Saturday, November 05, 2016

MMWR: Investigation of the First Seven Reported Cases of Candida auris In the United States


Just over 4 months ago the CDC issued a Clinical Alert to U.S. Healthcare facilities about the Global Emergence of Invasive Infections Caused by the Multidrug-Resistant Yeast Candida auris, an emerging fungal pathogen first isolated (roughly 7 years ago) from the discharge from a Japanese patient's external ear (hence the name `auris').

This announcement was followed a week later by a report (see PHE On The Emergence Of Candida auris In The UK) that unveiled the details of C. auris detections in the UK, including a large (and ongoing since April 2015) nosocomial outbreak at an adult critical care unit in England.

Unlike most systemic Candida infections, which usually arise when a previously colonized person is weakened from illness or infirmity, this strain has been linked to nosocomial transmission.

Complicating matters:

  1. C. auris infections have a high fatality rate
  2. The strain appears to be resistant to multiple classes of anti-fungals 
  3. And it can be difficult for labs to differentiate between Candida strains

In late August, in mSphere: Comparative Pathogenicity of UK Isolates of the Emerging Candida auris, we looked at a study that found that C. auris isolates displayed varying growth characteristics in vitro, with the most virulent isolates exhibited pathogenicity comparable to that of C. albicans - considered to be the most pathogenic strain - in the G. melonella model.

Yesterday the CDC published a detailed MMWR report, along with a press release, on the first 7 confirmed cases of C. auris in the United States.

Due to its length I'll only reproduce the link, and summary to the MMWR report, and some excerpts from the press release.  Follow the links for more detailed information.

Investigation of the First Seven Reported Cases of Candida auris, a Globally Emerging Invasive, Multidrug-Resistant Fungus — United States, May 2013–August 2016

November 4, 2016
  Candida auris, an emerging fungal pathogen that can cause invasive infections, is associated with high mortality and is often resistant to multiple antifungal medications. This report describes the first seven cases of C. auris infection in the United States reported to CDC as of August 31, 2016.


What is already known about this topic?Candida auris is an emerging pathogenic fungus that has been reported from at least a dozen countries on four continents during 2009–2015. The organism is difficult to identify using traditional biochemical methods, some isolates have been found to be resistant to all three major classes of antifungal medications, and C. auris has caused health care–associated outbreaks.

What is added by this report?
 This is the first description of C. auris cases in the United States. C. auris appears to have emerged in the United States only in the last few years, and U.S. isolates are related to isolates from South America and South Asia. Evidence from U.S. case investigations suggests likely transmission of the organism occurred in health care settings.

What are the implications for public health practice?
 It is important that U.S. laboratories accurately identify C. auris and for health care facilities to implement recommended infection control practices to prevent the spread of C. auris. Local and state health departments and CDC should be notified of possible cases of C. auris and of isolates of C. haemulonii and Candida spp. that cannot be identified after routine testing.

From the CDC Press release:

First cases of Candida auris reported in United States

Drug-resistant fungal infection can spread in healthcare settings
Thirteen cases of Candida auris (C. auris), a serious and sometimes fatal fungal infection that is emerging globally, have been identified in the United States, according to the Centers for Disease Control and Prevention (CDC). Seven of the cases occurred between May 2013 and August 2016 and are described today in CDC’s Morbidity and Mortality Weekly Report (MMWR). The other six cases were identified after the period covered by the report and are still under investigation.
The report is the first to describe U.S. cases of C. auris infection. C. auris is often resistant to antifungal drugs and tends to occur in hospitalized patients. In June 2016, CDC issued a clinical alert describing the global emergence of C. auris and requesting that laboratories report C. auris cases and send patient samples to state and local health departments and CDC. Since then, CDC has been investigating reports of C. auris with several state and local health departments. The agency expects to continue to investigate possible cases as awareness of the emerging infection increases.
“We need to act now to better understand, contain and stop the spread of this drug-resistant fungus,” said CDC Director Tom Frieden, M.D., M.P.H. “This is an emerging threat, and we need to protect vulnerable patients and others.”
Among the seven cases detailed in the report, patients with C. auris were reported in four states: New York, Illinois, Maryland and New Jersey. All of the patients had serious underlying medical conditions and had been hospitalized an average of 18 days when C. auris was identified. Four of the patients died; it is unclear whether the deaths were associated with C. auris infection or underlying health conditions.
In two instances, two patients had been treated in the same hospital or long-term-care facility and had nearly identical fungal strains. These findings suggest that C. auris could be spread in healthcare settings. 
(Continue . . .)

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