Through A Glass Darkly

Abstract
Appearances to the mind are of four kinds. Things either are what they appear to be; or they neither are, and do not appear to be; or they are, and do not appear to be; or they are not, yet appear to be. Rightly to aim in all these cases is the wise man's task. Epictetus The experience recounted by Lynch and his co-workers in this issue of theArchives(see p 65) epitomizes two phenomena that are being encountered with increasing frequency by present-day hospital epidemiologists, "pseudoepidemics" and "pseudoinfections." A pseudoepidemic of nosocomial infections is the occurrence of an increased number of infections in the hospital, usually caused by one species, that is misconstrued as denoting a true epidemic. Recognizing a nosocomial epidemic—which, believe it or not, can often be exceedingly difficult if it is caused by a common pathogen or smolders on over a prolonged period1—is