Epidemiology of Oropharyngeal CandidaColonization and Infection in Patients Receiving Radiation for Head and Neck Cancer

ABSTRACTOral mucosal colonization and infection with Candidaare common in patients receiving radiation therapy for head and neck cancer. Infection is marked by oral pain and/or burning and can lead to significant patient morbidity. The purpose of this study was to identify Candidastrain diversity in this population by using a chromogenic medium, subculturing, molecular typing, and antifungal susceptibility testing of clinical isolates. These results were then correlated with clinical outcome in patients treated with fluconazole for infection. Specimens from 30 patients receiving radiation therapy for head and neck cancer were cultured weekly forCandida. Patients exhibiting clinical infection were treated with oral fluconazole. All isolates were plated on CHROMagar Candida and RPMI medium, subcultured, and submitted for antifungal susceptibility testing and molecular typing. Infections occurred in 27% of the patients and were predominantly due to Candida albicans(78%). Candidacarriage occurred in 73% of patients and at 51% of patient visits. Yeasts other than C. albicanspredominated in carriage, as they were isolated from 59% of patients and at 52% of patient visits. All infections responded clinically, and all isolates were susceptible to fluconazole. Molecular typing showed that most patients had similar strains throughout their radiation treatment. One patient, however, did show the acquisition of a new strain. With this high rate of infection (27%), prophylaxis to prevent infection should be evaluated for these patients.