Resistance to macrocyclic lactone anthelmintics and associated risk factors on sheep farms in the lower North Island of New Zealand

Hughes, Paul L.; Dowling, A F; Callinan, A. P. L.

doi:10.1080/00480169.2007.36764

Cited by 35 publications

(27 citation statements)

References 24 publications

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“…In New Zealand, an analysis of sheep AR through a field survey indicated refugia as an important risk factor (HUGHES et al 2007). Their results showed that the prevalence of AR was higher on farms on which more than 50% of lambs were weaned onto paddocks not grazed for a long period by lambing ewes and where lambs were not always returned to the same paddock after drenching.…”

Section: Discussionmentioning

confidence: 99%

Risk factors for anthelmintic resistance development in cattle gastrointestinal nematodes in Argentina

Suárez

Cristel²

2014

Rev. Bras. Parasitol. Vet.

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Risk factors for anthelmintic resistance (AR) on bovine ranches were studied. Data were derived from a survey made to 50 ranch owners, who had conducted a faecal egg-count-reduction test. The questionnaire contained descriptors of bovine ranch management and nematode control. A case-control design study was undertaken and AR cases were present in 26 herds. Associations between the binary outcome variable (AR versus not AR) and risk factors recorded in the questionnaire were evaluated. Variables associated with the presence of AR at P< 0.15 and/or odds ratio (OR) > 2 were subjected to a multivariable logistic regression model. The main effects contributing to general AR (avermectin AVM and/or benzimidazole) in the final model were total number of annual treatments (OR 7.68; 95% CI 2.4 to 28.3) and use of more than 75% of AVM in the past (OR= 18.6; 95% CI 1.3 to 97.3), whereas for AVM resistance alone were total number of AVM annual treatments (OR= 11.5; 95% CI 2.9 to 45.5) and number of AVM Nov-Jan treatments (OR= 5.8; 95% CI 1.71 to 47.9). The results showed that treatment frequency, date of treatment and frequency of treatment in the past with a single drug were the main risk factors involved in AR development.Keywords: Nematode, cattle, anthelmintic resistance, risk factor. ResumoFatores de risco para resistência anti-helmíntica (AR) em fazendas de criação de bovinos foram estudados de dados obtidos de um levantamento em 50 propriedades. Em todas foram conduzidos testes de redução de contagem de ovos (opg) e um questionário preenchido pelos proprietários sobre o manejo e o controle de verminose nessas fazendas. Um estudo com desenho de caso controlado foi realizado e casos de AR estavam presentes em 26 rebanhos. Associações foram avaliadas entre a variável binária produzida (AR versus sem AR) e fatores de risco registrados nos questionários. Variáveis associadas com o resultado de interesse a P<0.15 e/ou razão de prevalência (OR) > 2 foram usados num modelo de regressão logística multivariável. Os principais efeitos contribuintes para AR geral (avermectina AVM e/ou benzimidazole), no modelo final, foram número total de tratamentos anuais (OR 7,68; 95% IC 2,4 a 28,3) e uso no passado mais que 75% de AVM (OR= 18,6; 95% IC 1,3 a 97,3), e para resistência à AVM foram número total de tratamentos anuais (OR=11,5; 95% IC 2,9 a 45,5), número de tratamentos com AVM de novembro a janeiro (OR= 5,8; 95% IC 1,71 a 47,9). Estes resultados mostraram que a frequência dos tratamentos, a época do ano em que foram feitos os tratamentos e a frequência dos tratamentos no passado com uma única droga foram os principais fatores de risco implicado no desenvolvimento de AR.Palavras-chave: Nematóide, gado, resistência anti-helmíntica, fator de risco.

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Section: Discussionmentioning

confidence: 99%

Risk factors for anthelmintic resistance development in cattle gastrointestinal nematodes in Argentina

Suárez

Cristel²

2014

Rev. Bras. Parasitol. Vet.

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“…Early recommendations for sustainable parasite control were either based on evidence regarding key molecular processes involved in selection for resistance (Dobson et al, 2001), or simulation models (Leathwick et al, 1995). In recent years, several observational studies (Suter et al, 2004;Lawrence et al, 2006;Hughes et al, 2007;Calvete et al, 2012) and clinical trials Leathwick et al, 2008;Waghorn et al, 2008Waghorn et al, , 2009 have been performed to investigate the association between putative risk factors and AHR. While all these studies may provide valuable information in isolation, they sometimes describe conflicting results.…”

Section: Introductionmentioning

confidence: 99%

A systematic review and meta-analysis of factors associated with anthelmintic resistance in sheep

Falzon

O’Neill

Menzies

et al. 2014

Preventive Veterinary Medicine

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“…However, recent research highlights that this practice may increase the selection pressure for resistance (e.g. Hughes et al 2007). Therefore, this result should be taken with caution.…”

Section: Initial Larvae Pasture Densitymentioning

confidence: 84%

“…Moreover, nutrient supplementation is expensive in Western Australia, particularly in extensive farming systems. In contrast, refugia is easy to implement on-farm and appears a practical means of slowing the development of resistance (Van Wyk et al 2006;Hughes et al 2007).…”

Section: Introductionmentioning

confidence: 99%

“…This study focuses solely on refugia as a complementary strategy to chemical control because there is little understanding pertaining to its profitability. This is important as there is practical and scientific evidence highlighting its capacity to delay resistance in other farming environments (Besier and Love 2003;Hughes et al 2007). A key focus is to evaluate the pattern of drench application that occurs across time under profitable management given the link between treatment frequency, use of refugia and resistance development.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Economic management of anthelmintic resistance: model and application*

Pech¹,

Doole²,

Pluske³

2009

Aus J Agri & Res Econ

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The increasing prevalence of anthelmintic (drench) resistance in gastrointestinal parasite populations is decreasing the profitability of the Australian sheep industry. Refugia management can delay its development by not exposing a proportion of the worm population to chemical control. A dynamic-optimisation model is used to assess the economic value of refugia for management of the worm species Teladorsagia circumcincta and macrocyclic lactone drenches in an application to Western Australian sheep flocks. A low rate of refugia (2 per cent) is most profitable under standard circumstances because it slows the development of resistance, but also reduces the proportion of the flock not exposed to chemical control. Frequent drench application should remain the primary method of control. However, its efficacy should be preserved through refugia management, rather than greatly reducing treatment frequency.

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Resistance to macrocyclic lactone anthelmintics and associated risk factors on sheep farms in the lower North Island of New Zealand

Cited by 35 publications

References 24 publications

Risk factors for anthelmintic resistance development in cattle gastrointestinal nematodes in Argentina

Risk factors for anthelmintic resistance development in cattle gastrointestinal nematodes in Argentina

A systematic review and meta-analysis of factors associated with anthelmintic resistance in sheep

Economic management of anthelmintic resistance: model and application*

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