Colonisation and antifungal susceptibility patterns of candida auris among patients at intensive care units at Mulago hospital.

Abstract

Candida auris is a multidrug-resistant yeast identified as a global priority pathogen by the World Health Organization due to its ability to cause severe, difficult-to-treat infections, particularly in intensive care settings. Colonisation with C. auris — the presence of the organism on the skin or mucosal surfaces without overt infection — is a well-documented precursor to invasive disease. It facilitates nosocomial transmission, persistence in hospital environments, and eventual progression to bloodstream and deep-seated infections. Although multiple outbreaks have been reported globally and in neighboring countries such as Kenya and South Africa, there is limited data currently on C. auris colonisation or antifungal resistance in Uganda.Objective:To determine the prevalence of Candida auris colonisation, antifungal susceptibility patterns, and associated epidemiological risk factors among patients admitted to the intensive care units (ICUs) of Mulago National Referral Hospital in Uganda.Methods:A cross-sectional study was conducted over six months, involving 65 ICU patients enrolled through convenience sampling. Swabs were collected from the axilla, groin, ear canal, and nose, along with environmental swabs from the patients’ surroundings. Samples were cultured on Sabouraud Dextrose Agar with chloramphenicol and CHROMagar Candida Plus, and incubated at both 35°C and 42°C to exploit the thermotolerance of C. auris. Colonies with characteristic morphology underwent Gram staining and germ tube testing before confirmation using the VITEK 2 Compact system. Antifungal susceptibility testing was performed using VITEK AST-YS08 cards, and results were interpreted using EUCAST Clinical Breakpoints (version 11.0). Patient clinical and demographic data were extracted from medical records. Associations between colonisation and potential risk factors were assessed using modified Poisson regression with robust standard errors.Results: Candida auris was isolated in 21 of the 65 patients, yielding a colonisation prevalence of 32.3% (95% CI: 21.9–44.9%). The most frequently colonised sites were the axilla (33.3%) and groin (28.6%), areas prone to moisture and clinical manipulation. All 21 isolates were resistant to fluconazole and amphotericin B (100%) but were susceptible to echinocandins (micafungin and caspofungin). One isolate showed intermediate susceptibility to voriconazole. Colonisation with C. auris, a key step preceding clinical infection, was independently associated with low hemoglobin levels (anemia) (PR = 2.55; 95% CI: 1.09–5.99; p = 0.031), suggesting a link with underlying immunosuppression or chronic illness. Conclusion: The study reveals a significant burden of Candida auris colonisation among ICU patients in Uganda, with one in three patients colonised. The complete resistance to fluconazole and amphotericin B highlights the challenge of treating potential infections that may evolve from colonisation. The strong association between colonisation and anemia highlights the vulnerability of immunocompromised individuals. Given that colonisation precedes infection in over half of C. auris cases globally, early detection through routine screening and antifungal stewardship are urgently needed to prevent invasive disease and control transmission in ICU settings. Key Words: Candida auris, colonisation, antifungal resistance, ICU, Mulago Hospital, VITEK 2, fluconazole, echinocandins, anemia, nosocomial infection.