Epidemiology, etiology, and clinical features of septic arthritis in children younger than 24 months
P. Yagupsky, Y. Bar-Ziv, C. B. Howard and R. Dagan
Clinical Microbiology Laboratories, Soroka Medical Center, Ben-Gurion University of the Negev, Beer Sheva, Israel.
OBJECTIVE: To examine the incidence, etiology, and clinical features of
septic arthritis in patients younger than 24 months. DESIGN: Retrospective,
1988 through 1993 period, chart review-based survey. PATIENTS: All children
with bacteriologically proved septic arthritis that was diagnosed at a
medical center serving southern Israel (population 320,000). Septic
arthritis was defined by clinical evidence of joint inflammation and a
positive synovial fluid or blood culture, antigen detection test, or a
standard tube agglutination titer of 160 or greater for Brucella species.
INTERVENTIONS: None. RESULTS: During the 6-year period, 40 children had
septic arthritis diagnosed. Twenty-six (65%) were male. The annual
incidence of septic arthritis was 37.1 per 100,000. The two most common
organisms isolated were Kingella kingae in 19 (48%) and Haemophilus
influenzae type b in eight (20%). The clinical presentation was frequently
mild: a body temperature of less than 38.3 degrees C was recorded in 14
(35%) of 40 children, leukocyte count of less than 15 x 10(9)/L in 13 (34%)
of 38, and erythrocyte sedimentation rate of less than 30 mm per hour in
four (11%) of 35. In eight (36%) of 22 patients, less than 50 x 10(9)/L
leukocytes were counted in the synovial fluid. CONCLUSIONS: The diagnosis
of septic arthritis in young children requires a high index of suspicion,
and the disease cannot be excluded on the basis of lack of fever or normal
results of laboratory tests. Kingella kingae appears to be the most common
cause of septic arthritis in patients younger than 24 months, although
confirmatory studies from other geographic areas are still needed.
