Clinical features and treatment outcomes of bone and joint nontuberculous mycobacterial infections according to immune status: a 9-year retrospective observational cohort.

OBJECTIVES: Nontuberculous mycobacteria (NTM) bone and joint infections (BJIs) are uncommon. We evaluated the characteristics of BJIs and identified differences according to immune status. METHODS: We performed a multicenter retrospective study in France involving patients with documented NTM BJI over a 9-year period. We collected the clinical and microbiological characteristics, management, and clinical outcomes of the patients. RESULTS: Overall, 95 patients were included, of whom 50.5% (48/95) were immunosuppressed. Tenosynovitis was more frequent in the immunocompetent group, and native arthritis more common in the immunosuppressed group. Mycobacerium marinum and M. abscessus complex were significantly more frequent in the immunocompetent group, and M. avium and M. xenopi were significantly more frequent in the immunosuppressed group. The combination of antibiotherapy with surgery tended to be more frequent in the immunocompetent than the immunosuppressed group (63.8% (30/47) vs 47.8% (22/46), respectively); of the latter, 45.7% (21/46) received antimicrobial therapy alone, a higher frequency than in the immunocompetent group (23.4%, 11/47). The median duration of antimicrobial treatment was similar in the two groups (11 months). Mortality was significantly higher in the immunosuppressed group. CONCLUSIONS: Although the clinical presentations and the NTM species involved in BJI differed according to immune status, most recovered completely after treatment.

Ultrasonography performed by an infectiologist in hip and knee prosthetic joint and native joint infections.

INTRODUCTION: Clinical ultrasonography (US) by infectiologists has only recently been developing, and as now there is little literature on the subject. Our study focuses on the conditions and diagnostic performance of clinical ultrasound imaging by infectiologists in cases of hip and knee prosthetic and native joint infection. METHODS: A retrospective study carried out between June 1st 2019 and March 31st 2021 in the University Hospital of Bordeaux, South-Western France. We measured US sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV), combined or not with the analysis of articular fluid, compared to the MusculoSketetal Infection Society (MSIS) score in prosthetic joints, or to expert diagnosis in native joints. RESULTS: Fifty-four patients underwent US by an infectiologist in an infectious disease ward, including 11 (20.4%) for native joint and 43 (79.6%) for prosthetic joint. Joint effusion and/or periarticular collection were highlighted in 47 (87%) patients, and US led to 44 punctures. In all patients (n = 54), Se, Sp, PPV and NPV of US alone were 91%, 19%, 64% and 57%, respectively. When US was combined with fluid analysis, Se, Sp, PPV, NPV were 68%, 100%, 100%, 64% in all patients (n = 54), 86%, 100%, 100%, 60% in acute arthritis (n = 17) and 50%, 100%, 100% and 65% respectively in non-acute arthritis (n = 37). CONCLUSION: These results suggest that US by infectiologists effectively diagnoses osteoarticular infections (OAIs). This approach has many applications in infectiology routines. Consequently, it would be interesting to define the contents of a first level of infectiologist competence in US clinical practice.

An Infected Arterial Aneurysm and a Dog Bite: Think at Capnocytophaga canimorsus!

We describe the fourth cases of arterial aneurysm consecutive to Capnocytophaga canimorsus infection in a 77-year-old man. The infection occurred after a dog bite. He presented fever. The thoracic-abdominal computed tomography angiography revealed aneurysms on the abdominal aorta, left common femoral artery, and left popliteal artery. The diagnosis was performed by a blood culture positive for Capnocytophaga canimorsus. The outcome was favorable with surgery and antibiotic therapy.

Added value of [18F]fluorodeoxyglucose positron emission tomography/computed tomography for the diagnosis of post-operative instrumented spine infection.

PURPOSE: Post-operative instrumented spine infection (PISI) is an infrequent complication. Diagnosis of spinal implant infection can be difficult, especially in case of chronic infection. METHODS: This retrospective study attempts to evaluate the diagnostic performance of [18F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in PISI. Imagings were performed between April 2010 and June 2018 among patients referred for suspected chronic spinal implant infection. PET/CT were performed more than 12 weeks after surgery. PET/CT images were re-interpreted independently by two nuclear medicine physicians without knowledge of the patient's conditions. PET/CT data were analyzed both visually and semi-quantitatively (SUVmax). MRI results were collected from medical records. The final diagnosis of infection was based on bacteriological cultures or a twelve-month follow-up. RESULTS: Forty-nine PET/CT were performed in 44 patients (22 women, median age 65.0 years). Twenty-two patients had a diagnosis of infection during follow-up. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for PET/CT were 86.4%, 81.5%, 79.2%, and 88.0%. Sensitivity, specificity, PPV and NPV were 66.7%, 75.0%, 66.0%, 75.0% respectively for MRI and 50.0%, 92.6%, 84.6% and 69.4% for serum C-reactive protein (CRP). Although these values were higher for PET/CT than for MRI or CRP, the differences were not statistically significant. In this setting, false positives with PET/CT can be observed in case of previous spine infection or adjacent segments disc disease. False negatives can result of extensive instrumented arthrodesis or infection with low virulence bacteria. CONCLUSION: PET/CT is useful for the diagnosis of PISI. These results should be evaluated in further prospective study.

Contribution of a multiplex serological test for the preoperative diagnosis of prosthetic joint infection: a prospective study.

BACKGROUND: Prosthetic joint infection (PJI) is a severe complication of orthopaedic surgery. Preoperative diagnosis, although sometimes difficult, is key to choose the relevant treatment. METHODS: We conducted a prospective study aimed at evaluating the diagnostic performance of a multiplex serological test for the pre-operative diagnosis of PJI. Blood samples were collected between 1 July 2016 and 31 July 2017 among patients referred for suspected PJI that occurred at least six weeks prior. Infection diagnosis was confirmed using intraoperative bacteriological cultures during prosthetic exchange. RESULTS: Seventy-one patients were included, with a median age of 73 years (interquartile range [IQR]: 66-81) and 40 (56%) were male. Twenty-six patients had aseptic loosening and 45 patients had PJI. Among the latter, median time since the last surgery was 96 weeks (IQR: 20-324). Intraoperative cultures found Staphylococcus spp, Streptococcus spp or both in 39, 5 and 1 patients, respectively. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 81.8, 95.4, 97.3 and 72.4%, respectively, for all patients and 87.5, 93.5, 94.6 and 85.3%, respectively, for staphylococcal infections. Patients with false negative (FN) results had a significantly lower blood lymphocyte count (p = .045). CONCLUSIONS: Multiplex serological test performed well among patients with chronic staphylococcal prosthetic infection. This approach could contribute to PJI diagnosis especially in patients for whom the pre-operative analysis of joint fluid is not informative.

Efficacy of debridement, antibiotic therapy and implant retention within three months during postoperative instrumented spine infections.

BACKGROUND: Postoperative instrumented spine infection (PISI) is a severe complication of invasive spine procedures. METHODS: Retrospective study of patients treated for PISI between 1st January 2008 and 31st December 2012 in a French University Hospital. The objectives of this study were to describe the outcome of patients treated with debridement-irrigation, antibiotic therapy and implant retention (DAIR) within three months after the occurrence of PISI and to identify factors associated with relapse. RESULTS: Among 4290 patients who underwent spinal arthrodesis surgery during the 5-year study period, 129 had PISI treated by debridement-irrigation in the first three months (3.0%, 95% confidence interval [95%CI]: 2.5-3.5). Fifty-two (40%) were female and the median age was 57 years. Fourteen patients (10.8%) had diabetes and 73 (56.6%) had a BMI (Body Mass Index) ≥25 kg/m2. Staphylocccus aureus, enterobacteria or polymicrobial infections were identified in 44.0, 18.0 and 13.0% of cases, respectively. One hundred and six patients (82.2%) and one hundred and twenty-one patients (93.8%) were cured after one DAIR and after two DAIR, respectively. In multivariate logistic analysis, polymicrobial infection was associated with relapse (Odd Ratio [OR] = 3.81; 95%CI: 1.06-13.66; p = .03), while a BMI ≥25 kg/m2 was a protective factor (OR =0.25; 95%CI: 0.07-0.89; p = .03). CONCLUSION: DAIR may be effective for PISI when performed within the first 3 months after onset of infection. Relapses are significantly associated with polymicrobial infection and negatively associated with moderate overweight. These results need to be confirmed in future prospective studies.

Nontuberculous Mycobacterial Infections in a French Hospital: A 12-Year Retrospective Study.

BACKGROUND: Nontuberculous mycobacteria (NTM) are environmental organisms associated with a range of infections. Reports of NTM epidemiology are mainly focused on pulmonary infections and isolations, and extrapulmonary infections are less frequently described. METHODS: We conducted a retrospective study of NTM infections at the Bordeaux University Hospital, France, between January 2002 and December 2013. We used the microbiologic component of the American Thoracic Society/Infectious Diseases Society of America's pulmonary NTM disease criteria to define cases of pulmonary NTM, and patients with isolates from a normally sterile site were classified as having extrapulmonary disease. RESULTS: In our setting, 170 patients were included. Pulmonary cases predominated (54.1%), followed by skin and soft tissue infections (22.9%), disseminated cases (10.6%), lymphadenitis (7.7%), bone and joint infections (2.9%) and the remaining 1.8% catheter-related infections. Overall, 16 NTM species were isolated. Mycobacterium avium (31.8%) and M. intracellulare (20%) were the most common species identified, followed by M. marinum (13.5%), M. kansasii (10.6%), M. xenopi (9.4%), rapidly growing mycobacteria (9.4%) and other slowly growing mycobacteria (5.3%). In general, NTM isolates were largely prevalent in people older than 50 (62.4%); patients aged 1-10 year-old exclusively yielded M. avium from lymph nodes, almost cases having being diagnosed after 2007. Among the 121 patients with complete follow-up, 78 (64.5%), 24 (19.8%), and 19 (15.7%) were cured, experienced relapse, or died, respectively. CONCLUSION: In our study, extrapulmonary NTM infections represented almost half of cases, consisting mainly in skin and soft tissue infections. The increase lymphadenitis cases in children after 2007 could be linked to the cessation of mandatory BCG vaccination in France. We observed similar cure rates (64%) between pulmonary and extrapulmonary infections.

B-cell non-Hodgkin lymphoma linked to Coxiella burnetii.

Bacteria can induce human lymphomas, whereas lymphoproliferative disorders have been described in patients with Q fever. We observed a lymphoma in a patient with Q fever that prompted us to investigate the association between the 2 diseases. We screened 1468 consecutive patients of the 2004 to 2014 French National Referral Center for Q fever database. The standardized incidence ratios (SIRs) of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) were calculated comparatively to the 2012 Francim Registry. The presence of Coxiella burnetii was tested using immunofluorescence and fluorescence in situ hybridization using a specific 16S ribosomal RNA probe and genomic DNA probe. Seven patients (0.48%) presented mature B-cell lymphoma consisting of 6 DLBCL and 1 FL. An excess risk of DLBCL and FL was found in Q fever patients compared with the general population (SIR [95% confidence interval], 25.4 [11.4-56.4] and 6.7 [0.9-47.9], respectively). C burnetii was detected in CD68(+) macrophages within both lymphoma and lymphadenitis tissues but localization in CD123(+) plasmacytoid dendritic cells (pDCs) was found only in lymphoma tissues. Q fever patients with persistent focalized infection were found more at risk of lymphoma (hazard ratio, 9.35 [1.10-79.4]). Interleukin-10 (IL10) overproduction (P = .0003) was found in patients developing lymphoma. These results suggest that C burnetii should be added to the list of bacteria that promote human B-cell non-Hodgkin lymphoma, possibly by the infection of pDCs and IL10 overproduction. Screening for early lymphoma diagnosis should be considered in the management of patients with Q fever, especially those with persistent focalized infections.

Prognostic factors of calcaneal osteomyelitis.

BACKGROUND: Calcaneal osteomyelitis is difficult to manage and requires a multidisciplinary approach. The aim of this study was to describe the characteristics and outcomes of calcaneal osteomyelitis, and to determine prognostic factors. METHODS: This was an observational and retrospective study including all patients presenting with calcaneal osteomyelitis referred to a tertiary referral centre between January 2005 and December 2010. RESULTS: Forty-two patients (mean age 50.7 y, range 22-89 y) were included. Fifteen were female. The mean duration of follow-up was 20 months (range 12-48 months). Twenty-six (62%) were post-traumatic osteomyelitis and 16 (38%) were secondary to neurological damage (sensitivity or motor impairment). All patients underwent surgical management with bone curettage and appropriate antibiotic therapy. Staphylococcus aureus was the most commonly isolated bacterium and was found in 29 patients. Polymicrobial samples were observed in 29 patients. Pseudomonas aeruginosa was associated with calcaneal osteomyelitis secondary to neurological damage (n = 7; 44% p = 0.045). Twenty-eight patients (66.7%) healed without the need to resort to amputation. The mean time to healing was 29 weeks with a range of 4-144 weeks. Relapse of bone infection occurred in 17 patients (40.5%). Seven patients (16.7%) required amputations. Favourable prognostic factors for healing without amputation were an American Society of Anesthesiologists (ASA) score < 2 (p < 10(-4)), post-traumatic calcaneal osteomyelitis (p = 0.001), age < 65 y (p = 0.02), absence of neuropathy (p = 0.005), and absence of diabetes mellitus (p = 0.02). CONCLUSIONS: Calcaneal osteomyelitis is characterized by frequent relapse with delayed wound healing. Clinicians should take into account the impact of older age, as well as co-morbidities such as diabetes mellitus or the presence of neuropathy, during the routine management of patients with this difficult-to-treat bone infection.

Characteristics of prosthetic joint infections leading to bacteremia: a case-control study.

The possible systemic infectious consequences of prosthetic joint infections (PJI) are poorly documented in the literature. We assessed the frequency of postoperative prosthetic hip and knee infections leading to bacteremia and investigated their associated factors among patients treated between 2005 and 2009. Among 633 patients with PJI, 62 (9.8%) also had positive blood cultures (95% confidence interval (CI) 7.5-12.1). After complete investigations, the prosthesis was considered as the direct cause of bacteremia in 14 cases (2.2%; 95% CI 1.1-3.4). In the conditional logistic regression analysis, PJI leading to bacteremia was more frequently observed in cases of relapses of a prior PJI (adjusted odds ratio (aOR) 7.3, p = 0.07) and in patients with a C-reactive protein value upon admission ≥ 180 mg/l (aOR 4.5, p = 0.04). None of the 8 bacteremic patients treated with surgical debridement and prosthetic retention were cured from joint infection. These preliminary results raise concerns about the fact that debridement with prosthetic retention may not be an appropriate option in the context of PJI leading to bacteremia, contrary to PJI resulting from hematogenous seeding.

Candida prosthetic infections: case series and literature review.

Candida prosthetic joint infections are considered to be rare. We retrospectively studied patients treated for Candida prosthetic infections between 1 January 1995 and 31 December 2007 in our infectious diseases department, a tertiary referral centre. We identified 7 patients, 4 with knee and 3 with hip prosthetic infections. The most frequent fungal agent was Candida albicans (4 cases), followed by Candida parapsilosis (2 cases) and Candida guillermondii (1 case). All the patients received antifungal treatment for a prolonged period. Five patients had their prosthesis removed and 3 had reimplantation, 1 patient was treated with debridement and prosthetic retention, and the last patient refused surgery. The mean follow-up time was 2.5 y. At the last evaluation, 3 patients were considered as cured, 3 patients presented a secondary bacterial infection leading to amputation for 2 of them, and 1 patient died from heart failure. During Candida prosthetic joint infections, the epidemiological characteristics and the location of the prosthesis are very similar to bacterial prosthetic infections. The benchmark antifungal therapies remain amphotericin B and/or fluconazole.

Association between psoas abscess and prosthetic hip infection: a case-control study.

BACKGROUND AND PURPOSE: The relationship between prosthetic hip infection and a psoas abscess is poorly documented. We determined the frequency of prosthetic hip infections associated with psoas abscesses and identified their determinants. METHODS: We conducted a 2-year observational study. Data from patients with psoas abscesses that were associated with prosthetic hip infections were examined in a case-control study. RESULTS: Of 106 patients admitted to the Infectious Diseases Department with prosthetic hip infection, 13 also had a psoas abscess (12%; 95% CI: 6-19). By conditional logistic regression analysis, psoas abscesses were observed more frequently in cases of hematogenous prosthetic infections (OR = 93, p = 0.06) and in patients with a history of neoplasm (OR = 20, p = 0.03). INTERPRETATION: Our results suggest that the presence of psoas abscesses is a frequent but under-diagnosed complication of prosthetic hip infection. We recommend that an abdominal CT scan be performed on patients with hematogenous prosthetic hip infection or with a history of neoplasm.

Drug-drug interactions with systemic antifungals in clinical practice.

PURPOSE: We describe drug-drug interactions (DDIs) encountered with antifungals in clinical practice. METHODS: Retrospective observational study of hospitalized adults receiving systemic antifungal treatment in the intensive care unit (ICU) and in the infectious diseases unit (IDU) of the University Hospital of Bordeaux, France between 1996 and 2001. All treatment episodes with antifungal agent were examined and all prescribed concomitant medication identified for potential drug-drug interactions (PDDI)-serious events occurring during treatment were adjudicated for clinical DDI. RESULTS: There were 150 treatment episodes with antifungal agent in 105 patients. Fluconazole was used in 48% of the treatment episodes, amphotericin B in 46%, itraconazole in 4.7% and flucytosine in 1.3%. One hundred and sixteen PDDIs were identified related to the use of amphotericin B (81.0%), fluconazole (17.2%) or itraconazole (1.7%). Of these, 22 were associated with a clinical evidence of adverse interaction (hypokalemia, increased creatininemia or nephrotoxicity). All these clinical drug-drug interactions (CDDIs) were with amphotericin B. They were due to furosemide (36.4%), cyclosporine (31.8%) and hydrocortisone (18.2%). PDDIs were mostly associated with leukaemia (40.4%), HIV infection (24.6%) and cancer (10.5%). CONCLUSIONS: In ICU and IDU, systemic antifungal treatments lead to many PDDIs, mainly related to the type of antifungal used and to the pathology treated. Clinical DDI seem more common with amphotericin.