Epidemiology of Aspergillus species causing keratitis in Mexico

Abstract

Background: The incidence of fungal keratitis has increased in recent years. While the epidemiology and clinical roles of various Candida and Fusarium species have been relatively well-identified in infections of the eye, data regarding keratitis caused by Aspergillus species are scant. Accurate and rapid diagnosis is important for successful management of this infection.

Objectives: To present the first molecular epidemiological data from Mexico during a 4-year period of cases admitted with Aspergillus keratitis to a tertiary care eye institution in Mexico City.

Patients/methods: A total of 25 cases of keratitis were included in the study. Aspergillus isolates were identified by sequencing the calmodulin gene. Antifungal susceptibility was tested according to CLSI.

Results: The aetiological agents belonged to Aspergillus flavus (n = 13), Aspergillus effusus (n = 1), Aspergillus tamarii (n = 4), Aspergillus sydowii (n = 1), Aspergillus protuberus (n = 3) and Aspergillus terreus (n = 3). All strains had low minimum inhibitory concentrations (MICs) of itraconazole and voriconazole (VCZ). Amphotericin B and natamycin showed moderate elevated MICs.

Conclusions: Early diagnosis and application of topical VCZ 1% were associated with good outcome. Monitoring of local epidemiological data plays an important role in clinical practice.

Keywords: Aspergillus; antifungals; calmodulin; epidemiology; keratitis; trauma.