# Long-Term Prevalence of Fungal Keratitis at a Swiss Tertiary Eye Clinic

## TL;DR

This study examines the long-term prevalence of fungal eye infections in Switzerland, finding that contact lens use is common and coinfections are frequent.

## Contribution

The study provides a long-term, single-center analysis of fungal keratitis in a high-income country with a temperate climate.

## Key findings

- Contact lens use was reported in 74.8% of patients with fungal keratitis.
- Molds were 1.8 times more common than yeasts as pathogens.
- Coinfections with Acanthamoeba, HSV-1, and VZV were found in a notable percentage of cases.

## Abstract

Fungal keratitis is a rare yet severe infection of the cornea. Fungal species distribution depends on the climate and socioeconomic status and can show regional variation. This retrospective single-center study was conducted at a tertiary eye care center and the collaborating Institute of Medical Microbiology in Switzerland. On investigating all fungal-positive corneal scrapings and contact lens assessments of patients with keratitis from January 2012 to December 2023, 206 patients were identified, of which 113 (54.9%) were female. The median age was 38 (IQR 29.8, [18–93]), and 154 (74.8%) applied contact lenses. The most commonly found pathogen was Candida spp., followed by Fusarium spp. Molds were 1.8 times more common than yeasts. Linear regression showed no significant increase or decrease in the infection rate over time (p = 0.5). In addition, 10 patients (4.9%) were found to have coinfections with Acanthamoeba, 11 (5.3%) with HSV-1, none with HSV-2, and 4 (1.9%) with VZV. This study provides a long-term overview of fungal-positive corneal scrapings and contact lens specimens of patients with fungal keratitis. Based on our results, coinfections with Acanthamoeba, HSV, and VZV are frequent, especially in patients wearing contact lenses. Thus, wearing contact lenses may facilitate coinfection in fungal keratitis.