Adenovirus cross-infection: a continuing problem

Nosocomial outbreaks of epidemics of adenovirus keratoconjunctivitis are frequently reported even though the simple measures to prevent or limit such occurrences are well documented. There have been two such outbreaks associated with the accident and emergency department (A&E) of a large, urban eye hospital in recent years. In the first--involving at least 200 cases--there was a delay of two months in initiation of control measures, with consequent potentiation and prolongation of the outbreak. The delay resulted because of the time taken for isolation of the virus responsible (adenovirus type 8). In the second outbreak--23 cases--the use of a rapid diagnostic test--adenovirus immune dot-blot (IDBT)--allowed prompt identification of adenovirus and enabled early introduction of control measures. Important to this strategy was the routine surveillance of eye infections in patients attending the A&E. Many clinicians are reluctant to investigate possible ocular adenovirus disease because of the cost and the delay involved in isolation of the virus in cell culture. Adenovirus IDBT provides a rapid and economic alternative (mean time for IDBT reporting five days compared to 33 days for cell culture isolation). Concerns over sensitivity of IDBT (67-84%) vs. culture are now being addressed with molecular biological approaches to diagnosis offering sensitivity close to that achieved by culture (91% vs. culture) but with the added advantage of same day reporting.