ABSTRACT
ABSTRACT Objective: Bacterial keratitis occurs worldwide, and despite recent developments, it remains a potentially blinding condition. This study assesses the presence of herpes simplex virus (HSV-1 and -2) and varicella zoster virus (VZV) by quantitative real-time polymerase chain reaction (qPCR) in corneal scrapings from patients with bacterial keratitis. Methods: A total of 65 patients with clinical diagnoses of infectious corneal ulcers prospectively underwent clinical eye examinations. Corneal scrapings were investigated by Gram staining, Giemsa staining, culture, and qPCR (the study group). Risk factors and epidemiological data were recorded. The control group comprising 25 eyes with typical herpes dendritic keratitis was also analyzed by qPCR. Results: From the study group (n=65), nine patients (13.8%) had negative smears, cultures, and qPCR findings. Fifty-six (86.2%) patients had positive cultures: 51 for bacteria, 4 for fungi, and 1 for amoebae. Of the patients who had positive bacterial cultures, qPCR identified 10 patients who were also positive for virus: one for VZV and nine for HSV-1. Of the 25 patients in the control group, 21 tested positive for HSV-1 by qPCR analysis. Conclusions: Herpes may be present in patients with bacterial corneal ulcers, and qPCR may be useful in its detection.
RESUMO Objetivo: Ceratites bacterianas ocorrem mundialmente e apesar dos novos desenvolvimentos permanece como uma condição que pode levar à cegueira. Avaliar a presença de herpes simples (-1 e -2) e vírus varicella zoster (VZV) por reação em cadeia quantitativa de polimerase em tempo real (qPCR) em raspados corneanos de pacientes com ceratite bacteriana. Métodos: Sessenta e cinco pacientes com ceratite infecciosa foram submetidos a raspados corneanos estudados para gram, Giemsa, cultura e qPCR (grupo de estudo). Foram avaliados fatores de risco e epidemiológicos. O grupo controle foi composto por 25 casos de úlcera dendrítica típica por herpes analisados por qPCR. Resultados: Do grupo de estudo (n=65), nove pacientes (13,8%) apresentaram cultura, qPCR e raspado negativos. Cinquenta e seis (86,2%) pacientes apresentaram cultura positiva, 51 para bacteria, 4 para fungo e 1 para ameba. A qPCR identificou 10 pacientes do grupo de cultura positiva para bactéria que também foram positivos para vírus, um VZV e 9 para HSV-1. Dos 25 pacientes que compunham o grupo controle, 21 apresentaram qPCR positivo para HSV-1. Conclusão: Herpes pode estar presente em pacientes com úlceras de córnea bacterianas e a qPCR pode ser útil na sua detecção.
Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Keratitis, Dendritic/microbiology , Herpesvirus 2, Human/isolation & purification , Herpesvirus 1, Human/isolation & purification , Herpesvirus 3, Human/isolation & purification , Cornea/virology , Real-Time Polymerase Chain Reaction/methods , Keratitis/microbiology , DNA Probes , Eye Infections, Bacterial/microbiology , Keratitis, Dendritic/diagnosis , Keratitis, Dendritic/virology , Prospective Studies , Keratitis/diagnosis , Keratitis/virologyABSTRACT
One of the main causes of blindness in Egypt is corneal blindness. Infections account most causes of corneal blindness. The aim of this work to study the epidemiological characteristics, risk factors, laboratory diagnosis, and treatment outcome of patients with microbial keratitis in Sohag. A descriptive study of 300 patients with corneal ulceration referred to ophthalmology department of Sohag University Hospital over a 1-year period, September 2008 through August 2009. A specially designed questionnaire sheet was administered from all cases. Then all cases were subjected to, general and eye examination, direct smear examination, final diagnosis and treatment. Pure bacterial keratitis cases were 85[28.4%], which showed gram positive and negative cocci, pure fungal 75[25%], and the largest number of studied cases 110 [36.6%] had mixed bacterial and fungal infection, viral nature of keratitis accounted for 10 [3.3%] of cases. 20 [6.6%] of cases could not be microbiologically identified. More than half of patients of mixed, bacterial, fungal and viral kiratitis were above 50 years old. The majority of the patients of mixed, bacterial, fungal and viral kiratitis were, fanners. Diabetes mellitus and eye trauma were more frequently noted in keratitis of both pure and polymicrobial etiology. Corneal injury with vegetative matter was identified as the predominant risk factor in fungal kiratitis and the predominant fungal species isolated was filamentous spp. Regarding the treatment outcome, healing with dense scar occurs in 100 [91%] of mixed and 46 [61%] of fungal infections. All viral keratitis cases healed uncomplicated with faint superficial scar. Suppurative keratitis continues to be a cause of concern to ophthalmologists in Sohag. Old age, male sex, diabetes mellitus, eye trauma and the predominance of agricultural activity are the principal risk factors of keratitis of both pure and polymicrobial etiology