Ocular Fungal Infection Trends, Pathogens Identified for Northern China

Ocular fungal infections occur most often during the Chinese harvesting season between October and December and the fusarium, aspergillus, and alternaria species are the most common causative agents, according to a hospital-based, retrospective study published in the Journal of Infection and Public Health. 

Researchers retroscopically reviewed medical charts of 11,635 patients with a suspected ocular fungal infection from a single tertiary eye care center between January 2001 and December 2020. Patients underwent demographic analysis and sample collection via corneal scraping or aspiration with a syringe needle. The research team examined positive culture rates, identified causative pathogens, and assessed associations with age and season.

Among the study participants, the positive culture rate of ocular fungal infection was 23.6%, according to the report. Most of the samples (83.1%) were taken from the cornea and their culture positivity was 26.9%. 

When stratified by age, individuals aged 40 to 60 years accounted for most fungal keratitis cases (59.4%). Fungal keratitis occurred more frequently during the harvesting season which lasts from October to December (34.0%) compared with other seasons (22.0%). The most common fungal species of ocular mycotic infections were fusarium (53.2%), aspergillus (15.9%) and alternaria (12.5%). 

Among 2562 organisms identified from corneal scraping, 1443 (56.3%) were fusarium sp, 403 (15.7%) were aspergillus sp, and 329 (12.8%) were alternaria sp. Among the 120 fungi isolated from the intraocular fluid, the most common species were aspergillus (33.3%),fusarium (24.2%), and candida (15.0%). 

“Ocular fungal infection is an important cause of corneal morbidity, scarring, and blindness,” according to the researchers. “The microbial epidemiology and pathogen spectrum of fungal isolates may often vary in different regions and change over time. Therefore, it is important to conduct periodic surveys to report local information as a reference for clinicians.”

This study was limited by a single center design and an overrepresentation of participants who were men in the study sample.