Microbial keratitis at a referral center in Brazil

Abstract

To describe the epidemiological and laboratory characteristics of microbial keratitis at a referral center in Brazil. Charts of all patients referred to the Ocular Microbiology Laboratory at Federal University of São Paulo (UNIFESP) from July 1975 to September 2007 were retrospectively reviewed. The following data were recorded: age, gender, involved eye, use of ocular medication, previous trauma or surgery, contact lens wear and the results of laboratory cultures. The study included 6,804 corneal cultures. The mean age was 42.1 ± 21.4 years. The male-to-female ratio was 1.5:1. Positive cultures were obtained in 3,309 (48.6%) cases. Of these, bacteria were isolated in 2,699 (39.7%), fungi in 364 (5.3%) and Acanthamoeba in 246 (3.6%) samples. Positive bacterial cultures were 2.7-fold more frequent in patients with previous use of steroids (P < 0.01), and a 30% reduction in positive bacterial cultures was observed in patients with previous use of antibiotics (P < 0.01). A total of 1,524 patients (22.4%) had a past history of ocular surgery. Contact lens wearers showed a 1.7 times greater chance of having an Acanthamoeba-positive culture (P < 0.01). Previous ocular trauma was present in 1,118 (16.4%) cases and injury caused by plants showed a 3.8 times greater chance of a positive fungal culture (P < 0.01). Bacterial organisms were identified as the most frequent agent followed by fungi and Acanthamoeba. Prescription of steroids and antibiotics prior to corneal scrapings may modify the laboratory test results. Previous corneal surgery, contact lens wear and ocular trauma have been shown to be risk factors for bacterial, Acanthamoeba and fungal keratitis, respectively.

The Spectrum of Microbial Keratitis: An Updated Review

“…The aetiology of microbial keratitis was found to differ depending on the geographical location of the patient and the infective pathogen [11]. Fungal keratitis is comparatively uncommon in temperate climates, though in tropical areas it can constitute a significant proportion of microbial keratitis [2, 13,165]. The tropical climate, combined with greater agricultural and vegetation exposure in lower socioeconomic countries causes an increased risk of contracting fungal keratitis in populations [166,167].…”

Fusarium keratitis in Brazil: genotyping, in vitro susceptibilities, and clinical outcomes

“…Brazil, like other countries having an important territorial part in the tropical zone, has a significant number of fungal keratitis cases, ranging from 11% to 56% of all positive cultures 1,2. In countries like India and People’s Republic of China, fungi can be the etiology in up to 36% and 62%, respectively, of all keratitis cases 3,4.…”

“…Among the fungi causing keratitis, Fusarium species is the most prevalent. Studies show that 45%–67% of fungal keratitis in Brazil is caused by this microorganism 1,2,5–7. Among the Fusarium species that are pathogenic to the eye, Fusarium solani is the most common (found in up to 91% of isolates),7 followed by Fusarium oxysporum and Fusarium dimerum.…”

Efeito terapêutico do crosslinking corneal na ceratite infecciosa

“…It is a leading cause of monocular blindness in developing countries (1)(2)(3)(4) . Most cases are bacterial, but the condition can also be caused by fungi, protozoa, and viruses (5)(6)(7)(8)(9) . The current standard therapy for bacterial and fungal keratitis is based on antibiotics and antifungals (10,11) .…”