Duration of Methicillin-Resistant Staphylococcus aureus Carriage, According to Risk Factors for Acquisition

Objective. To examine the duration of methicillin-resistant Staphylococcus aureus (MRSA) carriage and its determinants and the influence of eradication regimens. Design. Retrospective cohort study. Setting. A 1,033-bed tertiary care university hospital in Bern, Switzerland, in which the prevalence of methicillin resistance among S. aureus isolates is less than 5%. Patients. A total of 116 patients with first-time MRSA detection identified at University Hospital Bern between January 1, 2000, and December 31, 2003, were followed up for a mean duration of 16.2 months. Results. Sixty-eight patients (58.6%) cleared colonization, with a median time to clearance of 7.4 months. Independent determinants for shorter carriage duration were the absence of any modifiable risk factor (receipt of antibiotics, use of an indwelling device, or presence of a skin lesion) (hazard ratio [HR], 0.20 [95% confidence interval {CI}, 0.09-0.42]), absence of immunosuppressive therapy (HR, 0.49 [95% CI, 0.23-1.02]), and hemodialysis (HR, 0.08 [95% CI, 0.01-0.66]) at the time MRSA was first MRSA detected and the administration of decolonization regimen in the absence of a modifiable risk factor (HR, 2.22 [95% CI, 1.36-3.64]). Failure of decolonization treatment was associated with the presence of risk factors at the time of treatment (P = .01). Intermittent screenings that were negative for MRSA were frequent (26% of patients), occurred early after first detection of MRSA (median, 31.5 days), and were associated with a lower probability of clearing colonization (HR, 0.34 [95% CI, 0.17-0.67]) and an increased risk of MRSA infection during follow-up. Conclusions. Risk factors for MRSA acquisition should be carefully assessed in all MRSA carriers and should be included in infection control policies, such as the timing of decolonization treatment, the definition of MRSA clearance, and the decision of when to suspend isolation measure

A New Multiantigen Immunoassay for the Quantification of IgG Antibodies to Capsular Polysaccharides of Streptococcus pneumoniae

A new nitrocellulose-based solid-phase multiantigen immunoassay (MAIA) for the detection of serum antibodies to Streptococcus pneumoniae capsular polysaccharides (PPSs) is presented. Evaluation with human sera showed that the MAIA test is reproducible, sensitive, and specific. It correlated well with a conventional ELISA method. The multiantigen strip system allowed quantification of antibodies against several PPS serotypes simultaneously and with a minimal amount of serum specimen. The presented solid-phase immunoassay for the quantification of anti-PPS antibodies seems to be a superior and attractive alternative to currently used ELISA tests and offers possibilities for standardizatio

Paediatric, invasive pneumococcal disease in Switzerland, 1985-1994

Background Costeffectiveuse of new vaccines against pneumococcal disease in children requires detailed information about the local epideniiology of pneumococcal infections. Methods Data on 393 culture-confirmed cases of invasive pneumococcal infection in children (<17 years) hospitalized in Swiss paediatric clinics were collected retrospectively for the years 1985-1994. Results Meningitis (42%) was most frequent, followed by pneumonia (28%) and bacteraeniia (26%). The overall annual incidence was 2.7 cases per 100 000 children <17 years old and 11 cases per 100 000 children <2 years old. Annual incidence rates were stable over the study period. Lethality was high for meningitis (8.6%) and bacteraemia (8.9%). A history of basal skull fracture was reported in 3.3% of children with pneurnococcal meningitis. Residence in a rural region was associated with an increased risk of pneumococcal infection (relative risk = 1.45, 95% confidence interval: 1.01-2.00). Conclusions Paediatric, invasive pneumococcal disease seems to be less frequent in Switzerland than in other European and non-European countries. This may be due to differences in diagnostic strategies and lower frequency of risk factors such as the use of day care. Children with a history of basal skull fracture are at increased risk for pneurnococcal meningitis. Further investigation of the association of invasive pneumococcal infection with rural residence and the use of antibiotics for upper respiratory tract infections might give new insight into the dynamics of Streptococcus pneumoniae infection and the development of antibiotic resistanc

Nationwide Surveillance of Nasopharyngeal Streptococcus pneumoniae Isolates from Children with Respiratory Infection, Switzerland, 1998-1999

The surveillance of pneumococcal antibiotic resistance and serotype distribution is hampered by the relatively low numbers of invasive pneumococcal infections. In Switzerland, a nationwide sentinel surveillance network was used to assess antibiotic resistance and serotype distribution among 1179 pneumococcal isolates cultured from 2769 nasopharyngeal swabs obtained from outpatients with acute otitis media or pneumonia during 1998 and 1999. The proportion of penicillin-susceptible pneumococcal isolates overall (87%) and among infants <2 years old (81%) was comparable to that of invasive isolates (90% and 81%, respectively). The high number of nasopharyngeal isolates allowed for the detection of a rapid increase in the number of penicillin-nonsusceptible pneumococcal (PNSP) strains in the West region of Switzerland, partly because of an epidemic caused by the 19F clone of Streptococcus pneumoniae. Clustering of risk factors for the carriage of PNSP isolates further explained the geographic variation in resistance rates. The nationwide sentinel surveillance of nasopharyngeal pneumococcus proved to be valuable for the monitoring of antibiotic resistance, risk factors for carriage of PNSP isolates, and serotype distribution and for the detection of the emergence of a new epidemic clon

Treatment of Joint Prosthesis Infection in Accordance with Current Recommendations Improves Outcome

Background. Recently recommended treatment modalities for prosthetic joint infection (PJI) were evaluated. Methods. A retrospective cohort analysis of 68 patients with PJI of hip or knee who were treated from 1995 through 2004 was conducted at the University Hospital Bern (Bern, Switzerland). Results. A 2-stage exchange was the most frequent (75.0%) surgical strategy, followed by retention and/or debridement (17.6%), 1-stage exchange (5.9%), and resection arthroplasty or suppressive antimicrobial treatment (1.5%). The chosen strategy was in 88% agreement with the recommendations. Adherence was only 17% for retention and/or debridement and was 0% for 1-stage exchange. Most PJIs (84%) were treated with an adequate or partially adequate antimicrobial regimen. Recurrence-free survival was observed in 51.5% of PJI episodes after 24 months of follow-up. The risk of treatment failure was significantly higher for PJI treated with a surgical strategy other than that recommended (hazard ratio, 2.34; 95% confidence interval, 1.10-4.70; P=.01) and for PJIs treated with antibiotics not corresponding to recommendations (hazard ratio, 3.45; confidence interval, 1.50-7.60; P=.002). Other risk factors associated with lack of healing were a high infection score at the time of diagnosis (hazard ratio, 1.29; 95% confidence interval, 1.10-1.40; P<.001) and presence of a sinus tract (hazard ratio, 2.35; 95% confidence interval, 1.10-5.0; P=.02). Conclusions. Our study demonstrates the value of current treatment recommendations. Inappropriate choice of conservative surgical strategies (such as debridement and retention) and inadequate antibiotic treatment are associated with failur

Randomized, Double-Blind Comparative Trial of Subunit and Virosomal Influenza Vaccines for Immunocompromised Patients

Background.. To our knowledge, no study to date has compared the effects of a subunit influenza vaccine with those of a virosomal influenza vaccine on immunocompromised patients. Methods.. A prospective, double-blind, randomized study was conducted to compare the immunogenicity and reactogenicity of subunit and virosomal influenza vaccines for adult patients who had an immunosuppressive disease or who were immunocompromised as a result of treatment. Results.. There were 304 patients enrolled in our study: 131 with human immunodeficiency virus (HIV) infection, 47 with a chronic rheumatologic disease, 74 who underwent a renal transplant, 47 who received long-term hemodialysis, and 5 who had some other nephrologic disease. There were 151 patients who received the subunit vaccine and 153 patients who received the virosomal vaccine. A slightly higher percentage of patients from the subunit vaccine group were protected against all 3 influenza vaccine strains after being vaccinated, compared with patients from the virosomal vaccine group (41% vs. 30% of patients; P=.03). Among HIV-infected patients, the level of HIV RNA, but not the CD4 cell count, was an independent predictor of vaccine response. Among renal transplant patients, treatment with mycophenolate significantly reduced the immune response to vaccination. The 2 vaccines were comparable with regard to the frequency and severity of local and systemic reactions within 7 days after vaccination. Disease-specific scores for the activity of rheumatologic diseases did not indicate flare-ups 4-6 weeks after vaccination. Conclusions.. For immunosuppressed patients, the subunit vaccine was slightly more immunogenic than the virosomal vaccine. The 2 vaccines were comparable with regard to reactogenicity. Vaccine response decreased with increasing degree of immune suppression. Among HIV-infected patients, the viral load, rather than the CD4 cell count, predicted the protective immune response to the vaccine. Clinical trials registration.. NCT0078338