The Frequency, Level, and Distribution of Fecal Contamination in Day-Care Center Classrooms

Abstract

Children in day care are at higher risk of infectious diarrhea than those who remain at home.1,2 Diarrhea in day care centers (DCCs) is propagated through the fecal-oral route,3,4 a mode of transmission that is enhanced by fecal contamination. Knowledge of the pattern and degree of fecal contamination in DCC classrooms can identify important sources of enteropathogens to be targeted by hygienic interventions. This study was undertaken to qualitatively and quantitatively describe fecal contamination in DCC classrooms and to determine the relative stability of patterns of contamination across time. Fecal coliforms occur in large numbers in human feces and can be presumptively identified on differential culture media. Each discrete colony represents a bacterial cell originally present on the surface that was sampled. In principle, the number of fecal coliforms rather than the frequency of positive samples reported in previous DCC studies5,6 should more accurately reflect enteropathogen characteristics of infectious dose and survival in the environment. Therefore, fecal contamination was measured by the number of viable fecal coliforms recovered from environmental surfaces and the hands of children and DCC staff members. The distribution of fecal contamination was described in terms of coliform presence and coliform density (counts) for individual classroom sites. METHODS Fecal contamination was measured during two prospective studies in North Carolina. In study 1, 13 Cumberland County DCCs served as controls during a hygienic intervention trial and were sampled from April 1989 to March 1990; in study 2, 25 Research Triangle Area DCCs were sampled between January and August 1991.