The epidemiology and clinical manifestations of mucormycosis: a systematic review and meta-analysis of case reports

Abstract

Background: The epidemiology of mucormycosis in the era of modern diagnostics is relatively under-explored.

Objectives: To examine the contemporary epidemiology, clinical manifestations, diagnosis and causative pathogens of mucormycosis.

Data sources: Ovid MEDLINE and Ovid EMBASE from January 2000 to January 2017.

Study eligibility criteria: Published case reports/series of proven/probable mucormycosis.

Participants: Patients ≥18 years old.

Methods: Patient characteristics, disease manifestations and causative pathogens were summarized descriptively. Categorical variables were assessed by chi-square test or Fischer's exact test, and continuous variables by the Wilcoxon-Mann-Whitney or Kruskal-Wallis test. Risk factors for the different clinical manifestations of mucormycosis were identified using multivariate logistic regression.

Results: Initial database searches identified 3619 articles of which 600 (851 individual patient cases) were included in the final analysis. Diabetes mellitus was the commonest underlying condition (340/851, 40%) and was an independent risk for rhino-orbital-cerebral mucormycosis (odds ratio (OR) 2.49; 95% CI 1.77-3.54; p < 0.001). Underlying haematological malignancy was associated with disseminated infection (OR 3.86; 95% CI 1.78-8.37; p 0.001), whereas previous solid organ transplantation was associated with pulmonary (OR 3.19; 95% CI 1.50-6.82; p 0.003), gastrointestinal (OR 4.47; 95% CI 1.69-11.80; p 0.003), or disseminated (OR 4.20; 95% CI 1.68-10.46; p 0.002) mucormycosis. Eight genera (24 species) of Mucorales organisms were identified in 447/851 (53%) cases, of which Rhizopus spp. (213/447, 48%) was the most common. Compared with other genera, Rhizopus spp. was predominantly observed in patients with rhino-orbital-cerebral mucormycosis (75/213, 35% versus 34/234, 15%; p < 0.001). Death was reported in 389/851 (46%) patients. Mortality associated with Cunninghamella infections was significantly higher than those caused by other Mucorales (23/30, 71% versus 185/417, 44%; p < 0.001). However, Cunninghamella spp. were isolated primarily in patients with pulmonary (17/30, 57%) or disseminated disease (10/30, 33%).

Conclusions: Findings from the current review have helped ascertain the association between various manifestations of mucormycosis, their respective predisposing factors and causative organisms.

Keywords: Diagnosis; Epidemiology; Mucorales; Mucormycosis; Systematic review.