Epidemiology of Microbial Keratitis at a Tertiary Care Hospital in Southern Thailand

This study aimed to ascertain the microbial profiles and predisposing risk factors for microbial keratitis and to analyze the trend of mixed microbial infection cases over 8 years.

In this retrospective analysis, we reviewed the electronic medical records of inpatients diagnosed with microbial keratitis between January 2012 and December 2019. Data on demographics, risk factors, and causative pathogens were analyzed. Multivariate logistic regression models were utilized to identify risk factors associated with pathogens.

This study included 640 eyes of 638 patients. Trauma was the most common predisposing risk factor (57.2%), followed by a combination of factors (14.4%). Among diagnostic test results, bacteria, fungi, and mixed pathogens were identified in 46.72%, 46.56%, and 21.41% of cases, respectively. Positive culture results were obtained in 324 eyes (53.6%), with Pseudomonas aeruginosa (25.1%) and Fusarium spp. (17.4%) being the most prevalent pathogens. In the multivariate logistic regression model, contact lens use, presence of diabetes mellitus, and HIV infection were statistically significant risk factors for Pseudomonas aeruginosa infection (p = 0.001, p = 0.046, and p = 0.04, respectively). Trauma was associated with Fusarium spp. infection (p = 0.001). An increase in the percentage of mixed microbial infection cases was observed when comparing the periods of 2016-2019 with 2012-2015 (p = 0.023).

Bacteria and fungi are equally common causes of microbial keratitis, with Pseudomonas aeruginosa and Fusarium spp. being the predominant pathogens causing bacterial and fungal infections. Trauma is the primary predisposing risk factor for microbial keratitis. There was a notable increase in mixed infection cases over the study period.