Abstract:
The purpose of this investigation was to determine
the clinical and corneal microbial profile of infectious keratitis
in a high human immunodeficiency virus (HIV) prevalence
setting in rural South Africa. Data in this cross-sectional study
were collected from patients presenting with symptoms of
infectious keratitis (n = 46) at the ophthalmology outpatient
department of three hospitals in rural South Africa. Corneal
swabs were tested for herpes simplex virus type 1 (HSV-1)
and 2 (HSV-2), varicella zoster virus (VZV) and adenovirus
DNA by real-time polymerase chain reaction (PCR) and for
bacteria and fungi by culture. Based on clinical history, disease
characteristics and laboratory results, 29 (63 %) patients
were diagnosed as viral keratitis, including 14 (48 %) viral keratitis cases complicated by bacterial superinfection, and
17 (37 %) as bacterial keratitis. VZV and HSV-1 DNA was
detected in 11 (24 %) and 5 (11 %) corneal swabs, respectively.
Among clinically defined viral keratitis cases, a negative
viral swab was predominantly (93 %) observed in cases with
subepithelial inflammation and was significantly associated
with an increased duration of symptoms (p=0.003). The majority
of bacteria cultured were Gram-positive (24/35), including
Staphylococcus epidermidis and S. aureus. Viral aetiology
was significantly associated with a history of herpes zoster
ophthalmicus (p < 0.001) and a trend was observed between
viral aetiology and HIV infection (p = 0.06). Twenty-one
(47 %) keratitis cases were complicated by anterior uveitis,
of which 18 (86 %) were HIV-infected cases with viral keratitis.
The data implicate a high prevalence of herpetic keratitis,
in part complicated by bacterial superinfection and/or uveitis,
in HIV-infected individuals presenting with infectious keratitis
in rural South Africa.
