Laboratory identification of donor-derived coxsackievirus b3 transmission.

Unexpected donor-to-recipient infectious disease transmission is an important, albeit rare, complication of solid organ transplantation. Greater work and understanding about the epidemiology of these donor-derived transmissions is continually required to further mitigate this risk. Herein we present the first reported case of proven donor-derived transmission of coxsackievirus serogroup-3, an enterovirus, following solid organ transplant. Swift and effective communication between the organ donation agency, treating physicians, laboratory testing and notification ensured a coordinated approach. The resulting clinical syndromes in the organ recipients were mild. This case highlights the requirement for ongoing surveillance over a broad range of infecting pathogens that may present as a donor-derived infection.

Community-associated methicillin-resistant Staphylococcus aureus transmission in households of infected cases: a pooled analysis of primary data from three studies across international settings.

Diverse strain types of methicillin-resistant Staphylococcus aureus (MRSA) cause infections in community settings worldwide. To examine heterogeneity of spread within households and to identify common risk factors for household transmission across settings, primary data from studies conducted in New York (USA), Breda (The Netherlands), and Melbourne (Australia) were pooled. Following MRSA infection of the index patient, household members completed questionnaires and provided nasal swabs. Swabs positive for S. aureus were genotyped by spa sequencing. Poisson regression with robust error variance was used to estimate prevalence odds ratios for transmission of the clinical isolate to non-index household members. Great diversity of strain types existed across studies. Despite differences between studies, the index patient being colonized with the clinical isolate at the home visit (P < 0·01) and the percent of household members aged <18 years (P < 0·01) were independently associated with transmission. Targeted decolonization strategies could be used across geographical settings to limit household MRSA transmission.

Community-onset Staphylococcus aureus infections presenting to general practices in South-eastern Australia.

Community-acquired Staphylococcus aureus infections are a public health concern, yet little is known about infections that do not present to hospital. We identified community-onset S. aureus infections via specimens submitted to a community-based pathology service. Referring doctors confirmed eligibility and described infection site, severity and treatment. Isolates were characterized on antibiotic resistance, PFGE, MLST/SCCmec, and Panton-Valentine leukocidin (PVL), representing 106 community-onset infections; 34 non-multiresistant methicillin-resistant S. aureus (nmMRSA) (resistant to <3 non-ß-lactam antibiotics), 15 multiply antibiotic-resistant MRSA (mMRSA) and 57 methicillin-sensitive S. aureus (MSSA). Most (93%) were skin and soft tissue infections. PVL genes were carried by 42% of nmMRSA isolates [95% confidence interval (CI) 26-61] and 15% of MSSA (95% CI 8-28). PVL was associated with infections of the trunk, head or neck (56·4% vs. 24·3%, P=0·005) in younger patients (23 vs. 52 years, P<0·001), and with boils or abscesses (OR 8·67, 95% CI 2·9-26·2), suggesting underlying differences in exposure and/or pathogenesis.

Vancomycin minimum inhibitory concentration, host comorbidities and mortality in Staphylococcus aureus bacteraemia.

We reported an association between elevated vancomycin MIC and 30-day mortality in patients with Staphylococcus aureus bacteraemia (SAB), including patients with methicillin-susceptible S. aureus (MSSA) treated with flucloxacillin. A detailed analysis of comorbidities and disease severity scores in the same cohort of patients was performed to ascertain if unknown clinical parameters may have influenced these results. The association between elevated vancomycin MIC and 30-day mortality in SAB remained significant (p 0.001) on multivariable logistic regression analysis even when accounting for clinical factors. In addition, the association persisted when restricting analysis to patients with MSSA bacteraemia treated with flucloxacillin. This suggests that elevated vancomycin MIC is associated with but not causally linked to an organism factor that is responsible for increased mortality.

Long-term follow-up of contacts exposed to multidrug-resistant tuberculosis in Victoria, Australia, 1995-2010.

SETTING: The effectiveness of public health strategies following exposure to multidrug-resistant tuberculosis (MDR-TB) is not clear. OBJECTIVE: To perform long-term follow-up of MDR-TB contacts and review individual outcomes and management approaches. DESIGN: Retrospective review of MDR-TB contacts identified by the Victorian Department of Health from 1995 to 2010. Health records, including personal medical and pharmacy records and statewide clinical and laboratory TB databases, were searched to identify management strategies and individual outcomes. RESULTS: A total of 570 contacts of 47 MDR-TB cases were identified, with a total follow-up period of 3093 person-years of observation (PYO) since exposure. Of 570 contacts, 49 (8.6%) were considered likely to have been infected with Mycobacterium tuberculosis from index cases, and 11/49 (22.5%) of these were prescribed preventive therapy tailored to isolate susceptibility. No MDR-TB cases occurred in those receiving preventive treatment, while two cases were observed in those not treated (incidence 2878/100 000 PYO during the first 2 years post exposure). CONCLUSIONS: The risk of MDR-TB transmission to close contacts in this low-prevalence setting highlights the potential for public health strategies involving preventive treatment.

Doxycycline vs. macrolides in combination therapy for treatment of community-acquired pneumonia.

We assessed the comparative efficacy of empirical therapy with beta-lactam plus macrolide vs. beta-lactam plus doxycycline for the treatment of community-acquired pneumonia (CAP) among patients in the Australian Community-Acquired Pneumonia Study. Both regimens demonstrated similar outcomes against CAP due to either 'atypical' (Chlamydophila, Legionella or Mycoplasma spp.) or typical bacterial pathogens.

Intravascular large B cell lymphoma: an elusive cause of pyrexia of unknown origin diagnosed postmortem.

Intravascular large B cell lymphoma (IVLBCL) is a rare cause of pyrexia of unknown origin. Because of its protean clinical manifestations, diagnosis is elusive and is often made postmortem. We report here a case of IVLBCL that evaded diagnosis despite multiple investigations in vivo for pyrexia of unknown origin over a 5‐month period.

Association between severe pandemic 2009 influenza A (H1N1) virus infection and immunoglobulin G(2) subclass deficiency.

BACKGROUND: . Severe pandemic 2009 influenza A virus (H1N1) infection is associated with risk factors that include pregnancy, obesity, and immunosuppression. After identification of immunoglobulin G(2) (IgG(2)) deficiency in 1 severe case, we assessed IgG subclass levels in a cohort of patients with H1N1 infection. METHODS: Patient features, including levels of serum IgG and IgG subclasses, were assessed in patients with acute severe H1N1 infection (defined as infection requiring respiratory support in an intensive care unit), patients with moderate H1N1 infection (defined as inpatients not hospitalized in an intensive care unit), and a random sample of healthy pregnant women. RESULTS: Among the 39 patients with H1N1 infection (19 with severe infection, 7 of whom were pregnant; 20 with moderate infection, 2 of whom were pregnant), hypoabuminemia (P < .001), anemia (P < .001), and low levels of total IgG (P= .01), IgG(1) (P= .022), and IgG(2) (15 of 19 vs 5 of 20; P= .001; mean value +/- standard deviation [SD], 1.8 +/- 1.7 g/L vs 3.4 +/- 1.4 g/L; P= .003) were all statistically significantly associated with severe H1N1 infection, but only hypoalbuminemia (P= .02) and low mean IgG(2) levels (P= .043) remained significant after multivariate analysis. Follow-up of 15 (79%) surviving IgG(2)-deficient patients at a mean (+/- SD) of 90 +/- 23 days (R, 38-126) after the initial acute specimen was obtained found that hypoalbuminemia had resolved in most cases, but 11 (73%) of 15 patients remained IgG(2) deficient. Among 17 healthy pregnant control subjects, mildly low IgG(1) and/or IgG(2) levels were noted in 10, but pregnant patients with H1N1 infection had significantly lower levels of IgG(2) (P= .001). CONCLUSIONS: Severe H1N1 infection is associated with IgG(2) deficiency, which appears to persist in a majority of patients. Pregnancy-related reductions in IgG(2) level may explain the increased severity of H1N1 infection in some but not all pregnant patients. The role of IgG(2) deficiency in the pathogenesis of H1N1 infection requires further investigation, because it may have therapeutic implications.

Prospective comparison of the clinical impacts of heterogeneous vancomycin-intermediate methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-susceptible MRSA.

Although methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) strains with reduced susceptibility to vancomycin (RVS-MRSA; including vancomycin-intermediate S. aureus [VISA] and heterogeneous VISA [hVISA]) have been linked with vancomycin treatment failure, it is unclear whether they are more pathogenic than vancomycin-susceptible MRSA (VS-MRSA). We prospectively assessed patients with clinical MRSA isolates during a 10-month period to determine clinical status (infection versus colonization) and therapeutic outcome before correlating these findings with the results of detailed in vitro assessment of vancomycin susceptibility, including population analysis profile (PAP) testing. hVISA and VISA were defined by standard PAP criteria (area-under-the-curve ratio compared to that of the reference hVISA strain Mu3 [>or=0.9]) and routine CLSI criteria (vancomycin MIC, 4 to 8 microg/ml), respectively. Among the 117 patients assessed, 58 had RVS-MRSA isolates (56 hVISA and 2 VISA) and 59 had VS-MRSA isolates; the patient demographics and comorbidities were similar. RVS-MRSA was associated with a lower rate of infection than VS-MRSA (29/58 versus 46/59; P = 0.003), including a lower rate of bacteremia (3/58 versus 20/59, respectively; P < 0.001). The cure rates in RVS-MRSA and VS-MRSA groups were not statistically different (16/26 versus 31/42; P = 0.43), but the post hoc assessment of treatment regimes and study size made detailed conclusions difficult. The results of the macro method Etest correlated well with the PAP results (sensitivity, 98.3%, and specificity, 91.5%), but broth microdilution and our preliminary RVS-MRSA detection method correlated poorly. All isolates were susceptible to linezolid and daptomycin. These data suggest that detailed prospective laboratory identification of RVS-MRSA isolates may be of limited value and that, instead, such in vitro investigation should be reserved for isolates from patients who are failing appropriate anti-MRSA therapy.

High rates of fecal carriage of nonenterococcal vanB in both children and adults.

We examined the rate of fecal carriage of vanB in the absence of cultivable vancomycin-resistant enterococci in three distinct populations (children, community adults, and hemodialysis patients). Nonenterococcal vanB carriage was similarly high in hemodialysis patients (45%) and community adults (63%; P = 0.066) and significantly more common among community adults than children (27%; P = 0.001).

Low rates of cutaneous adverse reactions to alcohol-based hand hygiene solution during prolonged use in a large teaching hospital.

We assessed cutaneous adverse reactions (CARs) to alcohol-based hand rub (ABHR) after the introduction of a hand hygiene culture change program at our institution. CARs were infrequent among exposed health care workers (HCWs) (13/2,750; 0.47%; 1 CAR per 72 years of HCW exposure) and were not influenced by the duration or intensity of ABHR use but were associated with the presence of irritant contact dermatitis.

Diagnosis of Mycobacterium tuberculosis infection using ESAT-6 and intracellular cytokine cytometry.

Diagnosis of infection with Mycobacterium tuberculosis (MTB) using tuberculin skin testing (TST) is often hampered by prior Bacille Calmette-Guérin (BCG) vaccination. ESAT-6 is a protein that is expressed by MTB but absent in BCG. It has been postulated that it might be useful in distinguishing MTB-specific immune responses. This study measured CD4 T cell responder frequencies specific for ESAT-6 and the TST reagent purified protein derivative (PPD) in patients with tuberculosis (n = 16), controls with non-tuberculous pneumonia (n = 8) and normal subjects (n = 7). Responses were identified using the intracellular cytokine staining technique and flow cytometry on whole blood samples, and performed blinded to the patient condition. Antigen-specific CD4 cells were defined by CD69 positivity and one or more cytokine [interleukin (IL)-2, IL-4, IL-10, interferon (IFN)-gamma] and/or CD40L positivity. With ESAT-6 stimulation it was found that TB patients had significantly higher frequencies of IFN-gamma and CD40L-positive CD4 T cells compared to the normal group, while no significant differences were measured with PPD stimulation. A responder frequency of 0.01% or higher for at least one of the measured cytokines/CD40L was defined as a positive response. Using this criterion to compare the two patient groups, PPD had 100% sensitivity but 0% specificity while ESAT-6 had 100% sensitivity and 88% specificity. Use of MTB-specific proteins such as ESAT-6 in combination with intracellular cytokine staining and flow cytometry has the potential to identify individuals with MTB infection.

Molecular characterization of vanB elements in naturally occurring gut anaerobes.

Previously, we reported the isolation of 10 vancomycin-resistant gram-positive anaerobic bacilli carrying the vanB ligase gene from nine hemodialysis patients (S. A. Ballard et al., Antimicrob. Agents Chemother. 49:77-81, 2005; T. P. Stinear et al., Lancet 357:855-856, 2001). In the present study, the molecular and evolutionary relationship of the vanB resistance element within these 10 anaerobes and two vancomycin-resistant Enterococcus faecium strains were examined. PCR analysis and nucleotide sequencing demonstrated that all 12 isolates carried the vanB operon associated with an element identical to Tn1549 and Tn5382 of Enterococcus. Restriction fragment length polymorphism analysis of the vanB operon in these isolates revealed two distinct patterns, and sequencing showed that minor base differences existed. PCR amplification of the joint region of a circular intermediate was demonstrated in nine of these organisms, a finding indicative of an ability to excise and circularize, an intermediate step in transposition and conjugative transfer. Southern hybridization with a vanB-vanX(B) probe suggests that there is one insert of the transposon in all isolates. Sequence analysis of the integration site revealed distinct sequences: the Tn1549/5382 element within E. faecium was inserted within the host chromosome, whereas nucleotide sequences surrounding the Tn1549/5382 element in the 10 anaerobes showed no significant homology to sequences in the GenBank database. We demonstrate considerable similarity between the Tn1549/5382 element identified in 10 anaerobe isolates with that found in enterococci. The homology and potential to transpose suggest a recent horizontal transfer event may have occurred. However, the original direction of transposition and the mechanism involved remains unknown.

Low-level vancomycin resistance in Staphylococcus aureus--an Australian perspective.

Low-level vancomycin resistance in Staphylococcus aureus has emerged as a clinical problem over the past 8 years. The clinical relevance of this resistance has been questioned, and laboratory detection remains difficult and time consuming. There is, however, increasing evidence linking low-level vancomycin resistance with glycopeptide treatment failure in serious Staphylococcus aureus infections. Diagnostic laboratories and clinicians need to be aware of this resistance phenotype, to have procedures in place to detect the resistance, and to have strategies for managing patients with infections caused by resistant strains.

Comparison of three PCR primer sets for identification of vanB gene carriage in feces and correlation with carriage of vancomycin-resistant enterococci: interference by vanB-containing anaerobic bacilli.

We assessed the sensitivities and specificities of three previously described PCR primers on enrichment broth cultures of feces for the accurate detection of fecal carriage of vancomycin-resistant enterococci (VRE). In addition, we investigated specimens that were vanB PCR positive but VRE culture negative for the presence of other vanB-containing pathogens. Feces from 59 patients (12 patients carrying vanB Enterococcus faecium strains and 47 patients negative for VRE carriage) were cultured for 36 h in aerobic brain heart infusion (BHI) broth, anaerobic BHI (AnO(2)BHI) broth, or aerobic Enterococcosel (EC) broth. DNA was extracted from the cultures and tested for the presence of vanB by using the PCR primers of Dutka-Malen et al. (S. Dutka-Malen, S. Evers, and P. Courvalin, J. Clin. Microbiol. 33:24-27, 1995), Bell et al. (J. M. Bell, J. C. Paton, and J. Turnidge, J. Clin. Microbiol. 36:2187-2190, 1998), and Stinear et al. (T. P. Stinear, D. C. Olden, P. D. R. Johnson, J. K. Davies, and M. L. Grayson, Lancet 357:855-856, 2001). The sensitivity (specificity) of PCR compared with the results of culture on BHI, AnO(2)BHI, and EC broths were 67% (96%), 50% (94%), and 17% (100%), respectively, with the primers of Dutka-Malen et al.; 92% (60%), 92% (45%), and 92% (83%), respectively, with the primers of Bell et al.; and 92% (49%), 92% (43%), and 100% (51%) respectively, with the primers of Stinear et al. The primers of both Bell et al. and Stinear et al. were significantly more sensitive than those of Dutka-Malen et al. in EC broth (P = 0.001 and P < 0.001, respectively). The poor specificities for all primer pairs were due in part to the isolation and identification of six anaerobic gram-positive bacilli, Clostridium hathewayi (n = 3), a Clostridium innocuum-like organism (n = 1), Clostridium bolteae (n = 1), and Ruminococcus lactaris-like (n = 1), from five fecal specimens that were vanB positive but VRE culture negative. All six organisms were demonstrated to contain a vanB gene identical to that of VRE. VanB-containing bowel anaerobes may result in false-positive interpretation of PCR-positive fecal enrichment cultures as VRE, regardless of the primers and protocols used.

Treatment and outcome of 104 hospitalized patients with legionnaires' disease.

BACKGROUND: Large outbreaks of Legionella pneumonia are rare, but when they occur provide an opportunity to assess predictors of mortality and efficacy of drug therapy. Although erythromycin has been the treatment of choice for many years, newer antimicrobials with increased activity against Legionella are available. A large outbreak of legionnaires' disease associated with the Melbourne Aquarium occurred in April 2000. AIM: To describe the patterns and impact of Legionella therapy, and predictors of outcome in a large group of hospitalized patients with legionnaires' disease. METHODS: A 6-month retrospective audit of hospitalized patients with proven legionnaires' disease around the time of the Melbourne Aquarium outbreak was conducted. Statistical analysis was performed using SAS version 8.0 (SAS Institute Inc., NC, USA). RESULTS: Data were obtained on 104 patients (71 aquarium related, 33 not related). There were six deaths (mortality rate 5.8%), three of which were attributable directly to progressive legionnaires' disease. The major predictors of death were pre-existing cardiac failure (P = 0.0035) and renal disease (P = 0.026). Erythro-mycin is still the most commonly used antibiotic (80% received i.v. erythromycin) with clinicians prescribing more than one active Legionella drug in the majority of cases (76%). Choice of initial antibiotic therapy did not statistically affect outcome as measured by death, length of hospital stay or time to defervescence, although there was a trend towards improved survival with i.v. erythromycin (P = 0.063). Intravenous erythromycin was associated with a 19% rate of phlebitis, whereas side-effects from other antibiotics were uncommon. CONCLUSION: The most commonly used Legionella therapy in Australia remains erythromycin. This continues to be an effective agent, however, side-effects are common.

Management of Aspergillus osteomyelitis: report of failure of liposomal amphotericin B and response to voriconazole in an immunocompetent host and literature review.

Presented here is a case of Aspergillus osteomyelitis in an immunocompetent patient that progressed despite surgery and prolonged treatment with liposomal amphotericin B; the report is followed by a review of the literature. The review of this case and 41 similar cases found an overall cure rate of 69%. The importance of surgery when amphotericin B is used as first-line therapy is indicated by a 14% cure rate when amphotericin B is used alone compared to 75% when combined with surgery. When therapy is failing or surgery is contraindicated, dose escalation using a lipid formulation was not effective. On review, the addition of another agent, in particular 5-fluorocytosine, appears to be more beneficial. The patient reported here responded rapidly to voriconazole, a promising new antifungal agent for Aspergillus infections.

Immunologic memory in Haemophilus influenzae type b conjugate vaccine failure.

AIMS: To compare the convalescent antibody response to invasive Haemophilus influenzae type b (Hib) disease between conjugate vaccine immunised and unimmunised children, to look for evidence of priming for immunologic memory. METHODS: Unmatched case-control study in the UK and Eire 1992-2001 and Victoria, Australia 1988-1990. A total of 93 children were identified as having invasive Hib disease following three doses of conjugate vaccine in infancy through post licensure surveillance throughout the UK and Eire; 92 unvaccinated children admitted to an Australian paediatric hospital with invasive Hib disease were used as historical controls. Convalescent serum was taken for measurement of Hib antibody concentration, and clinical information relating to potential disease risk factors was collected. The geometric mean concentrations of convalescent Hib antibodies were compared between immunised and unimmunised children, using raw and adjusted data. RESULTS: Hib conjugate vaccine immunised children had higher serum Hib antibody responses to disease (geometric mean concentration (GMC) 10.81 microg/ml (95% CI 6.62 to 17.66) than unimmunised children (1.06 microg/ml (0.61 to 1.84)) (p < 0.0001). However, following adjustment for the significant confounding influences of age at presentation and timing of serum collection, a difference persisted only in children presenting with meningitis (vaccinated GMC 3.78 microg/ml (2.78 to 5.15); unvaccinated GMC 1.48 microg/ml (0.90 to 2.21); p = 0.003). CONCLUSIONS: Higher antibody responses to invasive Hib disease in vaccinated children with meningitis reflect priming for immunologic memory by the vaccine. Although a majority of children in the UK are protected from Hib disease by immunisation, the relative roles of immunologic memory and other immune mechanisms in conferring protection remain unclear.