The Microbiological Profile and Antibiotic Susceptibility of Fracture Related Infections in a Low Resource Setting Differ from High Resource Settings: A Cohort Study from Cameroon.

Fracture-related infection (FRI) is a common and devastating complication of orthopedic trauma in all settings. Data on the microbiological profile and susceptibility of FRI to antibiotics in low-income countries are scarce. Therefore, this study aimed to investigate the microbial patterns and antimicrobial susceptibility of FRI in a sub-Saharan African setting in order to provide guidance for the formulation of evidence-based empirical antimicrobial regimens. We conducted a retrospective analysis of patients treated for FRI with deep tissue sampling for microbiological culture from January 2016 to August 2023 in four tertiary-level hospitals in Yaoundé, Cameroon. There were 246 infection episodes in 217 patients. Cultures were positive in 209 (84.9%) cases and polymicrobial in 109 (44.3%) cases. A total of 363 microorganisms from 71 different species were identified, of which 239 (65.8%) were Gram-negative. The most commonly isolated pathogens were Staphylococcus aureus (n = 69; 19%), Enterobacter cloacae (n = 43; 11.8%), Klebsiella pneumoniae (n = 35; 9.6%), Escherichia coli (n = 35; 9.6%), and Pseudomonas aeruginosa (n = 27; 7.4%). Coagulase-negative staphylococci (CoNS) were isolated in only 21 (5.9%) cases. Gram-negative bacteria accounted for the majority of the infections in early (70.9%) and delayed (73.2%) FRI, but Gram-positive bacteria were prevalent in late FRI (51.7%) (p < 0.001). Polymicrobial infections were more frequent in the early (55.9%) and delayed (41.9%) groups than in the late group (27.6%) (p < 0.001). Apart from Staphylococcus aureus, there was no significant difference in the proportions of causative pathogens between early, delayed, and late FRI. This study found striking resistance rates of bacteria to commonly used antibiotics. MRSA accounted for 63% of cases. The most effective antibiotics for all Gram-positive bacteria were linezolid (96.4%), vancomycin (92.5%), clindamycin (85.3%), and fucidic acid (89.4%). For Gram-negative bacteria, only three antibiotics displayed a sensitivity >50%: amikacin (80.4%), imipenem (74.4%), and piperacillin + tazobactam (57%). The most effective empirical antibiotic therapy (with local availability) was the combination of vancomycin and amikacin or vancomycin and imipenem. In contrast to the literature from high-resource settings, this study revealed that in a sub-Saharan African context, Gram-negative bacteria are the most common causative microorganisms of FRI. This study revealed striking resistance rates to commonly used antibiotics, which will require urgent action to prevent antimicrobial resistance in low and middle-income countries.

Predictive factors for fracture-related infection in open tibial fractures in a Sub-Saharan African setting.

INTRODUCTION: The management of open tibial fractures (OTF) is challenging in low and middle-income countries (LMICs) where appropriate human resources and infrastructure (including equipment, implants and surgical supplies) are not readily available and medical care is not readily accessible. OTF are not rarely associated with a subsequent fracture-related infection (FRI), which is one of the most devastating and difficult to cure complications in orthopaedic trauma care. The aim of this study was to determine the rate and the predictive factors of FRI in OTF in a limited-resource setting of sub-Saharan Africa. METHODS: Patients with OTF who underwent surgery from July 2015 to December 2020 and followed-up for at least 12 months in a tertiary care teaching hospital in Yaoundé (Cameroon) were retrospectively investigated. Diagnosis of FRI was based on the confirmatory criteria of the International FRI Consensus definition. All patients with bone infections, occurring at any time point during follow-up, were included. Logistic regression was used to determine the predictive factors for FRI. RESULTS: One hundred and five patients with OTF were studied. With a mean follow-up period of 29.5 ± 16.6 months, 33 patients (31.4%) presented with FRI. Gustilo-Anderson type of OTF, compliance with antibiotics, blood transfusion, time to first washing of the wounds and method of bone fixation were factors associated with the occurrence of FRI. In multivariable logistic regression, 6-hours delay to first washing of the wounds (OR=8.07, 95% CI: 1.43-45.31, p = 0.01), and compliance with antibiotics (OR=11.33, 95%CI: 1.11-115.6, p = 0.04) were the only independent predictors of FRI. CONCLUSION: The overall rate of FRI in open tibial fracture is still high in the sub-Saharan African context. For similar low-resources settings, this study supports the recommendations (1) to perform a very early washing-dressing-splinting of OTF on admission of the patient, (2) to administer antibiotics early, and (3) to perform surgery as soon as reasonably possible, once appropriate personnel, equipment, implants and surgical supplies are available.

Early posttraumatic ankle osteoarthritis following ankle fracture-dislocations in a sub-Saharan African setting.

INTRODUCTION: Ankle fracture-dislocation (AFD) represents a major threat to the joint and a potential source of complication and functional disability. This study was performed to assess the outcome of AFD in a resource-limited setting and factors associated with the posttraumatic ankle osteoarthritis (PTAOA). We hypothesized that conservative treatment after AFD was associated with higher risk of PTAOA compared to surgical treatment. PATIENTS AND METHODS: Data from 52 consecutive patients (mean age 37.2±11.1years, with 57.7% n=30, males) who were treated and followed in a teaching hospital for AFD during a period of six years were collected. Forty-four of these patients were obtained at the time of the study for a retrospective evaluation. Functional outcome was assessed using the American Orthopaedic Foot and Ankle Society (AOFAS), ankle-hindfoot scale, and the patient's global satisfaction index. Radiographs were performed and analyzed for PTAOA. Logistic regression was used to determine factors associated with the presence of PTAOA. RESULTS: PTAOA was found in 19 (43.2%) patients after an average follow-up period of 27.2±18.3months. Anatomic fracture reduction was achieved in 22 (50%) patients, while the talus was centered in the mortise in 30 (68.2%) patients. Despite these poor anatomical results, the clinical outcome was good to excellent in 33 (75%) patients, and 88.6% was satisfied or very satisfied. Factors associated with the presence of PTAOA were the non-anatomical reduction (OR=11.07; p=0.007, 95% CI: 2.096-58.77) and the time elapsed since trauma (OR=1.073; p=0.007, 95% CI: 1.109-1.129). CONCLUSION: This study indicates that AFDs are associated with high rate of early and severe PTAOA. Non-anatomical realignment and a delay since trauma were positive predictors of PTAOA. There was no difference regarding the occurrence of PTAOA after AFD whatever the type of treatment, surgical or conservative. LEVEL OF EVIDENCE: IV; retrospective cohort study.