Pyogenic Sacroiliac Arthritis Resulting in Septic Shock in a Postpartum Patient: A Rare Problem with a Rare Organism

In developed countries, the incidence of postpartum infection following live childbirth is 6%1. Septic shock is a rare sequela of postpartum infection, occurring in only 0.1 to 0.6 per 1000 deliveries2. The leading cause of infection after a vaginal delivery is mastitis, followed by urinary tract infection. Other causes include endometritis, episiotomy site infection, respiratory complications related to anesthesia, retained products of conception, and septic pelvic phlebitis1,3. Many postpartum infections are polymicrobial, but common pathogens include gram-positive organisms (Streptococcus and Staphylococcus species), gram-negative rods ( Escherichia coli ), sexually transmitted pathogens ( Chlamydia trachomatis ), and anaerobic bacteria4. Osteoarticular infection after childbirth is perhaps the rarest of postpartum infections, and there are little data about its incidence. Case reports describing septic arthritis of the sacroiliac joint or osteomyelitis of the pelvis have been published5-8. In all of these reports, common pathogens such as Staphylococcus aureus or E. coli were the causative agents. We report a case of acute pyogenic sacroiliac arthritis caused by Fusobacterium necrophorum resulting in septic shock following an uncomplicated, spontaneous vaginal delivery. To our knowledge, no such report has been published previously in the literature. The patient was informed that data concerning her case would be submitted for publication, and she provided consent. Eleven days following an uncomplicated, spontaneous vaginal delivery (with an episiotomy) of a healthy baby girl, a previously well, gravida-1, para-1, nineteen-year-old woman presented to a community urgent care clinic with progressive fatigue and non-bloody diarrhea as well as abdominal, back, and buttock pain. She denied having had fevers, chills, or night sweats. Physical examination revealed tachycardia, tachypnea, and hypotension. Laboratory data revealed acute renal failure (creatinine [Cr], 3.8 mg/dL [normal, 0.4 to 1.1 mg/dL]), a white blood-cell count (WBC) of 10,800/μL (normal, 4.0 …