EPA Revises Guidance to Ensure Effectiveness of Antimicrobial Pesticides Against Candida auris

For Release: October 15, 2021

The U.S. Environmental Protection Agency (EPA) has revised its guidance for evaluating the efficacy of antimicrobial pesticides against Candida auris (C. auris). Pesticide manufacturers seeking to register their products with a C. auris claim should use this updated guidance to test the effectiveness of the products against a drug-resistant strain of C. auris.

C. auris is an emerging, multidrug-resistant yeast (a type of fungus). It can cause serious infections and spreads easily among hospitalized patients and nursing home residents. According to the Centers for Disease Control and Prevention (CDC), more than one in three patients with an invasive (e.g., affecting the blood, heart, or brain) C. auris infection die.

In 2017, in consultation with the CDC, EPA issued interim guidance for testing the effectiveness of hospital disinfectants against C. auris. Subsequently, based on input from the CDC on their tracking of clinical cases of multi-drug resistant C. auris isolates in the United States, the laboratory data were generated to ensure antimicrobial efficacy against a more relevant strain of the pathogen.

Working closely with experts from the CDC, EPA conducted a comparative evaluation of isolates and found that the drug-resistant isolates were more tolerant to some disinfectant treatments. Since a drug-resistant isolate (AR Bank #0385) is highly relevant to current outbreaks in the United States, it is considered a suitable test microbe for regulatory purposes. 

Under the updated guidance issued today, all new products seeking registration with claims against C. auris should test for efficacy using the more relevant strain (AR Bank #0385). Efficacy testing using AR Bank #0381 is acceptable in cases where the study initiation date is between Oct. 15, 2020, and Oct. 15, 2021. Existing antimicrobial products with C. auris claims based on the previous strain (AR Bank #0381) will be allowed to retain their claim of effectiveness against C. auris. To claim effectiveness against drug-resistant C. auris, the Agency recommends retesting with the more relevant strain (AR Bank #0385) identified in the updated guidance.

See the updated guidance for more information.