Epidemiological Features of Invasive Kingella kingae Infections and Respiratory Carriage of the Organism

Abstract

The age, sex, and seasonal distributions of invasive Kingella kingae infections in southern Israel were examined and compared to the epidemiology of respiratory carriage of the organism. Medical records of all patients diagnosed between 1988 and 2002 were reviewed, and 2,044 oropharyngeal specimens were cultured on selective media during two periods (February to May and October to December) in 2001. Invasive infections significantly affected children (73 of 74 patients [98.6%] were younger than 4 years), 50 patients (67.8%) were males (P ‫؍‬ 0.045), and 55 episodes (74.3%) occurred between July and December (P ‫؍‬ 0.004). Carriage was higher in the 0-to 3-year-old group and decreased with increasing age (P for trend ‫؍‬ 0.0008). Carriage rates were similar in both sexes and did not significantly differ between the February-to-May and October-toDecember periods. The highest rate of carriage of K. kingae coincided with the age (less than 4 years) at which invasive infections were especially frequent. The peculiar sex and seasonal distributions of invasive disease, however, cannot be readily explained by the epidemiology of respiratory carriage. Viral infections and other yet-to-be-defined cofactors may play a role in the causation of invasive K. kingae infections.For most of the four decades that elapsed since the first characterization of Kingella kingae, this gram-negative bacterium was considered a rare cause of human disease and therefore was mostly neglected (5,8,20). In recent years, as the result of improved isolation techniques, there has been an increasing number of reports on invasive K. kingae infections in the United States, Western Europe, and Israel, suggesting that the organism is an important cause of bacteremia and septic arthritis in pediatric patients (2,4,6,7,13,14,21,22,25). Moreover, studies conducted to elucidate the natural niche of K. kingae have shown that the organism is a frequent component of the oropharyngeal flora of young children and is readily transmitted from person to person among day care center (DCC) attendees (19,24).Despite the enlarging body of information on the clinical and diagnostic aspects of K. kingae infections, the epidemiology of the organism remains largely unknown. A study was performed to investigate the sex, age, and seasonal distributions of invasive K. kingae infections and to correlate these data with the respiratory carriage of the organism. MATERIALS AND METHODSSoroka University Medical Center (SUMC) is a 950-bed university hospital located in the city of Beer-Sheva and is the only medical facility providing inpatient medical services to the entire population of southern Israel (450,000 inhabitants). The Clinical Microbiology Laboratory (CML) of SUMC provides diagnostic microbiology services to hospitalized patients and to the outpatient population of 139 community clinics in the area.Bacteriological methods. Patients referred to the emergency department or hospitalized at SUMC with a febrile illness undergo routine blood cultures with the BACTEC system (B...

Oropharyngeal Kingella kingae carriage in children: characteristics and correlation with osteoarticular infections

“…Prior studies demonstrated that the prevalence of K. kingae colonization in young children ranged between 3.2 and 17.5%, and was stable throughout the year (8)(9)(10)(11). K. kingae is not usually isolated in infants under 6 mo of age and carriage is highest among 7-36 mo old children.…”

“…Variation in K. kingae carriage rates, however, has not been shown to explain variations in incidence of invasive disease. Most studies on oropharyngeal carriage of K. kingae have been among children of southern Israel, so these results may represent a regional epidemiologic phenomenon (8)(9)(10). The aim of this epidemiologic study was to determine the respiratory carriage of K. kingae among a Swiss population of healthy children aged from 7 to 48 mo using our K. kingae-specific rt-PCR, which is more sensitive than seminested broad-range 16S rRNA gene PCR, and standard culture in detecting K. kingae (11,12).…”

“…There is evidence that K. kingae colonize the oropharynx before hematogenous spread to distant sites (5). Respiratory carriage of K. kingae appears to be a prerequisite for distant infection of the joint and bone (6)(7)(8).…”

Kingella kingae orbital cellulitis in a 3-year-old

“…K. kingae is a short Gram-negative medium-sized Correspondence coccus or rod with tapered ends exhibiting features of B-haemolyis, with an aerobic or facultative anaerobic metabolism. 4 There are four known species of Kingella (K. indologenes, K. dentrificans, K. oralis and K. kingae). They are rare causes of human disease with a recent increase in pathogenecity due to improved isolation techniques.…”

“…[1][2][3] Dermatobia hominis may very occasionally cause ophthalmomyiasis externa, with eyelid, and conjunctival involvement. [4][5][6] Conventional treatment consists of the removal of the larvae from the affected sites, although sometimes access is difficult to such areas. 4,7 This paper describes a case of ophthalmomyiasis externa caused by D. hominis in a child successfully treated with oral ivermectin, making surgical extraction by incision and exploration unnecessary.…”