Microbiology Section DOI : 10.7860/JCDR/2020/43153.13477
Year : 2020 | Month : Feb | Volume : 14 | Issue : 02 Page : DC01 - DC04

Assessment of Risk Factors and Microbial Profile of Otomycosis in Patients Attending Tertiary Level Hospital of Western Rajasthan, India

Vishakha Ashopa1, Usha Verma2, Pooja Nareda3, Eshank Gupta4, Prabhu Prakash5

1 Senior Demonstrator, Department of Microbiology, Dr SNMC, Jodhpur, Rajasthan, India.
2 Senior Demonstrator, Department of Microbiology, Dr SNMC, Jodhpur, Rajasthan, India.
3 Resident, Department of Microbiology, Dr SNMC, Jodhpur, Rajasthan, India.
4 Senior Demonstrator, Department of Microbiology, Dr SNMC, Jodhpur, Rajasthan, India.
5 Professor, Department of Microbiology, Dr SNMC, Jodhpur, Rajasthan, India.


NAME, ADDRESS, E-MAIL ID OF THE CORRESPONDING AUTHOR: Dr. Prabhu Prakash, 3KA 9, First Puliya, CHB, Jodhpur, Rajasthan, India.
E-mail: dr.prabhuprakash@gmail.com
Abstract

Introduction

Otomycosis or fungal otitis externa is a superficial, subacute or chronic infection of External Auditory Canal (EAC) with irregular complications involving the middle ear, which is characterised by inflammation, pruritus, scaling, otalgia, fullness of ear, tympanic membrane perforation, hearing impairment and ear discharge. Fungi can either be the primary pathogen or be superimposed on bacterial infections.

Aim

To identify causative agents of otomycosis and to determine the associated predisposing factors.

Materials and Methods

The present study was a hospital based prospective study which was conducted from April to September 2019 in Department of Microbiology and Department of Ear Nose and Throat (ENT) in a tertiary level hospital. Total 150 samples was collected from clinically diagnosed patients of otomycosis of any age group. Identification of fungal and bacterial isolates were done by standard microbiological procedures, and demographic profile, occupation, predisposing factors were evaluated. Categorical data was presented as frequencies and percentages. The association between the pre-disposing factors (Ear pricking, oil instillation) and the prevalence of otomycosis was analysed by chi-square test. The p-values <0.05 was considered significant.

Results

Male to female ratio in present study was 1:1.30, females were more than males. Maximum cases were in the age group of 21-30 years i.e., 37 (24.67%), occupation wise maximum cases were seen in housewives 55 (36.67%). Ear pricking was the most common predisposing factor leading to otomycosis i.e., 122 (81.33%). Aspergillus species and Candida species were the most commonly identified fungal pathogens in otomycosis 76 (70.37%) and 17 (15.74%), respectively. In bacterial isolates Pseudomonas species 20 (13.33%) was the most common causative agent, cases of mixed bacterial and fungal infection were also seen.

Conclusion

In the present study, Aspergillus species was found to be the most common fungi involved in otomycosis. There is need to educate the community about the common practice of ear pricking and instilling oil in ear which leads to otomycosis.

Introduction

Otomycosis or fungal otitis externa is a superficial, subacute or chronic infection of External Auditory Canal (EAC) with irregular complications involving the middle ear [1], which is characterised by inflammation, pruritus, scaling, otalgia, fullness of ear, tympanic membrane perforation, hearing impairment and ear discharge. In study done by Fasunla J et al., and Pontes ZB et al., concluded that otomycosis prevalence depends upon different climatic conditions with higher number of cases in the hot, humid and dusty areas of the tropics and subtropics [2,3]. In India otomycosis is a common medical problem and health hazard [4,5]. There are many predisposing factors of otomycosis which may be systemic or local. Long term use of antimicrobial agents, immuno-compromised status or co-morbid conditions like diabetes are systemic predisposing factors of otomycosis while high humidity in EAC, accumulation of epithelial debris or instrumentation or trauma caused by the use of unsterile sharp or pointed objects like key, hair pins and match sticks etc. may be local predisposing cause of otomycosis [6].

Fungi can either be the primary pathogen or be superimposed on bacterial infections [7]. There are wide spectrum of fungi which leads to otomycosis but Aspergillus niger and Candida albicans are most common offenders [4,5,8].

The present study was conducted with the aim to identify both fungal and bacterial agents which causes otomycosis and to determine the associated risk factors.

Materials and Methods

The present study was a hospital based prospective study which was conducted from April to September 2019 in the Department of Microbiology at Umaid Hospital, Dr. SNMC Jodhpur, Rajasthan, India. Total 150 samples were collected.

Inclusion criteria: Clinically diagnosed patients of otomycosis with symptoms like itching, pain, feeling of blocked ear, tinnitus, deafness, discharge and otoscopic findings revealing wet or dry matted masses of hyphae or white cheesy material and those who gave their written consent, attending ENT outpatient department at MDM hospital, Dr SNMC, Jodhpur.

Exclusion criteria: Patient who refused to give their consent.

Institutional Ethical Clearance was taken and ethical certificate reference number is SNMC/IEC/2019/PLAN/204.

To evaluate and analyse demographic profile (age, sex, and occupation), predisposing factors, presenting complaints, a predesigned proforma was used in clinically diagnosed patients of otomycosis.

Two ear swabs were collected aseptically. One ear swab was used for direct microscopy (Gram’s staining, 10% KOH and wet mount) and second swab was used for culture (mycological and bacteriological culture). For fungus culture, Sabouraud’s Dextrose Agar (SDA) with chloramphenicol (Himedia, India), was used as selective medium [9]. Ear swabs were inoculated on two slants of SDA with chloramphenicol and incubated at 25°C in Biological Oxygen Demand (BOD) incubator and at 37°C incubator for four weeks and slants were examined at regular interval for fungal growth. In case of any filamentous fungal growth, Lactophenol Cotton Blue (LPCB) mount and microscopy was done for identification of filamentous fungal isolate. For characterisation of Candida isolates, colonies were inoculated on HiChrome agar (Himedia, India) for species identification [10].

For aerobic pyogenic identification, sample was cultured on Blood Agar and MacConkey Agar for 48 hours and examined for bacterial growth. Identification of the bacterial isolates was done by standard bacteriological procedures [11].

Statistical Analysis

The prevalence of otomycosis was analysed with the chi-square test using SPSS version 25 and p values <0.05 were considered significant. Categorical data were presented as frequencies and percentages.

Results

Based on clinically diagnosed patients of otomycosis according to complaints. Sensation of blocked ear 99 (66%) and itching 50 (33.33%), were maximum while minimum complaint were noted in ear discharge and in tinnitus which were 13 (8.66%) and 21 (14%) respectively [Table/Fig-1]. In male to female ratio there was pre dominance in female patients as compared to males in a ratio of 1:1.30 (65:85). While in urban population females were affected more in comparison to males in a ratio of 1.34:1 [Table/Fig-2]. The maximum cases were found in the age group of 21-30 years i.e., 37 (24.67%) while minimum cases were detected in the age group of >60 years i.e., 10 (6.66%) [Table/Fig-3]. Out of 150 cases 117 (78%) patients were from urban background in compare to rural population in which 33 (22%) patients were engaged for this study. Maximum cases were housewives 55 (36.67%) followed by student 51 (34.00%), farmer 12 cases (8%) while minimum cases were seen in auto driver, cobbler, engineer, mechanic, shopkeeper, supervisor, welding and handicraft workers (1 case in each) [Table/Fig-4].

Distribution according to patients complaints.

Clinical manifestationYesNo
1Itching50 (33.33%)100 (66.66%)
2Blocked ear99 (66%)51 (34%)
3Ear pain84 (56%)66 (44%)
4Ear discharge13 (8.66%)137 (91.33)
5Tinnitus21 (14%)129 (86%)

Demographic distribution of cases.

AreaSexUrban%Rural%Total
Male5033.33%1510.00%65
Female6744.67%1812.00%85
Total11778.00%3322.00%150

Distribution of causative agent in relation to age and sex.

Sl. No.Age (years)MaleFemaleTotal%
1<1012102214.67
211-2014132718.00
321-3016213724.67
431-4009202919.33
541-5003101308.67
651-6005071208.00
7>6006041006.66
Total6585150100

Occupation wise distribution.

Sl. No.OccupationNo%
1Student5134.00
2Auto driver0100.67
3Businessman1208.00
4Carpenter0201.33
5Cobbler010.67
6Engineer010.67
7Factory worker0201.33
8Farmer1208.00
9Handicraft worker0100.67
10House wife5536.67
11Labour0302.00
12Mechanic0100.67
13Shopkeeper0100.67
14Supervisor0100.67
15Teacher0100.67
16Welding worker0100.67

Ear pricking, use of local and systemic antimicrobial agents and oiling were most common predisposing factors leading to otomycosis i.e., 122 (81.33%), 37 (24.67%) and 33 (22%), respectively. While minimum cases were seen in diabetic patients i.e., 02 (1.33%) and in this study all patients were HIV negative [Table/Fig-5].

Predisposing factors.

Sl. No.Predisposing factorsNo. of cases%
1Ear pricking12281.33
2Oiling3322.00
3Swimming1308.67
4Use of local and systemic antimicrobials3724.67
5Diabetes0201.33
6Any history of discharge1308.67

In present study, maximum number of mould enrolled were Aspergillus niger i.e., 54 (50%) followed by Aspergillus fumigatus 10 (9.25%), Aspergillus flavus 08 (7.40%), Aspergillus terreus 04 (3.70%). While minimum cases were enrolled in Scopularasis spp. 1 (0.92%) followed by Rhizopus microsporus, Rhizomucor spp., Syncephalastrum spp., Basidiobolus spp., Paecilomyces spp. (1 in each) [Table/Fig-6].

Spectrum of isolates among patients.

Sl. No.Fungal isolateNumber (%) of samples positive for fungi, n=108Associated bacterial isolates (n)
1Aspergillus niger54 (50%)Pseudomonas spp.67.14%
Klebsiella spp.44.76%
CONS1214.28%
Micrococcus spp.011.19%
Aspergillus flavus08 (7.40%)Klebsiella spp.022.38%
CONS011.19%
Aspergillus fumigatus10 (9.25%)Micrococcus spp.011.19%
CONS022.38%
Aspergillus terreus4 (3.70%)Klebsiella spp.011.19%
2Rizomucor spp.Rhizopus Microsporus1 (0.92%)1 (0.92%)---
3C. albicansC.dubiliensisC. kruseiC. parapsilosis1 (0.92%)1 (0.92%)14 (12.96%)1 (0.92%)Pseudomonas spp.022.38%
CONS033.57%
4Alternaria spp.Bipolaris spp.Cladosporium spp.Curvularia spp.Crysosporium spp.Syncephalastrum spp.Basidiobolus spp.Paecilomyces spp.Scopularasis spp.1 (0.92%)1 (0.92%)1 (0.92%)1 (0.92%)1 (0.92%)3 (2.77%)1 (0.92%)1 (0.92%)1 (0.92%)Pseudomonas spp.011.19%
CONS033.57%
5Mixed Fungal InfectionWith 2 fungiAspergillus spp.:10{(9.25%)(A.niger complex, A.fumigatus complex, A.flavus complex} Candida spp.-3 (2.77%)CONS011.19%
Pseudomonas spp.011.19%
6With no fungi (48)Staph.aureus022.38%
CONS2428.57%
Micrococcus spp.022.38%
E. coli011.19%
Pseudomonas spp.1011.90%
Klebsiella spp.044.76%

In dematiaceous fungi, Chrysosporium spp. was associated with 01 (0.92%), Alternaria spp. 01 (0.92%), Bipolaris spp.01 (0.92%), Cladosporium spp. 01 (0.92%), Curvularia spp.01 (0.92%).

In yeast like fungi, Candida krusei were isolated from 14 (12.96%), Candida albicans 01 (0.92%), Candida dubliniensis 01 (0.92%), Candida parapsilosis 01 (0.92%).

In aerobic pyogenic bacteria, Pseudomonas spp. was most common isolate in 20 (13.33%) cases, Klebsiella spp. in 11 (10.1%) cases, Escherichia coli in 01 (0.67%) and Staphylococcus aureus were present in 02 (2.38%) cases.

Discussion

Agarwal P and Devi LS and many other researchers concluded high prevalence of fungal otitis externa in tropical and subtropical regions of the world including India in the last few decades [1-4,6,8,9,12].

Occurrence of otomycosis was high in present study 108 (72%) which is similar to the studies conducted by Kaur R et al., and Barati B et al., who reported 74.6% and 69%, respectively [5,13]. As fungi are found abundantly on decayed plant matter and are saprophytic in nature, workers in moldy or dusty environment are usually affected more. The higher cases of otomycosis may be due to humidity [9]. In this study, ratio of females 85 (56.66%) were more as compared to males 65 (43.33%) which is in concordance with the studies done by Fasunla J et al., Pontes ZB et al., Barati B et al., and Yehia MM et al., who reported predominance in female cases 233 (61.64%), 12 (60%), 86 (50.3%), 65.4%, respectively [2,3,13,14].

In the present study, the incidence of infection was seen in all age groups but in age group 21-30 years incidence was 24.67%, followed by 31-40 years 19.33% [Table/Fig-3] which is similar to the studies conducted by Prasad SC et al., and Agarwal P and Devi LS who reported 21.33% and 66.31%, respectively [1,9]. Out of 150 samples, maximum cases were seen in housewives 55 (36.67%) which is similar to the study conducted by Adoga AS and Iduh AA who reported 28.60% [15], while by the studies conducted by Prasad SC et al., maximum cases were seen in patients who were indulged in agriculture 70% and Agarwal P and Devi LS reported maximum cases in outdoor farmers and labours who were exposed to fungal spores together with dust owing to their working conditions [1,9].

In all the patients of otomycosis, predominant symptoms were itching, blocked sensation of the ear; there was complaint of ear discharge, ear pain and tinnitus also. The incidence of otomycosis was high in patients with history of ear pricking (81.33%) habit of cleaning ear with contaminated objects such as key, hair pin etc., leads to inoculation of fungal debris in EAC which is similar to the study conducted by Pontes ZB et al., [3] while, instilling coconut oil into the ear was the most common i.e., 42% causative agent in the study done by Prasad SC et al., [1]. The use of topical antibiotic ear drops and use of systemic antimicrobial agents was in 24.67% and the habit of instilling oil in the ear was recorded in 22% cases.

In study done by Prasad SC et al., Aspergillus spp. were isolated in 80% cases, Penicillium spp. in 8%, C.albicans 4%, Rhizopus spp. and Chrysosporium spp. in 1% each [1]. In fungal bacterial association in the study group, aerobic pyogenic bacteria were isolated as Pseudomonas spp. in 20 (13.33%) cases similar to the study done by Singer DE et al., [16].

In this study, Aspergillus spp. and Candida spp. were the most commonly identified fungal pathogens in otomycosis which is similar to the studies conducted by Agarwal P and Devi LS, Aneja KR et al., and Hagiwara S et al., [9,17,18].

Although antifungal agents are effective in eradicating infection and removing the predisposing factors have to be taken into consideration. Most of the fungi thrive in moist atmosphere and in the presence of epithelial debris; tropical drugs do not act unless these debris and discharge is removed. Hence careful drying and cleaning of EAC and personal hygiene is recommended in treatment of otomycosis.

Limitation(s)

Anaerobic culture, molecular and genetic identification of isolates were not done due to non-availability of facilities.

Conclusion(s)

Fungal otitis externa is seen highly prevalent in tropical and subtropical regions of the world. In the present study, Aspergillus spp. were found to be the most common fungi involved in otomycosis along with other rare fungi like Candida spp., Rhizomucor, Dematiaceous fungi with bacterial co-infection by Pseudomonas spp. and other bacterial isolates. As ear pricking was most common pre-disposing factor leading to otomycosis, there is need to educate community about its serious consequences.

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