical model of T. cruzi transmission among triatomines, dogs, humans, and rodents. We used the model to evaluate the impact of dog treatment regimens on T. cruzi transmission dynamics to determine their effectiveness in reducing T. cruzi infection among hosts. We show that a 3-month treatment regimen may reduce T. cruzi incidence among humans by 59-80% in a high transmission setting, and 26-82% in a low transmission setting. An annual treatment may reduce incidence among humans by 49-74% in a high transmission setting, and by 11-76% in a low transmission setting. However, dog treatment may substantially increase T. cruzi prevalence among dogs if dog consumption of dead triatomines increases. Our model indicates that dog treatment may reduce T. cruzi infections among humans, but it may increase infections in dogs. Therefore, a holistic approach targeting different hosts is necessary for Chagas elimination.
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Affiliation(s)
- Edem Fiatsonu
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77845, USA; (A.D.); (M.L.N.-M.)
| | - Aniruddha Deka
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77845, USA; (A.D.); (M.L.N.-M.)
| | - Martial L. Ndeffo-Mbah
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77845, USA; (A.D.); (M.L.N.-M.)
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, TX 77845, USA
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Durden C, Tian Y, Knape K, Klemashevich C, Norman KN, Carey JB, Hamer SA, Hamer GL. Fluralaner systemic treatment of chickens results in mortality in Triatoma gerstaeckeri, vector of the agent of Chagas disease. Parasit Vectors 2023; 16:178. [PMID: 37268980 DOI: 10.1186/s13071-023-05805-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 05/10/2023] [Indexed: 06/04/2023] Open
Abstract
BACKGROUND Chagas disease remains a persistent vector-borne neglected tropical disease throughout the Americas and threatens both human and animal health. Diverse control methods have been used to target triatomine vector populations, with household insecticides being the most common. As an alternative to environmental sprays, host-targeted systemic insecticides (or endectocides) allow for application of chemicals to vertebrate hosts, resulting in toxic blood meals for arthropods (xenointoxication). In this study, we evaluated three systemic insecticide products for their ability to kill triatomines. METHODS Chickens were fed the insecticides orally, following which triatomines were allowed to feed on the treated chickens. The insecticide products tested included: Safe-Guard® Aquasol (fenbendazole), Ivomec® Pour-On (ivermectin) and Bravecto® (fluralaner). Triatoma gerstaeckeri nymphs were allowed to feed on insecticide-live birds at 0, 3, 7, 14, 28 and 56 days post-treatment. The survival and feeding status of the T. gerstaeckeri insects were recorded and analyzed using Kaplan-Meier curves and logistic regression. RESULTS Feeding on fluralaner-treated chickens resulted 50-100% mortality in T. gerstaeckeri over the first 14 days post-treatment but not later; in contrast, all insects that fed on fenbendazole- and ivermectin-treated chickens survived. Liquid chromatography tandem mass spectrometry (LC-QQQ) analysis, used to detect the concentration of fluralaner and fenbendazole in chicken plasma, revealed the presence of fluralaner in plasma at 3, 7, and 14 days post-treatment but not later, with the highest concentrations found at 3 and 7 days post-treatment. However, fenbendazole concentration was below the limit of detection at all time points. CONCLUSIONS Xenointoxication using fluralaner in poultry is a potential new tool for integrated vector control to reduce risk of Chagas disease.
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Affiliation(s)
- Cassandra Durden
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, USA
- Schubot Center for Avian Health, Department of Veterinary Pathobiology, Texas A&M University, College Station, USA
| | - Yuexun Tian
- Department of Entomology, Texas A&M University, College Station, USA
| | - Koyle Knape
- Department of Poultry Science, Texas A&M University, College Station, USA
| | - Cory Klemashevich
- Integrated Metabolomics Analysis Core, Texas A&M University, College Station, USA
| | - Keri N Norman
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, USA
| | - John B Carey
- Department of Poultry Science, Texas A&M University, College Station, USA
| | - Sarah A Hamer
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, USA
- Schubot Center for Avian Health, Department of Veterinary Pathobiology, Texas A&M University, College Station, USA
| | - Gabriel L Hamer
- Department of Entomology, Texas A&M University, College Station, USA.
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Rokhsar JL, Raynor B, Sheen J, Goldstein ND, Levy MZ, Castillo-Neyra R. Modeling the impact of xenointoxication in dogs to halt Trypanosoma cruzi transmission. PLoS Comput Biol 2023; 19:e1011115. [PMID: 37155680 PMCID: PMC10194993 DOI: 10.1371/journal.pcbi.1011115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 05/18/2023] [Accepted: 04/19/2023] [Indexed: 05/10/2023] Open
Abstract
BACKGROUND Chagas disease, a vector-borne parasitic disease caused by Trypanosoma cruzi, affects millions in the Americas. Dogs are important reservoirs of the parasite. Under laboratory conditions, canine treatment with the systemic insecticide fluralaner demonstrated efficacy in killing Triatoma infestans and T. brasiliensis, T. cruzi vectors, when they feed on dogs. This form of pest control is called xenointoxication. However, T. cruzi can also be transmitted orally when mammals ingest infected bugs, so there is potential for dogs to become infected upon consuming infected bugs killed by the treatment. Xenointoxication thereby has two contrasting effects on dogs: decreasing the number of insects feeding on the dogs but increasing opportunities for exposure to T. cruzi via oral transmission to dogs ingesting infected insects. OBJECTIVE Examine the potential for increased infection rates of T. cruzi in dogs following xenointoxication. DESIGN/METHODS We built a deterministic mathematical model, based on the Ross-MacDonald malaria model, to investigate the net effect of fluralaner treatment on the prevalence of T. cruzi infection in dogs in different epidemiologic scenarios. We drew upon published data on the change in percentage of bugs killed that fed on treated dogs over days post treatment. Parameters were adjusted to mimic three scenarios of T. cruzi transmission: high and low disease prevalence and domestic vectors, and low disease prevalence and sylvatic vectors. RESULTS In regions with high endemic disease prevalence in dogs and domestic vectors, prevalence of infected dogs initially increases but subsequently declines before eventually rising back to the initial equilibrium following one fluralaner treatment. In regions of low prevalence and domestic or sylvatic vectors, however, treatment seems to be detrimental. In these regions our models suggest a potential for a rise in dog prevalence, due to oral transmission from dead infected bugs. CONCLUSION Xenointoxication could be a beneficial and novel One Health intervention in regions with high prevalence of T. cruzi and domestic vectors. In regions with low prevalence and domestic or sylvatic vectors, there is potential harm. Field trials should be carefully designed to closely follow treated dogs and include early stopping rules if incidence among treated dogs exceeds that of controls.
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Affiliation(s)
- Jennifer L. Rokhsar
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University, Philadelphia, Pennsylvania, United States of America
- ORISE Fellow, Emerging Leaders in Data Science and Technologies Program Fellowship, National Institute of Allergy and Infectious Diseases (NIAID), NIH, United States of America
| | - Brinkley Raynor
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Justin Sheen
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Neal D. Goldstein
- Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Michael Z. Levy
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Ricardo Castillo-Neyra
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru
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Rokhsar JL, Raynor B, Sheen J, Goldstein ND, Levy MZ, Castillo-Neyra R. Modeling the impact of xenointoxication in dogs to halt Trypanosoma cruzi transmission. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.01.24.23284917. [PMID: 36747723 PMCID: PMC9901065 DOI: 10.1101/2023.01.24.23284917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Background Chagas disease, a vector-borne parasitic disease caused by Trypanosoma cruzi , affects millions in the Americas. Dogs are important reservoirs of the parasite. Under laboratory conditions, canine treatment with the systemic insecticide fluralaner demonstrated efficacy in killing Triatoma infestans and T. brasiliensis, T. cruzi vectors, when they feed on dogs. This form of pest control is called xenointoxication. However, T. cruzi can also be transmitted orally when mammals ingest infected bugs, so there is potential for dogs to become infected upon consuming infected bugs killed by the treatment. Xenointoxication thereby has two contrasting effects on dogs: decreasing the number of insects feeding on the dogs but increasing opportunities for exposure to T. cruzi via oral transmission to dogs ingesting infected insects. Objective Examine the potential for increased infection rates of T. cruzi in dogs following xenointoxication. Design/Methods We built a deterministic mathematical model, based on the Ross-MacDonald malaria model, to investigate the net effect of fluralaner treatment on the prevalence of T. cruzi infection in dogs in different epidemiologic scenarios. We drew upon published data on the change in percentage of bugs killed that fed on treated dogs over days post treatment. Parameters were adjusted to mimic three scenarios of T. cruzi transmission: high and low disease prevalence and domestic vectors, and low disease prevalence and sylvatic vectors. Results In regions with high endemic disease prevalence in dogs and domestic vectors, prevalence of infected dogs initially increases but subsequently declines before eventually rising back to the initial equilibrium following one fluralaner treatment. In regions of low prevalence and domestic or sylvatic vectors, however, treatment seems to be detrimental. In these regions our models suggest a potential for a rise in dog prevalence, due to oral transmission from dead infected bugs. Conclusion Xenointoxication could be a beneficial and novel One Health intervention in regions with high prevalence of T. cruzi and domestic vectors. In regions with low prevalence and domestic or sylvatic vectors, there is potential harm. Field trials should be carefully designed to closely follow treated dogs and include early stopping rules if incidence among treated dogs exceeds that of controls. Author summary Chagas disease, caused by the parasite Trypanosoma cruzi , is transmitted via triatomine insect vectors. In Latin America, dogs are a common feeding source for triatomine vectors and subsequently an important reservoir of T. cruzi . One proposed intervention to reduce T. cruzi transmission is xenointoxication: treating dogs with oral insecticide to kill triatomine vectors in order to decrease overall T. cruzi transmission. Fluralaner, commonly administered to prevent ectoparasites such as fleas and ticks, is effective under laboratory conditions against the triatomine vectors. One concern with fluralaner treatment is that rapid death of the insect vectors may make the insects more available to oral ingestion by dogs; a more effective transmission pathway than stercorarian, the usual route for T. cruzi transmission. Using a mathematical model, we explored 3 different epidemiologic scenarios: high prevalence endemic disease within a domestic T. cruzi cycle, low prevalence endemic disease within a domestic T. cruzi cycle, and low prevalence endemic disease within a semi-sylvatic T. cruzi cycle. We found a range of beneficial to detrimental effects of fluralaner xenointoxication depending on the epidemiologic scenario. Our results suggest that careful field trials should be designed and carried out before wide scale implementation of fluralaner xenointoxication to reduce T. cruzi transmission.
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Affiliation(s)
- Jennifer L. Rokhsar
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK,Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA,ORISE Fellow, Emerging Leaders in Data Science and Technologies Program Fellowship, National Institute of Allergy and Infectious Diseases (NIAID), NIH, USA
| | - Brinkley Raynor
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Justin Sheen
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA,Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Neal D. Goldstein
- Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA
| | - Michael Z. Levy
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA,One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Ricardo Castillo-Neyra
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA,One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru,Corresponding author:
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Fiatsonu E, Busselman RE, Hamer GL, Hamer SA, Ndeffo-Mbah ML. Effectiveness of fluralaner treatment regimens for the control of canine Chagas disease: A mathematical modeling study. PLoS Negl Trop Dis 2023; 17:e0011084. [PMID: 36693084 PMCID: PMC9897538 DOI: 10.1371/journal.pntd.0011084] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 02/03/2023] [Accepted: 01/09/2023] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Canine Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and transmitted by insect triatomine vectors known as kissing bugs. The agent can cause cardiac damage and long-term heart disease and death in humans, dogs, and other mammals. In laboratory settings, treatment of dogs with systemic insecticides has been shown to be highly efficacious at killing triatomines that feed on treated dogs. METHOD We developed compartmental vector-host models of T. cruzi transmission between the triatomine and dog population accounting for the impact of seasonality and triatomine migration on disease transmission dynamics. We considered a single vector-host model without seasonality, and model with seasonality, and a spatially coupled model. We used the models to evaluate the effectiveness of the insecticide fluralaner with different durations of treatment regimens for reducing T. cruzi infection in different transmission settings. RESULTS In low and medium transmission settings, our model showed a marginal difference between the 3-month and 6-month regimens for reducing T. cruzi infection among dogs. The difference increases in the presence of seasonality and triatomine migration from a sylvatic transmission setting. In high transmission settings, the 3-month regimen was substantially more effective in reducing T. cruzi infections in dogs than the other regimens. Our model showed that increased migration rate reduces fluralaner effectiveness in all treatment regimens, but the relative reduction in effectiveness is minimal during the first years of treatment. However, if an additional 10% or more of triatomines killed by dog treatment were eaten by dogs, treatment could increase T. cruzi infections in the dog population at least during the first year of treatment. CONCLUSION Our analysis shows that treating all peridomestic dogs every three to six months for at least five years could be an effective measure to reduce T. cruzi infections in dogs and triatomines in peridomestic transmission settings. However, further studies at the local scale are needed to better understand the potential impact of routine use of fluralaner treatment on increasing dogs' consumption of dead triatomines.
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Affiliation(s)
- Edem Fiatsonu
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Rachel E. Busselman
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Gabriel L. Hamer
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Sarah A. Hamer
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Martial L. Ndeffo-Mbah
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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Tielemans E, Rautenbach C, Besselaar JF, Beugnet F. Efficacy of a topical product combining esafoxolaner, eprinomectin and praziquantel against bedbug (Cimex lectularius) experimental infestations in cats. Parasite 2022; 29:59. [PMID: 36562440 PMCID: PMC9879142 DOI: 10.1051/parasite/2022060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Bedbugs (Cimex lectularius) are a persistent nuisance pest for humans and their home environment, and may also opportunistically feed on other mammals, including household pets like dogs and cats. NexGard® Combo is a topical endectoparasiticide product for cats combining esafoxolaner, an isoxazoline compound with insecticidal and acaricidal properties, the nematocide eprinomectin and the cestocide praziquantel. The insecticidal efficacy of this product was evaluated in cats experimentally infested with C. lectularius in a blinded, negative controlled and randomized study. Two groups of 7 cats were formed: an untreated control group, and a NexGard® Combo group treated once on Day 0 at the label dose. Cats were then challenged weekly, each with twenty unfed adult C. lectularius, on Days 1, 7, 14, 21 and 28. After close contact with the cat's skin for 15 min, live fed C. lectularius were collected and incubated for 96 h. The weekly efficacy evaluations were based on a comparison of the number of surviving bedbugs in the control and the treated group after 48, 72 and 96 h of incubation. The model was demonstrated to be robust as in the control group the average feeding rate after the 15-minute challenge was 94%, and as 96% of incubated bed bugs were alive after 96 hours of incubation. Significant live bedbug reductions were demonstrated in the Nexgard® Combo treated group: after 96 h of incubation, the reductions ranged from 80.6 to 88.0% during the Day 1 to Day 21 period, and dropped to 58% at Day 28.
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Affiliation(s)
- Eric Tielemans
- Boehringer-Ingelheim Animal Health 29 avenue Tony Garnier 69007 Lyon France
| | - Carin Rautenbach
- Clinvet International (Pty) Ltd. P.O. Box 11186, Universitas Bloemfontein 9321 Republic of South Africa
| | - JF Besselaar
- Clindata International (Pty) Ltd. P.O. Box 11186, Universitas Bloemfontein 9321 Republic of South Africa
| | - Frederic Beugnet
- Boehringer-Ingelheim Animal Health 29 avenue Tony Garnier 69007 Lyon France
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Hamer SA, Saunders AB. Veterinary Chagas Disease (American Trypanosomiasis) in the United States. Vet Clin North Am Small Anim Pract 2022; 52:1267-1281. [DOI: 10.1016/j.cvsm.2022.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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10
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Gürtler RE, Laiño MA, Alvedro A, Enriquez GF, Macchiaverna NP, Gaspe MS, Cardinal MV. Treatment of dogs with fluralaner reduced pyrethroid-resistant Triatoma infestans abundance, Trypanosoma cruzi infection and human-triatomine contact in the Argentine Chaco. Parasit Vectors 2022; 15:257. [PMID: 35831874 PMCID: PMC9277862 DOI: 10.1186/s13071-022-05343-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Background Triatomine elimination efforts and the interruption of domestic transmission of Trypanosoma cruzi are hampered by pyrethroid resistance. Fluralaner, a long-lasting ectoparasiticide administered to dogs, substantially reduced site infestation and abundance of pyrethroid-resistant Triatoma infestans Klug (Heteroptera: Reduviidae) in an ongoing 10-month trial in Castelli (Chaco Province, Argentina). We assessed the effects of fluralaner on vector infection with T. cruzi and blood meal sources stratified by ecotope and quantified its medium-term effects on site infestation and triatomine abundance. Methods We conducted a placebo-controlled, before-and-after efficacy trial of fluralaner in 28 infested sites over a 22-month period. All dogs received either an oral dose of fluralaner (treated group) or placebo (control group) at 0 month post-treatment [MPT]. Placebo-treated dogs were rescue-treated with fluralaner at 1 MPT, as were all eligible dogs at 7 MPT. Site-level infestation and abundance were periodically assessed by timed manual searches with a dislodging aerosol. Vector infection was mainly determined by kDNA-PCR and blood meal sources were determined by enzyme-linked immunosorbent assay. Results In fluralaner-treated households, site infestation dropped from 100% at 0 MPT to 18–19% over the period 6–22 MPT while mean abundance plummeted from 5.5 to 0.6 triatomines per unit effort. In control households, infestation dropped similarly post-treatment. The overall prevalence of T. cruzi infection steadily decreased from 13.8% at 0–1 MPT (baseline) to 6.4% and subsequently 2.3% thereafter, while in domiciles, kitchens and storerooms it dropped from 17.4% to 4.7% and subsequently 3.3% thereafter. Most infected triatomines occurred in domiciles and had fed on humans. Infected-bug abundance plummeted after fluralaner treatment and remained marginal or nil thereafter. The human blood index of triatomines collected in domiciles, kitchens and storerooms highly significantly fell from 42.9% at baseline to 5.3–9.1% over the period 6–10 MPT, increasing to 36.8% at 22 MPT. Dog blood meals occurred before fluralaner administration only. The cat blood index increased from 9.9% at baseline to 57.9–72.7% over the period 6–10 MPT and dropped to 5.3% at 22 MPT, whereas chicken blood meals rose from 39.6% to 63.2–88.6%. Conclusion Fluralaner severely impacted infestation- and transmission-related indices over nearly 2 years, causing evident effects at 1 MPT, and deserves larger efficacy trials. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05343-2.
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Affiliation(s)
- Ricardo Esteban Gürtler
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina.
| | - Mariano Alberto Laiño
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Alejandra Alvedro
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Gustavo Fabián Enriquez
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Natalia Paula Macchiaverna
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina.
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11
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Laiño MA, Cardinal MV, Gaspe MS, Enriquez GF, Alvedro A, Macchiaverna NP, Gürtler RE. Control of pyrethroid-resistant populations of Triatoma infestans, the main vector of Trypanosoma cruzi, by treating dogs with fluralaner in the Argentine Chaco. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:149-158. [PMID: 34866216 DOI: 10.1111/mve.12561] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/12/2021] [Accepted: 11/24/2021] [Indexed: 06/13/2023]
Abstract
We assessed whether fluralaner administered to outbred healthy dogs reduced or supressed site infestation and abundance of pyrethroid-resistant populations of Triatoma infestans Klug (Heteroptera: Reduviidae). We conducted a placebo-controlled before-and-after efficacy trial in 28 infested sites in Castelli (Argentine Chaco) over 10 months. All 72 dogs initially present received either an oral dose of fluralaner (treated group) or placebo (control group) at month 0 posttreatment (MPT). Preliminary results justified treating all 38 control-house dogs with fluralaner 1 month later, and 71 of 78 existing dogs at 7 MPT. Site-level infestation and triatomine abundance were evaluated using timed manual searches with a dislodging aerosol. In the fluralaner-treated group, infestation dropped significantly from 100% at baseline to 19% over 6-10 MPT whereas mean abundance fell highly significantly from 5.5 to 0.8-0.9 triatomines per unit effort. In the placebo group, site infestation and mean abundance remained stable between 0 and 1 MPT, and strongly declined after fluralaner administration from 13.0-14.7 - triatomines at 0-1 MPT to 4.0-4.2 over 6-10 MPT. Only one of 81 noninfested sites before fluralaner treatment became infested subsequently. Fluralaner significantly reduced the site-level infestation and abundance of pyrethroid-resistant T. infestans and should be tested more widely in Phase III efficacy trials.
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Affiliation(s)
- Mariano Alberto Laiño
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - María Sol Gaspe
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Gustavo Fabián Enriquez
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Alejandra Alvedro
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Natalia Paula Macchiaverna
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Ricardo E Gürtler
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
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12
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Allen KE, Lineberry MW. Trypanosoma cruzi and Other Vector-Borne Infections in Shelter Dogs in Two Counties of Oklahoma, United States. Vector Borne Zoonotic Dis 2022; 22:273-280. [PMID: 35580215 DOI: 10.1089/vbz.2021.0078] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Trypanosoma cruzi is an emerging zoonotic vector-borne parasite infecting dogs and other mammals in the United States. In this study we evaluated shelter dogs in one northeastern and one southeastern county in Oklahoma for prevalence of exposure to T. cruzi. Dogs were tested for antibodies against T. cruzi using the Chagas STAT PAK® assay and for T. cruzi in circulation by PCR. In addition, dogs were tested for evidence of infection with other vector-borne organisms using the SNAP® 4Dx® Plus Test and PCR. Overall, 26 of 197 (13.2%) shelter dogs had detectable antibodies against T. cruzi and 3 of 189 (1.6%) dogs were PCR positive. In addition, we found that 42 of 197 (21.3%) shelter dogs had evidence of exposure to or were infected with at least one vector-borne agent other than T. cruzi based on serology and/or PCR; 9 of 42 (21.4%) of these dogs were also positive for T. cruzi antibodies. Other infections identified in dogs included Anaplasma phagocytophilum, Anaplasma platys, Babesia sp. (Coco), Dirofilaria immitis, Ehrlichia canis, Ehrlichia chaffeensis, Ehrlichia ewingii, and Hepatozoon americanum. This study serves to boost state-wide veterinary and public health awareness of T. cruzi and other vector-borne pathogens infecting shelter dogs in Oklahoma. Results indicate the need for more comprehensive screening of shelter dogs in Oklahoma for exposure to vector-borne agents to enhance surveillance and to identify dogs in need of additional specific veterinary care.
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Affiliation(s)
- Kelly E Allen
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Megan W Lineberry
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
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13
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Allen KE, Lineberry MW. Detection of Trypansoma cruzi in Kissing Bugs (Hemiptera: Reduviidae: Triatominae) Collected Across Oklahoma. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:675-680. [PMID: 34993549 DOI: 10.1093/jme/tjab211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Indexed: 06/14/2023]
Abstract
Trypanosoma cruzi is the causative agent of Chagas disease in humans and dogs in the Americas. Transmission predominantly occurs via the feces of infected kissing bugs (Hemiptera: family Reduviidae; subfamily Triatominae) contaminating bite site wounds or mucous membranes. To better understand Chagas disease entomologic risk in Oklahoma, kissing bugs collected from within the state were tested for T. cruzi DNA. Data including county of insect collection, species and instar, and specific locations where specimens were found were collated. Triatomines were also tested by PCR to potentially identify DNA of vertebrate species on which specimens had recently fed. In total, 110 kissing bugs from 22 counties were tested. All triatomines were identified as Triatoma sanguisuga nymphs or adults, with the exception of one possible T. lecticularia adult. Trypanosoma cruzi DNA was detected in 22 (20%) triatomines from 12 counties spanning the state. The majority of T. cruzi PCR positive kissing bugs were found inside homes or associated structures (i.e., garages, porches). Vertebrate DNA was identified in 27 (24.5%) triatomines, with human DNA detected in 25 (92.6%) of these specimens, and canine and raccoon DNA detected in one specimen each (3.7%). Two specimens tested positive for both T. cruzi and human DNA and one specimen tested positive for both T. cruzi and raccoon DNA. Results from this study indicate that kissing bugs carrying T. cruzi are widespread in Oklahoma, that positive kissing bugs infest homes and associated structures, and that human-vector, canine-vector, and wildlife-vector contact all occur within the state.
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Affiliation(s)
- Kelly E Allen
- Department of Veterinary Pathobiology, Oklahoma State University's College of Veterinary Medicine, Stillwater, OK, USA
| | - Megan W Lineberry
- Department of Veterinary Pathobiology, Oklahoma State University's College of Veterinary Medicine, Stillwater, OK, USA
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14
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Opazo A, Bacigalupo A, Urrutia S, Chávez G. Detection of Trypanosoma cruzi infection by PCR in Canis lupus familiaris and their ectoparasites in Chile. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:88-96. [PMID: 34716716 DOI: 10.1111/mve.12554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 10/05/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
Chronic Chagas disease affects humans and animals, involving rural and urban inhabitants. Dogs participate in the maintenance and transmission of Trypanosoma cruzi. The objective of this study was to evaluate the presence of T. cruzi in dogs and their ticks and fleas, in a rural area of Central Chile. Trypanosoma cruzi was detected by PCR both in dogs and ectoparasites. From the blood samples obtained, 57% were infected by T. cruzi, 5.4% of the ticks detected were positive, and all fleas were negative. Additionally, we performed electrocardiograms and found supraventricular arrhythmia in 44% of T. cruzi-positive dogs. Nevertheless, their risk for supraventricular arrhythmias was not higher in infected versus noninfected dogs. Considering the detected infection levels, dogs act as T. cruzi hosts in Central Chile, and ticks could be used as an indicator of infection when blood samples are not available. However, at this point, there is no indication that these ticks could pass on the parasite to another host. Periodic ectoparasitic treatment of pets should reduce the chance of vectorial transmission of T. cruzi and improve canine health; however, this is an uncommon practice among rural communities, so governmental programs are encouraged to tackle this problem.
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Affiliation(s)
- A Opazo
- Universidad Andres Bello, Escuela Medicina Veterinaria, Facultad Ciencias de la Vida, Concepcion, Chile
| | - A Bacigalupo
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, U.K
| | - S Urrutia
- Escuela de Medicina Veterinaria, Facultad de Recursos Naturales y Medicina Veterinaria, Universidad Santo Tomás, Concepción, Chile
| | - G Chávez
- Escuela de Medicina Veterinaria, Facultad de Recursos Naturales y Medicina Veterinaria, Universidad Santo Tomás, Viña del Mar, Chile
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15
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Bongiorno G, Meyer L, Evans A, Lekouch N, Doherty P, Chiummo R, Gradoni L. Insecticidal efficacy against Phlebotomus perniciosus in dogs treated orally with fluralaner in two different parallel-group, negative-control, random and masked trials. Parasit Vectors 2022; 15:18. [PMID: 34998427 PMCID: PMC8742344 DOI: 10.1186/s13071-021-05128-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/12/2021] [Indexed: 12/02/2022] Open
Abstract
Background Dogs are the reservoir host of Leishmania infantum, the agent of zoonotic visceral leishmaniasis (VL), which is transmitted by the bite of phlebotomine sand flies. The sand fly Phlebotomus perniciosus is the main vector of zoonotic VL in the western Mediterranean region. Fluralaner has been shown to effectively kill this vector. The aim of this study was to evaluate the insecticidal efficacy of oral fluralaner in dogs bitten by P. perniciosus. Methods Two parallel-group, negative-controlled, randomized, masked laboratory trials with equivalent designs were performed in two different locations using two different pathogen-free laboratory-bred P. perniciosus strains for the challenge. In each trial, 12 purpose-bred beagles, initially ranked on natural attractiveness to sand flies, were randomly allocated to two groups (6 animals/group). Dogs in one group received fluralaner orally at the approved dose on day 0, and dogs in the control group were not treated. Each dog was subsequently exposed to an average of 70 unfed live sand fly females on days 1, 28, 56 and 84. Viability of blood-fed females was then evaluated for up to 96 h after exposure, and insecticidal efficacy was measured as the survival rate of flies fed on the fluralaner-treated dogs versus that of dogs in the control group. Significance was calculated for the proportion of live fed sand fly counts from treated versus control group dogs. Results Comparison of the survival proportions between treated and control groups showed that fluralaner insecticidal efficacy was highly significant in both trials (P < 0.001 or P < 0.01 in different assessments) through to day 56. In the first trial, efficacy reached 100% on days 1 and 28, and 99.1% on day 56; in the second trial, the insecticidal efficacy was 98.5, 100 and 85.9%, respectively on the same days. On day 84, efficacy was in the range of 53–57% (P < 0.05) in the first trial and 0% in the second trial. Conclusion A single oral fluralaner administration to dogs under laboratory conditions results in strong and reproducible insecticidal efficacy against P. perniciosus for at least 8 weeks. Graphical Abstract ![]()
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Affiliation(s)
- Gioia Bongiorno
- Unit of Vector-Borne Diseases, Istituto Superiore Di Sanità, 00161, Rome, Italy
| | | | | | | | - Padraig Doherty
- Iorras Product Development Limited, Glenamoy-Ballina, Co. Mayo, F26Y286, Ireland
| | - Rafael Chiummo
- MSD Animal Health Innovation GmbH, 55270, Schwabenheim an der Selz, Germany
| | - Luigi Gradoni
- Unit of Vector-Borne Diseases, Istituto Superiore Di Sanità, 00161, Rome, Italy.
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16
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Ortega-Pacheco A, Poot-Ramos A, Chan-Pérez JI, Gutiérrez-Blanco E, Acevedo-Arcique CM, Baak-Baak CM, Jiménez-Coello M. Evaluation of the effectiveness of fluralaner against adult stages of Rhodnius prolixus in dogs. Parasitol Int 2021; 87:102508. [PMID: 34781015 DOI: 10.1016/j.parint.2021.102508] [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] [Received: 06/05/2021] [Revised: 10/26/2021] [Accepted: 11/06/2021] [Indexed: 11/29/2022]
Abstract
Triatomines are vectors of American Trypanosomiasis also known as Chagas´ disease where several reservoirs including dogs are involved in the transmission cycle of the causal agent (Trypanosoma cruzi). Considering that the prevalence of American trypanosomiasis in dogs is higher than in humans and that dogs in addition are susceptible of this disease, and are involved in peridomestic transmission to humans, the search for new alternatives for vector control of the triatomines responsible for transmission in dogs is required. Over the 20 weeks the study lasted, 600 individual female, adult of Rhodnius prolixus were offered to the 15 dogs treated with a single oral dose of Fluralaner (Bravecto®, MSD). Feeding pattern of triatomines was not affected by the treatment during the whole study. The fluralaner-induced mortality of R. prolixus had a significant effect until week 12 at which time 100% mortality was observed. Mortality decreased to 67.5% at week 16 to practically nil 0.8% on week 20. Fluralaner achieved 100% mortality of triatomines between 12- and 48-h post-feeding. It was demonstrated that a single oral dose of fluralaner in dogs is highly effective in producing mortality in adult R. prolixus for the time guaranteed by the manufacturer for other blood-sucking insects, with a considerable effective residual effect for up to 16 weeks. Due to this high efficacy, fluralaner could be considered in strategies to control the transmission vectors of Chagas disease in dogs and in turn decrease the peri-domestic transmission cycle, particularly in hyperendemic areas.
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Affiliation(s)
- Antonio Ortega-Pacheco
- Departamento de Salud Animal y Medicina Preventiva, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Mexico
| | - Anabel Poot-Ramos
- Departamento de Salud Animal y Medicina Preventiva, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Mexico
| | - Jose I Chan-Pérez
- Centro de Investigaciones Regionales "Dr Hideyo Noguchi", Universidad Autónoma de Yucatán, Mexico
| | - Eduardo Gutiérrez-Blanco
- Departamento de Salud Animal y Medicina Preventiva, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Mexico
| | | | - Carlos M Baak-Baak
- Centro de Investigaciones Regionales "Dr Hideyo Noguchi", Universidad Autónoma de Yucatán, Mexico
| | - Matilde Jiménez-Coello
- Centro de Investigaciones Regionales "Dr Hideyo Noguchi", Universidad Autónoma de Yucatán, Mexico.
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Busselman RE, Hamer SA. Chagas Disease Ecology in the United States: Recent Advances in Understanding Trypanosoma cruzi Transmission Among Triatomines, Wildlife, and Domestic Animals and a Quantitative Synthesis of Vector-Host Interactions. Annu Rev Anim Biosci 2021; 10:325-348. [PMID: 34758274 DOI: 10.1146/annurev-animal-013120-043949] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chagas disease, a neglected tropical disease present in the Americas, is caused by the parasite Trypanosoma cruzi and is transmitted by triatomine kissing bug vectors. Hundreds of vertebrate host species are involved in the ecology of Chagas disease. The sylvatic nature of most triatomines found in the United States accounts for high levels of animal infections but few reports of human infections. This review focuses on triatomine distributions and animal infections in the southern United States. A quantitative synthesis of available US data from triatomine bloodmeal analysis studies shows that dogs, humans, and rodents are key taxa for feeding triatomines. Imperfect and unvalidated diagnostic tools in wildlife complicate the study of animal T. cruzi infections, and integrated vector management approaches are needed to reduce parasite transmission in nature. The diversity of animal species involved in Chagas disease ecology underscores the importance of a One Health approach for disease research and management. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Rachel E Busselman
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA;
| | - Sarah A Hamer
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA;
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Queiroga TBD, Gomez LCP, de Sena ER, Dos Santos WV, Ferreira HRP, de Araújo-Neto VT, Barbosa-Silva AN, Brito CRDN, Lima RKDR, Fagundes-Neto JC, Galvão LMDC, de Medeiros HR, da Câmara ACJ, Nascimento MSL, Gama RA, Guedes PMM. Insecticidal efficacy of fluralaner (Bravecto ®) against Triatoma brasiliensis, a major vector of Trypanosoma cruzi in Brazil. Parasit Vectors 2021; 14:456. [PMID: 34488865 PMCID: PMC8422713 DOI: 10.1186/s13071-021-04978-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Triatomines are responsible for the vector transmission of the protozoan parasite Trypanosoma cruzi, which causes Chagas disease. Triatoma brasiliensis is the main vector of the parasite in Brazil, and dogs are an important reservoir of the parasite. The aim of this study was to evaluate the insecticidal effect of fluralaner (Bravecto®) on T. brasiliensis after a blood meal in treated dogs. METHODS Healthy mongrel dogs (n = 8) were recruited from the Zoonoses Control Center (ZCC) in the city of Natal, Rio Grande do Norte, Brazil, and randomized into two groups, a fluralaner (Bravecto®)-treated group (n = 4) and a control group (n = 4). Colony-reared third-, fourth- and fifth-instar nymphs of T. brasiliensis nymphs (n = 10) were allowed to feed on dogs from both groups for 30-40 min, once monthly, for up to 12 months. Bug mortality was observed up to 5 days after each blood meal. RESULTS Mortality in triatomines which had a blood meal on fluralaner (Bravecto®)-treated dogs was 100% for up to 7 months after treatment, with mortality decreasing to 66.4% after 8 months, 57% after 9 months, 35% after 10 months, 10% after 11 months and 0% after 12 months. The mortality of triatomines that fed on non-treated control dogs was always ≤ 2.5%. CONCLUSIONS Our results suggest that fluralaner (Bravecto®) treatment of dogs induces long-term mortality of T. brasiliensis after the blood meal. This is a potential approach to be used to control vector transmission of T. cruzi, the etiological agent of Chagas disease, especially in endemic areas.
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Affiliation(s)
| | | | - Eduardo Rodrigues de Sena
- Graduate Program in Parasitary Biology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Wilo Victor Dos Santos
- Graduate Program in Parasitary Biology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | | | - Vicente Toscano de Araújo-Neto
- Graduate Program in Pharmaceutical Sciences, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Andressa Noronha Barbosa-Silva
- Graduate Program in Pharmaceutical Sciences, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Carlos Ramon do Nascimento Brito
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | | | | | - Lúcia Maria da Cunha Galvão
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Henrique Rocha de Medeiros
- Agricultural School of Jundiaí, Federal University of Rio Grande Do Norte, Macaíba, Rio Grande Do Norte, Brazil
| | - Antônia Cláudia Jácome da Câmara
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Manuela Sales Lima Nascimento
- Department of Microbiology and Parasitology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Renata Antonaci Gama
- Department of Microbiology and Parasitology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Paulo Marcos Matta Guedes
- Department of Microbiology and Parasitology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil.
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Using data-driven approaches to improve delivery of animal health care interventions for public health. Proc Natl Acad Sci U S A 2021; 118:2003722118. [PMID: 33468627 PMCID: PMC7865124 DOI: 10.1073/pnas.2003722118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Rabies is arguably the exemplar of the One Health Agenda in which preventative health care in one species can improve health of other species. Interrogation of large epidemiology datasets offers the potential to deliver health care initiatives in a more efficient and cost-effective manner. However, real-life examples demonstrating this potential are limited. Here, we report a real-time, data-driven approach to improve cost effectiveness of dog vaccination campaigns in urban sub-Saharan African settings, which eliminates the need of expensive door-to-door vaccination by replacing them with strategically positioned fixed and roaming static points (SPs). This approach has the potential to act as a template for future successful and sustainable urban SP-only dog vaccination campaigns. Rabies kills ∼60,000 people per year. Annual vaccination of at least 70% of dogs has been shown to eliminate rabies in both human and canine populations. However, delivery of large-scale mass dog vaccination campaigns remains a challenge in many rabies-endemic countries. In sub-Saharan Africa, where the vast majority of dogs are owned, mass vaccination campaigns have typically depended on a combination of static point (SP) and door-to-door (D2D) approaches since SP-only campaigns often fail to achieve 70% vaccination coverage. However, D2D approaches are expensive, labor-intensive, and logistically challenging, raising the need to develop approaches that increase attendance at SPs. Here, we report a real-time, data-driven approach to improve efficiency of an urban dog vaccination campaign. Historically, we vaccinated ∼35,000 dogs in Blantyre city, Malawi, every year over a 20-d period each year using combined fixed SP (FSP) and D2D approaches. To enhance cost effectiveness, we used our historical vaccination dataset to define the barriers to FSP attendance. Guided by these insights, we redesigned our vaccination campaign by increasing the number of FSPs and eliminating the expensive and labor-intensive D2D component. Combined with roaming SPs, whose locations were defined through the real-time analysis of vaccination coverage data, this approach resulted in the vaccination of near-identical numbers of dogs in only 11 d. This approach has the potential to act as a template for successful and sustainable future urban SP-only dog vaccination campaigns.
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Tsurim I, Wasserberg G, Ben Natan G, Abramsky Z. The Potential of Systemic Control of Sand Flies Using Fipronil in the Novel Leishmania major (Kinetoplastida: Trypanosomatidae) Reservoirs Meriones tristrami (Rodentia: Muridea) and Meriones crassus (Rodentia: Muridea). JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:969-973. [PMID: 33155653 DOI: 10.1093/jme/tjaa200] [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: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Leishmania major (Yakimoff & Schokhor, 1914), an important causative agent of Old World Cutaneous Leishmaniasis (CL), is transmitted by sand flies among a limited number of gerbilline reservoir-species. We can take advantage of this strong dependency to break the pathogen transmission cycle by using systemic insecticides that render the host toxic to the blood-feeding vector. We evaluated the potential of this approach with two novel reservoir species, incriminated for CL expansion in several sites in the Middle East. Specifically, we evaluated: 1) the residuality of the systemic insecticide fipronil in Meriones tristrami (Thomas, 1892) fed on fipronil-treated baits and 2) the treatments' adulticide effect on sand flies that blood fed on treated and untreated M. tristrami and M. crassus (Sundevall, 1842). We fed M. tristrami with food pellets containing 0.1 g/kg fipronil and used gas chromatograph-mass spectrometery analysis and bioassays to examine its residual toxicity to blood-feeding female sand flies. In M. tristrami, fipronil was rapidly metabolized to fipronil sulfone, found in the blood, urine, and feces for ≥31 d after fipronil admission. The survival of sand flies that blood fed on fipronil-treated M. tristrami and M. crassus was significantly reduced for at least 15 and 9 d respectively, after fipronil admission. These results hold promise for the potential contribution of systemic control approaches to CL integrated management strategies against novel CL (due to L. major) outbreaks in Israel and elsewhere.
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Affiliation(s)
- Ido Tsurim
- Department of Life Sciences, Achva Academic College, Israel
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Gideon Wasserberg
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC
| | - Gil Ben Natan
- Department of Life Sciences, Achva Academic College, Israel
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Zvika Abramsky
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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21
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Beugnet F, Rautenbach C, van der Mescht L, Lebon W, Aouiche N, Liebenberg J. Insecticidal efficacy of afoxolaner against bedbugs, Cimex lectularius, when administered orally to dogs. ACTA ACUST UNITED AC 2021; 28:7. [PMID: 33528356 PMCID: PMC7852378 DOI: 10.1051/parasite/2021004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/11/2021] [Indexed: 11/14/2022]
Abstract
The objective of this experimental study was to assess the insecticidal efficacy of afoxolaner (NexGard®) against bedbugs (Cimex lectularius) on dogs. For each challenge, 20 bedbugs were placed in two chambers positioned in contact to the dog’s skin for 15 min, after which live fed parasites were counted and incubated for survival evaluations. On Day 0, 7 dogs assigned to the treated group were administered afoxolaner orally at the registered dose. All 14 dogs were challenged on Days 1, 7, 14, 21 and 28, and the collected live fed C. lectularius incubated for 72 h (Day 1), and 72 h and 96 h (Days 7, 14, 21 and 28) for survival evaluation. The percent feeding in the control group ranged from 95% to 98.6% and the percent of live fed bedbugs at 96 h ranged from 99.3% to 100% in the control group, demonstrating the viability of the strain and their capacity to feed on dogs. Significantly fewer live fed bedbugs were counted in the treated group, compared to the control group, at all time-points. The reduction of live fed C. lectularius in the afoxolaner group was 41.4% at 72 h after the Day 1 challenge, and 77.2%, 82.7%, 85.0% and 63.5% at 96 h after the Days 7, 14, 21 and 28 challenges, respectively. It is hypothesized that monthly treatment of dogs with afoxolaner could help in preventing a bed bug population from installing in a household if bedbugs bite dogs in the presence of humans.
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Affiliation(s)
| | - Carin Rautenbach
- ClinVet, PO Box 11186 Universitas, 9321, Bloemfontein, South Africa
| | | | - Wilfried Lebon
- Boehringer-Ingelheim, 29 Av. Tony Garnier, 69007 Lyon, France
| | - Nesrine Aouiche
- Boehringer-Ingelheim, 29 Av. Tony Garnier, 69007 Lyon, France
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22
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Khaligh FG, Jafari A, Silivanova E, Levchenko M, Rahimi B, Gholizadeh S. Endectocides as a complementary intervention in the malaria control program: a systematic review. Syst Rev 2021; 10:30. [PMID: 33455581 PMCID: PMC7812718 DOI: 10.1186/s13643-021-01578-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/02/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Malaria is the most common vector-borne disease transmitted to humans by Anopheles mosquitoes. Endectocides and especially ivermectin will be available as a vector control tool soon. The current review could be valuable for trial design and clinical studies to control malaria transmission. METHODS PubMed/MEDLINE, Scopus, Web of Science, and Science Direct were searched for original English published papers on ("Malaria chemical control" OR "Malaria elimination" OR "Anopheles vector control" OR "Malaria zooprophylaxis") AND ("Systemic insecticides" OR "Endectocides" OR "Ivermectin"). The last search was from 19 June 2019 to 31 December 2019. It was updated on 17 November 2020. Two reviewers (SG and FGK) independently reviewed abstracts and full-text articles. Data were extracted by one person and checked by another. As meta-analyses were not possible, a qualitative summary of results was performed. RESULTS Thirty-six published papers have used systemic insecticides/endectocides for mosquito control. Most of the studies (56.75%) were done on Anopheles gambiae complex species on doses from 150 μg/kg to 400 μg/kg in several studies. Target hosts for employing systemic insecticides/drugs were animals (44.2%, including rabbit, cattle, pig, and livestock) and humans (32.35%). CONCLUSIONS Laboratory and field studies have highlighted the potential of endectocides in malaria control. Ivermectin and other endectocides could soon serve as novel malaria transmission control tools by reducing the longevity of Anopheles mosquitoes that feed on treated hosts, potentially decreasing Plasmodium parasite transmission when used as mass drug administration (MDA).
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Affiliation(s)
- Fereshteh Ghahvechi Khaligh
- Social Determinants of Health Research Center, Clinical Research Institute, Urmia University of Medical Sciences, Urmia, Iran.,Medical Entomology Department, School of Public Health, Urmia University of Medical Sciences, Urmia, Iran
| | - Abbas Jafari
- Department of Clinical Toxicology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.,Cellular and Molecular Research Center, Research Institute on Cellular and Molecular Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Elena Silivanova
- All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology, Branch of Federal State Institution Federal Research Centre Tyumen Scientific Centre, Siberian Branch of the Russian Academy of Sciences (ASRIVEA - Branch of Tyumen Scientific Centre SB RAS), Institutskaya st. 2, Tyumen, Russian Federation, 625041
| | - Mikhail Levchenko
- All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology, Branch of Federal State Institution Federal Research Centre Tyumen Scientific Centre, Siberian Branch of the Russian Academy of Sciences (ASRIVEA - Branch of Tyumen Scientific Centre SB RAS), Institutskaya st. 2, Tyumen, Russian Federation, 625041
| | - Bahlol Rahimi
- Department of Health Information Technology, School of Applied Medical Sciences, Urmia University of Medical Sciences, Urmia, Iran
| | - Saber Gholizadeh
- Social Determinants of Health Research Center, Clinical Research Institute, Urmia University of Medical Sciences, Urmia, Iran. .,Medical Entomology Department, School of Public Health, Urmia University of Medical Sciences, Urmia, Iran.
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23
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Queiroga TBD, Ferreira HRP, Dos Santos WV, de Assis ABL, de Araújo Neto VT, da Câmara ACJ, Fagundes Neto JC, Dos Reis RK, Nascimento MSL, Gama RA, Guedes PMM. Fluralaner (Bravecto®) induces long-term mortality of Lutzomyia longipalpis after a blood meal in treated dogs. Parasit Vectors 2020; 13:609. [PMID: 33276818 PMCID: PMC7716428 DOI: 10.1186/s13071-020-04489-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/19/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Leishmania infantum is the etiological agent of visceral leishmaniasis (VL) in the New World, where the sand fly Lutzomyia longipalpis and domestic dogs are considered the main vector and host reservoirs, respectively. Systemic insecticides have been studied as an alternative to control vector-borne diseases, including VL. Fluralaner, an isoxazoline class compound, is a systemic insecticide used in dogs, with proven efficiency against different species of phlebotomine sand flies. However, to date no studies have demonstrated the efficacy of fluralaner on Lu. longipalpis. The aim of this study was to evaluate the insecticidal effect of fluralaner (Bravecto®) on the sand fly Lu. longipalpis after blood meal in treated dogs. METHODS Healthy mongrel dogs (n = 8) were recruited from the Zoonoses Control Center in the city of Natal, Rio Grande do Norte, Brazil, and randomized into two groups: fluralaner treated (n = 4) and non-treated control (n = 4). Colony-reared female specimens of Lu. longipalpis (n = 20) were allowed to feed on all dogs for 40 min before treatment (for fluralaner-treated dogs), at day 1 after treatment and then monthly until 1 year post-treatment. RESULTS In the treatment group, there was 100% mortality of Lu. longipalpis for up to 5 months after treatment initiation, decreasing to 72.5% at 6 months post-treatment initiation. The efficacy of fluralaner ranged from 100% at day 1 (P = 0.0002) to 68% ( P = 0.0015) at 6 months, decreasing to 1.4% at 1 year post-treatment. Sand fly mortality carried out blood meal in non-treated control dogs remained constant at ≤ 15%. CONCLUSIONS Taken together, our results suggest that fluralaner may be used as a control strategy for VL in dogs in VL endemic areas.
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Affiliation(s)
| | | | - Wilo Victor Dos Santos
- Graduate Program in Parasitary Biology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Ana Beatriz Lourenço de Assis
- Graduate Program in Parasitary Biology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Vicente Toscano de Araújo Neto
- Graduate Program in Pharmaceutical Sciences, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Antônia Cláudia Jácome da Câmara
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | | | | | - Manuela Sales Lima Nascimento
- Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Renata Antonaci Gama
- Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Paulo Marcos Matta Guedes
- Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
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Rust MK. Recent Advancements in the Control of Cat Fleas. INSECTS 2020; 11:insects11100668. [PMID: 33003488 PMCID: PMC7600267 DOI: 10.3390/insects11100668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/25/2020] [Accepted: 09/26/2020] [Indexed: 11/16/2022]
Abstract
Simple Summary The cat flea Ctenocephalides felis felis is the most important pest of domesticated cats and dogs worldwide. This review covers the recent advancements in the control of cat fleas. Over the years, there has been an interest in using ecologically friendly approaches to control fleas. To date, no biological, natural, or cultural means have been discovered that mitigate flea infestations. The recent registration of novel topical and oral therapies promises a new revolution in the control of fleas and ticks and the diseases associated with them. Abstract With the advent of imidacloprid and fipronil spot-on treatments and the oral ingestion of lufenuron, the strategies and methods to control cat fleas dramatically changed during the last 25 years. New innovations and new chemistries have highlighted this progress. Control strategies are no longer based on the tripartite approach of treating the pet, the indoor environment, and outdoors. The ability of modern therapies to break the cat flea life cycle and prevent reproduction has allowed for the stand-alone treatments that are applied or given to the pet. In doing so, we have not only controlled the cat flea, but we have prevented or reduced the impact of many of the diseases associated with ectoparasites and endoparasites of cats and dogs. This review provides an update of newer and non-conventional approaches to control cat fleas.
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Affiliation(s)
- Michael K Rust
- Department of Entomology, University of California, Riverside, CA 92521, USA
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25
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Bongiorno G, Meyer L, Evans A, Lekouch N, Bianchi R, Khoury C, Chiummo R, Thomas E, Gradoni L. A single oral dose of fluralaner (Bravecto®) in dogs rapidly kills 100% of blood-fed Phlebotomus perniciosus, a main visceral leishmaniasis vector, for at least 1 month after treatment. MEDICAL AND VETERINARY ENTOMOLOGY 2020; 34:240-243. [PMID: 31769060 PMCID: PMC7318609 DOI: 10.1111/mve.12420] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/20/2019] [Accepted: 10/27/2019] [Indexed: 06/10/2023]
Abstract
Dogs are the reservoir host of zoonotic visceral leishmaniasis (VL) caused by Leishmania infantum (Kinetoplastida: Trypanosomatidae). Both subclinically-infected and sick animals can be infectious to competent phlebotomine vectors. The degree and duration of insecticidal efficacy of an oral dose of fluralaner (Bravecto®; Merck Animal Health) was determined in dogs exposed to bites of Phlebotomus perniciosus (Diptera: Psychodidae), a main Mediterranean vector of VL. Twelve dogs allocated to two groups of six animals each were included in a parallel-group designed, negative-controlled, randomized, blinded, single-centre efficacy study. Group 2 was treated with fluralaner on day 0, and sand-fly exposure of both groups was performed on days 1, 28 and 84. Viability of blood-fed females was assessed up to 96 h after exposure and efficacy was measured as the survival rate of specimens fed on Group 2 versus those fed on Group 1. A mortality of 100% was recorded at 24 h in females fed on Group 2 at both days 1 and 28. Significant insecticidal efficacy was still observed on day 84, with > 50% mortality recorded by 48 h post blood meal in Group 2. Fluralaner treatment of dogs represents a promising and affordable method for reducing the pool of infected vectors in endemic settings of zoonotic VL.
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Affiliation(s)
- G. Bongiorno
- Unit of Vector‐borne DiseasesIstituto Superiore di SanitàRomeItaly
| | - L. Meyer
- Clinvet SA MoroccoMohammediaMorocco
| | - A. Evans
- Clinvet SA MoroccoMohammediaMorocco
| | | | - R. Bianchi
- Unit of Vector‐borne DiseasesIstituto Superiore di SanitàRomeItaly
| | - C. Khoury
- Unit of Vector‐borne DiseasesIstituto Superiore di SanitàRomeItaly
| | - R. Chiummo
- MSD Animal Health Innovation GmbHSchwabenheimGermany
| | - E. Thomas
- MSD Animal Health Innovation GmbHSchwabenheimGermany
| | - L. Gradoni
- Unit of Vector‐borne DiseasesIstituto Superiore di SanitàRomeItaly
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Sheele JM. A Preliminary Report Showing Spinosad and Fluralaner Are Able to Incapacitate Cimex lectularius L., the Common Bed Bug. Cureus 2020; 12:e7529. [PMID: 32377477 PMCID: PMC7198093 DOI: 10.7759/cureus.7529] [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] [Indexed: 11/05/2022] Open
Abstract
Cimex lectularius L., the common bed bug, is a hematophagous human ectoparasite. The veterinary drugs, spinosad and fluralaner, were studied for their ability to incapacitate C. lectularius when administered in a blood meal using an artificial feeding system under laboratory conditions. Tested drug doses were based on the reported peak blood levels in animals given the drugs. Spinosad at doses 1,000 ng/mL or higher resulted in 75% or greater bed bug incapacitation (defined as death or immobility). Fluralaner at doses 500 ng/mL or higher had 100% bed bug incapacitation. Both drugs were significantly more effective than controls at these doses (P < 0.001).
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A study of the effects of imidacloprid under laboratory and field conditions on nymphs of Triatoma infestans (Hemiptera: Reduviidae). Vet Parasitol 2020; 280:109092. [DOI: 10.1016/j.vetpar.2020.109092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 11/18/2022]
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28
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Ucan-Mézquita A, Jimenez-Coello M, Guzmán-Marín E, Gutierrez-Blanco E, Chan-Pérez JI, Travi BL, Hernandez-Cortazar I, Ortega-Pacheco A. Efficacy of a topical combination of fipronil-permethrin against Rhodnius prolixus on dogs. Vet Parasitol 2019; 276:108978. [PMID: 31765865 DOI: 10.1016/j.vetpar.2019.108978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/05/2019] [Accepted: 11/11/2019] [Indexed: 02/02/2023]
Abstract
A controlled clinical trial was carried out to assess the mortality and repellency of a new topical combination of fipronil-permethrin (Effitix® Virbac, Mexico) against Rhodnius prolixus in dogs. Ten medium-size dogs (10-15 kg) with short hair were used. The dogs were exposed to 8 adult triatomines once weekly for 7 weeks. On the control day (D0), the dogs were exposed to the insects without treatment. On D7, the dogs were immediately treated with a spot-on 2.2 ml pipette containing 134 mg of fipronil and 1200 mg permethrin after exposure to the insects. The dose was repeated after 4 weeks following the manufacturer's instructions. Repellency at D0 was, 0 % and the insects had a high blood content. After 12 h post-contact, repellency was 86.3 % and slowly decrease though D21 and D28. On D7, none of the insects survived after 3 h of feeding on the treated dogs. On D14, D35 and D42, all insects died within 12 h post-feeding, whereas no mortality was observed in the control D0 (P < 0.05). The results of this study indicated that administration of the product following the manufacturer's instructions was efficacious at inducing rapid mortality of R. prolixus and therefore could be useful to prevent the transmission of American trypanosomiasis in dogs.
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Affiliation(s)
- A Ucan-Mézquita
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carr. Merida-Xmatkuil, AP 4-116, Merida, Yucatan, Mexico
| | - M Jimenez-Coello
- Centro de Investigaciones Regionales "Dr. Hideyo Noguchi" Av. Itzaes Centro, Mérida, Yucatán, Mexico
| | - E Guzmán-Marín
- Centro de Investigaciones Regionales "Dr. Hideyo Noguchi" Av. Itzaes Centro, Mérida, Yucatán, Mexico
| | - E Gutierrez-Blanco
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carr. Merida-Xmatkuil, AP 4-116, Merida, Yucatan, Mexico
| | - J I Chan-Pérez
- Centro de Investigaciones Regionales "Dr. Hideyo Noguchi" Av. Itzaes Centro, Mérida, Yucatán, Mexico
| | - B L Travi
- University of Texas Medical Branch, Department of Internal Medicine - Division of Infectious Diseases, Galveston, TX, USA
| | - I Hernandez-Cortazar
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carr. Merida-Xmatkuil, AP 4-116, Merida, Yucatan, Mexico; Centro de Investigaciones Regionales "Dr. Hideyo Noguchi" Av. Itzaes Centro, Mérida, Yucatán, Mexico; University of Texas Medical Branch, Department of Internal Medicine - Division of Infectious Diseases, Galveston, TX, USA
| | - A Ortega-Pacheco
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carr. Merida-Xmatkuil, AP 4-116, Merida, Yucatan, Mexico.
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Castillo-Neyra R, Toledo AM, Arevalo-Nieto C, MacDonald H, De la Puente-León M, Naquira-Velarde C, Paz-Soldan VA, Buttenheim AM, Levy MZ. Socio-spatial heterogeneity in participation in mass dog rabies vaccination campaigns, Arequipa, Peru. PLoS Negl Trop Dis 2019; 13:e0007600. [PMID: 31369560 PMCID: PMC6692050 DOI: 10.1371/journal.pntd.0007600] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 08/13/2019] [Accepted: 07/03/2019] [Indexed: 12/25/2022] Open
Abstract
To control and prevent rabies in Latin America, mass dog vaccination campaigns (MDVC) are implemented mainly through fixed-location vaccination points: owners have to bring their dogs to the vaccination points where they receive the vaccination free of charge. Dog rabies is still endemic in some Latin-American countries and high overall dog vaccination coverage and even distribution of vaccinated dogs are desired attributes of MDVC to halt rabies virus transmission. In Arequipa, Peru, we conducted a door-to-door post-campaign survey on >6,000 houses to assess the placement of vaccination points on these two attributes. We found that the odds of participating in the campaign decreased by 16% for every 100 m from the owner’s house to the nearest vaccination point (p = 0.041) after controlling for potential covariates. We found social determinants associated with participating in the MDVC: for each child under 5 in the household, the odds of participating in the MDVC decreased by 13% (p = 0.032), and for each decade less lived in the area, the odds of participating in the MDVC decreased by 8% (p<0.001), after controlling for distance and other covariates. We also found significant spatial clustering of unvaccinated dogs over 500 m from the vaccination points, which created pockets of unvaccinated dogs that may sustain rabies virus transmission. Understanding the barriers to dog owners’ participation in community-based dog-vaccination programs will be crucial to implementing effective zoonotic disease preventive activities. Spatial and social elements of urbanization play an important role in coverage of MDVC and should be considered during their planning and evaluation. In Peru and other dog rabies-affected countries, mass dog vaccination campaigns (MDVC) are implemented primarily through fixed-location vaccination points: owners have to bring their dogs to the vaccination points where they receive the vaccination. To stop rabies virus transmission, a high and even dog vaccination coverage is desired. In Arequipa, Peru, following a MDVC, we conducted a door-to-door survey of >6,000 houses to assess how the placement of vaccination points affected coverage of the campaign. When comparing dog owners with similar characteristics, we found that the odds of participating in the MDVC was reduced by 16% for every 100 m distance from the nearest vaccination point. Some social conditions were also associated with participating in the MDVC: for each child under 5 in the household, odds of participating in the MDVC decreased by 13%, and for each decade less lived in the area, the odds of participating in the MDVC decreased by 8%. Distance to the vaccination point and variation in social conditions across the city play important roles in achieving coverage of MDVC and should be considered during campaign planning and evaluation.
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Affiliation(s)
- Ricardo Castillo-Neyra
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
- * E-mail:
| | - Amparo M. Toledo
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
| | - Claudia Arevalo-Nieto
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
| | - Hannelore MacDonald
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Micaela De la Puente-León
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
| | - Cesar Naquira-Velarde
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
| | - Valerie A. Paz-Soldan
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
- Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
| | - Alison M. Buttenheim
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
- Department of Family and Community Health, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Michael Z. Levy
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Zoonotic Disease Research Lab, One Health Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Arequipa, Peru
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Laiño MA, Cardinal MV, Enriquez GF, Alvedro A, Gaspe MS, Gürtler RE. An oral dose of Fluralaner administered to dogs kills pyrethroid-resistant and susceptible Chagas disease vectors for at least four months. Vet Parasitol 2019; 268:98-104. [PMID: 30981313 DOI: 10.1016/j.vetpar.2019.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 03/15/2019] [Accepted: 03/16/2019] [Indexed: 11/24/2022]
Abstract
New vector control tools that can fit into a broader integrated vector management strategy are notably lacking. We conducted a seven-month randomized trial to assess the efficacy of a single oral dose of Fluralaner (Bravecto®) administered to dogs on the blood-feeding success, engorgement levels and mortality of pyrethroid-resistant and -susceptible Triatoma infestans third- and fifth-instar nymphs. The trial included 10 Fluralaner-treated and 10 placebo-treated (control) outbred healthy dogs residing in rural houses of the Argentine Chaco. Most (92.7%) of the 3017 triatomines exposed were able to blood-feed. Generalized linear models showed that blood-feeding success was not significantly modified by Fluralaner treatment, time posttreatment and their interaction. However, pyrethroid-susceptible fifth instars blood-fed significantly more frequently than susceptible third instars, and no significant differences were observed between the latter and resistant fifth instars. Engorgement levels were not significantly modified by Fluralaner treatment, time posttreatment and their interaction. Nearly all the triatomines that blood-fed on treated dogs up to 60 days posttreatment (DPT) died within 24 h regardless of pyrethroid susceptibility status combined with bug stage. Cumulative bug mortality over 4 days postexposure remained high over 90-120 DPT (70-81% in susceptible third and fifth instars, and 47-49% in resistant fifth instars), and was virtually nil at 210 DPT. Triatomines that fed on control dogs suffered marginal mortality (0-4%) except at 4 and 30 DPT. Fluralaner and xenointoxication are eligible for Phase III efficacy trials alone or combined with other methods in the frame of an integrated vector management strategy in areas with or without pyrethroid resistance.
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Affiliation(s)
- M A Laiño
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - M V Cardinal
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.
| | - G F Enriquez
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - A Alvedro
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - M S Gaspe
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - R E Gürtler
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
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Gomez SA, Lucientes J, Castillo JA, Peris MP, Delacour S, Ortega P, Oropeza RV, Picado A. A randomized, blinded, controlled trial to assess sand fly mortality of fluralaner administered orally in dogs. Parasit Vectors 2018; 11:627. [PMID: 30518412 PMCID: PMC6282346 DOI: 10.1186/s13071-018-3231-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 11/23/2018] [Indexed: 12/03/2022] Open
Abstract
Background Leishmania infantum is the parasite responsible for the disease in humans known as zoonotic visceral leishmaniasis (ZVL). Dogs are considered the main domestic reservoir of ZVL and sand flies are the proven vectors. The use of systemic insecticides in dogs has been studied as an alternative strategy to control ZVL in endemic areas. One systemic insecticide in dogs, fluralaner, has a proven anti-sand fly effect in membrane-fed studies. However, the efficacy and duration on sand flies directly feeding from dogs treated with fluralaner remains unknown. Methods Direct feeding bioassays were performed on 10 beagle dogs that had been randomly assigned to two groups: one with five dogs orally treated with Bravecto® (fluralaner) and other five as a control. About 30 females of Phlebotomus papatasi were allowed to directly feed from dogs at seven days before the administration of the treatment and Days 3, 17, 31, 45 and 73 post-treatment. Sand fly mortality after feeding was observed every 24 h for 5 days. The Kaplan-Meyer method, Henderson-Tilton formula and a negative binomial mixed model were used to respectively calculate: (i) mortality and its 95% confidence interval (CI); (ii) efficacy of the insecticide at killing sand flies in 24 h; and (iii) differences in the risk of sand fly death at 24 h after feeding. Results Control sand fly mortality 24 h after feeding was always ≤ 20% and mortality in the fluralaner group ranged from 2% (95% CI: 0–4%) 7 days before treatment to 100% at 3 days post-treatment. Fluralaner efficacy was 100, 93, 94 and 75% at Days 3, 17, 31 and 45, respectively (P < 0.0001). The increase in the risk of sand fly death was 32.9 (95% CI: 4–263), 76 (95% CI: 8–705), 95.8 (95% CI: 9–1029) and 10.6 times (95% CI: 1.43–79) on Days 3, 17, 31 and 45, respectively Conclusions The efficacy of fluralaner, orally administered to dogs, against sand-flies was above 90% for 31 days. Fluralaner administered to dogs should be further evaluated as a control strategy in ZVL endemic areas. Electronic supplementary material The online version of this article (10.1186/s13071-018-3231-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sonia Ares Gomez
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.
| | - Javier Lucientes
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Juan Antonio Castillo
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Maria Paz Peris
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Sarah Delacour
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Paula Ortega
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Ronald-Vladimir Oropeza
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Albert Picado
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.
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Gomez SA, Curdi JL, Hernandez JAC, Peris PP, Gil AE, Velasquez RVO, Hernandez PO, Picado A. Phlebotomine mortality effect of systemic insecticides administered to dogs. Parasit Vectors 2018; 11:230. [PMID: 29622033 PMCID: PMC5887228 DOI: 10.1186/s13071-018-2820-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Zoonotic visceral leishmaniasis (ZVL) caused by Leishmania (Leishmania) infantum is an important disease in humans and dogs. Different mammal species are reservoirs but dogs are considered to be the main one. Phlebotomine sand flies are the proven vector. Four systemic insecticides approved for their use in dogs were previously selected based on their potential to be used in endemic countries as part of the control programs of ZVL. These insecticides are proved to be safe and effective against the on-label insects and parasites, but there is no information about their activity against phlebotomine sand flies. METHODS The phlebotomine mortality of four systemic insecticides in dogs was evaluated using two randomized clinical trials. For the first trial, thirty dogs were randomly allocated into five groups: four treatments and one control, of equal size. The treatments evaluated were: Guardian®SR, Elanco (moxidectin); Comfortis®, Elanco (spinosad); Bravecto®, Merck Animal Health (fluralaner); and NexGard®, Merial (afoxolaner). Blood from dogs was taken at days 2, 4, 21 and 31 post-treatment (trial 1). The compound that showed the highest efficacy was selected for a second trial (trial 2) with 20 dogs sampled at days 0, 2, 4, 7, 14, 18, 32, 39, 51 and 84 post-treatment. Membrane feeding bioassays with Phlebotomus papatasi were used to evaluate the phlebotomine mortality efficacy of the different treatments. Phlebotomine mortality was observed every 24 h following the membrane feeding during 5 days. A mixed model for a negative binomial logistic regression, and a Cox proportional hazard mixed model were used to estimate phlebotomine mortality due to different treatments. RESULTS Fluralaner was the only compound that showed significant phlebotomine mortality. Fluralaner maintained the phlebotomine mortality between 60-80% for 30 days after treatment. In trial 1 we found that fluralaner increased the risk of death by 1.9 times (95% CI: 1.02-3.6) and 1.7 times (95% CI: 1.09-2.6) at days 2 and 4 after treatment. The Cox model resulted in an increase of 1.47 (95% CI: 1.1-1.96) times in hazard risk at day 2 and 1.89 (95% CI: 1.35-2.45) at day 4 after treatment. In trial 2 we found that fluralaner increased the risk of death by 1.64 times (95% CI: 1.16-2.54) and 1.97 times (95% CI: 1.23-3.17) at days 14 and 32. The hazard risk was also increased by 1.92 (95% CI: 1.4-2.64) times at day 14 after treatment. Phlebotomine survival including all experimental days was significantly lower in the fluralaner group in both trials. CONCLUSIONS A single oral treatment of fluralaner in dogs induces phlebotomine mortality. Systemic insecticides in dogs should be considered as a potential preventive measure of ZVL.
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Affiliation(s)
- Sonia Ares Gomez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Javier Lucientes Curdi
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | | | - Paz Peris Peris
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Adriana Esteban Gil
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | | | - Paula Ortega Hernandez
- Department of Animal Pathology, Faculty of Veterinary Medicine at the University of Zaragoza, Zaragoza, Spain
| | - Albert Picado
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
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