Prevalence of anthelmintic resistance in cattle nematodes: a systematic review-meta-analysis approach

MEDEROS, AMÉRICA; CARRACELAS, BEATRIZ; MINHO, ALESSANDRO; FERNÁNDEZ, ALICIA SILVINA; SÁCHEZ, JAVIER

Maastricht

Simposio; 13th International Symposium on Veterinary Epidemiology and Economics; 2012

International Society for Veterinary Epidmiology and Economics

A systematic review (SR) is a research synthesis method that follows a structured methodology minimizing biases and random errors. One of the goals of a meta-analysis (MA) is to summarize the results from similar studies (and addressing the same research question) with the aim to produce a more precise single estimate of an effect. The main goal of this study was to evaluate the prevalence of anthelmintic resistance (AR) in cattle nematodes. A systematic review protocol was designed a priori, validated and tested. A search algorithm was applied to four electronic databases and one level of relevance screening was conducted by two reviewers. Quality assessment and data extraction were performed in one single step. Random effect MA was performed with the anthelmintic resistance (AR) prevalence for each drug evaluated. Twenty three studies (5 cross-sectional, 9 prevalence surveys and 9 field trials) from 15 countries were included in this review. The overall percentage of farms with AR in at least one drug was 82.1% (95% CI=70.5 to 93.7), and the between study heterogeneity was high (I2=94.8%). The sub-group analysis showed the following prevalence by drug class: ivermectin 77.0%; moxidectin 74.2%; benzimidazole 44.3% and levamisole 35.0%. The main nematode genera involved in the AR were Cooperia (30.9%), Ostertagia (10.3%), Haemonchus (8.4%), Trichostrongylus (2.4%) and Oesophagostomum (1.4%). The results presented in this SR-MA suggested that AR in cattle nematodes is occurring where ivermectin and moxidectin seems to be the drugs with higher prevalence of AR. Additional results will be presented and discussed at the conference.