Non-Gonococcal (Septic) Bacterial Arthritis

Overview, Causes, & Risk Factors

Septic arthritis develops when bacteria spread from a source of infection through the bloodstream to a joint or the joint is directly infected by traumatic penetration or surgical procedures. The onset of the symptoms is usually rapid with joint swelling, intense joint pain, and low-grade fever.

Risk factors include a simultaneous bacterial infection, chronic illness, diseases or medications that suppress the immune system, rheumatoid arthritis, intravenous drug abuse, sickle cell disease, artificial joint implants, recent joint trauma, or recent joint arthroscopy or other surgery.

Septic arthritis may be seen at any age. In children, it occurs most often in those less than 3 years old. The hip is a frequent site of infection in infants.

Septic arthritis is uncommon from age 3 to adolescence, at which time the incidence increases again (appearing as gonococcal arthritis in females with cervical gonorrhea). Children with septic arthritis are more likely than adults to be infected with group B streptococcus and Haemophilus influenza.

Acute septic arthritis tends to be caused by organisms such as staphylococcus, streptococcus (pneumoniae) and group B streptococcus while chronic septic arthritis (which occurs less frequently) is caused by organisms such as Mycobacterium tuberculosis and Candida albicans. The knee and the hip are the most commonly infected joints.