Group Strep B Negative but showed up in cord blood?

Question

When I was tested at 36 weeks for Group Strep B, the test came back negative. My husband and I opted to save our baby's cord blood, and the cord blood bank called our pediatrician and told them they found Group Strep B in the cord blood. My son is now 10 days old and seems completely healthy to me- not showing any symptoms of being sick. My doctor says we shouldn't lose sleep over this, that she contacted Infectious Disease personnel and they think there's nothing to worry about, just to keep an eye on him and if he seems ill to call the doctor (which we would do anyway). My question is- has anyone else had this experience? Is it possible that I suddenly got Group Strep B in the last couple weeks of pregnancy after the test? Is it likely that there was contamination of our son's cord blood, either at the hospital or by the cord blood bank? Please, as much as they tell me not to worry, I am worried. This is my baby, and I would be devastated if anything happened to him.

Answer 1

Invasive Group B Strep disease is categorized into two sets, based on the time of onset of disease after birth. The most common course is illness within the first week of life. However, there is late-onset disease, typically occurring at 3 - 4 weeks of age, manifest by fever, irritability, poor feeding. It can lead to serious infection and illness.

Late onset disease was uncommon in my experience, but it did occur, and I regret I cannot be quite as reassuring as your pediatrician and infectious disease consultant.

The vast majority of situations like the one you present have favorable outcomes, but they cause grey hairs in parents and pediatricians alike, hence my avatar.