Emergence of azole-resistant Candida parapsilosis causing bloodstream infection: Results from laboratory-based sentinel surveillance in South Africa

Abstract

Objectives: To compare Candida species distribution and antifungal susceptibility at South African public- and private-sector hospitals. Methods: From February 2009 through to August 2010, laboratory-based surveillance for candidaemia was undertaken at 11 public-sector hospitals and > 85 private-sector hospitals across South Africa. A case was defined as a patient of any age admitted to a sentinel hospital with isolation of Candida species from blood culture. Viable isolates were identified and tested for antifungal susceptibility at a reference laboratory. Demographic and limited clinical data were abstracted from laboratory records. Results: In total, 2172 cases of candidaemiawere detected. Among patientswith available data, almost two-thirds were critically ill (719/1138, 63%). On multivariable analysis, neonates [adjusted OR (aOR), 2.2; 95% CI, 1.5-3.1; P < 0.001] and patients diagnosed in Gauteng province (aOR, 1.9; 95%CI, 1.3-2.7; P < 0.001) or in the private sector (aOR, 1.9; 95%CI, 1.2-3.2; P=0.008)were significantlymore likely to be infected with Candida parapsilosis than any other Candida species. Of 531 C. parapsilosis isolates, only 199 (37%) were susceptible to fluconazole and voriconazole; 44% (123/282) of fluconazole-resistant isolates were voriconazole cross-resistant. Factors associated with fluconazole non-susceptible C. parapsilosis infection onmultivariable analysis included diagnosis in Gauteng province (aOR, 4.2; 95%CI, 2.7-6.7; P < 0.001), an ICU (aOR, 2.3; 95% CI, 1.5-3.6; P < 0.001) or the private sector (aOR, 2.2; 95% CI, 1.4-3.5; P < 0.001). Conclusions: The dominance of triazole non-susceptible C. parapsilosis limits the choice of antifungal agents for management of candidaemia among critically ill neonates, children and adults in resource-limited South African hospitals.