FREQUENCY RATE OF ORAL CANDIDIASIS AMONG PATIENTS ON ONCOLOGY MANAGEMENT AT KHARTOUM ISOTOPE AND RADIATION TEACHING HOSPITAL

Nagla M.A. Mohammed 1 , El Fadil E. Omer and El-Nour EL-Amin A.. 1. Department of Medical Microbiology, Faculty of Medical Laboratory Sciences, Al-Neelain University 2. Department of Microbiology and Molecular biologyFaculty of Sciences and TechnologyAl-Neelain University. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

The colonized Candida can invade the underlying mucosa and enter the blood stream leading onto disseminated disease with considerable morbidity and mortality if not treated promptly. Fluconazole is one of the first line drugs used for the treatment of oral candidiasis in cancer patients [12,13]. Most studies place the crude mortality rate due to C. albicans infections at around 30%-40% , [14,15] but some have estimated this to be as high as 46%-75% [16].
A systematic review indicated that the weighed mean prevalence of clinical oral fungal infection during chemotherapy is 38% [17], and the most common forms of intraoral candidiasis reported in oncology patients are pseudomembranous and erythematous candidiasis [18,19]. Pseudomembranous candidiasis can usually be diagnosed on the basis of its characteristic clinical appearance and may be accompanied by burning pain and taste changes. The appearance of erythematous candidiasis is relatively nonspecific, and laboratory testing may be needed to confirm the diagnosis. It may be accompanied by a burning sensation of the affected tissues [20].
Chemotherapeutic agents and therapeutic radiation disrupts the mucosal banner of the mouth, leading to severe oral mucositis, gingivitis, oral candidiasis, cellulitis and viral mucosal eruptions [21]. The oral mucositis or inflammation of the oral mucosa is painful and is characterized by erythema, edema, and mucosal shedding, which can lead to ulceration and secondary infection [22].
The irradiation-induced histological changes leading to oral mucositis, together with salivary quantitative and qualitative changes, have been reported to facilitate yeast growth [23].
Oral candidiasis presents as a removable white pseudomembrane or erythematous patch on the tongue, palate and labial commissures. It causes taste alterations, mucosal soreness and oral burning sensations. Heavy accumulations of candida may dislodge causing esophagitis, fungemia and pose aspiration risk to the patient [24].

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The routine oral examination of cancer patients has revealed a greater incidence of Candida infections than that in most types of patients. Almost all surveys on fungal infections in cancer patients come from USA, Europe, and other developed countries, and little is known about this problem in developing countries, [1] particularly Sudan. For the first time we report on occurrence rate of oral Candidiasis among cancer patients at Isotope and Radiation center -Khartoum.

Materials and Methods:-
It was a cross-sectional, case control study conducted in a period of 2015 to 2016. The study involved 100 cancer patients (Out-patients ) as case study and 68 cancer patients (inpatients) as control groups, both group were under treatment of chemotherapy and/or radiotherapy in Radiation and Isotopes Centre Khartoum. Patients on antifungal therapy for past two weeks were excluded from the study. Both groups with a mean age of 48 years old, the patients were explained and informed consent was obtained from the patients. The demographic data, origin, type of cancer and treatment were considered in this study.
A total of 100 samples from cases and 68 from in-patients controls were included in the study. An examination of the oral cavity of the patients was performed and a sample from tongue, buccal mucosa and labial sulcus was taken with a sterile pre-moistened swab. All samples were processed for yeast isolation in Microbiology laboratory following collection.
Oral Candida colonization was defined as presence of yeasts in the oral cavity irrespective of signs and symptoms. Oral candidiasis was defined as presence of Candida spp. in the oral cavity together with signs and symptoms of oral candidiasis like inflammation/mucositis and/or presence of white plaques confirmed microbiologically by the presence of yeasts and/or hyphae or pseudohyphae on potassium hydroxide-treated smears of oral swabs [25].
For all patients, the clinical diagnosis was confirmed microscopically by the presence of yeasts and hyphae or pseudohyphae on 10% potassium hydroxide (KOH) preparation of oral swabs. Swabs were streaked onto Sabouraud ' s dextrose agar (SDA) to which chloramphenicol (0.05g/l) was added., which is the most useful and popular primary culture media [26]. Then the Plates were incubated at 37 0 C for 24-48 hours, and Candida colonies appeared as cream coloured smooth or rough, shiny or dull and convex.
According to classification of oral candidoses [27], identification of Candida species was made using direct microscopy of the Gram stained smears that show characteristic rounded , or oval budding cells of yeast blastospores (yeast form) with or without the hyphal phase, which can be distinguished readily from bacteria by their greater size (3-6 μm) , budding , oval shape and pseudohyphae,.Identification of Candida species from growth in SDA media was done by germ tube test which it was perform to identify C.albicans, and to differentiate C.albicans from non albicans groups. Lightly touched single yeast colonies with sterile wire loop from the culture plate was inoculated in fresh human pooled serum and incubated at 37 0 C for 2-3 hours. The wet mount preparation showed germ tube which is a hyphal projection, as mentioned in [28].
Statistical analysis:-Data analyzed using Spss 21 (Statistical package for social sciences) with reference p-value (.05), P-value ≤.05 conceder as significant result. Frequencies and percent obtained in frequency tables, chi-square testfor goodness of fitused to test these frequencies. The relations between variables tested using cross tables and chi-square (Fisher exact)test for independence.
Ethical consideration:-An approval was taken from the University, Faculty and Department of Medical microbiology management. Consent was taken from Ministry of health, hospital and participants before taking samples.-

Results:-
The subject (168) involved in this study were cancer patients with chemotherapy and/or radiotherapy treatment, they represented (100) outpatients and (68)  The colonized Candida can invade the underlying mucosa and enter the blood stream leading onto disseminated disease. For all cancer patients the prevalence of oral candidiasis was 23(33.3) while the prevalence of oral colonization was (66.7), and significantly the infection was more common among inpatients group than outpatients.( p value <0.05) ( Table 1 ). Table 1

:-Frequency of oral infection and colonization
In the present study it was found that C.albicans was significantly (P-<0.05) representing the most common isolated organism among both groups. (Figure 2)   Candida infection was more in patients treated with chemotherapy alone and least infection was shown in patients treated with radiotherapy (Table 3). The present study explained statistically significant distribution of oral candidiasis among cancer patients according to type of cancer ( Figure 3).

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According to the environment and inherited genes of the Sudanese State, although all patients were treated in Isotope and Radiation Center are coming from different State. The high numbers of examined patients are from Khartoum state followed by Gezira State (Table 4). And according to the tribes more infection in Al-Gaalia tribe 6 out of 69 (8.8%) followed by Zagaoa 4 out of 69 (5.9%).

Discussion:-
In the present study it was found that Candida species were isolated from 69 (41.1%) patients while 99(58.9 %) patients showed no growth. Also Lihua Xu, et al., [29] found that oral infection was prevalent in 46% (391/850) of all cancer patients. Other studies have reported the incidence of oral candidiasis ranging from 7 to 52% in cancer patients on chemotherapy and/or radiotherapy [30].
The present study revealed the frequency of Candida isolates to be significantly more prevalent in in-patients than out-patients group (51.5% vs. 34%). Similar finding were obtainedby Hanan, et al. [31].
Regarding the infection and colonization it was found that among the total examined patients, the prevalence of oral candidiasis was 33.3 while 66.7% was colonization. Relatively similar result reprted by Mohd, et al. in (2014), [32] they found the total colonization to be prevalent in 50% and oral candidiasis in 30% of all cancer patients. Also Rajesh, et al [33] found that in a systematic review of oral fungal infections in patients receiving cancer therapy, the weighed prevalence of clinical oral infection (oral candidiasis) and oral colonization during treatment was 39.1% and 72.2% , respectively.
In a study done by [31]. It was found that in-patients cancer group harboured Candida spp at significantly high levels than out patients. This study clearly demonstrated similar result that oral candidasis was significantly higher among in-patients (42.9%) (P value <0.05) than out patients group (8.8%), while colonization are more common in the out patients group Table (1). Several previous works [31, 28, and 34] that studied the prevalence of oral Candida spp demonstrated that Candia albicans was the most prevalent organism. Similarly the present study revealed Candida albicans to be the most common organism both among out-patients and in-patients control group (76.5% vs. 68.5%), respectively. also Shaheen, et al, found that C. albicans to be the only species recovered from non hospitalized patients(100%) while in hospitalize patients it was only 56%.
Oral infection was insignificantly more common among females than males (p <0.05). This may be due to increase number of females than males in this study. This finding is in agreement with the study of Intisar, et.al [35] who studied a total of 6771 cases of cancer incidence, they found females cases as 53.8% and males (46.2%).
Amongst the cases (n=168), 147 (87.5%) had solid organ malignancy and 21 (12.5%) patients with hematological malignancy. Breast cancer patients represented the higher group among different types of cancer in Sudan [36] this agrees with the fact that this type of cancer is a worldwide distribution in different countries. It was found the high frequently of Candida spp. appeared in patients with breast cancer, which is in accordance to other investigation [37], this is in agreement with this study.
The current study showed significant increased percentage (63.9%) of Candida isolates among chemotherapy treated patients as most of the cases 114 (67.9%) under chemotherapy treatment only. It is well known that cancer and chemotherapy result in immunosuppression which gives opportunity for emergence of Candida infection. The outcome is the immune dysfunction and mucosal damage which promote yeast infections such as mucositis, xerostomia and candidiasis [38,39]. It is well known that prolonged use of chemotherapy may lead to neutropenia, disruption of mucosal barrier and overall damage to cell mediated immunity which increases the risk of infection. [40].
Although the high number of cancer patients in the current study were represented at Khartoum State followed by Gezira State. Oral candidiasis was found more common among patients who are from North Sudan and South Darfor (13.2%) equally. and among those who belong to Al-gaalia tribe (8.8%) table (4). This may be due to either inherited genes or environmental factors, thus further studies must be carried out to enrich this field.

Conclusion:-
In the present study we demonstrate that C. albicans and other Non-C. albicans species are associated commonly with the oral cavity in immounocompromised patients. Oral colonization and infection by Candida spp. is a matter of concern especially among in-patients group as multiple risk factors contribute to such a scenario in this vulnerable group.
The incidence of this yeast varies depending on cancer type, sex, and age; type of cancer treatment, origin and tribe of patients.
The frequent occurrence of Candida species in oral cavity of immounocompromised patients indicates a need for effective management for the isolation and identification of this yeast prior to any treatment.