Antimicrobial-Resistant Fungi

Fungal infections that resist treatment are a challenge to the public’s health.

Illustration of Candida

Medical illustration of Candida spp.

The problem

Antifungal drugs treat fungal infections by killing or stopping the growth of dangerous fungi in the body. Fungi can develop resistance to antifungal drugs the same way bacteria can develop resistance to antibiotics. Resistance happens when germs develop the ability to defeat the drugs designed to kill them. That means the germs are not killed and continue to grow.

Currently, only a small number of antifungal drug types exist, so resistance can severely limit treatment options. Some types of fungi, like Candida auris, can become resistant to all the antifungal drugs normally used to treat these infections.1 Resistance is especially concerning for patients with invasive fungal infections—severe infections that affect the blood, heart, brain, eyes, or other parts of the body.

What causes antimicrobial-resistant fungi

Some species of fungi are naturally resistant to certain types of antifungal drugs. For example, the drug fluconazole does not work against infections caused by the fungus Aspergillus, a type of mold found throughout the environment. Resistance can also develop over time when fungi are exposed to antifungal drugs. This resistance can occur when antifungal drugs are used to treat sick people, especially if the drugs are used improperly (for example, when dosages are too low or when treatment courses are not long enough).

Use of fungicides in agriculture to prevent and treat fungal diseases in crops can also contribute to resistant disease in people. For example, when Aspergillus found in the environment is exposed to fungicides, which are similar to medical antifungal drugs, the Aspergillus can become resistant to the drugs used to treat infections in people. People can then breathe in those resistant Aspergillus spores from the environment and become sick.

Types of antimicrobial-resistant fungi

Resistant fungi include Aspergillus, certain Candida species, and certain dermatophytes. Candida auris is a newer species of Candida that is particularly resistant to antifungal drugs and can spread quickly in healthcare settings. Learn more:

Tackling antimicrobial-resistant fungi

Resistant fungi are a growing public health threat. Everyone—including CDC scientists, healthcare professionals, and the general public—has a role to play in preventing resistant fungal infections. This work complements CDC’s antimicrobial resistance investments, collectively known as CDC’s Antimicrobial Resistance Solutions Initiative. Through these investments, CDC is transforming how the nation combats and slows antimicrobial resistance at all levels.

CDC is:

  • Conducting surveillance: Tracking antimicrobial resistance in Candida infections at 10 sites across the country through the Emerging Infections Program (EIP).
  • Expanding lab capacity: Supporting a network of regional public health laboratories through the Antimicrobial Resistance Laboratory Network (AR Lab Network) to detect resistant fungi and perform antifungal susceptibility testing.
  • Using state-of-the-art lab technology: Using genetic sequencing and developing new laboratory tests to identify and understand specific mutations associated with antimicrobial resistance (fungi and bacteria).
  • Supporting surveillance globally: Through collaborations with the World Health Organization’s (WHO’s) Global Antimicrobial Resistance Surveillance System (GLASS), CDC continues to support increased detection and tracking of antimicrobial resistance to prevent illnesses and save lives.5
  • Using data for action: Analyzing antifungal prescribing patterns across healthcare facilities and promoting appropriate use of antifungal drugs.

Healthcare facility leadership and infection control staff can:

  • Assess antifungal use as part of their antimicrobial stewardship programs.
  • Ensure adherence to infection prevention and control guidelines, including proper hand hygiene and disinfection protocols.

Healthcare providers and other hospital personnel can:

  • Prescribe antifungal drugs appropriately and document the dose, duration, and indication for every antifungal prescription.
  • Test for resistant fungi in patients with fungal infections that are not improving with first-line antifungal drugs.6,7
  • Be aware of resistance patterns, including  resistant fungi, in their facility and community.

Hospital patients can:

  • Clean their hands.
  • Be sure everyone cleans their hands before entering the room.
  • Ask each day if a catheter is necessary, if the patient has one.
  • Talk to their healthcare provider about their risk for certain infections, especially if the patient has a weakened immune system.
  • Take antifungal drugs only when needed and exactly as prescribed.
  • Talk to their healthcare provider if they experience side effects or if they are not seeing their symptoms improve when taking antifungal drugs.
  1. Ostrowsky B, Greenko J, Adams E, Quinn M, O’Brien B, Chaturvedi V , et al. Candida auris isolates resistant to three classes of antifungal medications — New York, 2019. MMWR Morb Mortal Wkly Rep 2020;69:6–9
  2. Lortholary O, Desnos-Ollivier M, Sitbon K, Fontanet A, Bretagne S, Dromer F, et al. Recent exposure to caspofungin or fluconazole influences the epidemiology of candidemia: a prospective multicenter study involving 2,441 patients. Antimicrob Agents Chemother 2011;55:532–8.
  3. Shah DN, Yau R, Lasco TM, Weston J, Salazar M, Palmer HR, et al. Impact of prior inappropriate fluconazole dosing on isolation of fluconazole-nonsusceptible Candida species in hospitalized patients with candidemia. Antimicrob Agents Chemother 2012;56:3239–43.
  4. Ben-Ami R, Olshtain-Pops K, Krieger M, Oren I, Bishara J, Dan, M, et al. Antibiotic exposure as a risk factor for fluconazole-resistant Candida bloodstream infection. Antimicrob Agents Chemother 2012;56:2518–23.
  5. WHO: Global Antimicrobial Resistance Surveillance System (GLASS)
  6. Patterson TF, Thompson GR, 3rd, Denning DW, Fishman JA, Hadley S, Herbrecht R, et al. Practice guidelines for the diagnosis and management of aspergillosis: 2016 update by the Infectious Diseases Society of America. Clin Infect Dis 2016;63:e1–60.
  7. Pappas PG, Kauffman CA, Andes DR, Clancy CJ, Marr KA, Ostrosky-Zeichner L, et al. Clinical practice guideline for the management of candidiasis: 2016 update by the Infectious Diseases Society of America. Clin Infect Dis 2016;62:e1–50.