Affected patients:
(1) are often previously healthy children
(2) may have an acute concurrent respiratory or gastrointestinal tract infection
(3) may develop a bacteremia with or without endocarditis, especially if the patient has a chronic medical condition
Clinical features of the septic arthritis:
(1) painful and swollen joint(s)
(2) fever may or may not be present
(3) osteomyelitis may be present
(4) The neutrophil count in the joint aspirate may range from only slightly to markedly elevated.
(5) Gram-negative coccobacillus may or may not be seen on Gram stain
(6) markers of an acute phase reaction (CRP, etc) may or may not be elevated
Barriers to isolation of Kingella kingae in culture:
(1) fastidious micro-organism, which may require sterile horse serum or other nutritional supplement for enhanced growth
(2) slow growth
(3) inhibitory substances in the fluid
The difficulties associated with culture isolation of Kingella kingae make nucleic acid amplification a reasonable option for rapid diagnosis.
