Real-time polymerase chain reaction detection of methicillin-resistant Staphylococcus aureus: impact on nosocomial transmission and costs.

OBJECTIVES: To assess the impact of real-time polymerase chain reaction (PCR) detection of methicillin-resistant Staphylococcus aureus (MRSA) on nosocomial transmission and costs. DESIGN: Monthly MRSA detection rates were measured from April 1, 2000, through December 31, 2005. Time series analysis was used to identify changes in MRSA detection rates, and decision analysis was used to compare the costs of detection by PCR and by culture.Setting. A 1,200-bed, tertiary care hospital in Canada. PATIENTS: Admitted patients at high risk for MRSA colonization. MRSA detection using culture-based screening was compared with a commercial PCR assay. RESULTS: The mean monthly incidence of nosocomial MRSA colonization or infection was 0.37 cases per 1,000 patient-days. The time-series model indicated an insignificant decrease of 0.14 cases per 1,000 patient-days per month (95% confidence interval, -0.18 to 0.46) after the introduction of PCR detection (P=.39). The mean interval from a reported positive result until contact precautions were initiated decreased from 3.8 to 1.6 days (P<.001). However, the cost of MRSA control increased from Can$605,034 to Can$771,609. Of 290 PCR-positive patients, 120 (41.4%) were placed under contact precautions unnecessarily because of low specificity of the PCR assay used in the study; these patients contributed 37% of the increased cost. The modeling study predicted that the cost per patient would be higher with detection by PCR (Can$96) than by culture (Can$67). CONCLUSION: Detection of MRSA by the PCR assay evaluated in this study was more costly than detection by culture for reducing MRSA transmission in our hospital. The cost benefit of screening by PCR varies according to incidences of MRSA colonization and infection, the predictive values of the assay used, and rates of compliance with infection control measures.

Antibiotics for treating acute chest syndrome in people with sickle cell disease.

BACKGROUND: The clinical presentation of acute chest syndrome is similar whether due to infectious or non-infectious causes, thus antibiotics are usually prescribed to treat all episodes. Many different bacteria have been implicated as causative agents of acute chest syndrome. There is no standardized approach to antibiotic therapy and treatment is likely to vary from country to country. Thus, there is a need to identify the efficacy and safety of different antibiotic treatment approaches for people with sickle cell disease suffering from acute chest syndrome. OBJECTIVES: To determine whether an empirical antibiotic treatment approach (used either alone or in combination): (a) is effective in treating acute chest syndrome compared to placebo or standard treatment; (b) is safe in treating acute chest syndrome compared to placebo or standard treatment; (c) differs dependent on the regimen used in treating acute chest syndrome differ from each other with respect to efficacy and safety; and (d) varies between different age groups, regions or countries with respect to efficacy and safety. SEARCH STRATEGY: We searched The Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched the LILACS database (1982 to May 2006) and the website: http://www.clinicaltrials.gov (May 2006). Date of most recent search of the Haemoglobinopathies Trials Register: February 2007. SELECTION CRITERIA: We searched for published or unpublished randomised controlled trials. DATA COLLECTION AND ANALYSIS: Each author intended to independently extract data and assess trial quality by standard Cochrane Collaboration methodologies, but no eligible randomized controlled trials were identified. MAIN RESULTS: We were unable to find any randomised controlled trials on antibiotic treatment approaches for acute chest syndrome in people with sickle cell disease. AUTHORS' CONCLUSIONS: We were unable to identify randomised controlled trials on efficacy and safety of the antibiotic treatment approaches for people with sickle cell disease suffering from acute chest syndrome. Randomised controlled trials are needed to establish the optimum antibiotic treatment for this condition.

Impact and cost of infection control measures to reduce nosocomial transmission of extended-spectrum beta-lactamase-producing organisms in a non-outbreak setting.

We evaluated the impact of infection control interventions to reduce nosocomial extended-spectrum beta-lactamase (ESBL) transmission in a non-outbreak setting. This study was conducted at a tertiary 1200-bed hospital in Canada. The incidence of ESBLs was based on recovery of clinical isolates and assessed prospectively from 1999 to 2005. The incidence increased significantly from 0.28 to 0.67 per 1000 admissions during this period (P<0.001), reflecting an increase in the regional ESBL incidence from 1.32 to 9.28 per 100 000 population (P<0.001). Despite this increase, nosocomial ESBL rates increased only marginally, suggesting that infection control measures had an impact on nosocomial transmission. Infection control measures consisted of isolating all ESBL patients, as well as implementing the use of contact precautions for those with a high risk for transmission. The cost of these measures was CN$138 046.00 per year and CN$3191.83 per case admitted. A combination of control measures including active surveillance cultures, contact precautions for all colonized or infected patients and antimicrobial stewardship is required to significantly reduce the incidence of ESBLs.

Conjugate vaccines for preventing meningococcal C meningitis and septicaemia.

BACKGROUND: Meningococcal polysaccharide (MPLS) vaccines protect against Serogroup C disease, but do not produce an immune response in infants less than two years of age. This limitation can be overcome by linking C polysaccharide to carrier proteins ('conjugating'), to create meningococcal serogroup C conjugate (MCC) vaccines. In the absence of trial data, the immune response to vaccination has been considered to be a reasonable surrogate for vaccine protection. OBJECTIVES: To assess the immunogenicity, safety and efficacy of MCC vaccines for preventing meningitis and septicaemia. SEARCH STRATEGY: We searched the Cochrane Central Register Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2005); MEDLINE (1966 to September, Week 1 2005); and EMBASE (1990 to June 2005) and references of studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) in humans comparing MCC vaccines against a control vaccine or none. In the absence of any trials on vaccine efficacy, population-based observational studies about effectiveness were included. DATA COLLECTION AND ANALYSIS: Two authors independently screened the results of the literature searches, selected eligible studies, extracted the data and evaluated the quality of them. MAIN RESULTS: The studies showed that MCC vaccine was highly immunogenic in infants after two and three doses, in toddlers after one and two doses and in older age groups after one dose. In general higher titres were generated after MCC than after MPLS vaccines. Immunological hypo-responsiveness seen after repeated doses of MPLS vaccine may be overcome with MCC. Observational studies have documented a significant decline in meningococcal C disease in countries where MCC vaccines have been widely used. The timing of the vaccinations schedules, the specific conjugate used, and the vaccines given concomitantly or combined, may be important. AUTHORS' CONCLUSIONS: The MCC vaccine appears to be safe, immunogenic and able to induce immunological memory in all age groups. Observational studies strongly suggest that MCC is clinically effective.

Risk factors for mortality in Staphylococcus aureus bacteremia.

OBJECTIVE: To analyze risk factors for, and the role of methicillin resistance in, mortality in Staphylococcus aureus bacteremia. DESIGN: Nested case-control study. SETTING: General teaching hospital with a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains, in São Paulo, Brazil. PATIENTS: 136 patients over 14 years old with documented S aureus bacteremia. Those who died were compared with those who survived at least 14 days. RESULTS: Mortality within 14 days of bacteremia was 39% (53/136). Mean age was 47 years. Hospital-acquired bacteremia represented 86% (117/136) of episodes. In 26% (35/136), infection was related to an intravascular catheter and in 13% (17/136) to the respiratory tract. Septic shock occurred in 22% (30/136) of cases. MRSA was isolated in 66% (90/136). Multivariate analysis identified three variables that were significantly and independently associated with mortality: site of entry (lung, odds ratio [OR], 17.0; unknown, OR, 12.3; others, OR, 6.6); occurrence of shock (OR, 8.9), and resistance of S aureus to methicillin (OR, 4.2). CONCLUSION: Our study shows that S aureus bacteremia has a high mortality, especially when the lung is the source of infection and when shock develops; resistance to methicillin may be another risk factor for poor outcome.

Paracoccidioidomycosis associated with acquired immunodeficiency syndrome. Report of seven cases.

We report the clinical findings and evolution of seven patients (five men and two women), the majority of them intravenous drug users, with paracoccidioidomycosis associated to acquired immunodeficiency syndrome (AIDS). In four of the patients the paracoccidioidomycosis was restricted to the lung and in the three others was generalized with cutaneous involvement. Only two of them had lived recently in rural area, an indication of the possible reactivation of latent focal infection in the other five patients. The recognition of the role of cell-mediated immunity in host defense against Paracoccidioides brasiliensis leds to the prediction of a growing occurrence of the paracoccidioidomycosis-AIDS association in areas that are endemic for these diseases.