Clinical Scorecard: Infections of Bones and Joints in Tropical Regions: Prevalence of Gram-Negative Bacilli and Consequences for Initial Antibiotic Treatment
At a Glance
Category
Detail
Condition
Bone and joint infections (BJIs) including native septic arthritis, osteomyelitis, spondylodiscitis, prosthetic joint infections, and osteosynthesis-associated infections
Key Mechanisms
High prevalence of Gram-negative bacilli (GNB), including AmpC β-lactamase–producing Enterobacterales and Pseudomonas aeruginosa, with associated antimicrobial resistance impacting empirical antibiotic therapy
Target Population
Adults (≥18 years) with first microbiologically confirmed episode of BJI in tropical settings, specifically Guadeloupe, French West Indies
Care Setting
Tertiary care hospital (University Hospital of Guadeloupe) in a tropical region
Key Highlights
Gram-negative bacilli accounted for 41% of isolates in BJIs, predominating over other pathogens including MRSA (3%).
GNB prevalence varied by infection type: 31% in native septic arthritis, 33% in spondylodiscitis, 38% in prosthetic joint infections, 47% in osteosynthesis-associated infections, and 52% in osteomyelitis.
Empirical antibiotic cefazolin showed limited in vitro adequacy (48%–74%) against pathogens, whereas cefepime and piperacillin-tazobactam had higher adequacy rates (up to 92%).
Guideline-Based Recommendations
Diagnosis
Microbiological confirmation via culture from joint fluid, bone, deep tissue, or blood samples is essential for diagnosis.
Classification of BJIs into native septic arthritis, spondylodiscitis, osteomyelitis, prosthetic joint infections, and osteosynthesis-associated infections guides clinical management.
Management
Empirical antibiotic therapy should consider local epidemiology, emphasizing coverage for Gram-negative bacilli in tropical settings.
Cefepime and piperacillin-tazobactam are preferred empirical antibiotics over cefazolin due to higher likelihood of pathogen coverage.
Multidisciplinary approach is recommended to prevent functional impairments.
Monitoring & Follow-up
Surveillance of local bacterial epidemiology and resistance patterns is critical to adapt empirical treatment strategies.
Monitor clinical response and adjust antibiotics based on culture and susceptibility results.
Risks
History of bite/scratch wounds, contact with soil or vegetation, and lower limb infections are risk factors for GNB involvement.
Use of antibiotics with inadequate coverage may lead to treatment failure and increased morbidity.
Patient & Prescribing Data
Adults with first confirmed BJI episode in a tropical tertiary care setting
Empirical use of cefazolin may be insufficient due to high prevalence of GNB; cefepime and piperacillin-tazobactam provide broader coverage and higher adequacy rates.
Clinical Best Practices
Implement local microbiological surveillance to guide empirical antibiotic choices in tropical BJIs.
Consider patient history including environmental exposures (soil, vegetation, animal bites) when assessing risk for GNB infection.
Use broad-spectrum antibiotics such as cefepime or piperacillin-tazobactam empirically in tropical BJIs pending culture results.
Adopt a multidisciplinary management approach to optimize outcomes and prevent functional impairment.
