A baby girl was born by spontaneous vaginal delivery at 38 weeks to a healthy mother in a district general hospital. She was the second child in the family; there was no family history of concern, her mother was well, and the pregnancy had been uneventful. Breast feeding was established, and mother and baby were discharged home the following day with no specific advice as to umbilical care. At 10 days of life there was a yellowish discharge from her umbilicus; this was treated with topical fucidin by the general practitioner. Six days later there were increasing difficulties with breast feeding as the infant became more listless. The following morning, the mother noted swelling of the left knee: on admission …