Outbreak of Pythium keratitis during rainy season: a case series.
OBJECTIVE
To describe typical clinical and laboratory characteristics of severe fungal keratitis caused by Pythium insidiosum during the rainy season in Northeast Thailand and to report the efficacy of P. insidiosum vaccine in the treatment of Pythium keratitis.


METHODS
A series of hospital-based consecutive cases of Pythium keratitis were diagnosed and treated at Srinagarind Hospital (Khon Kaen University, Khon Kaen, Thailand). The clinical presentations, diagnostic tests, and management are described.


RESULTS
Severe fungal keratitis caused by P. insidiosum was diagnosed in 5 eyes of 4 patients between May 2009 and July 2009. All cases had a history of fungal keratitis after being exposed to contaminated water. Upon slit-lamp examination, subepithelial and superficial stromal opacities were observed in a reticular pattern in all cases. Pythium insidiosum was identified and confirmed by both microbiological culture and polymerase chain reaction. Clinical worsening was detected after conventional treatment with antifungal agents. Therapeutic penetrating keratoplasty with either donor cornea or scleral graft was performed together with topical antifungal administration and P. insidiosum vaccination. Subsequent evisceration was performed in 1 eye.


CONCLUSIONS
An outbreak of Pythium keratitis in Northeast Thailand was reported. Distinctive clinical features are a suggestive clue for early diagnosis. Combination treatment including topical antifungal agents, radical surgery, and P. insidiosum vaccine may be considered for the management of Pythium keratitis.
Department of Ophthalmology, Faculty of Medicine, Srinagarind Hospital, Khon Kaen University, Khon Kaen, Thailand.
Onsiri
O
Thanathanee
Orapin
O
Enkvetchakul
Ram
R
Rangsin
Sakda
S
Waraasawapati
Kittipan
K
Samerpitak
Olan
O
Suwan-apichon
D000328:Adult; D000935:Antifungal Agents / Q000627:therapeutic use; D003131:Combined Modality Therapy; D003320:Corneal Ulcer / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D004196:Disease Outbreaks; D015822:Eye Infections, Parasitic / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D005260:Female; D006801:Humans; D016233:Immunotherapy, Active; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D058968:Pythiosis / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D011775:Pythium / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D011891:Rain; D012621:Seasons; D055502:Secondary Prevention; D013785:Thailand / Q000453:epidemiology; D014611:Vaccination
D000935:Antifungal Agents; D012337:RNA, Ribosomal, 18S