The opioid epidemic and increased injection drug use (IDU) may be changing the epidemiology of candidemia, which is typically a hospital-associated infection, according to a new study from researchers at the US Centers for Disease Control and Prevention (CDC) and their state health partners.

For the study, the investigators examined candidemia cases reported during 2017 in patients older than 12 from 45 counties in nine states, comparing the information with data available from 2014 to 2017 from 21 counties in four states. They published their findings recently in Clinical Infectious Diseases.

Doubling of injection drug connection

For 2017, the researchers identified 1,191 candidemia case-patients, of whom 10.7% (128) had a history of IDU. The proportion was especially high (34.6%) in candidemia patients ages 19 to 44 years.

IDU-linked cases made up more than a quarter of all candidemia cases in two surveillance sites: New Mexico and Oregon. Also, data from surveillance sites with multiple years showed that the proportion of candidemia cases in patients with a history of IDU more than doubled from 2014 to 2017.

Patients with an IDU history trended younger, and those with recent IDU use were less likely to have typical risk factors for the disease, which include malignancy, abdominal surgery, and total parenteral nutrition. The infection in patients with IDU occurred more commonly in smokers, those with hepatitis C, and in people who were homeless.

The authors wrote that although IDU is a known risk factor for candidemia, the proportion in that group was unexpectedly elevated, given that the disease is typically a healthcare-associated infection. They suggested that clinicians screen for candidemia in people who inject drugs and screen for IDU in patients with candidemia who don't have the typical risk factors, especially in younger adults.

Findings mirror other studies

In a related commentary, David Andes, MD, with the department of medicine and microbiology and immunology at the University of Wisconsin, Madison, wrote that the findings mirror smaller recent studies and are consistent with surveillance in four states from 2012 to 2016.

He noted that the authors of the new study found that Candida albicans was more common than C glabrata, which more commonly affects older patients with earlier antifungal exposure. He added that the study, like other recent ones, identified multiple Candida species.

Though the findings confirm and extend the understanding of candidemia in IDU patients, key knowledge gaps remain, Andes notes, such as modifiable factors that predispose patients to infection and information on injection practices.

See also:

Nov 2 Clin Infect Dis abstract

Nov 2 Clin Infect Dis commentary