Prevalence of Candidiasis in Chennai Population

Keywords

Candidiasis; Candida Albicans; Hygiene; Infections.

Introduction

The normal flora of our oral cavity encompasses nutrients, epithelial debris and gland secretions in which it favors as a habitat for a diverse type of organisms. They are mostly fungi, mycoplasmas, protozoa, archaea and oral bacteria such as streptococci, lactobacilli, staphylococci and corynebacteria. Fungi are eukaryotic organisms that can be divided into round fungi (yeasts), filamentous fungi (moulds) and combination of both (dimorphic fungi). Candida is the shortened name used to recount a class of fungi that has a population of over 150 species. On top of that, there are approximately 700 species of microorganisms in our human oral cavity, among which 20 species of Candida [1-3].

Candida species are known as the beneficial flora that harmlessly exists in our human skin and mucosa. However, these species have been reported as risk pathogens as results of excessive intake of a broad spectrum of antibiotics, HIV infection, organ transplantation, long-term hospitalization and malignant diseases [4, 5]. The wide range of infections caused by these species include bloodstream infections (BSIs) and disseminated candidiasis. In the United States, Candida ranks fourth and seventh in Europe in relation to the BSI [6-8]. This lesion is mainly caused by the Candida albicans. Studies in India are very limited and only few studies have reported the prevalence of candidemia (6-18%) [9-11]. Candida species are considered as the inhabitants of the normal flora in the oral cavity and gastrointestinal tract. The most virulent and pathogenic among these species is known as Candida albicans. It is the principal species that is highly related in human oral mycoses [12-14].

Candidiasis is a common opportunistic fungal infection of Candida species that affects oral mucosa. The predominant ones are Candida albicans (the commonest), Candida tropicalis, Candida glabrata, Candida guilliermondii, Candida pseudotropicalis, Candida krusei, Candida lusitaniae, Candida parapsilosis, and Candida stellatoidea. This lesion is often misdiagnosed or undiagnosed in older people, especially in patients wearing dental prostheses and with poor oral hygiene care. It is also more prevalent in immunocompromised patients and systemic diseases such as diabetes mellitus, anemia and cardiac problems [15, 16]. 80% of clinical infections were reported in association of C. albicans, C. glabrata and C. tropicalis [17, 18]. On top of that, oral candida infection has been associated with several drugs. These drugs are known as predisposing factors for oral candidiasis in which they may have suppressive effects on the normal pH of the oral bacterial flora either through the T-cell mediated immunity or nonspecific inflammatory response and leads to Candida overgrowth. Antiadrenergics, antidepressants, anticholinergics, antipsychotics and antihypertensives are the potential drugs to cause dry mouth effects in oral candidiasis [17].

Globally, oral candidiasis is the most common fungal infection, primarily observed in the young aged and elderly population. The carriage rates were reported to be in the range of 20% to 75% for the past few decades [19, 20]. The prevalence of oral candidiasis in humans with predominant Candida albicans have been found to be 45% neonates, 45-65% in adolescents and 30-45% in healthy adults. Next, individuals with prolonged use of dentures presented with 50-65% incidence rate, 65-88% in those long-term hospital stay, 90% in those undergoing chemotherapy and radiotherapy of acute leukemia and 95% in patients with HIV infection [17, 21, 22]. In general, oral candidiasis is considered a common phenomenon and it is usually asymptomatic in systematically healthy people. Nevertheless, the severity and extensive growth rate of fungi can lead to symptoms of discomfort, dysgeusia, severe mucositis and swallowing difficulties, which leads to poor nutrition [23, 24].

The pathogenesis of oral candidiasis can be possibly explained with the ability of Candida albicans to transform into hyphal phase and germ tubes that are the onset of hyphal growth in this lesion [25]. Once the overgrowth colonization of this species in the oral cavity completes, it facilitates a pathway for yeasts to reach the respiratory system. Thereby, oral candidiasis poses a risk factor of systemic diseases and local mucosal infection, especially in elderly population [26]. Older aged communities are more vulnerable and harbor to candidiasis because of their low immunity system, some may have predisposed to systemic disorders and the medication intake [27, 28].

There is rarity in the literature of similar study within Indian population considering limited investigations and evidence regarding the prevalence of oral candidiasis in the general population. Thus, this study was conducted to assess the prevalence of candidiasis among the Chennai population.

Materials and Method

This is a retrospective cross sectional study carried out from June 2019 to March 2020 and it was covered by the following ethical approval number; SDC/SIHEC/2020/DIASDATA/0618-0319. It was taking place in Saveetha Dental College and Hospital in relation to the South Indian population. The advantage of this study was large data availability. However, it was conducted on a limited time frame and geographically only focused on the isolated population. Ethical approval for the study was obtained from the Institutional Ethics Committee. Case records of the patients were reviewed individually. Two external examiners were involved in this study. The sampling bias was minimized with all inclusion of data and cross verification done by verifying with photographs.

Data Collection

Data regarding patients diagnosed with candidiasis were retrieved after analyzing 86000 case sheets. The following parameters were evaluated based on the dental records; age and gender. Clinical examinations and treatment reports of the patients were examined for the data collection. Internal validity of this study was inclusion of all samples diagnosed with associated condition and external validity was defining the eligibility criteria of the sample and epidemiology perspective. The inclusion criterion of this study was dentate patients above 18 years diagnosed with candidiasis.

Statistical Analysis

All the data collected were tabulated in MS Excel and incomplete data was eliminated. Data analysis was carried out using IBM Statistical Package for Social Science (SPSS version 23). The statistical test used for the demographics was frequency distribution. Descriptive statistic was calculated using Chi-square t test. P value less than 0.05 was set as statistically significant. Frequency distribution for age and gender was calculated.

Results and Discussion

There are various types of oral candidiasis including acute pseudomembranous, acute atrophic, chronic hyperplastic, denture stomatitis, median rhomboid glossitis, and angular cheilitis. They generally exhibit as white plaques resembling curdled milk on the affected surfaces. The candidiasis may spread to the esophageal area which occasionally can be life threatening. The variables considered in this study include age and gender of the patients affected with candidiasis. According to the analysis done, 26 patients were found to be diagnosed with candidiasis. The prevalence of candidiasis was reported higher among male patients (69.23%) than female patients (30.77%), as displayed in Figure 1. The prevalence of oral candidiasis in this showed that more than halves of male patients were highly affected as compared to female patients. This is consistent with a previous study of oral candidiasis in Kolkata, which reported 27 were men (79.4%) and 7 were women (20.6%) [29]. Few previous studies also reported the percentage of males with Candida species infections were more predominant than females [30, 31]. The gender wise distribution of oral candidiasis by Rathod et al., demonstrated equal frequency in the both sexes, except where HIV infection in males outnumber females [27]. The probable factors of male predominance are males had poor oral hygiene than females and they are more related with systemic disease such as diabetes mellitus and HIV infection.

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In each age group of this study, Figure 2 depicts oral candidiasis was more frequent in 35-50 years and 51-60 years with the same percentage (34.62%). The smallest percentage was found in the age group of 20-35 years (11.54%). Therefore, the greatest percentage of candidiasis was seen in the older group, corroborating with Loster et al that older people were commonly infected with candidiasis [32]. Furnaleto et al., also found that infections caused by Candida species were more frequent in the elderly. The age distribution of this study also correlates the findings of another study that most of the patients infected were within the age group of 51-60 years [29]. A study with a background of postdisaster areas reported high Candida colonization among elderly aged 65-75 years or in patients associated with HIV, carcinoma or diabetes. The reported prevalence rates were 63.6% for total Candida and 53.4% for C. albicans. He also stated a stable non-progressive colonization of C. albicans and progressive colonization of non-Candida, harboured by the elderly population. This study suggested that incidence of oral candidiasis has been recognized in the elderly, which possibly could be linked with poor nutrition and weakened immune system. Additional reasons include extreme age, low salivary flow rate and the use of dentures [27].

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Based on the distribution of age groups in gender predilection, there was an increased proportion of males diagnosed with candidiasis regardless their age groups with insignificant difference (p=0.489), demonstrated in Figure 3. This suggested that a difference between both sexes did not occur though there was an increased proportion of males diagnosed with candidiasis regardless their age groups. Similarly, Loster et al revealed that the difference in the distribution of candidiasis across patient gender and age was not statistically significant with females showing the greatest frequency of candidiasis in respect to age groups distribution [32]. In corroborating to this, Sato et al also found insignificance correlation between both sexes either in the colony amount of C. albicans and non-Candida [27]. More detailed studies are required to investigate and determine the reason for this difference in gender prevalence.

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Our study was limited to a small sample size distribution within a short duration of investigation and geographic limitation. Other shortcomings of this study include the analysis based on the classification and types of oral candidiasis were not mentioned in this study. There is a need for extensive larger scale-study with richer clinical data in order to obtain more accuracy of the findings in association of different community-based investigations. Further, the research design of future studies can be established in both control areas and post-disaster areas with the inclusion of different species of C. albicans and non-Candida. Plus, systemic diseases, living conditions and oral status could affect the prevalence of Candidiasis.

Conclusion

Within the limits of this study, the prevalence of candidiasis in the Chennai population was substantially low. Male patients were more prevalent in having this infection as compared to female patients. Considering the higher prevalence of candidiasis among the middle-aged and elderly population, there should be absolute necessities in prevention and management approaches. Maintaining good oral hygiene and long term follow-up in elderly patients are also needed.

Acknowledgements

We would like to thank Saveetha Dental College and Hospital for the contributions and involvement through this study.