Fungal Organisms Associated with Ocular Infections in a Tertiary Care Hospital

Introduction

The eye is a unique organ that is almost impermeable to almost all external agents [1]. The defense mechanisms of the eye are the tears which contain several substances (e.g. lysozymes and interferon), the eyelids and eye lashes. Pathogenic microorganisms cause diseases to the eyes due to their virulence and host’s reduced resistance from many factors such as personal hygiene, living conditions, socio- economic status, nutrition, genetics, physiology, fever and age [1]. The areas in the eye that are frequently infected are the conjunctiva, lid and cornea [2].

Ocular infections in man are the contamination and invasion of ocular tissues by micro-organisms leading to the breakdown of the natural defense mechanisms of the eyes (i.e the bony orbits, eyelids, eyelashes and tears). This situation results in various ocular disorders including conjunctivitis, keratitis, blepharitis, lid abscess, external hordeolum, dacryocystitis and blepharo-conjuctivitis [3]. The effects of these ocular infections are enormous as they cause both physical, emotional stress including psychological trauma if it leads to blindness or severe ocular distortions [3]. The causative agents of ocular infections can be fungi, bacteria viruses and parasites [3].

These infections have been known to affect both male and female of various age groups. In addition, individuals of various occupations like farming, mining, welding etc have had cause to suffer ocular microbial infections [4]. Moreover, some habits especially those that involve cleaning or rubbing the eyes with contaminated hands/fingers transfer these pathogens to the eyes hence the infections. World Health Organization (WHO) reported that industries were dusts and particles are sent into the air has higher ocular microbial infections [4].

Several other factors have also been known to influence the spread of the microbial ocular invasion. Such factors may include the type of residence, social and attitudinal. Some of these infections carry poor prognosis as patients are at risk of losing either their sights or life, or both [5]. This has necessitated the prompt detection of the etiologic agent and the timely institution of appropriate antibiotic treatment for patients with ocular infections.

In Nigeria, conjunctivitis is one of the most common eye problems which causes “red eye” that affect all age groups. Infective keratitis is a major cause of vision loss and blindness second to cataract [6]. Blepharitis is an inflammation of the eyelid margins which can result in patient discomfort and decline in visual function while lid abscess may cause vision- threatening ocular complications [7]. Dacryocystitis is an inflammation of the lacrimal sac and duct [7]. Lastly, eyelid infection causes redness of the eyelids and the skin around the eyes [7].

Mycotic keratitis, the most frequently encountered fungal infections is usually caused by filamentous fungi and occurs in conjunction with trauma to the cornea with vegetation matter. In the tropics it is common in male agricultural workers. In temperate areas, eye trauma is also the cause of fungal keratitis. The common fungal genera involved are Fusarium, Alternaria and Aspergillus spp [8]. The ocular findings may be part of a widespread systematic infection.

The number of people attending various health institutions for eye related problems in Nigeria is currently in the increase. This has resulted in the establishment of optometry clinics in various hospitals across the country. Therefore, this study was carried out to determine the fungal organisms associated with Ocular Infections in Tertiary Care Hospitals in Abia State, Nigeria.

Results

Of the five hundred (500) patients, thirty-seven 37(7.4%) had fungal contamination. Out of 262 males examined, 22(8.4%) had various fungal contamination while 15(6.3%) of the females had similar contaminations. There was a statistical significance between the male and female (p=0.006). Age played a significant role (P = 0.001) on the prevalence of the contamination. Individuals of 30-45 years were more affected (13.1%), followed by the 45 - 60 year (8.5%) while the least was in the age group 0- 15 years (1.4%). The occupation of the subjects influenced the prevalence of the fungal contamination eyes. Those individuals who are engaged in farming activities had the highest contamination (12.2%) followed by stone quarrying activities (13.8%) and then metal miners (9.7%). The least came from the civil servants (2.5%), Statistical analysis showed a significant influence (P = 0.002).

Table 2 shows the Prevalence of fungal contaminates on eye. Aspergillus niger 40(8.0%) was the most prevalent, followed by Candida albicans 32(6.4%) while Aspergillus fumigatus had the least 22(4.4%). Aspergillus flavus and Fusarium spp prevalence were 5.6% and 5.4%, respectively.

Aspergillus niger 40(8.0%), Aspergillus flavus 28(5.6%), Aspergillus fumigatus 22(4.4%) and Candida albicans 10(31.3%) were isolated from Keratitis patients. Candida albicans was isolated from patients with Dacryocystitis 7(21.9%), Blepharitis 8(25.0%), Keratitis 10(31.3%), Blepharo-conjuctivitis 2(6.3%) and Lid abscess 5(15.6%). Fusarium spp was isolated in patients with only Conjunctivitis 27(5.4%).

Discussion

The culture positivity in this study was 37(7.4%), which was similar to the result from the work of Nwaugo et al. who got 68(15.11%) from patients attending the optometry clinic at Abia State University, Uturu, Nigeria [11]. The absence of fungal growth in some clinically diagnosed cases of ocular infection may be due to non-fungal causes like bacteria, viruses, eye allergies, post traumatic suppurative sclerititis or Hepatic keratitis [12].

The ocular infections were predominantly seen in males (55.3%) who were within the age group 30 - 45 years (77%). This may be attributed to their outdoor activities as people within this age range make up majority of the labor force. Similar result was seen in the study conducted in India [13]. More so, patients of low socio-economic group like farmers, stone quarriers, metal miners had a highest prevalence of ocular infections of (62.2%), (73.8%) and (71%) respectively. These people come in contact with the soil regularly. The soil is the home of all organisms; therefore organisms from the soil contaminate those who come in contact with it. Farming, stone quarrying and metal mining involves tiling the soil which stirs up dust particles. This results in direct contamination of the eyes through dust particles or by touching the eyes with contaminated hands. Alternatively, students and civil servants have little or nothing to do with the soil, thus are not highly contaminated. More so, students and civil servants being probably more educated, have more knowledge about mode of contamination from pathogens and how to prevent it through practice of safe personal hygiene [11]. This was in agreement with the study conducted in India13 and also, at Southern Ethiopia by Anteneh et al. who observed patients of low socio-economic group were most affected by ocular infections as a result of exposure to eye infection [6].

The fungal organisms observed in this study include Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Candida albicans and Fusarium species. Some authors and researchers from Nigeria and India had earlier mentioned them [11, 9, 14, 15]. Aspergillus species are known as contaminants of various materials, hence the high prevalence [11]. The isolation of Candida albicans is of enormous health significance. C. albicans has been known to cause various dermatological and human systemic infections while Fusarium spp are well known dermatophytes [14, 15]. The isolation of these fungi pathogens in this study signifies possible eye infection for the patients resulting in various eye complications.

Fusarium spp (5.4%) is the common organism causing conjunctivitis while keratitis was caused Aspergillus niger (8.0%), Aspergillus flavus (5.6%), Aspergillus fumigatus (4.4%) and C. albicans (31.3%). C. albicans was isolated from cases of Dacryocystitis (21.9%), Blepharitis (25%), Blepharo-conjuctivitis (6.3%) and Lid abscess (15.6%).

Leck, et al. reported that men are more susceptible to conjuctivitis than female [16]. In another studies Sharma et al and Shokohi, et al. reported that Mycotic Keratitis seems to be prevalent in males, in farmers and the most common predisposing factor remains trauma to the cornea [17, 18].

Conclusions

The culture positivity in this study was very high. The highest number of fungi species causing eye infection was observed in the case of keratitis. Fungal infections of the eye were mostly caused by Aspergillus Niger, Aspergillus flavus, Aspergillus fumigatus, C. albicans and Fusarium spp.

Conflicts of Interest

There are no conflicts of interest.