Global Epidemiology of Mucormycosis

Abstract

Mucormycosis is an angio-invasive fungal infection, associated with high morbidity and mortality. A change in the epidemiology of mucormycosis has been observed in recent years with the rise in incidence, new causative agents and susceptible population. The rise has been perceived globally, but it is very high in the Asian continent. Though diabetes mellitus overshadow all other risk factors in Asia, post-tuberculosis and chronic renal failure have emerged as new risk groups. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes mellitus, whereas, pulmonary mucormycosis in patients with haematological malignancy and transplant recipients. In immunocompetent hosts, cutaneous mucormycosis is commonly seen following trauma. The intriguing clinical entity, isolated renal mucormycosis in immunocompetent patients is only reported from China and India. A new clinical entity, indolent mucormycosis in nasal sinuses, is recently recognized. The causative agents of mucormycosis vary across different geographic locations. Though Rhizopus arrhizus is the most common agent isolated worldwide, Apophysomyces variabilis is predominant in Asia and Lichtheimia species in Europe. The new causative agents, Rhizopus homothallicus, Mucor irregularis, and Thamnostylum lucknowense are reported from Asia. In conclusion, with the change in epidemiology of mucormycosis country-wise studies are warranted to estimate disease burden in different risk groups, analyse the clinical disease pattern and identify the new etiological agents.

Keywords: Rhizopus arrhizus; diabetes mellitus; haematological malignancy; incidence; mucormycosis.

Figure 1

Underlying disease/ risk factors associated with mucormycosis. The percentage of values given in the figure was calculated based on the data given in the literature. Percentage counts in total are more than actual values, because multiple risk factors are counted more than once. The data was pooled from studies by Chakrabarti et al. 2006, 2001, 2009 [10,16,17].

Figure 2

Clinical forms of mucormycosis reported from different studies across the globe. The percentage of values given in the figure was calculated based on the data provided in the literature. Multiple sites of infection were reported in few studies: Roden et al. 2005 [3], Ruping et al. 2010 [75], Kennedy et al. 2016 [85]. The data was pooled from studies by Chakrabarti et al. 2006, 2001, 2009 [10,16,17].

Figure 3

Clinical forms of mucormycosis in various underlying disease. Abbreviations: DM: Diabetes Mellitus, HM: Haematological Malignancy, IC: Immunocompetent and SOT- Solid Organ Transplant.

Figure 4

Causative agents of mucormycosis.