Evaluations to ‘rule out sepsis’ (ROS) are commonly performed on term newborns with perinatal and/or neonatal risk factors or non-specific signs of sepsis.
Early onset sepsis typically occurs as a result of infection by microorganisms acquired from the mother either before birth or during labour and birth. The organisms most frequently impli- cated in early onset neonatal sepsis are Group B Streptococcus and Escherichia coli and together these represent about 90% of early onset infections, though other organisms which form part of the normal vaginal flora can constitute potential neonatal pathogens (Stoll et al., 2011).