A Unique Case Of Osteomyelitis Caused By Gardnerella Vaginalis And Streptococcus Parasanguinis In A Post-Menopausal Woman
BACKGROUND: Vertebral osteomyelitis or discitis is an infection of the vertebrae and intervertebral discs that can lead to spinal instability and neurologic deficits. It is most frequently caused by Staphylococcus aureus and is growing in incidence due to longer life expectancy and clinical ascertainment.
CASE HISTORY: A 61-year-old post-menopausal woman, who had recently become sexually active after having been celibate for over 10 years, presented with 2-weeks of progressive lower back pain and fever. She had a history of fibromyalgia, chronic back pain with prior L2-L3 fusion, and a recent episode of cystitis. Magnetic resonance imaging (MRI) revealed L3-L4 discitis and osteomyelitis of L4 (and likely L3) and paraspinous phlegmon with a right psoas muscle abscess. Cultures from a needle aspiration of right psoas muscle abscess grew Gardnerella vaginalis and Streptococcus parasanguinis. The patient was treated with a 6-week course of IV ceftriaxone and oral metronidazole.
CONCLUSIONS: This case represents an unusual co-infection of G. vaginalis and S. parasanguinis. These organisms are normally associated with infections of the genital tract and oral cavity, respectively. This case highlights the potential for Gardnerella to cause infection in atypical locations outside of the genital tract. The report also suggests that re-engagement of sexual activity by post-menopausal women may be a risk factor for opportunistic bacterial infections, including G. vaginalis induced spinal osteomyelitis.