Predominance of non-Candida albicans species oral colonisation among patients on anticancer therapy: Findings from a cross-sectional study in Tanzania

Abstract

ABSTRACT Objectives: This study aimed to determine the oral carriage prevalence of Candida species and identify factors associated with the carriage of Candida species among patients with cancer on treatment. Design: A hospital-based cross-sectional study. Setting: The study was conducted at a tertiary-level cancer hospital Ocean Road Cancer Institute (ORCI), Dar es Salaam, Tanzania. Participants: We enrolled 196 participants who consented to join the study. Oral swabs were collected from all participants and inoculated onto Sabouraud dextrose agar supplemented with 50 mg/mL gentamicin and 50 mg/mL chloramphenicol, and chromogenic agar for phenotypic identification of Candida species. Primary outcome: The study reported the high prevalence of oral carriage of Candida species among patients with cancer on treatment at the tertiary-level cancer hospital in Dar es Salaam, Tanzania. Results: A total of 196 participants were enrolled in the study. The overall oral carriage of Candida species was 37.8% (74/196). The prevalence was higher among patients undergoing chemotherapy and radiotherapy (44.4%) than those in monotherapy (13.3% chemotherapy, 20% radiotherapy). Candida krusei was the most common isolated species, 48.6% (36/74). Head and neck (adjusted OR (aOR) 15.09, 95% CI 3.05 to 74.59, p=0.00), gastrointestinal (aOR 14.14, 95% CI 2.25 to 88.63, p=0.00) malignancies and diabetes (aOR 3.18, 95% CI 1.03 to 9.77, p=0.04) were factors independently associated with oral carriage of Candida species. Conclusion: The oral carriage of Candida species among patients with cancer receiving treatment at ORCI is high, mainly due to C. krusei species. This is alarming since C. krusei has intrinsic resistance to fluconazole, a common antifungal agent used to manage adult fungal infections. Therefore, efforts should be put into conducting regular check-ups for such opportunistic pathogens as they can lead to subsequent infections. Furthermore, studies conducted to determine the antifungal profile of the causative agents are warranted since different causative agents might have different profiles. Keywords: microbiology, infectious diseases, diagnostic microbiology, mycology, head & neck tumors