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Published on: May 12, 2020
The Temporal Distribution and Microbial Spectrum in Infectious Keratitis: A Comprehensive Single-Center Study
Naoyuki Yamada1, Nanako Iwamoto1, Ayano Sakuma1
1Department of Ophthalmology, School of Medicine, Yamaguchi University, Ube 755-8505, Japan.
Abstract:
Purpose: To elucidate pathogen-specific seasonal patterns in infectious keratitis through a comprehensive long-term analysis of microbiologically proven cases in a Japanese tertiary care center. Methods: This retrospective study analyzed 500 consecutive cases of culture-proven infectious keratitis diagnosed and treated by corneal specialists at Yamaguchi University Hospital between 2009 and 2021. Seasonal distribution patterns were analyzed for each pathogen category and specific microorganisms. Results: Among the 500 cases, bacteria were identified in 249 eyes (49.8%), viruses in 173 eyes (34.6%), fungi in 51 eyes (10.2%), and Acanthamoeba in 27 eyes (5.4%). The top 10 causative microorganisms constituted 80.4% of all cases. Distinct seasonal patterns emerged: bacterial keratitis peaked during winter months (October-March), Pseudomonas aeruginosa infections clustered in late summer (August-September), Acanthamoeba keratitis showed summer predominance (June-August), and HSV keratitis was most frequent in winter to spring (January-May). Overall incidence peaked from January to March and reached its nadir in June. Conclusions: This long-term study revealed distinct seasonal patterns for specific pathogens causing infectious keratitis in Japan. The findings suggest that geographical location and climate may influence the temporal distribution of corneal infections. These pathogen-specific seasonal trends could aid in the preliminary diagnosis and empirical treatment of infectious keratitis.
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