A neonatal echovirus 11 outbreak in an obstetric clinic.

Corresponding author: Dr. Nan-Chang Chiu, Department of Pediatrics, Mackay Memorial Hospital, 92, 2nd Section, Chung-Shan North Road, Taipei, Taiwan. E-mail: ncc88@ms2.mmh.org.tw Enterovirus infection in neonates is difficult to diagnose because of the broad range of clinical syndromes caused by the virus, from nonspecific febrile illness to aseptic meningitis, encephalitis, myocarditis, and necrotizing hepatitis [1]. Enteroviruses are sometimes isolated from the oropharynx or feces of asymptomatic newborns [2]. The virus is transmitted primarily by the fecal-oral route by contaminated hands. Fomites such as tableware, food, or drinking water have also been implicated in transmission. At the peak of infection, it can also be transmitted by droplets. Group B coxsackie virus serotypes 2 to 5 and echovirus 11 are the enteroviruses most frequently associated with overwhelming systemic neonatal infection [3-6]. Vertical transmission usually occurs at birth by cervical or fecal contamination or occasionally by postnatal exposure. Horizontal transmission is usually through direct or indirect contact by the fecaloral route and respiratory secretions [6]. Most neonatal outbreaks have been reported from the neonatal unit of a hospital. Here we describe a neonatal enterovirus infection outbreak in the nursery of a standalone obstetric clinic. An echovirus 11 outbreak occurred among neonates in an obstetric clinic in November 2003. Thirteen neonates were transferred to our medical center, and all were found to have echovirus 11 infection. Viral studies were performed for 32 other infants born in the clinic during the same period, including 30 asymptomatic neonates and 2 febrile infants transferred to another hospital. Two of the asymptomatic infants had echovirus 11 isolated from rectal swabs. The first patient transferred to our medical center developed extensive hemorrhage and died 6 days later. Three family members of this infant were also proved to have echovirus 11 infections. One other infant had a fulminant course and had residual hepatic impairment. The other infants had no complications. Viral studies in the 24 nursery staff were all negative. This outbreak shows how a neonatal enterovirus outbreak can occur in a nursery, starting from an infected infant in the incubation period. Early recognition and prompt management of an outbreak is important to prevent further spread of the infection.