Yves Hansmann

Bartonella tribocorum sp. nov. : a new Bartonella species isolated from the blood of wild rats

Two Bartonella strains from blood of two wild rats (Rattus norvegicus) living in a rural environment were isolated. These strains were distinct from all previously known Bartonella species based on phenotypic and genotypic characteristics. This new species is distinguished by its trypsin-like activity, the absence of the ability to hydrolyse proline and tributyrin, its 16S rRNA and citrate synthase gene sequences and by whole-DNA hybridization data. This new species, for which the name Bartonella tribocorum sp. nov. is proposed, seems to be genetically related to Bartonella elizabethae, an agent isolated in a case of human endocarditis. The type strain of Bartonella tribocorum sp. nov. is IBS 506T (CIP 105476T).

Role of comorbidity in mortality related to Staphylococcus aureus bacteremia: a prospective study using the Charlson weighted index of comorbidity.

OBJECTIVE : To demonstrate the effectiveness of the Charlson weighted index of comorbidity (WIC) for controlling comorbidity in prospective studies focusing on mortality in patients with Staphylococcus aureus bacteremia (SAB). DESIGN: Cohort study. SETTING: Two tertiary-care, university-affiliated hospitals in France. PATIENTS: One hundred sixty-six inpatients 18 years or older consecutively diagnosed with SAB from May 15, 2001, to May 15, 2002. METHODS: Patients were prospectively assessed and cases were followed by the infectious diseases consult service at least 3 months after effective antibiotic therapy completion. The Charlson WIC was computed and dichotomized into scores of fewer than 3 points and 3 or more points. Bacteremia source, acute complication due to SAB acquisition in the ICU, and inappropriate empiric antibiotic therapy were recorded. The endpoint was death due to SAB and overall mortality. RESULTS: In univariate analysis, the Charlson WIC was able to predict overall mortality and S. aureus-related death. The following variables were found to be independently predictive of mortality due to SAB using the Cox model: an acute complication due to S. aureus (OR, 8.9; CI 95 , 4 to 19.7; P <.001), a Charlson WIC score of 3 or more (OR, 3; CI 95 , 1.3 to 5.5; P =.006), and age (OR, 1.04; CI 95 , 1.009 to 1.07; P <.01). CONCLUSIONS: Comorbidity contributes to death in patients with SAB. The Charlson WIC is a good predictor of mortality in this population and may be a useful instrument to control comorbidity in studies aiming to investigate risk factors for death due to bacteremia.

RELEVANCE OF THE ANTIBODY INDEX TO DIAGNOSE LYME NEUROBORRELIOSIS AMONG SEROPOSITIVE PATIENTS

Background: No consensual criteria exist to diagnose neuroborreliosis. The intrathecal anti-Borrelia antibody index (AI) is a necessary criterion to diagnose neuroborreliosis in Europe, but not in the United States. Previous studies to determine the diagnostic value of the AI found a sensitivity ranging from 55% to 80%. However, these studies included only typical clinical cases of meningitis or meningoradiculitis, and none had a control group with CSF anti-Borrelia antibodies. Methods: We studied a sample of 123 consecutive patients with clinical signs of neurologic involvement and CSF anti-Borrelia antibodies. We determined the AI for all patients and a final diagnosis was made. Patients were then divided into three groups (neuroborreliosis, possible neuroborreliosis, control). Results: Thirty of the 40 patients with neuroborreliosis had a positive AI (AI sensitivity = 75%). Two of the 74 patients with another neurologic diagnosis had a positive AI (AI specificity = 97%). Conclusion: The antibody index has a very good specificity but only moderate sensitivity. Given the lack of consensual criteria for neuroborreliosis and the absence of a “gold standard” diagnostic test, we propose pragmatic diagnostic criteria for neuroborreliosis, namely the presence of four of the following five items: no past history of neuroborreliosis, positive CSF ELISA serology, positive anti-Borrelia antibody index, favorable outcome after specific antibiotic treatment, and no differential diagnosis. These new criteria will need to be tested in a larger, prospective cohort.

Diagnosis of Cat Scratch Disease with Detection of Bartonella henselae by PCR: a Study of Patients with Lymph Node Enlargement

ABSTRACT Cat scratch disease (CSD) is mostly due to Bartonella henselae after inoculation of the organism through a skin injury. Since the causative bacteria cannot be easily cultured from human lymph node samples, the diagnosis usually relies on epidemiological, clinical, histological, and serological criteria (classical criteria). A study was performed to determine the diagnostic value of PCR analysis for the detection of B. henselae for the diagnosis of CSD and its place in the diagnostic strategy alongside the classical criteria. Over a 7-year period, lymph node biopsy specimens or cytopunctures from 70 patients were systematically tested by PCR for the presence of B. henselae DNA (htrA gene) in the Bacteriology Laboratory of the Hôpitaux Universitaires de Strasbourg. Serological testing by an immunofluorescence assay for B. henselae antibodies was also performed for each patient, and clinical, epidemiological, and histological data were collected. The patients were then divided into two groups according to the number of positive diagnostic criteria for CSD: 29 patients with definite CSD (two or more classical criteria) and 15 patients with possible CSD (less than two classical criteria). The remaining 26 patients for whom another diagnosis was retained were used as a control group. Among all criteria, PCR analysis had the best specificity (100%). The PCR assay for B. henselae was positive for 22 (76%; 95% confidence interval [CI95], 56.5 to 89.7%) of the 29 definite CSD patients and 3 (20%; CI95, 4.3 to 48.1%) of the 15 possible CSD patients. We then studied combinations of diagnostic criteria, including B. henselae PCR analysis. The best diagnostic performance was observed if at least two criteria were present among serologic, epidemiologic, histological, and molecular criteria.

Healthcare-associated Staphylococcus aureus bacteremia and the risk for methicillin resistance: is the Centers for Disease Control and Prevention definition for community-acquired bacteremia still appropriate?

OBJECTIVE To evaluate a new classification for bloodstream infections that differentiates hospital acquired, healthcare associated, and community acquired in patients with blood cultures positive for Staphylococcus aureus. DESIGN Prospective, observational study. SETTING Three tertiary-care, university-affiliated hospitals in Dublin, Ireland, and Strasbourg, France. PATIENTS Two hundred thirty consecutive patients older than 18 years with blood cultures positive for S. aureus. METHODS S. aureus bacteremia (SAB) was defined as hospital acquired if the first positive blood culture was performed more than 48 hours after admission. Other SABs were classified as healthcare associated or community acquired according to the definition proposed by Friedman et al. When available, strains of methicillin-resistant Staphylococcus aureus (MRSA) were analyzed by pulsed-field gel electrophoresis (PFGE). RESULTS Eighty-two patients were considered as having community-acquired bacteremia according to the Centers for Disease Control and Prevention (CDC) classification. Of these 82 patients, 56% (46) had healthcare-associated SAB. MRSA prevalence was similar in patients with hospital-acquired and healthcare-associated SAB (41% vs 33%; P > .05), but significantly lower in the group with community-acquired SAB (11%; P < .03). PFGE of MRSA strains showed that most community-acquired and healthcare-associated MRSA strains were similar to hospital-acquired MRSA strains. On multivariate analysis, Friedmans classification was more effective than the CDC classification for predicting MRSA. CONCLUSION These results support the call for a new classification for community-acquired bacteremia that would account for healthcare received outside the hospital by patients with SAB.

Babesiosis in Immunocompetent Patients, Europe

We report 2 cases of babesiosis in immunocompetent patients in France. A severe influenza-like disease developed in both patients 2 weeks after they had been bitten by ticks. Diagnosis was obtained from blood smears, and Babesia divergens was identified by PCR in 1 case. Babesiosis in Europe occurs in healthy patients, not only in splenectomized patients.

A new ELISA kit which uses a combination of Plasmodium falciparum extract and recombinant Plasmodium vivax antigens as an alternative to IFAT for detection of malaria antibodies

BackgroundThe methods most commonly used to measure malarial antibody titres are the Indirect Fluorescence Antibody Test (IFAT), regarded as the gold standard, and the Enzyme-Linked ImmunoSorbent Assay (ELISA). The objective here was to assess the diagnostic performance, i.e. the sensitivity and specificity, of a new malaria antibody ELISA kit in comparison to IFAT. This new ELISA kit, the ELISA malaria antibody test (DiaMed), uses a combination of crude soluble Plasmodium falciparum extract and recombinant Plasmodium vivax antigens.MethodsTwo groups were used: 95 samples from malaria patients to assess the clinical sensitivity and 2,152 samples from blood donors, who had not been exposed to malaria, to assess the clinical specificity.ResultsThe DiaMed ELISA test kit had a clinical sensitivity of 84.2% and a clinical specificity of 99.6% as compared with 70.5% and 99.6% respectively, using the IFAT method. The ELISA method was more sensitive than the IFAT method for P. vivax infections (75% vs. 25%). However, in 923 malaria risk donors the analytical sensitivity of the ELISA test was 40% and its specificity 98.3%, performances impaired by large numbers of equivocal results non-concordant between ELISA and IFAT. When the overall analytical performances of ELISA was compared to IFAT, the ELISA efficiency J index was 0.84 versus 0.71 for IFAT. Overall analytical sensitivity was 93.1% and the analytical specificity 96.7%. Overall agreement between the two methods reached 0.97 with a reliability k index of 0.64.ConclusionThe DiaMed ELISA test kit shows a good correlation with IFAT for analytical and clinical parameters. It may be an interesting method to replace the IFAT especially in blood banks, but further extensive investigations are needed to examine the analytical performance of the assay, especially in a blood bank setting.

Human Anaplasmosis Presenting as Atypical Pneumonitis in France

Human anaplasmosis is a febrile illness caused by Anaplasma phagocytophilum, an intracellular bacterium transmitted by Ixodes ticks in the United States and Europe. Although cough is reported in 30% of the American cases, interstitial pneumonitis has been noted only once. Of the 9 confirmed cases reported in Europe, 3 presented with atypical pneumonitis. A. phagocytophilum should be added to the list of agents responsible for interstitial pneumonitis, especially in areas where human anaplasmosis is endemic.

Bacterial epidemiology and antimicrobial resistance in ascitic fluid: a 2-year retrospective study.

The bacterial epidemiology of bacterascites and spontaneous bacterial peritonitis is evolving. Four hundred and eleven strains isolated from ascites in cirrhotic patients from 5 French hospitals were isolated in 2006 and 2007. Of these, 114 were definitely associated with spontaneous bacterial peritonitis. The proportion of Gram-positive and Gram-negative agents was quite similar, even after excluding coagulase-negative staphylococci, or when considering only definite spontaneous bacterial peritonitis or community-acquired strains. Staphylococci and Escherichia coli were the most frequent pathogens, but enterococci were also involved in nearly 15% of the cases. Among the E. coli, 28% were intermediate or resistant to amoxicillin+clavulanate, 5.3% expressed cephalosporinases or extended β-lactamases and 17.3% were intermediate or resistant to fluoroquinolones. Resistance to methicillin was observed in 27% of Staphylococcus aureus. Cefotaxime and amoxicillin–clavulanate remained the most effective ‘single’ agents, however on less than 70% of isolates. Some combinations (such as cefotaxime+amoxicillin) extended coverage to a further 15% of strains. Since inadequate empiric antibiotic therapy is associated with increased mortality, these combinations may be of great interest as first-line treatment, even though they may also lead to the development of antimicrobial resistance. Repeated epidemiological surveys and new clinical trials are thus needed.

Impact of malnutrition and social determinants on survival of HIV-infected adults starting antiretroviral therapy in resource-limited settings.

Objectives:Determining the impact of malnutrition, anaemia and social determinants on survival once starting antiretroviral therapy (ART) in a cohort of HIV-infected adults in a rural HIV care centre in Sihanoukville, Cambodia. Methods:Retrospective and descriptive cohort study of adults starting ART between December 2004 and July 2009. We used the Kaplan–Meier and Cox regression survival analyses to identify predictors of death. Results:Out of 1002 patients, 49.7% were men; median age was 40; median time of follow-up was 2.4 years and 10.4% died during the follow-up. At baseline, median CD4 cell count was 83 cells/&mgr;l, 79.9% were at WHO stage III or IV. In multivariate analysis, malnutrition appeared to be a strong and independent risk factor of death; 11.2% had a BMI less than 16 kg/m2 and hazard ratio was 6.97 [95% confidence interval (CI), 3.51–13.89], 21.5% had a BMI between 16 and 18 kg/m2 and hazard ratio was 2.88 (95% CI, 1.42–5.82), 30.8% had a BMI between 18 and 20 kg/m2 and hazard ratio was 2.18 (95% CI, 1.09–4.36). Severe anaemia (haemoglobin ⩽8.4 g/dl) and CD4 cell count below 100 cells/&mgr;l also predicted mortality, hazard ratio were 2.25 (95% CI, 1.02–4.34) and 2.29 (95% CI, 1.01–2.97), respectively. Social determinants were not significantly associated with death in univariate analysis. Conclusion:Malnutrition and anaemia are strong and independent prognostic factors at the time of starting ART. Nutritional cares are essential for the clinical success of HIV programs started in developing countries.