Invasive Kingella kingae infections in children: clinical and laboratory characteristics.
OBJECTIVE
Kingella kingae, a Gram-negative coccobacillus, is being increasingly recognized as an invasive pathogen in children, causing mainly bacteremia and arthritis; however, there have been only a few studies on K kingae infections to date, mostly small-scale series. The aim of this study was to report our experience with invasive K kingae infections in children who were hospitalized at a major tertiary medical center in Israel.


METHODS
The medical charts of 62 children with proven invasive K kingae infections were reviewed: 42 with positive blood culture results and 20 with positive synovial fluid culture results.


RESULTS
Most infections occurred among previously healthy children aged 5 to 22 months. Eighty percent had a mild concurrent illness of the respiratory or gastrointestinal tract. A chronic underlying disease was documented in 19% of the 1- to 15-year-old children with bacteremia. Three patients had persistent bacteremia, identified by 2 positive blood cultures drawn 1 to 4 days apart. Four (10%) patients from the bacteremia group had endocarditis, and 2 required emergency cardiac surgery. Only a mild-to-moderate elevation of serum inflammatory markers was noted except for patients with endocarditis or a prolonged course of arthritis. Patients with bacteremia received a diagnosis significantly later than those with arthritis, with no other between-group differences in age, month of disease onset, and inflammatory marker levels. All K kingae isolates were resistant to vancomycin and clindamycin.


CONCLUSIONS
Our large series indicates that invasive K kingae infections occur in previously healthy children, mostly during the first 2 years of life; affected older children usually have an underlying medical condition. The infection generally elicits only a mild inflammatory response unless accompanied by endocarditis. Despite its low virulence, K kingae might cause a life-threatening heart disease that requires emergent, aggressive treatment.
Dubnov-Raz
Gal
G
Department of Pediatrics, Mt Scopus, Hebrew University-Hadassah Medical Center, Jerusalem 91120, Israel. gal-d@bezeqint.net
Scheuerman
Oded
O
Chodick
Gabriel
G
Finkelstein
Yaron
Y
Samra
Zmira
Z
Garty
Ben-Zion
BZ
D000293:Adolescent; D017677:Age Distribution; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001170:Arthritis, Infectious / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D016470:Bacteremia / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004697:Endocarditis, Bacterial / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007557:Israel / Q000453:epidemiology; D017882:Kingella kingae / Q000302:isolation & purification*; D016014:Linear Models; D008297:Male; D008826:Microbial Sensitivity Tests; D016870:Neisseriaceae Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents