It ’ s unclear but there exist different hypotheses for why C . auris has spread so rapidly . I think this pathogen exemplifies the need for a One Health approach , a concept that explains how human health is intricately related to environmental health as well as animal health .”
— Victor Leung , MD
because as we have seen , DSB is less susceptible to disinfection , and that DSB can be transferred if you ’ re not careful about which disinfectant that you ’ re using . Effective elimination requires adequate friction , and the most important message you can relay to environmental services personnel is that they must apply elbow grease to DSB , as well as use an effective disinfectant that will not only facilitate removal , but also not transfer organisms .”
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In the second presentation of the Cleaning & Disinfection Symposium at 2023 IPAC Canada , Victor Leung , MD , medical director of infection prevention and control and the physician lead for antimicrobial stewardship at Providence Health Care in Vancouver , addressed Candida auris , an emerging fungal pathogen that is rapidly spreading around the globe .
“ It ’ s now recognized that fungal pathogens are a significant emerging threat , especially for healthcare facilities ,” Leung explained , adding that 50-plus countries are reporting C . auris cases , with a near-simultaneous emergence of distinct genetic clades . “ It was first isolated in 2009 , and shortly after that , based on genetic studies , researchers discovered that this was a new yeast , and it was closely related to some other yeast forms that have high thermal tolerance , meaning that most of the fungal pathogens that we encounter in the environment don ’ t survive high temperatures , like the human host defense mechanism of our body temperature . But unlike many of the other yeasts that survive in the environment , this one can have higher thermal tolerance . A surveillance system identified that there were six isolates of C . auris from 1998 to 2016 , so what they concluded is that this was an emerging pathogen in 2009 , not very common , but it wasn ’ t until 2013 or 2014 that it started to spread and become more prominent globally .”
Leung continued , “ One of the questions that remains unknown is how this pathogen has spread globally , but rapid emergence in isolated areas occurred simultaneously . And what makes this quite remarkable are the genetic differences between the different clades . It ’ s unclear but there exist different hypotheses for why C . auris has spread so rapidly . I think this pathogen exemplifies the need for a One Health approach , a concept that explains how human health is intricately related to environmental health as well as animal health . It ’ s been hypothesized that this is one of the possible first pathogens that are related to effects of climate change because of its high thermal tolerance and its ability to stay in the environment against automatic stressors like high saline concentrations . It ’ s thought that this pathogen originated from the environment in wetlands as a plant colonizer and because of its thermal tolerance and ability to withstand high salinity . It has spread globally , and then its growth promoted through use
of environmental fungicides and pharmaceuticals . When it goes into the hospital environment , that combination of factors seems to have allowed for its rapid emergence globally .”
Leung explained that in 2019 , the World Health Organization ( WHO ) included C . auris as a critical priority pathogen . “ C . auris is ranked with other fungal pathogens like Candida albicans and histoplasmosis , and cryptococcus is a high-priority fungal threat pathogen , meaning that more efforts need to be developed now because of the gaps in diagnosis , treatment , and prevention of transmission in both the environment and in healthcare . Recent research has identified some of the virulence mechanisms that this pathogen has to allow it to spread so rapidly , causing higher mortality in human hosts .”
He continued , “ When we look at the surveillance efforts for outbreaks that have been reported globally and in Canada , in 2018 , the Canadian Communicable Disease Report highlighted C . auris as an important pathogen , noting that it is multidrug-resistant , which is a significant concern because we have very limited antifungals in our toolkit already . Most of the antifungals have been used for many years and some of them are associated with high toxicity . So , when we have the combination of limited antifungals as well as a multidrug-resistant fungus , it becomes a significant threat .”
Leung reviewed who is most at risk of contracting C . auris , including those individuals who are treated in healthcare facilities for prolonged periods of time . “ These are similar risk factors that we have identified with other multidrug-resistant organisms , such as being in the intensive care unit ( ICU ) or having an indwelling device while living in a long-term care facility , or patients who are on ventilators for prolonged periods of time . Certain types of surgeries , specifically related to abdominal infections and prolonged catheter use , are also risk factors .”
He continued , “ In terms of diagnostics , what makes C . auris different compared to some of the other yeasts that we commonly deal with , is that in the past many of the diagnostics that we had in the lab would misidentify this pathogen . In the past , many of the phenotypic tools that we had in the laboratory would identify C . auris as a different type of Candida species , or sometimes not even Candida at all . So , it makes it more difficult for laboratories that are still using some of these phenotypic tests to be able to detect C . auris in clinical specimens . The other challenge for diagnostics is that many specimens that we receive in the microbiology laboratory — if yeast is identified and it ’ s not in a sterile site — it would not be identified to a genus-species level . So , if you are to perform surveillance cultures because you ’ ve identified a case in your hospital , it is recommended that you go very broadly in terms of screening . And for the surveillance cultures , possibly the highest yield
18 july 2023 • www . healthcarehygienemagazine . com