1) Late-onset Sepsis occurs between 7 and 89 days in term babies. However, it usually happens by 4-6 weeks.
2) It is usually caused by Gram-positive organisms, but don't forget E.Coli and other GNRs
3) Appropriate perinatal preventive care for GBS does not effect the incidence
4) Have a low index of suspicion. Babies are often not catastrophically ill at presentation, but then decompensate quickly
5) Meningitis is much more common. Seriously consider LP if you are at all concerned