Prevalence, Distribution, and Antifungal Susceptibility Patterns of Yeast Isolates at the Nairobi South Hospital

Abstract

BACKGROUND Yeast infections significantly impact global morbidity and mortality but remain underdiagnosed and underreported. Treatment failure due to antifungal resistance, particularly in critically ill patients, limits treatment options. The aim of this study was to retrospectively describe the proportion and distribution of yeast isolates recovered from inpatient records at The Nairobi South Hospital over five years and to describe the isolates' antifungal drug susceptibility patterns.

METHODOLOGY We reviewed inpatient records from 2018 to 2022, focusing on 308 fungal culture records that met the inclusion criteria. Clinical data included age, sex, ward, and year of admission. Laboratory data included sample type, yeast species, and antifungal susceptibility. Identification and antifungal susceptibility testing were performed using VITEK-2, and interpreted as per the Clinical and Laboratory Standards Institute guidelines (CLSI).

RESULTS Out of 2006 records, 308 (15%) yielded yeast isolates. Distribution was: Candida albicans (38%), non-albicans Candida (NAC) species (50%), Cryptococcus species (10%), and Trichosporon species (2%). The yeasts demonstrated reduced susceptibility to all tested antifungal agents. Based on Minimum Inhibitory Concentration (MIC) data and CLSI breakpoints, 90% of the isolates exhibited high MICs and were classified as resistant to amphotericin B, 70% to itraconazole, and 61% to fluconazole. In contrast, 74% and 44% of the isolates had low MICs and were susceptible to flucytosine and voriconazole, respectively.

CONCLUSION AND RECOMMENDATIONS Candida albicans remained the most common yeast species, although non-albicans Candida species are on the rise. Widespread antifungal resistance necessitates tracking yeast profiles and susceptibility patterns for effective patient management.