[Survey of general practitioners management of erysipelas]

PURPOSE

A few studies only have focused on ambulatory management of erysipelas.

METHODS

To assess the diagnostic and therapeutic management of erysipelas by general practitioners, and their adherence to the French Society of Infectious Diseases and Dermatology joint 2000 recommendations, we surveyed 114 general practitioners during a 1 year period (from May 1st, 2005 to April 30th, 2006).

RESULTS

Seventy-three general practitioners accepted to participate to the study and 54 cases of erysipelas were reported. Median age of patients was 63 years (range, 18-94) and sex ratio was 0.77. Lower limbs were affected in 83% out of the cases. A skin lesion was reported in 65% of the cases. None of the 15 doppler ultrasonography that were performed identified deep vein thrombosis. Five patients (9%) were initially hospitalized. Only 18% out of the patients were treated by amoxicillin. Most prescribed antimicrobial agents were pristinamycin (31%) and amoxicillin-clavulanate (27%). Median duration of treatment was 10 days. Six patients received an anti-inflammatory drug. Among the 44 patients who had a follow-up visit, 37 patients (84%) recovered and two patients were hospitalized after this follow-up assessment. Two patients experienced a recurrence of erysipelas during the study.

CONCLUSION

As previously reported in the literature, outcome of erysipelas after ambulatory management remains excellent, although recommendations are poorly followed.

Bacteraemia caused by third-generation cephalosporin-resistant Escherichia coli in France: prevalence, molecular epidemiology and clinical features

Escherichia coli is one of the major pathogens responsible for bactaeremia. Empirical antibiotherapy of these infections usually relies on third-generation cephalosporins (3GCs). Thus, the occurrence and epidemiology of 3GC-resistant strains have to be monitored. The French prospective multicentre study COLIBAFI collected 1081 strains of E. coli responsible for bacteraemia in 2005. In the present work, the prevalence of resistance to 3GCs was evaluated, and the implicated molecular mechanisms were characterized by specific PCR and sequencing. Phylogenetic grouping, O-typing, pulsed-field gel electrophoresis and virulence factor analysis were used to investigate the genetic background of the 3GC-resistant (3GC-R) strains. Clinical features of the patients with documented data (n = 1051) were analysed. Decreased susceptibility to 3GCs was observed in 41 strains (3.8%): 19, 18 and four had extended-spectrum β-lactamase (ESBL), AmpC cephalosporinase and OXA-type penicillinase phenotypes, respectively. Pulsed-field gel electrophoresis revealed that the 3GC-R strains constitute a diverse population. All but one of the strains with an ESBL phenotype produced a CTX-M-type enzyme, and six of them belonged to the widespread intercontinental clone O25b:H4-ST131. AmpC phenotype strains harboured various chromosomal ampC promoter and coding region mutations and/or the bla(CMY-2) plasmidic gene. 3GC-R strains carried fewer virulence factors and were more co-resistant to other antibiotics than 3GC-susceptible (3GC-S) strains. Infections with 3GC-R strains were mostly community-acquired and, as compared with those caused by their 3GC-S counterparts, were more severe. Underlying chronic disease and prior use of antibiotics were independent risk factors for development of a 3GC-R strain bacteraemia. The fact that the molecular support of 3GC resistance is mainly plasmid-mediated represents a potentially epidemic threat.

Differences in daptomycin and vancomycin ex vivo behaviour can lead to false interpretation of negative blood cultures

In clinical studies on bacteraemia, the negativity of blood cultures is an important endpoint for comparing the efficacy of different therapeutic regimens. In FAN anaerobic blood culture medium (BacT/ALERT system), daptomycin displayed increased MIC against Staphylococcus aureus and improved abolishment of its carryover effect in charcoal when compared with vancomycin. Differences between these two drugs can lead to a false interpretation of negative blood cultures. To compare different antibiotic regimens for the treatment of bacteraemia, preliminary studies are mandatory to ensure that ex vivo antibiotic behaviour is similar in the blood-culture system used.

Ostéomyélite de la base du crâne d'origine otosinusienne. Étude d'une série de cinq cas récents

INTRODUCTION

Skull base osteomyelitis is an uncommon but severe condition generally secondary to necrotizing otitis externa. The aim of this study was to determine the patients demographics, clinical and radiological findings, and outcomes of this condition.

MATERIAL AND METHODS

We prospectively follow 5 patients with a diagnosis of skull base osteomyelitis between 2004 and 2005. Clinical, biologic and imaging data were collected, and also follow-up during treatment.

RESULTS

The five patients were men and the average age at presentation was 75 years (63-89). All except one had a previous diabetes mellitus, with a more or less recent clinical story of otitis externa. All of them suffered of headaches and cranial nerve(s) deficits, particularly facial nerve. Diagnosis was made on MRI with gadolinium injection and fat saturation, and Pseudomonas aeruginosa identified as pathogen in all cases. One patient deceased of cranial nerves palsy complication. In 4 cases we found previously a too short or non adapted treatment of necrotizing otitis externa.

CONCLUSIONS

In the setting of headache, cranial nerves deficit and abnormal skull base imaging on MRI with Fat sat, osteomyelitis should be consider as the likely diagnosis. This complication should be avoided by optimal management of necrotizing otitis externa.

Schnitzler's syndrome: 3-year radiological follow-up

Schnitzler's syndrome comprises urticaria, monoclonal gammapathy, inflammatory signs (fever, enlarged lymph nodes, hyperleukocytosis), and bone lesions. We report the imaging findings and follow-up of a new case with extensive osteosclerosis of the iliac bone, associated with inflammatory signal changes on MRI and foci of increased uptake on bone scintigraphy. When a diagnosis of Schnitzler's syndrome is established, treatment should be towards symptoms only; a long follow-up is warranted, as a delayed evolution towards a lymphoproliferative syndrome is possible.

Efficacy of cethromycin, a new ketolide, against Streptococcus pneumoniae susceptible or resistant to erythromycin in a murine pneumonia model

Cethromycin is a ketolide with in vitro activity against macrolide-sensitive and -resistant strains of Streptococcus pneumoniae. We compared its in vivo efficacy to erythromycin in a mouse model of acute pneumonia induced by two virulent clinical strains: a serotype 3 susceptible strain (P-4241) (MICs: erythromycin, 0.03 microg/ml; cethromycin, 0.015 microg/ml) and a serotype 1 strain resistant to erythromycin (P-6254; phenotypically MLSB constitutive) (MICs: erythromycin, 1,024 microg/ml; cethromycin, 0.03 microg/ml). Immunocompetent mice were infected with 10(5) CFU of each strain. Six treatments given either subcutaneously (s.c.) or per os (p.o.) at 12-h intervals were initiated at 6 or 12 h after infection. Against P-4241, cethromycin given s.c. at 25 or 12.5 mg/kg protected 100% of the animals, with lungs and blood completely cleared of bacteria. Given p.o., cethromycin maintained its efficacy with 100 and 86% survival at 25 and 12.5 mg/kg, respectively. Erythromycin, given s.c. at 50 or 37.5 mg/kg, provided 50 and 38% survival rates, respectively. Against P-6254, cethromycin was effective at 25 mg/kg (100% survival) regardless of the administration route, whereas only 25 and 8% of animals survived after a 75-mg/kg erythromycin treatment given s.c. and p.o., respectively. The serum protein binding levels of cethromycin were 94.8 and 88.5% after doses of 12.5 and 25 mg/kg, respectively. The higher in vivo activity of cethromycin compared to erythromycin could be explained by favorable pharmacokinetic/pharmacodynamic indexes against P-6254 but not against P-4241.

Imaging does not predict the clinical outcome of bacterial vertebral osteomyelitis

OBJECTIVES

Magnetic resonance imaging (MRI) and computed tomography (CT) are useful for initial assessment of bacterial spondylodiscitis. However, clinical relevance of imaging changes during treatment is less well-documented.

METHODS

Between October 1997 and March 2005, 29 patients with documented bacterial spondylodiscitis were prospectively enrolled. They had clinical, biological and imaging examinations (MRI and/or CT) at M0 and M3, and in 22 cases, at M6.

RESULTS

Mean age was 58 yrs. Antimicrobial chemotherapy lasted an average of 98 days. The median follow-up was 18 months, including 12 months after the completion of treatment. Infection was cured in every patient. Biological markers of inflammation returned to normal at M3. Six patients had painful and/or neurological sequelae. Decreased disc height was a consistent and early sign, and remained stable during the follow-up. Vertebral oedema, present in 100% of cases initially, persisted in 67 and 15% of cases at M3 and M6, respectively. Discal abscesses and paravertebral abscesses, present in 65 and 39% of cases initially, persisted in, respectively, 42 and 9% of cases at M3 and in 18 and 3% of cases at M6. Epidural abscesses were present at diagnosis in 30% of cases, and had always disappeared by M3. Imaging abnormalities found at M0 and M3 did not differ between patients with and without late neurological or painful sequelae.

CONCLUSIONS

Imaging abnormalities often persist in patients with bacterial spondylodiscitis despite a favourable clinical and biological response to antibiotic treatment. They are not associated with relapses, neurological sequelae or persistent pain. Imaging controls are not necessary when bacterial spondylodiscitis responds favourably to treatment.

[Blood and respiratory diffusion of antibiotics. A critical analysis of predictive parameters for clinical effectiveness]

The implementation of a treatment for lower respiratory tract infections must integrate a pharmacokinetic/pharmacodynamic (PK-PD) approach of antibiotic dosing. The activity of beta-lactam antibiotics is best predicted by the duration of time during which serum concentrations exceed the MIC (T>MIC). T>MIC of 30-40% is sufficient to achieve clinical cure in immunocompetent patients. This threshold is achieved with amoxicillin for penicillin susceptible or resistant Sreptococcus pneumoniae and with amoxicillin-clavulanate and ceftriaxone for S. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. For macrolides, the activity is best predicted by T>MIC and for azithromycin and telithromycin by area-under-the-curve/MIC (AUC/MIC). Sufficient PK-PD values are only achieved for macrolides against susceptible strains of S. pneumoniae and against M. catarrhalis; for telithromycin, an AUC/MIC>25, which is necessary for bacterial eradication, is achieved in>99% of patients for S. pneumoniae and M. catarrhalis and>90% of patients for H. influenzae. For fluoroquinolones, both peak/MIC and AUC/MIC are predictors of clinical and bacteriological efficacy. AUC/MIC required ratios vary according to pathogens and severity of diseases from 48 to 125. These thresholds are reached for respiratory pathogens; for S. pneumoniae, AUC/MIC90 ratios of levofloxacin and moxifloxacin are 96 and 192, respectively; the presence of a mutation in parC increases the risk for the acquisition of additional mutations and failure.

[Cases of pertussis among healthcare workers in a maternity ward: management of a health alert]

Pertussis is a highly contagious acute respiratory tract infection, with a poor prognosis in non-vaccinated new-borns.

OBJECTIVES

The authors had for aim to investigate an epidemic of 5 pertussis cases among health care workers (HCW) in our maternity ward with potential exposure of new-borns and to evaluate HCW compliance and experience gain.

METHODS

A retrospective study was made using a questionnaire with HCW on preventive measures taken (antibiotic prophylaxis with erythromycin and wearing a mask).

RESULTS

Two hundred and thirty-eight patients were warned of a potential pertussis contamination. No nosocomial case was detected among patients or their new borns. Ten proved or probable cases were identified among 101 HCW having answered (N=101/210, 48%). Sixty percent of HCW people followed the antibiotic treatment and 85% wore a mask among whom 46% adequately. Non-compliance factors were mainly related to adverse effects (41%), delayed information (41%), and false vaccine protection (22%). Crisis communication was felt as unsatisfactory for 72% of HCW and recommendations not adapted for 39% of the staff.

CONCLUSION

This survey points out the difficulty of managing a pertussis alert in a medical ward.