PD013 - HAEMOPHILUS INFLUENZAE SEROTYPE A SEPTIC ARTHRITIS – AN EMERGING ENTITY (ID 1553)
Abstract
Title of Case:
HAEMOPHILUS INFLUENZAE SEROTYPE A SEPTIC ARTHRITIS – AN EMERGING ENTITY
Background:
Septic arthritis (SA) is a serious infection, usually affecting large joints such as the knee and hip, most commonly in children under 2 years and typically due to hematogenous spread. In the post-vaccine era, with the decline of type b invasive infections, there has been a rebound in the incidence of infections caused by other strains of Haemophilus influenzae, particularly serotype a.
Case Presentation Summary:
A 17 month-old boy was admitted in the emergency department for a 2-day history of right side claudication, hip pain, refusal to bear weight and fever. Additionally, productive cough and nasal congestion were noted. Objectively, he was lethargic, with right hip flexing position and pain to mobilization. Blood panel showed hemoglobin 11.4g/dL, leukocytes 16290/uL, ESR 65mm/h and CRP 6.7mg/dL. Hip x-ray was normal but a 4mm synovial effusion was noted on ultrasound. Blood cultures were drawn before empiric cefuroxime was started as the clinical suspicion for septic arthritis was high. Blood cultures were positive for H. influenzae type a (Hia), sensitive to cefuroxime. As the patient failed to improve initially, a hip MRI was ordered and showed moderated volume synovial effusion, with synovial and peri-articular inflammation. Diagnostic percutaneous drainage of fluid was performed and was positive for Hia DNA. The patient gradually improved and at discharge still had mild claudication but was able to walk unassisted. He completed a 3-week antibiotic course (1-week oral therapy).
Learning Points/Discussion:
This rare case of SA due to Hia in a 17-month-old immunocompetent child, up to date with the national vaccination program and with no relevant medical history, underlines the importance of serotyping H. influenzae in pediatric patients to document the etiologic changes and improve clinical management.
