Epidemiology of an outbreak in a maternity unit of infections with an antigenic variant of echovirus 11

After an 8‐day‐old child had died with clinical signs of septicemia, 6 other newborns fell ill. Virus was isolated from various sites from all the 6 children (28 isolations). The agent was identified by cross neutralization tests as an antigenic variant of Echovirus 11. The agent could not be isolated from mothers or nursery staff (49 people). We therefore tried to trace the path of infection by isolating specific IgM and IgG antibodies. A laboratory infection by the agent isolated enabled the time pattern of the serologic immune response to be roughly determined. The data collected indicate that the infection spread through close contact between the affected newborns and nurses working in the newborn room. Rigorous hygienic and isolation measures, initiated immediately, appeared to interrupt the spread of infection.