A large outbreak of epidemic keratoconjunctivitis: problems in controlling nosocomial spread

Between July 1985 and January 1986, 401 patients with adenovirus epidemic keratoconjunctivitis (EKC) were seen at the Illinois Eye and Ear Infirmary. Of the cases, 110 (27%) were nosocomial; the other 291 patients had community acquired infection. The highest attack rates of EKC occurred in patients attending specialty clinics; the overall attack rate among clinic patients was 4.7/1,000 clinic visits. All nosocomial cases were caused by adenovirus type 8; community acquired cases were a mixture of adenovirus types 8 and 37. Adenoviruses were isolated from conjunctival cultures up to 14 d after the onset of clinical illness. Initial efforts to prevent nosocomial transmission were unsuccessful. However, when a plan to triage all patients on entry to the infirmary and to sort patients and personnel caring for infected patients into cohorts was implemented, nosocomial transmission of EKC was promptly and effectively halted, despite the continuation of the community epidemic for another 4 mo. This outbreak clearly demonstrates the efficacy of rigorous infection control in preventing nosocomial transmission of adenovirus EKC.