Incidence and bacteriologic causes of septic arthritis in a general hospital in Saudi Arabia

Since data on the incidence and etiology of septic arthritis in Saudi Arabia is sparse, we analyzed the incidence and bacterial etiology of septic arthritis in a general hospital in Saudi Arabia.

Observational study of all hospitalized patients with native joint septic arthritis from 2005 to 2010.

We specifically collected data on demography, joint(s) affected, synovial fluid gram stain and culture, and blood culture. We also included the initial antimicrobial agents, length of stay (LOS) and any surgical interventions. Data were analyzed using simple descriptive statistics.

There were 58 cases of native joint septic arthritis with an annual incidence rate of 0.2-0.8 per 1000 discharges. There were 31 (53.4%) males and 27 (46.6%) females with a mean (SD) age of 44.2 (29.3) years. There were 18 (25.8%) children < 18 years of age. The most frequently affected joints were the knee (28, 48.3%), ankle (7, 12.1%), elbow (6, 10.3%), and shoulder (4, 6.9%). Of the synovial cultures, 17 (29.3%) were nega.tive and the most commonly isolated organism was methicillin-susceptible Staphylococcus aureus (16, 27.6%). Blood cultures were negative in 38 cases (67.8%) and positive in the remaining 32%. The most common or.ganism from blood cultures was S aureus (12.5%). There was no difference in the rate of positive synovial fluid cultures between children and adults (65% vs 82.4%, P=.22), but children were more likely to grow S aureus (53%) than adults (20%) (P=.024).

Septic arthritis is an uncommon disease in the study population and the most common organism is S aureus.