Invasive infections due to Candida were once thought to be rare, but have been increasing in incidence over the past two decades. The reason for the increase in fungal infections is likely multifactorial. Patients are living longer with chronic illnesses and often have frank or relative immunosuppression. The increased use of central venous catheters and antimicrobials are also felt to play a role. In addition, injection drug use has led to a concomitant increase in a variety of invasive infections including fungemia and osteomyelitis. This is particularly a problem in West Virginia as we have seen a sharp increase in injection drug use over the past decade. However, vertebral osteomyelitis due to Candida is still rare and can be difficult to diagnosis and treat. We evaluated the incidence of vertebral osteomyelitis due to Candida species at our facility to try to identify risk factors and determine outcomes.
We used our electronic record databases to search for patients with a diagnosis of osteomyelitis, and a positive fungal culture. From 2006 to 2018 our hospital had 14 cases of culture proven Candida vertebral osteomyelitis.
Candida albicans was the most frequently isolated organism , being cultured in 10/14 (71.4%) patients, followed by C. tropicalis (2/14), C. krusei (1/14), and C. parapsilosis (1/14). The two most common risk factors for infection were injection drug use (50%) and prior spinal surgery (35.7%). Almost all patients were treated with caspofungin followed by fluconazole. Ten patients (71.4%) required surgery. Short-term outcomes were favorable with no deaths.
The incidence of vertebral osteomyelitis due to Candida may be increasing. In our state, injection drug use seems to be a factor in the increase rate of infection. We have seen a rise in injection drug use as prescription narcotics are becoming more difficult to obtain. Physicians must have a high index of suspicion for fungal disease when treating osteomyelitis in patients with these risk factors. Short term outcomes seem favorable, but further studies are needed to evaluate long term outcomes and to determine optimal management.