Potential for misinterpretation of the faecal egg count reduction test for levamisole resistance in gastrointestinal nematodes of sheep

Grimshaw, W. T. R.; Hong, C.; Hunt, KR

doi:10.1016/0304-4017(95)00874-8

Cited by 35 publications

(16 citation statements)

References 8 publications

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“…Quando se utiliza levamisole, as larvas histotrópicas sensíveis podem sobreviver ao Ciência Rural, v.38, n.5, ago, 2008. tratamento e, quando as contagens de OPG são realizadas 10 a 14 dias após a medicação, elas podem ter se desenvolvido dando um resultado falso positivo de resistência. Por esse motivo, GRIMSHAW et al (1996) recomendam fazer a contagem de OPG sete dias após o tratamento. Todavia, algumas espécies resistentes às lactonas macrocíclicas podem sofrer uma inibição temporária da postura, dando um resultado negativo de resistência (JACKSON, 1993).…”

Section: Resultsunclassified

Resistência de helmintos gastrintestinais de bovinos a anti-helmínticos no Planalto Catarinense

et al. 2008

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Com o objetivo de avaliar focos de resistência de helmintos gastrintestinais parasitos de bovinos, com aptidão para corte, à ivermectina, ao fosfato de levamisole e ao sulfóxido de albendazole foram realizadas avaliações em 39 propriedades localizadas no Planalto Catarinense. Em cada uma foram coletadas, em média, 60 amostras de fezes de animais, com idade entre sete e 18 meses, para avaliar o número de ovos por grama de fezes (OPG), o cultivo e a identificação de larvas. Foram formados três grupos de animais com média de OPG semelhante. A média de OPG de todos os animais coletados, antes do tratamento, foi considerada como testemunha. Cada grupo recebeu um tratamento diferente por via subcutânea (ivermectina na dose de 0,2mg kg-1, fosfato de levamisole na dose de 5mg kg-1 e sulfóxido de albendazole na dose de 2,5mg kg-1). Sete dias após foram repetidas as avaliações por grupo. Considerou-se resistência quando a eficácia da droga foi menor que 95% e o limite inferior do intervalo de confiança IC95% menor que 90%. Entre as propriedades avaliadas, 82,1% apresentaram animais com helmintos resistentes à ivermectina, 15,4% ao fosfato de levamisole e 7,8% ao sulfóxido de albendazole. Em apenas 10,3% das propriedades, a eficácia de todos os anti-helmínticos foi superior a 95%. Com base no diagnóstico genérico, verificou-se que os gêneros predominantes resistentes à ivermectina foram Cooperia spp e Haemonchus spp, ao fosfato de levamisole, Ostertagia spp, Cooperia spp e Trichostrongylus spp, e ao sulfóxido de albendazole, Cooperia spp.

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Section: Resultsunclassified

Resistência de helmintos gastrintestinais de bovinos a anti-helmínticos no Planalto Catarinense

et al. 2008

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“…For example, it is known that the immature stages of some T. circumcincta populations are refractory to levamisole treatment (Grimshaw et al, 1996), which is the basis for conducting faecal egg count reduction tests (FECRT) on day 7 post-treatment (Coles et al, 2006). Under these circumstances levamisole treatments may inadvertently maintain refugia.…”

Section: Sources Of Refugiamentioning

confidence: 99%

The role of targeted selective treatments in the development of refugia-based approaches to the control of gastrointestinal nematodes of small ruminants

Kenyon

Greer

Coles

et al. 2009

Veterinary Parasitology

236

138

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“…In addition to the previously mentioned misuse of anthelmintics, some breeding management factors are associated with the occurrence of benzimidazole resistance [61,62]. Concerning levamisole and avermectin resistance, data remain scarce and must be interpreted with caution because of the discrepancies between field surveys based on faecal egg count reduction tests and laboratory results using in vitro or controlled tests [24,38,47]. Until now, levamisole resistance has been suspected in a few cases [12] whereas no information is available for the avermectin group.…”

Section: The Situation Of Anthelmintic Resistances In French Dairy Gomentioning

confidence: 99%

Control of gastrointestinal parasitism with nematodes in dairy goats by treating the host category at risk

Hoste¹,

Chartier

Frileux

2002

Vet. Res.

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-Infections of the gastrointestinal tract with parasitic nematodes remain one of the main limiting factors in grazing dairy goats. The usual mode of control of these parasitic diseases has up to now been based on the repeated use of anthelmintics. However, the prevalence rates of anthelmintic resistances, in particular to benzimidazoles, are now particularly high in the French dairy goat production. This situation makes it mandatory to reconsider the usual mode of control of these nematodes and to look for short term, alternative solutions which combine the control of gastrointestinal infections and management of anthelmintic resistances. One of the possible options is to leave a part of the flock without treatment during the grazing season in order to maintain alleles of susceptibility to anthelmintics within the worm populations. Previous epidemiological observations identifying the categories of host populations at risk are presented which provide the rationale for targeted applications of treatments. The results of assays on experimental flocks and from farm surveys examining the advantages and drawbacks of selective treatments are presented. The value of these results in combination with other alternative solutions of control are discussed in order to use minimum treatments with maximum benefits. dairy goat / anthelmintic / selective treatment / anthelmintic resistance / parasitic nematode Résumé -Maîtrise des strongyloses gastro intestinales chez les chèvres laitières par l'application de traitements ciblés. Les infestations par les nématodes du tractus gastro intestinal demeurent un des principaux facteurs limitant à l'élevage des chèvres laitières au pâturage. Le mode usuel de maîtrise de ce parasitisme reposait jusqu'à présent sur un usage répété de molécules anthelminthiques. Cependant, la prévalence des lignées résistantes aux anthelminthiques, en particulier aux benzimidazoles, en éle-vage caprin laitier en France, est désormais très élevée. Ce constat oblige à rechercher rapidement des 531

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Potential for misinterpretation of the faecal egg count reduction test for levamisole resistance in gastrointestinal nematodes of sheep

Cited by 35 publications

References 8 publications

Resistência de helmintos gastrintestinais de bovinos a anti-helmínticos no Planalto Catarinense

Resistência de helmintos gastrintestinais de bovinos a anti-helmínticos no Planalto Catarinense

The role of targeted selective treatments in the development of refugia-based approaches to the control of gastrointestinal nematodes of small ruminants

Control of gastrointestinal parasitism with nematodes in dairy goats by treating the host category at risk

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