To the Editors: We appreciate the opportunity to respond to the letter by Yagupsky regarding our multicenter study on pediatric bone and joint infections (BJIs) in Hungary.1,2 We thank him for his insights into the importance of identifying Kingella kingae through molecular techniques. However, we must respectfully disagree with the characterization of our case definitions and enrollment criteria. With respect, we believe Yagupsky may have misinterpreted our enrollment criteria, as fever was not a mandatory requirement for inclusion in our study. Our definitions for acute hematogenous osteomyelitis and septic arthritis followed international guidelines, requiring a combination of clinical signs (minimum 2 of: fever, swelling with warmth and pain with limited mobility) rather than any single mandatory symptom. Our data show that fever was present in only 77.3% of the total cohort, meaning nearly one-quarter of our patients were afebrile at diagnosis. This distinction is even more evident in the culture-negative subgroup, where 42.1% of patients did not present with a fever. These findings are largely consistent with other large-scale studies, such as the Spanish cohort by Calvo et al,3 reporting that 30% of BJI cases lacked fever. With this in mind, we agree that the afebrile patients in our culture-negative subcohort might have had infections due to Kingella kingae. We acknowledge that the absence of molecular diagnostics likely limited our ability to detect fastidious organisms like K. kingae, a pathogen increasingly recognized for its role in BJIs in young children. Recent research by Weselovski et al4 confirms that incorporating polymerase chain reaction significantly enhances diagnostic yield, particularly in patients under 5 years of age. However, we emphasize that molecular testing is not an infallible gold standard, as results should be interpreted alongside conventional culturing and within an appropriate clinical context, as false negatives and positives may occur, with some pathogens remaining undetected even with advanced molecular diagnostics. As noted by Sanchez et al,5 multiplex panels have a limited number of targets and may miss “off-panel” organisms that standard cultures can still recover. In conclusion, our study did not exclude afebrile patients, and we feel that the cohort accurately represents the clinical and microbiologic landscape of pediatric BJIs in Hungary within the current diagnostic framework of its tertiary care centers. Nonetheless, we do agree that transitioning toward integrated molecular and culture-based diagnostics is a vital next step for improving pediatric care in our region.
Hajósi-Kalcakosz et al. (Mon,) studied this question.