Risk factors for nasopharyngeal carriage of drug-resistant Streptococcus pneumoniae: data from a nation-wide surveillance study in Greece

<p>Abstract</p> <p>Background</p> <p>A nation-wide surveillance study was conducted in Greece in order to provide a representative depiction of pneumococcal carriage in the pre-vaccination era and to evaluate potential risk factors for carriage of resistant strains in healthy preschool children attending daycare centers.</p> <p>Methods</p> <p>A study group was organized with the responsibility to collect nasopharyngeal samples from children. Questionnaires provided demographic data, data on antibiotic consumption, family and household data, and medical history data. Pneumococcal isolates were tested for their susceptibility to various antimicrobial agents and resistant strains were serotyped.</p> <p>Results</p> <p>Between February and May 2004, from a total population of 2536 healthy children, a yield of 746 pneumococci was isolated (carriage rate 29.41%). Resistance rates differed among geographic regions. Recent antibiotic use in the last month was strongly associated with the isolation of resistant pneumococci to a single or multiple antibiotics. Serotypes 19F, 14, 9V, 23F and 6B formed 70.6% of the total number of resistant strains serotyped.</p> <p>Conclusion</p> <p>Recent antibiotic use is a significant risk factor for the colonization of otherwise healthy children's nasopharynx by resistant strains of <it>S pneumoniae</it>. The heptavalent pneumococcal conjugate vaccine could provide coverage for a significant proportion of resistant strains in the Greek community. A combined strategy of vaccination and prudent antibiotic use could provide a means for combating pneumococcal resistance.</p

Is Sustained Virological Response a Marker of Treatment Efficacy in Patients with Chronic Hepatitis C Viral Infection with No Response or Relapse to Previous Antiviral Intervention?

Background: Randomised clinical trials (RCTs) of antiviral interventions in patients with chronic hepatitis C virus (HCV) infection use sustained virological response (SVR) as the main outcome. There is sparse information on long-term mortality from RCTs.  Methods: We created a decision tree model based on a Cochrane systematic review on interferon retreatment for patients who did not respond to initial therapy or who relapsed following SVR. Extrapolating data to 20 years, we modelled the outcome from three scenarios: (1) observed medium-term (5 year) annual mortality rates continue to the long term (20 years); (2) long-term annual mortality in retreatment responders falls to that of the general population while retreatment non-responders continue at the medium-term mortality; (3) long-term annual mortality in retreatment non-responders is the same as control group non-responders (i.e., the increased treatment-related medium mortality “wears off”).  Results: The mean differences in life expectancy over 20 years with interferon versus control in the first, second, and third scenarios were -0.34 years (95% confidence interval (CI) -0.71 to 0.03), -0.23 years (95% CI -0.69 to 0.24), and -0.01 (95% CI -0.3 to 0.27), respectively. The life expectancy was always lower in the interferon group than in the control group in scenario 1. In scenario 3, the interferon group had a longer life expectancy than the control group only when more than 7% in the interferon group achieved SVR.  Conclusions: SVR may be a good prognostic marker but does not seem to be a valid surrogate marker for assessing HCV treatment efficacy of interferon retreatment. The SVR threshold at which retreatment increases life expectancy may be different for different drugs depending upon the adverse event profile and treatment efficacy. This has to be determined for each drug by RCTs and appropriate modelling before SVR can be accepted as a surrogate marker

Effect of heptavalent pneumococcal conjugate vaccination on invasive pneumococcal disease in preterm born infants

<p>Abstract</p> <p>Background</p> <p>Evidence for protection of preterm born infants from invasive pneumococcal disease (IPD) by 7-valent pneumococcal conjugate vaccination (PCV7) is relatively sparse. Data from randomized trials is based on relatively small numbers of preterm born children.</p> <p>Methods</p> <p>We report data from active prospective surveillance of IPD in children in Germany. The cohorts of preterm born children in 2000 and 2007 and the respective whole birth cohorts are compared regarding occurrence of IPD.</p> <p>Results</p> <p>After introduction of PCV7 we observed a reduction in the rate of IPD in preterm born infants comparing the 2000 and 2007 birth cohort. The rate of IPD among the whole birth cohorts was reduced from 15.0 to 8.5 notifications per 100,000 (<it>P </it>< .001). The impact among the preterm birth cohort was comparable: A reduction in notification rate from 26.1 to 16.7 per 100,000 comparing the 2000 with the 2007 preterm birth cohort (<it>P </it>= .39). Preterm born infants with IPD were either unvaccinated or vaccinated delayed or incomplete.</p> <p>Conclusions</p> <p>This adds to evidence that PCV7 also protects preterm born infants effectively from IPD. Preterm born infants should receive pneumococcal vaccination according to their chronological age.</p

Prevalence of Au-Ag and Au-Ab in transfused children with thalassaemia in Greece

The prevalence of Australia-antigen and -antibody was studied in 196 patients with thalassaemia, aged 10 months to 14 years. Au-Ag was detected in 14 patients (7%) and Au-Ab in 63 (32%). The prevalence of Au-Ag was in inverse relation to the age of the patients and in direct relation to the number of units of transfused blood. By contrast, the prevalence of Au-Ab was directly related to both the age and the number of transfused blood units. Au-Ab was detected in 61 % of patients who had received more than 60 units of blood, but in only 11 % of patients who had received less than 20 units. No sex difference was found in the prevalence of Au-Ag and Au-Ab. Only 2 patients with Au-Ag were without clinical or biochemical evidence of hepatitis; in all the remaining 12 patients Au-Ag persisted throughout the period of observation of from 5 to 18 months. During the same period Au-Ab was found to persist in all patients in whom it was detected. The persistence of Au-Ag and the synthesis of Au-Ab appear to be related to (a) repeated infection with type B virus and (b) the host&apos;s immune response

Inflammatory myofibroblastic tumor of the liver due to Mycobacterium tuberculosis in an immunocompetent girl

The case of a 9-year-old girl with a Mycobacterium tuberculosis inflammatory myofibroblastic tumor (IMT) of the left lobe of the liver is reported. The tumor was surgically excised and had histological features diagnostic of IMT, a positive Ziehl-Nielsen staining for acid-fast bacilli and a positive polymerase chain reaction for Mycobacterium tuberculosis. Surgical excision of the tumor followed by anti-tuberculosis treatment for 9 months resulted in full recovery. The patient had no apparent immune disorder, and there was no evidence of extrahepatic tuberculosis. These findings make this case exceptional because IMTs, due mostly to atypical mycobacteria, have been described only in immunocompromised patients

Pertusssis seroprevalence in different age groups in Greece

In order to target the appropriate age population for booster vaccination, we examined the antibody titres against pertussis toxin (PT) in different age groups in immunized and non-immunized individuals. In the immunized population, the highest anti-PT levels were observed in the 0- to 2-y age group and the lowest in the teenager and young adult groups. In contrast, in the control group, anti-PT levels were minimal in infants and young children, increasing in adolescence and early adulthood, and waning after 30 y of age. Antibody levels &gt;30 U/ml were observed with higher frequency in children &lt;2 y of age, in individuals with complete vaccination history and in non-immunized individuals. These findings may have important implications in optimizing vaccination policies

Evaluation of imipenem/imipenem+EDTA disk method for detection of metallo-β-lactamase-producing Klebsiella pneumoniae isolated from blood cultures

The objective of this study was to evaluate the imipenem (IMP) and IMP+EDTA (IMP/IMP+EDTA) disk method for the detection of metallo-β-lactamases (MBLs) in clinical isolates of Klebsiella pneumoniae with various MIC levels to IMP. Forty-one blood isolates of K. pneumoniae with MIC to IMP ranging from ≤0.5 to ≥16 μg/ml were examined. The MICs were determined by VITEK-2 (bioMerieux Vitek two, France). Disks of 10 μg IMP with and without the addition of 0.5 M EDTA were used for the IMP/IMP+EDTA disk method. The E-test (AB Biodisk, Solna, Sweden) for MBL detection was also used. All isolates were examined for the blaVIM-1 gene by PCR and for clonality of VIM-1-producing isolates by pulsed-field gel electrophoresis (PFGE). All isolates with MIC values of IMP ≤0.5 μg/ml exhibited no differences in inhibition zone diameters (IZD) produced by IMP and IMP+EDTA disks, whereas the isolates with MICs ≥1 μg/ml showed an increase in IZD, ranging from 8 to 26 mm. AH isolates with MIC values of ≥1 μg/ml were found positive for the blaVIM-1 gene by PCR and for MBL production by the E-test, whereas none of isolates with MICs ≤0.5 μg/ml was found positive by any of the tests. DNA restriction fragments generated by PFGE of VIM-1-producing isolates were classified in four main types. The IMP/IMP+EDTA disk method is simple to perform, sensitive, and specific for detection of MBL-producing K. pneumoniae clinical isolates. K. pneumoniae isolates with MICs of IMP ≥1 μg/ml and/or IZD produced by IMP disk ≤19 mm should be tested for MBL production. © Mary Ann Liebert, Inc

Prevalence of macrolide resistance genes among staphylococci in Cyprus

The aims of the present study were to evaluate the frequency of macrolide-resistant staphylococci in Cyprus and to examine the phenotypic and genotypic characteristics of these isolates. Antimicrobial susceptibility testing was performed by broth microdilution method and the macrolide resistance determinants were detected by PCR. The relatedness among the isolates was examined by pulsed-field gel electrophoresis. Ninety-six (67.61%) of the 142 Staphylococcus aureus and 19 (59.4%) of the 32 coagulase-negative staphylococci were resistant to erythromycin. Among the 115 erythromycin-resistant staphylococci, 70 expressed the MLSB-inducible phenotype, 38 the MLSB-constitutive, and 7 the MS. The predominant genes associated with macrolide resistance were the ermA for S. aureus and the ermC for coagulase-negative staphylococci, detected in 90.62% and 47.37% of the isolates respectively. Dissemination of one clone carrying the ermA gene accounted for macrolide resistance in the majority of S. aureus isolates. © E.S.I.F.T. srl