Home hospitalization facilities (HAD) have always been excluded from national surveys on the prevalence of nosocomial infections. However, a new survey on the prevalence of healthcare-associated infections (HAIs) was conducted in the HAD facilities of the Assistance publique - Hôpitaux de Paris (APHP) in May 2007. Its objectives were to obtain epidemiological data to evaluate the effectiveness of measures implemented since 2000 and to propose a methodology adapted to the specific characteristics of HAD care: the overlap between care settings and living environments, the geographic dispersion of care units, care provided by private practitioners, and the frequent absence of additional diagnostic tests. The study included 613 patients (99.8% of eligible patients). The prevalence of infected patients and that of healthcare-associated infections (HAIs) was 5.2%, and that of HAIs acquired during home healthcare was 2.6%. The acquired HAIs were urinary, respiratory, and cutaneous (9, 5, and 2, respectively). Community-acquired Enterobacteriaceae were the predominant microorganisms. No multidrug resistance was found; 16% of patients received antibiotic therapy, in one-third of cases for HAI. While it is difficult to conclude that there was a significant decrease in HAI acquired in APHP home care between 2000 and 2007, there is a real possibility of adapting the methodology of the next national prevalence survey so that home care facilities can participate. (R.A.)