Oropharyngeal candidiasis in the era of antiretroviral therapy

Abstract

Oropharyngeal candidiasis (OPC) remains a common problem in the HIV-infected population despite the availability of antiretroviral therapy (ART). Although Candida albicans is the most frequently implicated pathogen, other Candida species also may cause infection. The emergence of antifungal resistance within these causative yeasts, especially in patients with recurrent oropharyngeal infection or with long-term use of antifungal therapies, requires a working knowledge of alternative antifungal agents. Identification of the infecting organism and antifungal susceptibility testing enhances the ability of clinicians to prescribe appropriate antifungal therapy. Characterization of the responsible mechanisms has improved our understanding of the development of antifungal resistance and could enhance the management of these infections. Immune reconstitution has been shown to reduce rates of OPC, but few studies have evaluated the current impact of ART on the epidemiology of OPC and antifungal resistance in these patients. Preliminary results from an ongoing clinical study showed that in patients with advanced AIDS, oral yeast colonization was extensive, occurring in 81.1% of the 122 patients studied, and symptomatic infection occurred in one-third. In addition, resistant yeasts were still common, occurring in 25.3% of patients colonized with yeasts or with symptomatic infection. Thus, OPC remains a significant infection in advanced AIDS, even with ART. Current knowledge of the epidemiology, pathogenesis, clinical presentation, treatment, and mechanisms of antifungal resistance observed in OPC are important in managing patients with this infection and are the focus of this review.

FIGURE 1

Pseudomembranous form of OPC.

FIGURE 2

Erythematous candidiasis and angular cheilitis secondary to oropharyngeal candidiasis.

FIGURE 3

The agar dilution screening technique allows rapid discernment of isolates with decreased fluconazole susceptibility. Shown are two Chromagar Candida plates which allow rapid species determination based on colony color. More important to this screening method is the inclusion of Fluconazole (8 or 16 mcg/ml). The plate on the left has no fluconazole, and the one on the right contains 8 mcg/ml flu. Without fluconazole, the susceptible C. albicans overwhelms the growth of the other more resistant organisms. With fluconazole (on right), susceptible organisms are suppressed to pinpoint colonies and resistant yeasts are easily seen. Reproduced with permission .