Staphylococcus Aureus:
- The usual suspect in orthopaedics, very common in soft tissue infection generally especially in infections around the teeth. If you imagine someone has a tooth abscess that bacteria can enter the blood stream and then eventually get deposited in a joint. Most common form of Infection.
Streptococcus Pneumoniae
- Also very common, typically a community acquired pneumonia precedes a joint infection. Together Strep Pneumoniae and Staph Aureus make up 91% of cases of septic arthritis.
Neisseria Gonorrhoea
- More common in sexually active young people (fairly self explanatory). A rarer cause of septic arthritis however very pertinent to us because there is currently an ongoing outbreak of syphilis and gonorrhoea in Inverurie (October 2022)
MRSA
- More common in people who have been in hospital for a very long time or in people who live in care homes. Unlikely to be your normal cause of SA in the standard community setting.
Mycobacterium Tuberculosis
- Commoner in Immunosuppressed patients, think about your leukaemia patients and poorly controlled HIV patients. On a side note remember that well controlled HIV does NOT cause immune deficiency and if treating an HIV positive patient it is vital you take ana accurate history on how well controlled the condition is and how easily they are managing it.
