Analysis Underscores Substantial Burden of Candidemia in the United States

An analysis of candidemia surveillance from the US Centers for Disease Control and Prevention (CDC) Emerging Infections Program sheds light on the substantial burden of candidemia in the United States. Ongoing surveillance is needed to inform future estimates and help evaluate how effective intervention efforts are in preventing against infection.

Although candidemia is responsible for the majority of health care-associated bloodstream infections, no current estimates exist for understanding the burden that the infection has on the United States. Candidemia rates have increased over the past 20 years in the United States; however, rates have dipped in recent years.

To glean a better understanding of what the true burden of candidemia is in the country, officials from the CDC’s Emerging Infections program performed laboratory- and active population-based candidemia surveillance on 17 million individuals in 45 counties spanning 9 states—California, Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee.

In an exclusive interview with Contagion^® held at ID Week 2018, Sharon Tsay, MD, a medical epidemiologist in the Mycotic Diseases Branch of the Centers for Disease Control and Prevention, and lead author of the study, explained why burden estimates are needed (see video).

Dr. Tsay and her team defined a case as Candida species isolated from a blood sample collected from a surveillance area resident. In addition to blood samples, the investigators collected clinical and demographic data such as age, sex, and race via medical records.

To determine weighted estimates of national and regional incidence rates as well as mortality in individuals with candidemia—which they defined as death from any cause in 7 days of incident candidemia—the investigators used 2016 US census data.

A total of 1,226 cases of candidemia were identified in 2017; but, they estimated that 23,000 of the cases (95% confidence interval [CI] 20,000-25,000) actually occurred in the United States. Specifically, the overall estimated incidence was 7.0 /100,000 persons, the authors wrote. In adults 65 and older, males, and black individuals, rates of candidemia were higher—20.3/100,000, 8.0/100,000, and 12.6/100,000, respectively.

Incidence was highest in the South Atlantic region of the country at 8.0 infections /100,000 persons, according to the study results, while the Pacific region was determined to have the lowest incidence of candidemia (6.0/100,000). The estimated number of deaths associated with candidemia was 3000 (range 1000-5000).

“This is really just the tip of the iceberg because this was bloodstream infections,” Dr. Tsay stressed, “and we know that invasive Candida includes a number of other sites in the body. And so, this is just a number for us to start with.”

The analysis underscores the national burden of candidemia in the United States, according to Dr. Tsay and her team. To provide future estimates and help ascertain if preventive efforts are working, ongoing surveillance is needed.

“For candidemia, one of the biggest risk factors is broad-spectrum antibiotic use, and we’ve been trying to help clinicians understand that broad-spectrum antibiotic use can contribute to Clostridium difficile infections, but can also contribute to candidemia,” Dr. Tsay said. “Long-term, we’re hoping that with a burden estimate like this, if we continue to do interventions like antibiotic stewardship, that we may be able to see decreasing numbers over time with future burden estimates.”