ConditionBones, joints & muscles
Spinal Infection
A spinal infection is an infection of the bones of the spine (vertebral osteomyelitis), the disks between them (discitis) or the space around the spinal cord (spinal epidural abscess). It usually starts with bacteria spreading through the blood from another site, such as a skin, urine or heart valve infection, or after spine surgery. The main symptom is worsening back or neck pain, often constant and worse at night, sometimes with fever. Leg weakness, numbness or bladder problems signal an emergency.
Also called: Vertebral osteomyelitis, spinal osteomyelitis, discitis, spondylodiscitis, spinal epidural abscess
At a glance
- What it is
- Infection of the vertebrae, disks or epidural space of the spine.
- Common germs
- Staphylococcus aureus (including MRSA), streptococci, gut bacteria, and tuberculosis in some regions.
- Risk factors
- Diabetes, injecting drug use, dialysis, recent spine surgery, weakened immunity, older age, endocarditis.
- Symptoms
- Persistent, worsening back pain, often at night, tenderness, fever (not always), and nerve symptoms in severe cases.
- Treatment
- Weeks of IV then oral antibiotics, and surgery for abscess, nerve compression or instability.
When to get help
Call 911 or go to the ER
- Back or neck pain with new leg or arm weakness, numbness, loss of bladder or bowel control, or numbness in the groin or buttocks: call 911 or your local emergency number
- Back pain with high fever, confusion, a racing heart or low blood pressure (possible sepsis)
See a doctor within a day or two
- Severe, worsening back pain with fever or chills
- Back pain in someone who injects drugs, has diabetes, is on dialysis, or recently had spine surgery or a bloodstream infection
- Redness, swelling or drainage from a recent spine surgery wound
Book a routine appointment
- Back pain lasting more than 6 weeks that is constant, worse at night or not eased by rest
- Back pain with unexplained weight loss or night sweats
Types of spinal infection
| Type | Location | Key features |
|---|---|---|
| Vertebral osteomyelitis | Vertebral bones | Persistent back pain, local tenderness |
| Discitis | Intervertebral disk, usually with adjacent vertebrae (spondylodiscitis) | Pain with movement. In children, limping or refusing to walk |
| Spinal epidural abscess | Space around the spinal cord | Back pain, fever and rapidly progressing nerve deficits |
| Postoperative infection | Surgical site | Wound redness, drainage, pain after surgery |
| Spinal tuberculosis (Pott's disease) | Vertebrae, often thoracic | Slow onset, deformity, night sweats |
Causes and how infection reaches the spine
- through the bloodstream from skin infections, urinary infections, pneumonia, infected IV lines, dental infections or endocarditis
- direct spread during spine surgery or injections
- from nearby tissues such as a psoas abscess
Staphylococcus aureus is the most common cause. Others include streptococci, E. coli and other gram-negative bacteria (often from urinary sources), Pseudomonas (more common in people who inject drugs), tuberculosis, brucella in some regions, and fungi in people with weak immunity.
Risk factors
- diabetes
- injecting drug use
- hemodialysis
- older age
- weakened immunity (steroids, chemotherapy, HIV)
- recent spinal surgery or epidural injection
- endocarditis or recent bloodstream infection
- alcohol use disorder, cirrhosis, cancer
Symptoms
- back or neck pain that is constant, progressive and often worse at night
- tenderness over the spine
- stiffness and muscle spasm
- fever and chills, present in only about half of people
- night sweats and weight loss (especially TB)
- radiating pain into the legs or arms
- neurological signs in advanced cases: weakness, numbness, bladder or bowel dysfunction
The combination of back pain, fever and neurological deficit is classic for epidural abscess, but all three appear together in only a minority of patients. Diagnosis is often delayed, because back pain is so common.
Diagnosis
- blood tests: inflammatory markers (ESR and CRP are usually raised), white cell count
- blood cultures before antibiotics when possible
- MRI with contrast: the best imaging test, showing infection of bone, disk and the epidural space
- CT-guided or surgical biopsy to identify the germ when blood cultures are negative
- echocardiogram if Staph aureus is in the blood, to check for endocarditis
- TB tests when relevant
Treatment
Antibiotics
- targeted to the organism, usually IV at first
- typically at least 6 weeks in total, sometimes longer for abscesses, hardware infections or resistant organisms
- IDSA guidelines support delaying antibiotics until a sample is obtained in patients who are stable and neurologically intact, to improve identification of the germ
- treatment response is tracked with symptoms, CRP and sometimes repeat imaging
Surgery
Surgery is needed for:
- epidural abscess with neurological deficits or spinal cord compression
- spinal instability or deformity
- abscess that does not respond to antibiotics
- infected spinal hardware
- failure to obtain a diagnosis by other means
Supportive care
- pain control
- braces to support the spine
- physical therapy
- control of diabetes and other risk factors
Complications
- permanent paralysis or numbness from spinal cord compression
- spinal deformity and chronic pain
- sepsis
- recurrence
Outlook
Most people recover with prompt antibiotics, with or without surgery. The neurological outcome depends mainly on how much weakness was present before treatment, so early recognition is crucial.
Frequently asked questions
What are the symptoms of a spinal infection?
The main symptom is back or neck pain that is constant, worsening and often worse at night, with tenderness over the spine. Fever occurs in about half of people. Weakness, numbness or bladder problems signal a serious complication.
What causes spinal infections?
Most are caused by bacteria, especially Staphylococcus aureus, spreading through the bloodstream from another infection, or entering during spine surgery or injections. Tuberculosis and fungi are less common causes.
How is a spinal infection diagnosed?
Doctors use blood tests for inflammation, blood cultures and an MRI scan with contrast. A biopsy of the infected bone or disk may be needed to identify the germ so the right antibiotic can be chosen.
How long does it take to treat a spinal infection?
Antibiotic treatment usually lasts at least 6 weeks, often longer for abscesses or infected hardware. Pain usually improves within weeks, but full recovery can take months.
Can a spinal infection cause paralysis?
Yes. An epidural abscess or collapsing infected vertebrae can compress the spinal cord or nerves, causing weakness or paralysis. This is an emergency. Rapid surgery and antibiotics give the best chance of recovery.
Sources
This guide was written from current patient and clinical guidance, including:
- Infectious Diseases Society of America (IDSA): Clinical practice guidelines for the diagnosis and treatment of native vertebral osteomyelitis in adults
- American Association of Neurological Surgeons: Spinal infections
- North American Spine Society: Spinal infections
- MedlinePlus: Osteomyelitis
- Merck Manual: Spinal epidural abscess