Epidemiology of viral nosocomial infections in pediatrics.

Nosocomial viral infections account for at least 5 % of the fetal of NI and reach 23 % in pediatric wards. The nosocomial infection (NI) incidence rat e varies from 0.59 to 0.72 per 100 patients in pediatric wards. Many viruse s have been associated with NI in pediatric wards. Rotavirus and respirator y syncytial virus (RSV) are the most frequent Other Viruses frequently iden tified are :calicivirus, adenovirus, astrovirus, influenza et para-influenz a, rhinovirus and coronavirus. Asymptomatic infections occur frequently. Th e period of communicability varies and depends on the virus. It often begin s before the clinical signs appear and ends after the healing. Viral sheddi ng may be intermittent. Children and hospital environment and less frequent ly hospital staff are the main source for the virus. Poor handwashing resul ts in direct spread to patient or self-inoculation even for respiratory vir uses like RSV and rhinovirus. The main risk factors for NI are prolonged ho spital stay, past history of prematurity and low age. Immunocompromised pat ients constitute a special high-risk group. Understaffing is also a risk fa ctor. Minimal infective doses depend on the route of inoculation and the ki nd of virus. Low doses are for example sufficient for rotavirus, adenovirus and calicivirus. Viral inactivation is all the more easy when there is an envelope. Handwashing and appropriate isolation (technical and geographical ) are the mainstay of prevention of viral NI. Vaccines are promising, espec ially for rotavirus. (C) 2000 Editions scientifiques et medicales Elsevier SAS.