Evidence map›Paper›PMID 40296035›Full record

ArticleParasites & vectors2025

Acaricidal efficacy of fluralaner against Rhipicephalus microplus ticks under laboratory and field conditions in Brazil.

Daniel de Castro Rodrigues, Gabriel Webert Gomes, Francisca Leticia Vale, Ana Lúcia Coutinho Teixeira, Isabela Santos Silva, Haile Dean Figueiredo Chagas, Tom Strydom, Siddartha Torres, Rafael Paranhos de Mendonça, Fernando de Almeida Borges and 4 more

Abstract read
In one paragraph

Article in Parasites & vectors, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

14 authors.

Daniel de Castro RodriguesGraduate Program in Animal Science-School of Veterinary and Animal Science, Federal University of Goiás-Samambaia Campus, Nova Veneza Highway, Km 8, Goiânia, GO, 74690-900, Brazil.ORCID http://orcid.org/0000-0001-9792-5744
Gabriel Webert GomesUndergraduate Program in Veterinary Medicine, Federal University of Goiás-Samambaia Campus, Nova Veneza, Km 8, Goiânia, GO, 74690-900, Brazil.ORCID http://orcid.org/0000-0002-9731-6954
Francisca Leticia ValeGraduate Program in Animal Science-School of Veterinary and Animal Science, Federal University of Goiás-Samambaia Campus, Nova Veneza Highway, Km 8, Goiânia, GO, 74690-900, Brazil.ORCID http://orcid.org/0000-0002-1449-2582
Ana Lúcia Coutinho TeixeiraGraduate Program in Animal Science-School of Veterinary and Animal Science, Federal University of Goiás-Samambaia Campus, Nova Veneza Highway, Km 8, Goiânia, GO, 74690-900, Brazil.ORCID http://orcid.org/0000-0002-2851-3102
Isabela Santos SilvaGraduate Program in Animal Science-School of Veterinary and Animal Science, Federal University of Goiás-Samambaia Campus, Nova Veneza Highway, Km 8, Goiânia, GO, 74690-900, Brazil.ORCID http://orcid.org/0000-0002-2992-9636
Haile Dean Figueiredo ChagasGraduate Program in Animal Science-School of Veterinary and Animal Science, Federal University of Goiás-Samambaia Campus, Nova Veneza Highway, Km 8, Goiânia, GO, 74690-900, Brazil.ORCID http://orcid.org/0000-0002-8178-7997
Tom StrydomMSD Animal Health, 20 Spartan Road, Kempton Park 1619, Isando, South Africa.ORCID http://orcid.org/0009-0004-1490-5801
Siddartha TorresMerck Animal Health, 2 Giralda Farms, Madison, NJ, 07940, USA.ORCID http://orcid.org/0000-0003-3315-894X
Rafael Paranhos de MendonçaFederal University of Franca, Franca, São Paulo, Brazil.ORCID http://orcid.org/0000-0002-7694-2817
Fernando de Almeida BorgesFederal University of Mato Grosso do Sul, Av. Senador Felinto Muller, 2443, Campo Grande, MS, 79070-900, Brazil.ORCID http://orcid.org/0000-0002-8888-6269
Lívio Costa JuniorCCBS Research Center, Federal University of Maranhão, Avenida dos Santos, Portugueses, no. 1966, São Luís, MA, 65080-805, Brazil.ORCID http://orcid.org/0000-0002-1475-049X
Lorena Lopes FerreiraDepartment of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.ORCID http://orcid.org/0000-0003-0813-3054
Welber Daniel Zanetti LopesGraduate Program in Animal Science-School of Veterinary and Animal Science, Federal University of Goiás-Samambaia Campus, Nova Veneza Highway, Km 8, Goiânia, GO, 74690-900, Brazil.ORCID http://orcid.org/0000-0002-8009-8436
Caio MonteiroGraduate Program in Animal Science-School of Veterinary and Animal Science, Federal University of Goiás-Samambaia Campus, Nova Veneza Highway, Km 8, Goiânia, GO, 74690-900, Brazil. caiosat@gmail.com.ORCID http://orcid.org/0000-0001-5253-5451

Funding

Conselho Nacional de Desenvolvimento Científico e Tecnológico 317482/2021-1Coordenação de Aperfeiçoamento de Pessoal de Nível Superior 001
6 · The paper itself

Abstract

backgroundThe first isoxazoline-based acaricide (fluralaner) for the control of Rhipicephalus microplus was introduced onto the market in 2022, initially in Brazil, followed by other Latin American countries. Therefore, it is important to establish laboratory methods to monitor the susceptibility of populations of R. microplus to this molecule and to determine the relationship between the results of laboratory tests and those from field trials.

methodsA larval immersion test (LIT) was performed on 18 populations of R. microplus. The lethal concentration 50 (concentration causing 50% mortality [LC50]) values were calculated to determine the resistance ratios (RRs) of the populations. The lethal concentration 99 (concentration causing 99% mortality [LC99]) values were calculated to determine the discriminating doses (DDs = 2 × LC99). The DDs were applied in tests with the POA (susceptible) and GYN (resistant) strains, as well as in tests with the population that presented the lowest LC50 value (population 14) and with the two populations that presented the highest LC50 value (populations 10 and 16). Finally, we performed field trials with the population that presented the lowest and two highest LC50 values.

resultsIn the LIT with fluralaner, the LC50 values ranged from 0.144 to 0.481 µg/mL for the 18 R. microplus populations. The mortality rate was 100% in the tests of the DDs in the five populations tested. In the field trials, the efficacy of fluralaner was similar for the three populations of R. microplus tested (populations 14, 10 and 16), with therapeutic efficacy (until day 21) of 100% and persistent efficacy (between days 28 and 42) > 95%.

conclusionWe observed natural variability in the susceptibility of larvae from the different populations of R. microplus that had never been treated with this compound. Despite the observed variability in the in vitro results (LC50), a comparable efficacy of > 90% lasting until day 42 was observed in the field trials. Also, based on the results of the laboratory testing (LC50 and DD) and field trials, we can conclude that there was no resistance to fluralaner in the 18 studied tick populations.

Indexed as

AcaricidesIsoxazolesRhipicephalusTick InfestationsAnimalsBrazilDrug ResistanceLarvaLethal Dose 50A1443 compoundAcaricidesIsoxazolesCattle tickDiscriminating doseField trialIsoxazolinesLarval immersion test

Identifiers

PMID40296035
PMCPMC12039197

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.