Fungal Disease: A Growing Nemesis

Tom M. Chiller, MD, MPHTM


March 12, 2014

Editorial Collaboration

Medscape &

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In September 2012, the Centers for Disease Control and Prevention (CDC) and our partners at the US Food and Drug Administration (FDA), along with state and local health departments, started to investigate a multistate outbreak of fungal meningitis and other serious fungal infections among patients who received contaminated steroid injections from a single compounding pharmacy.[1] As many of you are well aware, this unprecedented outbreak is now recognized to be the largest healthcare-associated outbreak in US history, to date with 751 patients affected in 20 states.

A critical element to this outbreak was clinician recognition of an unusual infection, which led to quickly identifying that there was a problem and launching the response. This allowed for rapid public health action, including patient notification, recall of the contaminated medication, and rapid development of clinical guidelines and diagnostic testing, resulting in many lives saved and infections averted.

Hello. I'm Dr. Tom Chiller, Deputy Chief of the Mycotic Diseases Branch at the CDC. I'm pleased to speak with you as part of the CDC Expert Commentary Series on Medscape.

So let's talk fungus. Fungal diseases are an increasingly common problem for clinicians, but remain in many cases unrecognized until late in the course of disease, making them much more challenging to treat.

Reports of fungal infections are on the rise throughout the world. Some of these reports describe fungi not previously thought to be human pathogens (such as those that caused the outbreak of fungal meningitis), and some describe the emergence of known pathogens with new virulence mechanisms or appearance in new geographic areas. Many fungi, such as Aspergillus, are ubiquitous and are present in the environment worldwide, but other fungi, such as Coccidioides immitis (the cause of valley fever) are typically restricted to specific areas, and we generally refer to those as "endemic fungi."

This map shows approximate locations within the United States where the endemic fungal diseases blastomycosis, coccidioidomycosis, C gattii cryptococcosis, and histoplasmosis are most common; however, a handful of recent reports of these infections have come from outside these areas, suggesting spread of these fungi in the environment[2,3,4] (Figure).

Figure. Map of the United States indicating areas where fungal diseases are endemic.

Why the increases and spread of fungal diseases? Many factors are likely to be contributing to the observed emergence and increase in fungal diseases, including:

Rising numbers of people at risk. The widespread use of medical "hardware," such as central intravenous catheters, and the successful management of immunosuppression in an ever-increasing number of transplant recipients are some of the factors contributing to increasing numbers of persons at risk;

Changes in land use and the environment, and the use of azole antifungal agents in agriculture;

Increased seasonal migration and international travel; and

Changing patterns of weather, including extreme weather events and natural disasters.

Fungal infections are often difficult to detect. Diagnostic tests are limited for many of these infections, and culturing fungi is often challenging and time-consuming. We know that treating patients earlier with antifungal agents leads to better outcomes, so earlier recognition of a potential fungal disease is one of the keys to successful treatment.

As a healthcare provider, you can do the following to reduce morbidity and mortality from fungal infections:

Consider a fungal etiology in patients with presumed bacterial or viral infections who are not improving with treatment;

Familiarize yourself with fungal diseases that are common in your geographic area, and consider a patient's travel history to known endemic areas, even if the time spent there was limited;

Request that specific fungal diagnostic tests and cultures be performed;

Educate patients who are at high risk for fungal infections about avoiding risky activities (for example, digging in soil contaminated with bird guano, visiting bat caves); and

Be familiar with fungal disease reporting requirements in your area, and report cases to your state or local health department if applicable.

Tom M. Chiller, MD, MPHTM, became Associate Director for Epidemiologic Science in the Division of Foodborne, Waterborne, and Environmental Diseases at the National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) in June 2007. He also serves as Deputy Chief of the Mycotic Diseases Branch.

Between 2003 and 2006, Dr. Chiller was Chief of the National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) in CDC's Foodborne and Diarrheal Diseases Branch. He also served as CDC's lead for the Global Foodborne Infections Network, a World Health Organization program to build global capacity for enteric disease surveillance and response. In 2006, he became the epidemiology team lead in the Mycotic Diseases Branch and then shortly after assumed the role of Deputy Chief.

Dr. Chiller received his bachelor's degree from Dartmouth College and his medical and public health degrees from Tulane University. He completed a residency in internal medicine at University of Texas Southwestern, and then worked as an attending physician in HIV medicine. He completed a fellowship in infectious diseases and mycotics at Stanford University and then joined CDC to train in infectious disease epidemiology as an Epidemic Intelligence Service (EIS) officer in the Foodborne and Diarrheal Diseases Branch.

Dr. Chiller is board-certified in infectious diseases and is a faculty member in the Division of Infectious Diseases at the Emory School of Medicine. He practices infectious disease medicine at the Veterans Affairs Hospital in Atlanta. He has authored numerous articles and book chapters and given many lectures on public health surveillance and infectious diseases. Dr. Chiller is fluent in Spanish, French, and German.