What does the term "anthelmintic resistance" refer to?

The term "anthelmintic resistance" specifically refers to reduced effectiveness of drugs due to evolutionary changes in parasites. This phenomenon occurs when helminths, or parasitic worms, develop adaptations over time that enable them to survive treatments that were previously effective against them. Factors such as overuse or misuse of anthelmintic medications can accelerate this resistance by applying selective pressure, allowing only the those parasites that have mutations conferring resistance to survive and reproduce.

In contrast, other options do not capture the essence of resistance. The ability of drugs to cure infections indicates their effectiveness but does not address the evolving capacity of parasites to become less susceptible. The concept of complete eradication of parasites relates to treatment outcomes rather than the mechanisms governing resistance. Lastly, increased side effects from drug use, while relevant to pharmacology, pertains to the safety profile of the medications rather than the interaction between the drugs and parasite populations. Thus, the correct understanding of "anthelmintic resistance" centers on the evolutionary adaptations of parasites that diminish the effectiveness of treatments.