Epidemic keratoconjunctivitis outbreak at a tertiary referral eye care clinic

Abstract

An outbreak of epidemic keratoconjunctivitis (EKC) occurred at a tertiary referral eye care clinic between late September and mid-November 1995. Before the outbreak, instruments were cleaned with 70% isopropyl alcohol and handwashing between patients was not routine. Infection control measures were implemented when the outbreak was recognized in mid-October. Control measures included triaging suspected cases to a separate waiting area, cohorting cases to a specific examining room, endorsing the use of gloves and handwashing during examinations of patients, and cleaning instruments with a buffered bleach solution. Thirty-six cases were diagnosed before the infection control measures were taken, and 3 cases were seen after the control measures were taken. Also, numerous secondary cases occurred in the community. No additional cases were diagnosed from DEcember to February 25, 1996. Acquisition of the infection was linked to visits to 4 of 20 physicians in the eye clinic with 61% of cases associated with visits to 1 of those 4 physicians. The use of diagnostic lenses applied directly to the eye was associated with infection (odds ratio = 2.83, 95% confidence interval = 0.79 to 10.4), although this did not reach statistical significance. The use of tonometers, ophthalmic solutions, or laser therapy was not associated with infection, and all environmental cultures were negative. This outbreak emphasizes the need for implementation of routine infection control guidelines to prevent nosocomial transmission of epidemic keratoconjunctivitis and stresses the need for appropriate disinfection of instruments.