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1.
Vet Parasitol ; 278: 109036, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32004852

RESUMO

Amblyomma sculptum is a tick of medical-veterinary importance. Areas with high infestations need to be monitored, and parasitized hosts treated accordingly. Carbon dioxide (CO2) traps and acaricides are commonly deployed as control measures, although with some disadvantages such as high costs, challenging logistics and vertebrate intoxication. Semiochemicals have the potential to improve tick attraction to traps and monitoring devices and alleviate the burden of A. sculptum infestations. Four concentrations (10, 5, 2.5 and 1.25 %) of 13 semiochemical candidates (CO2 only at 5 % as the standard, benzaldehyde, benzoic acid, salicylic acid, 2,6 diclorophenol, R-limonene, S-limonene, methyl salicylate, 1-octen-3-ol, acetone, ammonium hydroxide, isobutyric acid and lactic acid) were tested on unfed A. sculptum nymphs and adults using a Y-tube olfactometer to evaluated repellence and attraction behaviors. All stages tested were attracted to CO2, whereas nymphs were repelled by benzaldehyde and R-limonene, both at 10 %, and isobutyric acid at 5 and 10 %. Nymphs were attracted by methyl salicylate, benzoic acid and salicylic acid, all at 1.25 %, and by ammonium hydroxide at 2.5 %. Males were attracted by benzoic acid at 2.5 %, while females were repelled by benzaldehyde at 5 %. Mixtures with the attractive compounds achieved no attraction response. The compounds that caused attractiveness in the olfactometer assay (CO2, methyl salicylate, benzoic acid, salicylic acid and ammonium hydroxide) were placed randomly in traps in a grassland plot naturally infested with A. sculptum in triplicate. Notably, dry ice (CO2) remained the best at luring ticks in the field (P < 0.001). Benzoic acid should be further investigated since attractant activity was strongly confirmed in both laboratory and field tests. On the other hand, isobutyric acid and R-limonene could be better exploited due to their repellent role revealed by the lab assay, which makes them worthwhile molecules as natural repellents for the management of this tick.


Assuntos
Repelentes de Insetos/farmacologia , Ixodidae/efeitos dos fármacos , Feromônios/farmacologia , Infestações por Carrapato/prevenção & controle , Animais
2.
Exp Parasitol ; 208: 107812, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31809704

RESUMO

The bovine tick, Rhipicephalus microplus, is the main ectoparasite of cattle and causes loss of billions of dollars worldwide in lost meat, milk, and leather production, as well as control expenses. In addition to systemically impacting the host during the parasitic act, this parasite is also an important disease vector. Traditionally, the main commercial control of the tick is achieved through application of chemical acaricides, which can leave residues in the meat and milk. Moreover, ticks can become resistant to these chemicals due to their massive and incorrect use. Many alternative methods have been tested including vaccines and natural products from plant origin. However, the efficacy of these treatments is variable and limited, especially when used alone. Arthropod-pathogenic fungi, such as Metarhizium anisopliae, are among the natural microbial agents with promising potential to be used alone or in association with other products, for example with chemical acaricides. This article discusses several aspects of bovine tick control related to the use of M. anisopliae, which is one of the most studied and viable alternative tools for effective tick control.


Assuntos
Doenças dos Bovinos/prevenção & controle , Metarhizium/fisiologia , Controle Biológico de Vetores/métodos , Rhipicephalus , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/economia , Doenças dos Bovinos/parasitologia , Controle Biológico de Vetores/normas , Rhipicephalus/microbiologia , Rhipicephalus/fisiologia , Infestações por Carrapato/economia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
3.
Parasit Vectors ; 12(1): 509, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666109

RESUMO

BACKGROUND: Haemaphysalis longicornis is the major tick affecting dogs in most of the East Asia/Pacific region and has recently been detected in a number of areas of the USA. This tick is a vector for a number of pathogens of dogs, other mammals and humans. In this study, the efficacy of a single oral administration of sarolaner (Simparica®, Zoetis) at the minimum label dosage (2 mg/kg) was evaluated against an existing infestation of H. longicornis and subsequent weekly reinfestations for 5 weeks after treatment. METHODS: Sixteen dogs were ranked on pretreatment tick counts and randomly allocated to treatment on Day 0 with sarolaner at 2 mg/kg or a placebo. The dogs were infested with H. longicornis nymphs on Days - 2, 5, 12, 19, 26 and 33. Efficacy was determined at 48 hours after treatment and subsequent re-infestations based on live tick counts relative to placebo-treated dogs. RESULTS: There were no adverse reactions to treatment. A single dose of sarolaner provided 100% efficacy on Days 2, 7, 14 and 21; and ≥ 97.4% efficacy on Days 28 and 35. Considering only attached, live ticks, efficacy was 100% for the entire 35 days of the study. Geometric mean live tick counts for sarolaner were significantly lower than those for placebo on all days (11.62 ≤ t(df) ≤ 59.99, where 13.0 ≤ df ≤ 14.1, P < 0.0001). CONCLUSIONS: In this study, a single oral administration of sarolaner at 2 mg/kg provided 100% efficacy against an existing infestation of H. longicornis nymphs and ≥ 97.4% efficacy (100% against attached ticks) against weekly reinfestation for at least 35 days after treatment.


Assuntos
Antiparasitários/uso terapêutico , Vetores Aracnídeos , Azetidinas/uso terapêutico , Doenças do Cão/tratamento farmacológico , Ixodidae , Compostos de Espiro/uso terapêutico , Infestações por Carrapato/veterinária , Administração Oral , Animais , Antiparasitários/administração & dosagem , Azetidinas/administração & dosagem , Doenças do Cão/parasitologia , Doenças do Cão/prevenção & controle , Cães , Compostos de Espiro/administração & dosagem , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/prevenção & controle
4.
Exp Appl Acarol ; 79(1): 99-106, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31489557

RESUMO

Given the difficulties of controlling the tick Rhipicephalus microplus due to acaricide resistance, this study aimed to ascertain whether shearing could reduce infestation in cattle. 17 taurine cattle were sheared on the anterior third of one randomly selected side. Shearing was undertaken using a machine with a blade, leaving coats with a thickness of 1 mm. Subsequently, eight evaluations were performed once a week, counting adult females of R. microplus with a diameter > 4.5 mm on the anterior third of both sides (shorn and unshorn). The coat length was also monitored by taking five hair samples from each animal fortnightly (1, 15, 29, 43 and 57 days post shorn) from a central area of both shoulders (shorn and unshorn). The tick counts and hair length data were transformed for normalisation and were analysed using mixed models. The tick and hair length means were significantly higher for the unshorn side. Tick counts were significantly lower on the sheared side until the fifth evaluation, with the final three presenting no differences between the sides. The hair length was significantly lower for the sheared side during the five evaluations. We conclude that as the hair length increased, there was also an increase in the number of ticks on the sheared side. Although this method is not practical for large herds, it can be deemed an option in extreme conditions of tick infestation. In addition, the study reinforces the suggestion that the selection and/or use of cattle with shorter hairs may contribute to reduced tick infestation.


Assuntos
Criação de Animais Domésticos/métodos , Doenças dos Bovinos/prevenção & controle , Cabelo , Rhipicephalus/fisiologia , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Feminino , Masculino , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
5.
Vet Parasitol ; 272: 1-12, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31395198

RESUMO

The identification of candidate protective antigens for the development of tick vaccines may be approached by selecting antigen candidates that play key biological functions. Tick midgut proteins that play essential functions in tick survival and disease transmission are upregulated in response to blood feeding and digestion. In this study, Ornithodoros erraticus midgut transcriptomic and proteomic data upon feeding were inspected to select functionally relevant antigens to be assessed as vaccine candidate antigens. For this, we primarily focused on proteins with relevant biological functions in key physiological processes for ticks and tick-host-pathogen interactions. Later, we used additional criteria based on overexpression after feeding, predicted antigenicity and cellular localisation, resulting in the selection of four theoretical candidates, two aquaporins (OeAQP, OeAQP1), one ABC transporter (OeABC) and one selenoprotein T (OeSEL). Rabbit vaccination with synthetic immunogenic peptides designed from the extracellular antigenic regions of the selected candidates induced humoral responses that reduced tick feeding and reproduction performance. Both AQPs and OeSEL demonstrated significant protection efficacy against the homologous species O. erraticus, but lower non-significant cross-species protection against Ornithodoros moubata. Conversely, OeABC showed no protection against the homologous species O. erraticus, but significant cross-species protection against O. moubata. These results are the first demonstration of the protective potential of argasid aquaporins, suggesting that they might be included in vaccines for the control of multiple tick species. Additionally, these results also unveiled two novel protective antigens from argasid ticks, OeABC and OeSEL, belonging to functional protein families that have never been explored as a source of vaccine candidates and are deserving of further studies. Finally, our data add value to the midgut as a protective candidate antigen source in argasids for the control of tick infestations.


Assuntos
Proteínas de Artrópodes/imunologia , Interações Hospedeiro-Parasita/imunologia , Ornithodoros/imunologia , Infestações por Carrapato/prevenção & controle , Animais , Proteínas de Artrópodes/metabolismo , Ornithodoros/química , Proteoma , Coelhos , Transcriptoma
6.
Ticks Tick Borne Dis ; 10(6): 101264, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31431351

RESUMO

As part of a TickNET collaboration we evaluated the knowledge, attitudes, and behaviors related to tick-borne disease (TBD) prevention among persons living in endemic areas of Connecticut (CT) and Maryland (MD). Up-to-date information on the use of various prevention methods, as well as attitudes toward available and potential prevention options, is critical for effective promotion of recommended behaviors. During 2016-2017, printed invitations were mailed via the post office to 27,029 households requesting participation in an online survey regarding knowledge of TBD, risk perceptions, and prevention behaviors. Prevention behaviors included tick checks, showering/bathing, insect repellents, pet tick control, and chemical or natural pesticide use on residential properties. Associations of sociodemographic characteristics and knowledge and attitude variables with prevention behaviors were assessed in unadjusted analyses and multivariable models to calculate adjusted odds ratios (aOR). Participants were also asked if they would be willing to get a Lyme disease (LD) vaccine, if one becomes available. Overall, 1883 (7%) persons completed the survey. Participants reported using preventive behaviors most of the time or always as follows: pet tick control (83%), tick checks (58%), showering/bathing (42%), insect repellent (31%), and chemical (23%) or natural (15%) pesticides on property. Self-rated knowledge of LD, perceived prevalence of LD, perceived severity of LD, and perceived likelihood of contracting LD or another TBD were significantly (p < 0.05) associated with performing a tick check [aOR 2.5, aOR 1.71, aOR 1.36, aOR 1.83, respectively]. Female gender and perceived prevalence of LD were significantly associated with applying insect repellent [aOR 1.56, aOR 1.64, respectively]. Perceived prevalence of LD was significantly associated with showering or bathing, insect repellents, and pet tick control [aOR 1.42, aOR 1.64, aOR 1.92, respectively]. Income > $100,000 was significantly associated with applying a chemical or natural pesticide to one's property [aOR 1.29, aOR 1.40, respectively]. A majority of respondents (84%) reported that they were very likely or somewhat likely to get a LD vaccine if one were available. Few behaviors (tick checks and pet tick control) were reported to be practiced by more than half of the respondents living in LD endemic areas. Perceived prevalence of LD was the only factor associated with performing most of the prevention behaviors (tick checks, showering/bathing, use of insect repellents, and pet tick control). Use of chemical or natural pesticides appears to be driven by income. Greater efforts are needed to encourage use of prevention behaviors in endemic areas, and this may be facilitated by increasing awareness of local prevalence.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Infestações por Carrapato/psicologia , Doenças Transmitidas por Carrapatos/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Connecticut , Doenças Endêmicas/prevenção & controle , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Maryland , Pessoa de Meia-Idade , Medição de Risco , Autorrelato , Fatores Sexuais , Controle de Ácaros e Carrapatos/estatística & dados numéricos , Infestações por Carrapato/prevenção & controle , Doenças Transmitidas por Carrapatos/prevenção & controle , Adulto Jovem
7.
Parasite ; 26: 49, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31432778

RESUMO

This experimental study aimed to determine the efficacy of Afoxolaner (NexGard®) to prevent Babesia rossi transmission by Haemaphysalis elliptica ticks on dogs. The study included three groups of seven dogs each. Groups 1 and 2 remained untreated, whereas group 3 dogs received NexGard® on Day 0. All dogs were infested by 50 Haemaphysalis elliptica adult ticks: Group 1 on Day 2, Group 2 on Day 28 and Group 3 on Days 2 and 28. The ticks were originally nymphs having fed on B. rossi infected donor dogs. Their infection rate, assessed by PCR, was 12.8% at Day 2 and 6% at Day 28. On Days 0, 7, 14, 21, 28, 35, 42, 49 and 56, and in case of suspicion of babesiosis, blood samples were collected for blood smears, PCR and ELISA. The B. rossi infection rate in the untreated group 1 was 100% (6/6, as one dog was inadvertently treated on Day 15 and removed from statistical analysis). The infection rate was 57.1% (4/7) in group 2, and 0% (0/7) in the afoxolaner treated group 3 at all time-points until the end of the study on Day 56. After tick removal and count 144 h after each infestation, the control groups had an arithmetic mean of ticks of 23.8 (group 1) and 26.8 (group 2). No tick was recovered from any treated dogs. This study demonstrated that NexGard® protected dogs against infection by B. rossi for at least 28 days.


Assuntos
Acaricidas/administração & dosagem , Babesiose/prevenção & controle , Doenças do Cão/prevenção & controle , Doenças do Cão/parasitologia , Isoxazóis/administração & dosagem , Naftalenos/administração & dosagem , Infestações por Carrapato/veterinária , Administração Oral , Animais , Babesia/genética , Babesiose/sangue , Babesiose/transmissão , Doenças do Cão/sangue , Cães/parasitologia , Feminino , Masculino , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Resultado do Tratamento
8.
Exp Appl Acarol ; 78(4): 579-593, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31352648

RESUMO

Rhipicephalus microplus causes high economic losses for Uruguay; the country is divided into a R. microplus-free area and an endemic area. The aim of this research was to evaluate the R. microplus and tick fever situation in Uruguay and the feasibility of implementing R. microplus control or elimination programs to reduce the number of infested farms. A representative survey was performed to determine the number of infested farms, the number of farms with outbreaks of tick fever and the control and preventive measures being used. Control or elimination programs using generational treatment were implemented on 30 farms. Previously, a situation diagnosis was performed by evaluating the background of each farm, identifying acaricide resistance, serologically evaluating the enzootic stability of tick fever, and analyzing the risk of R. microplus introduction to farms. According to the survey, R. microplus was present on 9544 (36%) farms, and 3436 (36%) of these farms experienced outbreaks of tick fever. Only 323 (9.4%) farmers used the tick fever vaccine. Of the 30 farms for which control or elimination programs were carried out, 18 reduced the number of treatments applied per year and six achieved the elimination of the cattle tick. It is concluded that by administering elimination or control programs, it is possible to reduce the number of infested farms and the number of treatments to maintain control. New surveys should be performed to measure the degree of technology adoption by farmers and to analyze the advances in tick control or elimination programs on farms.


Assuntos
Anaplasmose/epidemiologia , Babesiose/epidemiologia , Doenças dos Bovinos/prevenção & controle , Rhipicephalus/fisiologia , Controle de Ácaros e Carrapatos/estatística & dados numéricos , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Uruguai/epidemiologia
9.
Exp Appl Acarol ; 78(4): 565-577, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31352649

RESUMO

The objective of the present study was to evaluate the performance of Brangus and Nellore cattle in an extensive production system. Sixty growing bulls, 30 of the Brangus and 30 of the Nellore breeds that were naturally infested with Rhipicephalus microplus were subdivided into four groups: control Nellore (15 animals), treated Nellore (15), control Brangus (15), and treated Brangus (15). The animals in the treated groups underwent acaricidal treatments for 1 year. Tick counts, acaricidal treatments and animal weighing were performed every 18 days, and the costs of acaricidal, anti-myiasis, and preventive treatments for tick fever were recorded for cost evaluation. The treated Brangus and Nellore groups did not show a significant difference in weight gain, whereas Nellore weight gain was superior in the control groups. The cost of acaricidal treatment throughout the experimental period was $494 US. The costs of the preventive treatment for tick fever and myiasis were $98 US and $15 US, respectively. The highest rates of tick infestation were found in the control group of the Brangus animals, which served as the basis for the suggested implementation of a strategic control program for animals in the growth phase. Nellore animals showed low rates of infestation. Under the conditions of this study, the Nellore animals were more efficient than the Brangus animals because they achieved satisfactory weight gain, similar to the Brangus, and a low tick count even in the control group. This finding demonstrates that expenses related to the acaricidal, anti-myiasis and tick fever treatments are unnecessary in Nellore cattle, making these animals more profitable.


Assuntos
Criação de Animais Domésticos/economia , Doenças dos Bovinos/prevenção & controle , Rhipicephalus/fisiologia , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Animais , Brasil , Bovinos/classificação , Doenças dos Bovinos/parasitologia , Feminino , Masculino , Estações do Ano , Controle de Ácaros e Carrapatos/economia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
10.
Trop Anim Health Prod ; 51(7): 1989-1995, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31076993

RESUMO

Despite several decades of chemical control, the cattle tick Rhipicephalus microplus remains an important constraint for cattle farmers. The regular use of chemicals has led to the development of tick strains that are multi-resistant to acaricides. New methods of tick control are being developed and combined in integrated tick management programs. Grazing management is one part of these control methods. However, until now, grazing management consisted essentially of resting pastures for 4 to 5 months. This amount of time is generally sufficient to allow for natural tick larvae mortality to occur, but this method often compromises the quality of forages, which is less than optimal at the time of arrival of the animals in the paddock. In this paper, we propose a new approach to pasture management-based tick control that optimizes forage production. It is based on tick development biological parameters, herd management and strategic treatments. This approach was tested for 2 years on two farms raising tick-susceptible European breeds of cattle under tropical conditions. The number of chemical treatments decreased respectively by 82.9% and 70.9%. This cost-effective approach may prove useful in decreasing the number of acaricidal treatments on farms facing high tick loads.


Assuntos
Criação de Animais Domésticos/métodos , Doenças dos Bovinos/prevenção & controle , Pradaria , Rhipicephalus/fisiologia , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Animais , Bovinos , Fazendas , Infestações por Carrapato/prevenção & controle
11.
Exp Parasitol ; 201: 26-33, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31029699

RESUMO

The cattle tick Rhipicephalus (Boophilus) microplus is one of the most important ectoparasites for livestock in tropical and subtropical areas around the world. This tick economically impacts cattle production by reducing weight gain and milk production. Moreover, it is a vector of pathogens causing diseases such as babesiosis and anaplasmosis. Conventional tick control relies mainly on the use of chemical acaricides; however, their intensive use has led to the rapid appearance of resistant tick populations. It is therefore necessary to look for alternative tick control products. In that sense, plant extracts might represent a promising source of new acaricides. Previously, we reported a significant acaricide effect of essential oils from selected plant species. In the present study, we used a mixture design approach to develop phyto-formulations by combining individual essential oils. We produced several mixtures at 10% containing different proportions of individual essential oils (ranging from 0 to 1) from cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and allspice (Pimenta dioica) and tested their acaricidal activity against R. microplus ticks by means of larval packet test (LPT) and adult immersion test (AIT) assays. The optimal mixture predicted against R. microplus was composed of 66%, 17% and 17% of essential oils from C. zeylanicum, C. cyminum and P. dioica, respectively. We generated an estimated response surface contour plot that estimates 80%-100% acaricidal efficacy. In the optimal mixture 34 compounds were identified, which represent 98.65% of the total composition, with cinnamaldehyde (37.77%), ß-caryophyllene (13.92%), methyl eugenol (12.27%) and cuminaldehyde (8.99%) being the major components. Next, we developed emulsions by combining the optimal mixture with several surfactants and determined particle size, Zeta potential, stability and bioactivity. Emulsions containing 2% and 5% Tween 20 or Tween 80 remain stable after 14 days at 54 °C. Finally, optimized emulsion retained a high acaricidal activity against larval and adult R. microplus ticks. Taken together, our findings showed the usefulness of mixture design method for the development of essential oil mixtures with potent acaricidal activity. These formulations have the potential to successfully control tick infestations.


Assuntos
Doenças dos Bovinos/prevenção & controle , Óleos Voláteis , Extratos Vegetais , Rhipicephalus , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Acaricidas , Análise de Variância , Animais , Vetores Aracnídeos , Bovinos , Doenças dos Bovinos/parasitologia , Cinnamomum zeylanicum/química , Misturas Complexas/química , Cuminum/química , Emulsões/química , Feminino , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/química , Pimenta/química , Extratos Vegetais/química , Sementes/química , Infestações por Carrapato/prevenção & controle
12.
Parasit Vectors ; 12(1): 185, 2019 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-31029149

RESUMO

BACKGROUND: The southern cattle fever tick (SCFT), Rhipicephalus (Boophilus) microplus, remains endemic in Puerto Rico. Systematic treatment programmes greatly reduced and even eradicated temporarily this tick from the island. However, a systemic treatment programme that includes integrated management practices for livestock against SCFT remains to be established in the island. We describe a spatially-explicit, individual-based model that simulates climate-livestock-SCFT-landscape interactions. This model was developed as an investigative tool to aid in a research project on integrated management of the SCFT that took place in Puerto Rico between 2014 and 2017. We used the model to assess the efficacy of tick suppression and probability of tick elimination when applying safer acaricides at 3-week intervals to different proportions of a herd of non-lactating dairy cattle. RESULTS: Probabilities of eliminating host-seeking larvae from the simulated system decreased from ≈ 1 to ≈ 0 as the percentage of cattle treated decreased from 65 to 45, with elimination probabilities ≈ 1 at higher treatment percentages and ≈ 0 at lower treatment percentages. For treatment percentages between 65% and 45%, a more rapid decline in elimination probabilities was predicted by the version of the model that produced higher densities of host-seeking larvae. Number of weeks after the first acaricide application to elimination of host-seeking larvae was variable among replicate simulations within treatment percentages, with within-treatment variation increasing markedly at treatment percentages ≤ 65. Number of weeks after first application to elimination generally varied between 30 and 40 weeks for those treatment percentages with elimination probabilities ≈ 1. CONCLUSIONS: Explicit simulation of the spatial and temporal dynamics of off-host (host-seeking) larvae in response to control methods should be an essential element of research that involves the evaluation of integrated SCFT management programmes. This approach could provide the basis to evaluate novel control technologies and to develop protocols for their cost-effective use with other treatment methods.


Assuntos
Acaricidas/administração & dosagem , Doenças dos Bovinos/parasitologia , Simulação por Computador , Rhipicephalus , Infestações por Carrapato/prevenção & controle , Infestações por Carrapato/veterinária , Acaricidas/economia , Animais , Vetores Artrópodes , Bovinos/parasitologia , Clima , Indústria de Laticínios , Feminino , Lactação , Larva , Gado/parasitologia , Porto Rico , Análise Espacial , Processos Estocásticos , Infestações por Carrapato/economia
13.
Artigo em Inglês | MEDLINE | ID: mdl-30881925

RESUMO

Vaccines are an environmentally friendly alternative to acaracides for the control of tick infestations, to reduce the risk for tick-borne diseases affecting human and animal health worldwide, and to improve animal welfare and production. Subolesin (SUB, also known as 4D8) is the functional homolog of Akirin2 involved in the regulation of development and innate immune response, and a proven protective antigen for the control of ectoparasite infestations and pathogen infection. Oral vaccination combining protein antigens with immunostimulants has proven efficacy with increased host welfare and safety, but has not been used for the control of tick infestations. Here we describe the efficacy of oral vaccination with a formulation combining Rhipicephalus microplus SUB and heat inactivated Mycobacterium bovis (IV) on cattle tick infestations and fertility. The levels of IgG antibody titers against SUB and M. bovis P22, and the expression of selected immune response genes were determined and analyzed as possible correlates of protection. We demonstrated that oral immunization with the SUB+IV formulation resulted in 51% reduction in the number of female ticks and 30% reduction in fertility with an overall efficacy of 65% in the control of R. microplus infestations by considering the cumulative effect on reducing tick survival and fertility in cattle. The akr2, IL-1ß, and C3 mRNA levels together with antibody levels against SUB correlated with vaccine efficacy. The effect of the oral immunization with SUB+IV in cattle on tick survival and fertility is essential to reduce tick infestations, and extended previous results on the effect of R. microplus SUB for the control of cattle tick infestations. These results support the development of oral vaccines formulations for the control of tick infestations and the incidence of tick-borne diseases.


Assuntos
Antígenos/administração & dosagem , Antígenos/imunologia , Proteínas de Artrópodes/administração & dosagem , Proteínas de Artrópodes/imunologia , Mycobacterium bovis/imunologia , Rhipicephalus/crescimento & desenvolvimento , Rhipicephalus/imunologia , Infestações por Carrapato/prevenção & controle , Vacinação/métodos , Administração Oral , Animais , Bovinos , Modelos Animais de Doenças , Fertilidade , Fatores Imunológicos/análise , Incidência , Análise de Sobrevida , Resultado do Tratamento
14.
Vet Parasitol ; 270 Suppl 1: S12-S18, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30914264

RESUMO

The efficacy of a single application of a new topical formulation containing selamectin plus sarolaner (Revolution® Plus / Stronghold® Plus, Zoetis) was evaluated against fleas and ticks infesting cats enrolled as veterinary patients in two field studies conducted in Japan and against Haemaphysalis longicornis ticks on cats in a laboratory study. In the laboratory study, sixteen cats were ranked based on pre-treatment tick counts and allocated randomly to treatment on Day 0 with either selamectin plus sarolaner or placebo. Cats were infested with adult H. longicornis on Days -2, 5, 12, 19, 26 and 33. Efficacy relative to placebo was based on live attached tick counts conducted 48 h after treatment and subsequent re-infestations. Selamectin plus sarolaner reduced live, attached H. longicornis counts by 96.4% within 48 h of treatment, and by ≥91.7% within 48 h of weekly re-infestation for 35 days, based on arithmetic means. In the field studies, 67 client-owned cats harboring six or more live fleas and 63 cats harboring four or more live attached ticks were enrolled to evaluate selamectin plus sarolaner for efficacy and safety compared with a registered product. Cats were allocated randomly to treatment with selamectin plus sarolaner or fipronil plus (S)-methoprene based on order of presentation. Treatment was administered once on Day 0 and efficacy was assessed by parasite counts conducted on Days 14 and 30 compared to the pre-treatment count. In the flea field study, live flea counts on Days 14 and 30 were reduced by 99.5% and 99.9% in the selamectin plus sarolaner group, and by 97.6% and 98.6% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Clinical signs typically associated with flea allergy dermatitis improved following treatment. In the tick field study, live tick counts on Days 14 and 30 were reduced by 97.5% and 97.7% in the selamectin plus sarolaner group, and by 91.5% and 93.4% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Selamectin plus sarolaner was determined to be non-inferior to fipronil plus (S)-methoprene in both field studies. There were no treatment-related adverse events in any study. A single topical dose of Revolution® Plus / Stronghold® Plus providing a minimum dosage of 6.0 mg/kg selamectin and 1.0 mg/kg sarolaner was confirmed to be effective against H. longicornis ticks on cats for one month and safe and effective in the treatment of fleas and ticks on cats enrolled as veterinary patients in Japan.


Assuntos
Azetidinas/administração & dosagem , Doenças do Gato/tratamento farmacológico , Infestações por Pulgas/veterinária , Ivermectina/análogos & derivados , Compostos de Espiro/administração & dosagem , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Acaricidas/administração & dosagem , Administração Tópica , Animais , Doenças do Gato/prevenção & controle , Gatos , Composição de Medicamentos/veterinária , Feminino , Infestações por Pulgas/tratamento farmacológico , Infestações por Pulgas/prevenção & controle , Inseticidas/administração & dosagem , Ivermectina/administração & dosagem , Japão , Masculino , Metoprene/administração & dosagem , Pirazóis/administração & dosagem , Distribuição Aleatória , Sifonápteros/efeitos dos fármacos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/prevenção & controle , Carrapatos/efeitos dos fármacos , Resultado do Tratamento
15.
Ticks Tick Borne Dis ; 10(3): 621-627, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30799282

RESUMO

Amblyomma sculptum is a tick affecting animal and human health across Argentina, Bolivia, Paraguay and Brazil. Donkeys, Equus asinus, are known to be resistant to A. sculptum, suggesting that they can produce non-host tick semiochemicals (allomones), as already demonstrated for some other vertebrate host/pest interactions, whereas horses, Equus caballus, are considered as susceptible hosts. In this study, we tested the hypothesis that donkeys produce natural repellents against A. sculptum, by collecting sebum from donkeys and horses, collecting the odour from sebum extracts, and identifying donkey-specific volatile compounds by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS). From the complex collected blends, five main compounds were identified in both species. Hexanal, heptanal and (E)-2-decenal were found predominantly in donkey extracts, whilst ethyl octanoate and ethyl decanoate were found predominantly in horse extracts. One compound, (E)-2-octenal, was detected exclusively in donkey extracts. In Y-tube olfactometer bioassays 36 different A. sculptum nymphs were tested for each extract, compound and concentration. The dry sebum extracts and the compounds identified in both species induced neither attraction nor repellency. Only (E)-2-octenal, the donkey-specific compound, displayed repellency, with more nymphs preferring the arm containing the solvent control when the compound was presented in the test arm across four concentrations tested (p < 0.05, Chi-square test). A combination of a tick attractant (ammonia) and (E)-2-octenal at 0.25 M also resulted in preference for the control arm (p < 0.05, Chi-square test). The use of semiochemicals (allomones) identified from less-preferred hosts in tick management has been successful for repelling brown dog ticks, Rhipicephalus sanguineus sensu lato from dog hosts. These results indicate that (E)-2-octenal could be used similarly to interfere in tick host location and be developed for use in reducing A. sculptum numbers on animal and human hosts.


Assuntos
Equidae/fisiologia , Repelentes de Insetos/isolamento & purificação , Feromônios/isolamento & purificação , Rhipicephalus sanguineus/efeitos dos fármacos , Sebo/química , Infestações por Carrapato/veterinária , Aldeídos/isolamento & purificação , Aldeídos/farmacologia , Alcenos/isolamento & purificação , Alcenos/farmacologia , Animais , Caprilatos/isolamento & purificação , Caprilatos/farmacologia , Cromatografia Gasosa , Decanoatos/isolamento & purificação , Decanoatos/farmacologia , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Cavalos/fisiologia , Repelentes de Insetos/farmacologia , Ninfa/efeitos dos fármacos , Feromônios/farmacologia , Infestações por Carrapato/prevenção & controle
16.
Med Vet Entomol ; 33(3): 352-359, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30773654

RESUMO

Impacts of sheep ticks Ixodes ricinus on livestock, gamebirds and wildlife are of concern across Europe. The present study describes livestock and tick management by 36 farmers from three upland sites of conservation importance in North Wales, where farmers consider that ticks have increased during the last 25 years. Sheep, average densities of 2.0 animals per ha were treated with pour-on acaricides in spring, again in July, and also when removed from the moor in autumn. Given acaricide efficacy rates, sheep were susceptible to tick bites for half the period on the moor. Sheep from 17 farms were examined for ticks. Infestations were similar between farms and in relation to the acaricide used, averaging 9.3 ticks per sheep, although they were lower where the interval between successive acaricide treatments was shorter. Repeated sampling of sheep and red grouse chicks showed no annual difference in tick burdens on grouse chicks, which averaged 6.2 ticks per chick, although there were three-fold fewer ticks on sheep in 2018 than in previous years. Tick bite rates on sheep and grouse were higher than elsewhere in the U.K. Most farmers interviewed would aim to improve their tick management using longer-lasting acaricides and treating sheep more frequently, although they would need advice and financial help, which is currently unavailable via Government funded agri-environment schemes.


Assuntos
Criação de Animais Domésticos , Conservação dos Recursos Naturais , Galliformes/fisiologia , Ixodes , Doenças dos Ovinos/prevenção & controle , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Animais , Fazendas , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , País de Gales
17.
Med Vet Entomol ; 33(2): 317-321, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30746727

RESUMO

An indoor terrarium population of Amblyomma geoemydae was established subsequent to the import of a single yellow-marginated box turtle Cuora flavomarginata. This indoor tick population revealed an unexpected resistance against de-ticking trials, with persistence between 2010 and 2015, when the ticks were successfully eliminated. Ticks were collected from the bodies and shells of turtles, as well as from terraria soil. Species diagnosis of ticks was carried out according to distinguishable morphological characters and supported by molecular analysis using DNA-barcoding. Introduced exotic ticks are potential vectors of pathogens and can have an impact on wildlife, domestic animals and the human population. This case emphasizes the need for sharp surveillance and control measures on imported reptiles.


Assuntos
Ixodidae/fisiologia , Infestações por Carrapato/veterinária , Tartarugas , Animais , Animais de Zoológico , Áustria , Código de Barras de DNA Taxonômico/veterinária , Feminino , Espécies Introduzidas , Ixodidae/classificação , Ixodidae/genética , Ixodidae/crescimento & desenvolvimento , Larva/classificação , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ninfa/classificação , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Estações do Ano , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
18.
East Mediterr Health J ; 24(11): 1082-1087, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30701523

RESUMO

Background: Ticks are able to transmit important diseases to humans, including Rocky Mountain spotted fever, Q fever, Crimean-Congo haemorrhagic fever, summer Russian encephalitis, and relapsing fever. Aims: To determine the repellency effect of 1% flumethrin pour-on formulation against hard ticks. Methods: The concentration of flumethrin pour-on formulation was 1 mg/10 kg body weight and was administered on the dorsal midline from the head to the base of the tail. The livestock included cows, goats, oxen and sheep in 2 villages in Ardabil Province, Islamic Republic of Iran. Results: We studied 200 livestock comprising 5 age groups (< 2, 3-4, 5-6, 7-8 and >8 years). The main hard ticks identified were Hyalomma species (62.5%) and Rhipicephalus bursa (37.5%). In the treatment village, the maximum number of ticks per animal was 11.6 in oxen, 9.5 in sheep, 8.9 in goats and 8.6 in cattle. The repellency effect of flumethrin remained for 2 months. Conclusions: Flumethrin provided 2 months protection against hard ticks. Therefore, it could be used in the livestock industry. Control of ticks is important for prevention of disease transmission.


Assuntos
Febre Hemorrágica da Crimeia/prevenção & controle , Repelentes de Insetos , Ixodidae , Piretrinas , Infestações por Carrapato/veterinária , Animais , Bovinos/parasitologia , Cabras/parasitologia , Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia/transmissão , Humanos , Irã (Geográfico) , Ixodidae/virologia , Rhipicephalus/virologia , Ovinos/parasitologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
19.
Med Vet Entomol ; 33(2): 312-316, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30671993

RESUMO

This work was performed to test the efficacy of winter-spring control strategies against Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) infestations on cattle in the area ecologically most favourable for the development of this tick in Argentina. Two control schemes using three and four annual applications of acaricides, respectively, were evaluated. Animals in Group 1 were treated with ivermectin 3.15% on day 0, fluazuron on day 34, and fipronil on day 85. Animals in Group 2 were treated with ivermectin 3.15% on day 0, fluazuron on day 34, flumethrin on day 85, and fipronil on day 114. Animals in Group 3 represented the control group. Both treatment schemes provided appropriate levels of efficacy against R. microplus and also prevented the occurrence of the major peak in the frequency of this tick in autumn. The two treatment schemes were similar in terms of efficacy and thus the addition of a fourth treatment does not seem to confer any further advantage. The results of this work indicate that these strategic control methods provide appropriate levels of control against R. microplus.


Assuntos
Acaricidas/farmacologia , Doenças dos Bovinos/prevenção & controle , Erradicação de Doenças/métodos , Rhipicephalus/efeitos dos fármacos , Infestações por Carrapato/veterinária , Animais , Argentina , Bovinos , Doenças dos Bovinos/parasitologia , Ecossistema , Feminino , Rhipicephalus/fisiologia , Estações do Ano , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
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