Journal of Infection and Public Health (2012) 5, 109—111
CASE REPORT
Rhizopus-associated soft tissue infection in an immunocompetent air-conditioning technician after a road traffic accident: A case report and review of the literature Nada B. Rabie a, Abdulhakeem O. Althaqafi a,b,∗ a
Department of Medicine, King Abdulaziz Medical City, National Guard Health Affairs, Jeddah, Saudi Arabia b College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia Received 14 February 2011 ; received in revised form 7 October 2011; accepted 10 October 2011
KEYWORDS Rhizopus; Immunocompetent; Air conditioning
Summary Rhinocerebral or sinopulmonary mucromycosis is a well-recognized human fungal infection found among immunocompromised and diabetic patients. However, the infection is rare among immunocompetent hosts. We are reporting the case of an adult immunocompetent male patient working as an air-conditioning technician. The patient was a victim of a road traffic accident (RTA) and sustained multiple fractures in the proximal part of the left tibia, distal femur, and scapula. Two weeks postoperatively, Rhizopus microspores were isolated from an infected traumatic wound over the distal femur. Surgical debridement was performed, and the patient was started on amphotericin B. Occupational exposure history and workplace environmental sanitation are crucial for the prevention of this potentially fatal yet preventable infection. © 2011 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.
Introduction Zygomycosis is a rare, highly invasive fungal infection caused by fungi of the Zygomycetes class [1]. ∗ Corresponding author at: Infectious Diseases Section, Department of Medicine, King Abdulaziz Medical City, National Guard Health Affairs, PO Box 9515, Jeddah 21423, Saudi Arabia. Tel.: +966 505665621. E-mail address: thaqafi
[email protected] (A.O. Althaqafi).
Mucorales is the largest and best studied order of Zygomycete fungi. Rhizopus is the most common fungal genus causing mucromycosis; other less common causes of infection include Mucor and Rhizomucor [1]. Rhizopus is ubiquitous in nature, and a number of its species can be used in food fermentation and the production of hydrolytic enzymes [2]. Although mucromycosis encompasses a wide range of clinical presentations caused by the family Mucoracae, the infection commonly presents
1876-0341/$ — see front matter © 2011 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.jiph.2011.10.002
110 as two clinical syndromes: sinopulmonary and rhinocerebral mucromycosis [3]. Other reported rare forms include cutaneous, intestinal and pulmonary diseases. The infection can be acquired through inhalation or direct traumatic inoculation through the skin or mucosa [4]. Mucromycosis has been recognized as an emerging fungal infection in immunocompromised patients, especially those with hematological malignancy after stem cell transplantation and in cases of diabetic ketoacidosis. However, mucromycosis soft-tissue infection remains extremely rare in immunocompetent hosts [1].
Case report A 41-year-old Pakistani male patient working as an air-conditioning technician was injured in a road traffic accident while returning home from work. The accident resulted in multiple fractures involving the mid-shaft right humerus, scapula, distal left tibia, fibula, and proximal left femur. Open reduction and internal fixation were performed for the humeral, femoral and tibial fractures. Two weeks postoperatively, an infected wound with pus was noted in the upper left leg. A swab from the pus was sent for microbiological culture. Subsequently, the culture came back positive for Rhizopus microspores, and the patient was started on amphotericin B. The initial dose was 0.1 mg/kg IV, which was increased to 0.7 mg/kg daily IV with 50 mg of oral prednisolone and 25 mg of oral diphenydramine 30 min before the amphotericin dose. One week after the administration of amphotericin B, the wound size had decreased. Unfortunately, we were not able to follow the patient, who was transferred to another hospital because he was not eligible to continue management at the same hospital because of his medical insurance coverage.
Discussion Because Rhizopus, the most common fungal genus causing mucromycosis, displays a rapid growth rate and a highly angioinvasive nature in human beings, it tends to be associated with high mortality rates, especially when no surgical intervention is implicated [5]. The current case is a relatively young (41 years old) immunocompetent patient whose work as an air-conditioning technician exposes him to a wide range of fungal spores. These spores contaminate
N.B. Rabie, A.O. Althaqafi his skin and clothes. Additionally, living with three other roommates in an overcrowded building in Thoal, a small village in Saudi Arabia, in a humid environment might increase the risk of fungal overgrowth. Humidity offers a good environment for the growth of Rhizopus, including Rhizopus oryzae, the most frequently recovered species in mucromycosis. (The optimum temperature for the growth of Rhizopus is 35 ◦ C, but it can still grow at temperatures up to 45 ◦ C [6].) Consequently, direct inoculation of the Rhizopus microspores during the road traffic accident was most probably the cause of the deep soft-tissue infection. Contamination with spores usually happens when there is a break of the skin and underlying mucosa, such as in intravenous catheterization, spider bites, contaminated dressings, contaminated wounds or surgical site infections [5,7]. This contamination can rapidly lead to progressive tissue necrosis [1,8]. However, dissemination and deep-tissue involvement are unusual complications of cutaneous mucromycosis [7]. Antifungal therapy and surgical debridement remain the cornerstones for the management of such cases [9]. Without surgical intervention, mortality can be as high as 60%. Early diagnosis and early surgical intervention can reduce the mortality to 11% [10,11]. A high index of suspicion is required to ensure early intervention. To date, there is no consensus regarding the antifungal agent of choice [12]. Amphotericin B has the best activity against most of the Mucorales and should be seriously considered in empiric coverage [1,12]. An amphotericin dose of 1.0—1.5 mg/kg/day up to a total cumulative dose of 2—4 g is recommended [1]. Azoles lack good coverage for Zygomycosis, and Voriconazole has no role in the treatment of Zygomycosis [12]; however, oral Posaconazole therapy may be effective, especially in refractory cases [13]. Our patient was treated with early surgical debridement upon arrival to the hospital and received Amphotericin B empiric coverage. During the hospital stay, daily wound dressing was performed with silver nitrite, and the wound showed significant improvement thereafter.
Conclusion In this case presentation, a previously healthy and immunocompetent patient working as an air-conditioning technician developed Rhizopusrelated soft-tissue infection after a road-traffic accident. Notably, a high index of suspicion is needed to reach a diagnosis. Although rare,
Rhizopus-associated soft tissue infection in an immunocompetent air-conditioning technician Rhizopus-related infection can be very serious and cause considerable morbidity and mortality, but these outcomes are preventable. Environmental sanitation, monitoring and proper maintenance of air conditioning equipment are mandatory to decrease the burden of such serious environmentrelated infections. Effective health education programs should be implemented to improve the awareness of workers in such jobs to wear clean clothes before going home as a method to minimize the spread of such workplace biological hazards in the community.
[6]
[7]
[8]
[9]
References [10] [1] Severo CB, Guazzelli LS, Severo LC. Chapter 7: Zygomycosis. J Bras Pneumol 2010;36(1):134—41. [2] Ikasari L, Mitchell DA. Protease production by Rhizopus oligosporus in solid-state fermentation. World J Microbiol Biotechnol 1994;10(3):320—4. [3] Marr KA, Carter RA, Crippa F, Wald A, Corey L. Epidemiology and outcome of mould infections in hematopoietic stem cell transplant recipients. Clin Infect Dis 2002;34:909—17. [4] Thomson SR, Bade PG, Taams M, Chrystal V. Gastrointestinal mucormycosis. Br J Surg 1991;78(8):952—4. [5] Kontogiorgi M, Floros L, Koroneos A, Vamvouka C, Paniara O, Roussos C, et al. Fatal post-traumatic zygomycosis
[11]
[12]
[13]
111
in an immunocompetent young patient. J Med Microbiol 2007;56(Pt 9):1243—5. EI-Gholl NE, Baer H, Schubert TS. Fungal posing occupational hazards in agricultural environments; 1991, January. Plant Pathology Circular No. 339. Roden MM, Zaoutis TE, Buchanan WL, Knudsen TA, Sarkisova TA, Schaufele RL, et al. Epidemiology and outcome of zygomycosis: a review of 929 reported cases. Clin Infect Dis 2005;41(5):634—53. Severo LC, Oliveira FD, Dreher R, Teixeira PZ, Porto ND, Londero AT, et al. A report of eleven cases and a review of the Brazilian literature. Rev Iberoam Micol 2002;19(1): 52—6. Arnáiz-García ME, Alonso-Pe˜ na D, González-Vela MC, García-Palomo JD, Sanz-Giménez-Rico JR, Arnáiz-García AM. Cutaneous mucormycosis: report of five cases and review of the literature. J Plast Reconstr Aesthet Surg 2009;62(11):e434—41. Eucker J, Sezer O, Graf B, Possinger K. Mucormycoses Mycoses 2001;44(7—8):253—60. Tedder M, Spratt JA, Anstadt MP, Hegde SS, Tedder SD, Lowe JE. Pulmonary mucormycosis: results of medical and surgical therapy. Ann Thorac Surg 1994;57(4):1044—50. Alastruey-Izquierdo A, Castelli MV, Cuesta I, Zaragoza O, Monzón A, Mellado E, et al. In vitro activity of antifungals against Zygomycetes. Clin Microbiol Infect 2009;15(October (Suppl. 5)):71—6. Greenberg RN, Mullane K, van Burik JA, Raad I, Abzug MJ, Anstead G. Posaconazole as salvage therapy for zygomycosis. Antimicrob Agents Chemother 2006;50(1): 126—33.
Available online at www.sciencedirect.com
