First Report on Concomitant Infection of Nasal Myiasis and Trichosporonosis in an Uncontrolled Diabetic Patient: Case Report

Abstract

Myiasis is an infestation of living tissue of animals or humans by fly larvae. It is quite common in tropical countries due to hot and humid climates. Trichosporonosis is an invasive disseminated fungal infection caused by Trichosporon species. Disseminated trichosporonosis is usually a fatal disease with poor prognosis. The aim of this manuscript is to report a clinical case of concomitant nasal myiasis and Trichosporonosis infection in an uncontrolled diabetic patient which was treated successfully by two weeks of Voriconazole therapy.

Introduction

Nasal myiasis is an infestation of nasal cavity by larvae of fly known as “Peenash” and “Scholechiasis” and is usually seen during rainy season. Trichosporon species are part of flora in skin and gastrointestinal tract but have recently emerged as an invasive/opportunistic pathogen in immunocompromised patients [1].

Case Report

A 28-year-old male patient reported with chief complaints of low grade fever, headache and swelling over right side of face and eyelid for 5 days. He was a known case of Type II Diabetes Mellitus for last 10 years and was on irregular insulin therapy. The patient’s past medical history (five months back) revealed that he had undergone an emergency endoscopic debridement of sinonasal cavity for sinonasal mucormycosis followed by intravenous administration of Amphotericin B for 3 weeks.

On examination, he was confused and irritable. Ocular examination revealed bilateral ptosis (right > left), right lateral rectus and left superior rectus palsy, which he developed due to mucormycosis infection previously. Local examination revealed diffuse oedema over right side of face and periorbital region (Fig. 1a). Live, wriggling larvae were seen in bilateral nasal and oral cavity.

Fig. 1.

a Diffuse edema in right side of face, b Coronal CT scan shows postoperative changes with subcutaneous edema over the face, c MRI T1 image showing postoperative changes

Radiological examination (Computed Tomography of Nose and Paranasal sinuses, Magnetic Resonance Imaging of brain with contrast) revealed mild mucosal thickening in all paranasal sinuses with postoperative endoscopic debridement changes. There was no intracranial involvement. (Fig. 1b,c)

Biochemical investigations revealed elevated HbA1C (9.1%) with decreased serum sodium (128 mmol/L) and positive ketone test in urine.

Diagnostic nasal endoscopy was done and maggots were removed from the bilateral nasal cavity. The maggots were creamy white in colour with corkscrew appearance of body with tapering ends and cylindrical body with ten segmental rings (Fig. 2a). Roomy nasal cavity was noticed with no septum and turbinate which might be due to either previous rhinocerebral mucormycosis or postoperative changes. The debrided sample from the nasal cavity was sent for fungal examination. KOH mount showed no fungal elements but fungal culture on SDA (Sabouraud’s dextrose agar) revealed white to cream coloured smooth colonies (Fig. 2b). Gram stain of these colonies revealed the presence of septate hyphae with rectangular arthrospores (Fig. 2c). It also showed hydrolysis of urea. Trichosporon asahii was identified based on colony characters, gram stain, lactophenol cotton blue findings and biochemical tests. It was further confirmed as the same by MALDI-TOF MS (Matrix assisted Laser desorption ionization time of flight mass spectroscopy) with a confidence interval of more than 1.80. Histopathological report showed only inflammatory changes. The maggots were managed with topical turpentine oil administration and systemic Ivermectin therapy. Patient was put on Tablet Ivermectin 6 mg once daily for 2 days to paralyse the larvae.

Fig. 2.

a Expelled maggot from nasal cavity, b Gram stained smear showing hyphae, arthrospores and budding yeast cells, c Colony morphology of Trichosporon asahii on Sabouraud’s Dextrose Agar showing white, creamy and wrinkled colonies

Injection Voriconazole 400 mg 12 hourly was administered intravenously for one day followed by oral Voriconazole 200 mg 12 h for two weeks. Patient recovered well with resolution of signs and symptoms. Patient was reassessed after two months for nasal discharge and there were no symptoms suggestive of recurrence of disease and diagnostic nasal endoscopy revealed no myiasis and necrotic tissue. To the best of our knowledge, this is the first case report of concomitant infection of Nasal Myiasis and Trichosporonosis.

Discussion

Myiasis is an infestation of living tissue of animals or humans by fly larvae. In India, the incidence of Human myiasis is high due to warm and humid climate, poor sanitation and inadequate hygiene due to people living close to livestock. Most commonly affected are older age, poor socioeconomically status, poor nutritional status, immunocompromised patients, Atrophic rhinitis and Leprosy patients [2].

The agents responsible for nasal myiasis are Cochliomyiahominivorax, Chrysomyabezziana, Oestrus ovius, Wohlfahritamagnifica, Luciliasericata, Drosophilia melanogaster and Musca domestica [3].

In our case, due to the unavailability of essentially required resources the causative species of maggots could not be identified.

The aim of treatment is to remove all larvae. Mixture of chloroform and turpentine (1:4), ethylene chloride, irrigation of nasal cavity with cocaine, Ivermectin (1%), lignocaine and naphtha are the conventional methods for removal of larvae with the help of nasal endoscopy. Use of Oral Ivermectin dose of 200 mcg/kg or 6 mg OD for 2 days is currently used for paralysing the larvae [2]. The same treatment protocol was followed in our patient with success.

Trichosporonosis is an invasive systemic infection caused by Trichosporon species. Trichosporon species are yeast like anamorphic organism and belong to basidiomycetes yeasts. Presently, the genus Trichosporon includes the following species as potential human pathogens: Trichosporon cutaneum, Trichosporon asahii, Trichosporon asteroides, Trichosporon mucoides, T. inkin, etc., Out of these, two species which are frequently involved with deep fungal infections are T. asahii and T. mucoides. T. ashaii infections are most commonly implicated in haematogenous dissemination, while T. mucoides is recovered from the central nervous system disease [4]. Trichosporon causing fungal sinusitis is very rare worldwide. One case of fungal sinusitis caused by Trichosporon inkin have been reported from South India by Janagond et al. [5].

Voriconazole is considered as most effective drug against trichosporonosis and considered as the first line treatment for patient having disseminated disease. Itraconazole and fluconazole can also be used as second line treatment options. Amphotericin B is usually reserved for Voriconazole resistant trichosporonosis [6]. The prognosis also depends upon the immune status of the patient.

Our patient had uncontrolled Diabetes Mellitus on admission, positive fungal culture for Trichosporon and negative for Mucorales with necrotic bony tissue on endoscopic examination. On basis of Invasive Fungal Infection Cooperative Group (IFICG) and National Institute of Allergy and Infectious Disease Mycoses Study Group (NIAID/MSG) criteria, diagnosis of probable invasive trichosporonosis was made [7].

As there were necrotic findings due to myiasis on endoscopy and CT scan was suggestive of only postoperative changes, Patient was only managed with voriconazole without any need of further surgical debridement. Patient also responded well with Voriconazole for 2 weeks. It is well established that in a case of Diabetes Mellitus with complicated sinusitis, Mucormycosis should be ruled out. However, our patient with same features turned out to be case of nasal myiasis and Trichosporonosis.

Conclusion

This case highlights the heightened susceptibility of an Immuno compromised host with uncontrolled Diabetes Mellitus who suffered from myriad of opportunistic infections like Sinonasal Mucormycosis, followed by Trichosporonosis and Nasal Myiasis, all of which may have very poor outcomes if not timely detected and managed.