[Vertical transmission of human coronavirus. Prospective pilot study]

Human coronaviruses (HCoV) have been implicated in neonatal nosocomial respiratory infection. Prior to our study, several cases of neonatal infection were observed in infants born at our hospital. This prospective pilot monocentric pilot study investigates the possibility of maternofetal transmission of HCoV responsible for cases of neonatal infection observed within the first 24 hours of life.

Three samples from mother-child couples, maternal vaginal (VM) and respiratory (RM) samples during labor; newborn gastric sample (GNN), were assessed for viral analysis using real time RT-PCR for the detection of HCoV 229-E and OC43. Clinical follow-up of infants and mothers was up to Day 3 after birth.

One hundred (and) fifty-nine mother-child couples were included between July 2003 and August 2005. HCoV 229-E only was detected in 11 samples from 6 mother-child couples. For 2 couples, all 3 samples (VM, RM and GNN) were tested positive (cases 1 and 2). For case 3, both VM and GNN were positive. For 2 couples, only RM was positive (cases 4 and 5). In case 6, only VM was positive. Of the 3 positive GNN, no infant was symptomatic.

Possible vertical transmission of HCoV was evidenced in this pilot study and requires further investigation on a larger scale. Equally indicated is the inclusion of tests to detect recently identified human coronaviruses HCoV NL63 and HKU1, as well as genomic profile analysis of HCoV 229-E detected in the 3 positive mother-child couples.