An inconvenient truth: global worming and anthelmintic resistance.

This research paper discusses the increasing global problem of anthelmintic resistance in parasites affecting livestock, calling for a change in strategy for controlling parasites as well as improvements in methods for diagnosing anthelmintic resistance.

Increasing Anthelmintic Resistance

• The research highlights a distressing increase in both the prevalence and magnitude of anthelmintic resistance around the world over the last 10-15 years.
• The researchers illuminate instances of multiple antivirus resistances in single species of parasites and resistance across several parasite species in almost all livestock animals.
• This ever-increasing resistance has left livestock producers with limited options for treating many critical parasite species.

Lack of New Anthelmintic Classes

• The paper points out that since the introduction of Ivermectin in 1981, no new anthelmintic classes were developed for use in livestock until recently when Monepantel was introduced in New Zealand.
• Developing new anthelmintic classes with unique mechanisms of action could potentially solve the issue of increasing resistance; however, these drugs are expensive to develop and are expected to cost more than the pre-existing ones.

Need for a New Approach to Parasite Control and Diagnosis

• The research pointedly states that the long-standing “Global Worming” approach to parasite control must change, advocating for a new strategy that prioritizes both control and sustainability of livestock production.
• It calls on parasitologists to improve the design of studies, data analysis methods, and, most importantly, diagnosis techniques for anthelmintic resistance. The paper criticizes the reliance on the Fecal Egg Count Reduction Test (FECRT) which is currently used for diagnosis, as there are only set standards for this test in sheep, while they are lacking for horses and cattle.
• The researchers highlight issues with the arbitrary definition of resistance and insufficient data analysis, leading to common errors in assigning resistance status.

Comparing Data and Future Projections

• The lack of set standards for diagnosing resistance makes it difficult to compare data across different studies.
• The paper touches on the significance of creating universally accepted standards as it becomes increasingly important to accurately diagnose anthelmintic resistance due to the lack of alternative treatments and the slow introduction of new drug options in the market.