Prevalence of oropharyngeal candidiasis in geriatric inpatients.

Abstract

To the Editor: Acute or subacute oropharyngeal candidiasis (OC) includes erythematous or pseudomembranous stomatitis1 and thrush in 30% of cases.2 Focal glossitis, uvulitis, perlèche, and retrocommissural stomatitis represent chronic OC. Other forms are unusual.3Candida albicans represents 95% of cases,3 but C. tropicalis and C. krusei are frequently isolated.4 Poor dental hygiene and presence of dentures are associated with OC.4 Colonization occurs in 36.8% of subjects with normal dentition and 78.3% of subjects with dentures.5 OC prevalence ranges from 34% to 51% in geriatric inpatients.2, 4, 6 Prevention consists of immunocompetence reinforcement,7 nutrition improvement, mouthwashes,8 and denture maintenance.6 The objectives of this cross-sectional study were to determine OC prevalence in inpatients according to sex, ward type, candidiasis form, and denture wearing and to identify the Candida species distribution. Ninety percent of our inpatients wear dentures. Over a 1-month period, all patients age 65 and older of either sex referred to short-stay, intermediate-stay, and long-stay wards for more than 48 hours were included. OC diagnosis relied on clinical and mycological data (culture> 20 yeast colonies).9 The presence of dentures was scored as total (upper and lower) or partial. Dentures were considered to be worn when used at least once a day. Oral brushing was performed in patients presenting suggestive clinical signs. Yeast identification was performed with direct examination and culture (3-mm-diameter colonies for 48 hours at 30°C). C. albicans was identified by a blast test. The other Candida species were identified by fermentation. Of 713 inpatients, 557 (78.1%; 125 men (M) and 432 women (F); F/M sex ratio of 3.4) with a mean age ± standard deviation of 87.6 ± 8.1 (range 65–104) were included in the study; 57.6% were age 86 and older. Three hundred eighty-five (69.1%) were admitted to long-stay wards, 131 (23.5%) to intermediate-stay wards, and 41 (7.4%) to short-stay wards. The mean stay duration was 626.2 days (long-stay, 880.2 days; intermediate-stay, 68.2 days, and short-stay, 24.4 days). OC was clinically established in 127 cases, consisting of focal glossitis (63%), pseudomembranous stomatitis (15.1%), and erythematous stomatitis (10.8%). Ninety-three (73.3%) were confirmed by microbiology. OC prevalence was 16.7% (95% confidence interval = 13.6–19.8). The OC definition chosen may explain this low prevalence rate, the pathogenicity criterion being classically inferior to 20 colonies per field.10 OC prevalence was previously estimated at 34% in short-stay patients,2 47% in a long-stay setting according to systematic microbiological culture, and 51% in long-stay patients according to clinical and microbiological criteria.11 The specific prevalence by clinical form of candidiasis is displayed in Table 1. Twenty-six percent of patients (28.2% of women and 18.4% of men, P < .05) wore dentures, either complete (15%) or partial (11.1%). Forty-five percent of the population in intermediate-stay wards wore dentures versus 22% in short-stay wards and 20% in long-stay wards (P < .05). OC prevalence was 20.5% in women with dentures versus 12.9% in women without (P < .05). OC prevalence was 21.7% in men with dentures versus 22.6% in men without (P = .93). The OC prevalence in older patients with dentures has been estimated at 65%.12 The prevalence of chronic atrophic candidiasis in 137 long-stay patients with dentures was 38%.10 Dentures were significantly more frequent (45%) in our patients referred to intermediate-stay wards, whereas their prevalence rate was only 20% in long-stay and 22% in short-stay wards (P < .05). For short-stay patients, dentures still fit properly at admission. In long-stay patients, dentures may be lost or no longer fit properly after weight loss or evolving neurological disease. Of the 93 cases of candidiasis, 60 samples (64.5%) contained a single species, 32 (34.4%) contained two different species, and one (1.1%) contained three different species. The Candida species distribution is displayed in Figure 1. C. albicans was either alone (43%) or associated with C. glabrata (31.2%), the most frequent combination. Focal glossitis represented 46.4% of all Candida infections and was predominantly due to C. albicans, C. glabrata, or combined infection of both species. There is only one other study, to our knowledge, that reports the frequent isolation (10%) of several Candida species on a same sample—35.5% in our experience.10 Of the patients suffering from OC, 26% had angular stomatitis.10 The differential diagnosis of erythematous stomatitis versus severe mucosal dryness relied upon microbiological examination. Erythematous stomatitis represented 15% of our cases, versus 38% elsewhere,10 but the average age and total dependency rate (52%) of our population also differed from those of previous studies (61%).11 Distribution of Candida species isolated from cases of oropharyngeal candidiasis (colorimetric kit Auxacolor®, Sanofi, Paris, France). To establish efficient rules of prevention, diagnosis, and standardized treatment of OC by antifungal agents, evaluating oral hygiene care and radiographic dental status is mandatory in patients age 65 and older.