Successful containment of horizontal enterovirus infection in a neonatal unit in Singapore through diagnosis by polymerase chain reaction (PCR) and direct sequence analysis

Background: Enterovirus (EV) outbreaks often coincide with seasonal peaks in the community. However, they may also sporadically occur in neonatal units. Identification of EV infection in neonates can be challenging, as they tend to present with mild or nonspecific symptoms. This study reports an EV outbreak in the Neonatal Unit at KK Women's and Children's Hospital, Singapore.

Methods: This is a single-center, retrospective cohort study of neonates who had positive results for EV during the outbreak. Demographic characteristics, clinical presentations and outcomes were analyzed. Control measures used to limit the spread of infection are reported.

Results: A total of 7 cases of EV infection were identified. Their median birth weight and gestational age were 1240 g (750 -2890 g) and 28 weeks (26-35 weeks), respectively. Symptoms occurred at a median age of 48 days (9-103 days). All cases presented initially with recurrent apnea and 4 needed assisted ventilator support with CPAP (2) and mechanical ventilation (2). Serious complications occurred in 3 infants (2 with necrotizing enterocolitis and 1 with meningitis) and none died. EV was detected from rectal swabs (n = 6), CSF (n = 2) and nasopharyngeal swabs (n = 2). Viral subtyping uniformly revealed echovirus 25. Surveillance of all exposed infants by nasopharyngeal swabs was implemented, along with strict contact precautions and cohorting measures.

Conclusions: Premature infants with EV are more prone to serious complications, which can lead to significant morbidity. Thus, early recognition of symptoms, rapid diagnosis and prompt implementation of infection control measures are key to prevent further spread of infection.