Search

There is a global outbreak of infections due to Mycobacterium chimaera associated with cardiac surgery. The most serious infections involve prosthetic material implantation, and all have followed surgical procedures involving cardiopulmonary bypass. We describe a cluster of four cases following cardiac surgery at a tertiary referral centre in Sydney, Australia. We report novel clinical findings, including haemolysis and kidney rupture possibly related to immune reconstitution inflammatory syndrome. The positive effect of corticosteroids on haemodynamic function in two cases and the failure of currently recommended antimicrobial therapy to sterilise prosthetic valve material in the absence of surgery despite months of treatment are also critically examined. Positron emission tomography was positive in two cases despite normal transoesophageal echocardiograms. The proportion of cases with M. chimaera infection after aortic valve replacement (4/890, 0.45%; 95% confidence interval 0.18-1.15%) was significantly higher than after all other cardiothoracic surgical procedures (0/2433, 0%; 95% confidence interval 0-0.16%).

Background Diabetic foot infections (DFI) present a major morbidity, mortality and economic challenge for the tertiary health sector. However, lack of high quality evidence for specific treatment regimens for patients with DFIs may result in inconsistent management. This study aimed to identify DFI caseload proportion and patterns of clinical practice of Infectious Diseases (ID) Physicians and Trainees within Australia and New Zealand. Methods A cross-sectional online survey of Australian and New Zealand ID Physicians and Trainees was undertaken, to estimate the overall ID caseload devoted to patients with DFIs and assess clinicians’ management practices of patients with DFIs. Results Approximately 28% (142/499) of ID Physicians and Trainees from Australia and New Zealand responded to the survey. DFI made up 19.2% of all ID consultations. Involvement in multidisciplinary teams (MDT) was common as 77.5% (93/120) of those responding indicated their patients had access to an inpatient or outpatient MDT. Significant heterogeneity of antimicrobial treatments was reported, with 82 unique treatment regimens used by 102 respondents in one scenario and 76 unique treatment regimens used by 101 respondents in the second scenario. The duration of therapy and the choice of antibiotics for microorganisms isolated from superficial swabs also varied widely. Conclusions Patients with DFIs represent a significant proportion of an ID clinician’s caseload. This should be reflected in the ID training program. Large heterogeneity in practice between clinicians reflects a lack of evidence from well-designed clinical trials for patients with DFI and highlights the need for management guidelines informed by future trials. Electronic supplementary material The online version of this article (10.1186/s13047-018-0256-3) contains supplementary material, which is available to authorized users.

Background Antibiotic allergy labels have a direct impact on individual patient care and on the consumption of broad-spectrum antibiotics. Objective Our aim was to establish the prevalence of antibiotic allergies and to determine whether patients with documented antibiotic allergy labels received guideline concordant antimicrobial therapy. Additionally we wanted to evaluate the quality of allergy documentation in the medical record. Methods Prospective audit of all patients presenting to the Emergency Department of an adult teaching hospital in Sydney over a 4 month period. Documented allergy labels, diagnoses, antibiotic administration and outcomes were recorded. Appropriateness of antibiotic choice was based on the Australian National Antimicrobial Prescribing Survey. Results 9.9% of presentations had at least one antibiotic allergy recorded. Significantly more women than men had antibiotic allergies documented. One third of patients with documented antibiotic allergies were prescibed inappropriate antibiotic therapy and some had significant adverse events. Conclusions The documentation of antibiotic allergy labels and choice of antibiotic treatment can be significantly improved. Strategies to safely de-label people with documented allergies who are not truly allergic need to be implemented.

Increasing numbers of women are choosing to travel during pregnancy. In the presence of an altered immune state, exposure to certain microbes can be particularly harmful. We have undertaken a review of the literature in order to provide strategies to minimize the infectious disease risks of pregnant travel. Included is a discussion of common immunizing agents and their safety in pregnancy.

Asplenic or hyposplenic patients are at risk of fulminant sepsis. This entity has a mortality of up to 50%. The spectrum of causative organisms is evolving as are recommended preventive strategies, which include education, prophylactic and standby antibiotics, preventive immunizations, optimal antimalarial advice when visiting endemic countries and early management of animal bites. However, there is evidence that adherence to these strategies is poor. Consensus-updated guidelines have been developed to help Australian and New Zealand clinicians and patients in the prevention of sepsis in asplenic and hyposplenic patients.

Background Up to 25% of patients admitted to hospital have an antibiotic allergy label (AAL), most of which are towards penicillin. However, up to 90% of patients who claim to be allergic to penicillin are actually able to tolerate them1. Whilst skin testing is safe and efficacious in de-labeling patients with a penicillin allergy label, it is usually not widely available. Therefore, we investigated the feasibility of de-labeling based solely upon clinical grounds. Quality of allergy documentation and subsequent antibiotic use was also assessed. Methods This was a cross-sectional study assessing all patients admitted to a tertiary referral teaching hospital over a 5-month period in 2016. All newly admitted patients were prospectively screened for the presence of an antibiotic allergy documented in their electronic medical record. Unless unable to participate, patients were interviewed regarding the detailed nature of their antibiotic allergy. Information regarding allergy documentation, medical condition and antibiotic use was obtained from medical records. Results 3855 patients were screened, 553 (14.35%) had an AAL, and 352 were interviewed. There were 426 allergies, 276 (64.8%) towards a penicillin. Only 52% of patients had a convincing history consistent with antibiotic allergy, and 48% of these were mild cutaneous reactions. It was felt that de-labeling and direct re-challenge would be relatively safe in 70% (298/42) of AALs (if the mild cutaneous allergic group were included). In patients who were prescribed antibiotics during study admission, 25.6% (41/160) of antibiotic prescriptions in our cohort were found to be inappropriate in patients with AALs. Conclusion Direct re-challenge based upon clinical grounds appears to be a feasible clinical option in many patients with AALs and would allow de-labeling of these patients. The major barriers continue to be patient acceptance and risk of severe adverse reactions. Our study also found that major improvements could be made in the specific documentation of allergy and also in selection of guideline-recommended alternate antibiotics. 1. Joint Task Force on Practice Parameters. Drug Allergy: An Updated Practice Parameter. Ann Allergy Asthma Immunol. 2010; 105(4): p. 259–273. Disclosures All authors: No reported disclosures.

Background Allogeneic hematopoietic stem cell transplantation (alloHSCT) recipients are at high risk of invasive pneumococcal disease (IPD). We investigated the incidence and risk factors of IPD in alloHSCT recipients from 4 regional transplant centers over an 11-year period. This study aimed to inform future improvements in post-transplant care. Methods We conducted a retrospective nested 1:2 case–control study in patients aged ≥18 years who underwent alloHSCT between 2001 and 2011 in 4 major allogeneic transplant centers. Controls were matched with IPD cases on the basis of conditioning intensity and donor relationship (related or unrelated). Demographics and clinical characteristics of cases and controls were summarized. Univariate analysis of risk factors in matched case–control sets, and multivariate conditional logistic regression to control for confounding, were performed. Results In 23 alloHSCT recipients, 26 IPD episodes were identified. The cumulative incidence over 11 years was 2.3% (95% confidence interval [CI] 1.45–3.15) and the incidence density 956 per 100,000 transplant years of follow-up (95% CI 580–1321). Multivariate risk factor analysis and backwards elimination showed a significant positive association between mycophenolate mofetil (MMF), hyposplenism/asplenia, and IPD, whereas trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis for Pneumocystis jirovecii pneumonia (PJP) was associated with lower odds of IPD cases. Of alloHSCT recipients with IPD, 38.5% required intensive care, and, of deaths documented in cases over the period of review, 30% were attributable to IPD. Serotypes causing IPD matched currently available vaccines in 15/22 (68.1%) episodes. Conclusions The incidence of IPD in alloHSCT recipients is an important cause of morbidity and mortality, with rates of disease being many fold higher than the general population. Patients with evidence of hyposplenism/asplenia define a high-risk group in the alloHSCT population for IPD, and the independent association with IPD and MMF in the adjusted model from this study requires further evaluation. The occurrence of post-transplant IPD may be reduced by measures such as vaccination with both 13-valent and 23-valent pneumococcal vaccines. TMP/SMX prophylaxis for the prevention of PJP may offer incidental protection against IPD in alloHSCT recipients.

Objective To evaluate the immune status and vaccination needs of first-year medical students in relation to bloodborne viruses and common vaccine-preventable diseases. Design, setting and participants Survey of first-year medical students at the University of New South Wales, Sydney, NSW, attending a mandatory screening and vaccination clinic, 2002-2005. Main outcome measures Self-reported history of vaccination or natural infection; serological evidence of immunity to measles, mumps, rubella and varicella (presence of specific IgG) and hepatitis B (presence of hepatitis B virus surface antibodies) or infection with hepatitis B and C viruses and HIV; and Mantoux test results. Results 733 students attended the clinic (85% of those enrolled). Four students were positive for HBsAg and four had hepatitis C antibodies. None were HIV-positive. Twenty-nine per cent (216/733) were not immune to hepatitis B, 33% (238/724) to mumps, 26% (190/724) to measles, 13% (91/724) to rubella and 10% (75/724) to varicella. About 23% (91/237) needed further testing for tuberculosis. Immunity corresponded poorly with self-reported history of vaccination. More students reported vaccination against rubella (96%), measles (81%) and mumps (80%) than were immune, and fewer reported vaccination against hepatitis B (44%). Conclusions Many students were not immune to vaccine-preventable diseases, and a small number had a previously undiagnosed bloodborne virus infection (hepatitis B or C). The level of immunity to vaccine-preventable infections was unacceptable and justified the provision of an easily accessible program for screening and vaccination.

Human infection by Cryptococcus neoformans var. neoformans is well characterised and usually occurs in immunocompromised patients. Less is known about infection by Cryptococcus neoformans var. gattii, which usually produces disease in previously normal individuals. In two cases of human pulmonary infection by Cryptococcus neoformans var. gattii, we observed a mixed inflammatory pattern, including granulomas associated with numerous T lymphocytes and a lymphocytic interstitial pneumonitis with B lymphocytes and formation of follicles. We also established a murine model of pulmonary infection by Cryptococcus neoformans var. gattii, which reproduced most of these features. This model is likely to prove useful in studies of the pathogenesis of this infection.

A case of necrotizing cutaneous infection in an immunocompetent host caused by the dematiaceous fungus, Curvularia brachyspora is presented. A 58-year-old man was transferred to the Prince Henry Hospital for treatment of necrotizing cellulitis involving both thighs that developed following cryotherapy. The patient did not respond to antibacterial therapy and hyperbaric oxygen. He was empirically commenced on intravenous amphotericin B and began to respond even before the pathogen C. brachyspora was identified.

The diagnosis of vertebral osteomyelitis is easily missed, particularly for the elderly in whom signs of sepsis may not manifest. The case records of 20 patients with vertebral osteomyelitis who were treated at our hospital between January 1989 and April 1993 were reviewed. The average age of the patients was 72 years. Infection was most commonly due to intravenous cannula-related sepsis. Eighty-five percent of patients presented with back pain, and only 30% had a fever. Computerized tomography and magnetic resonance imaging were the most useful radiological investigations; nuclear scanning was sensitive but insufficiently specific. Staphylococcus aureus was the infecting organism in 13 of 16 patients whose microbiological diagnosis was made by blood or bone cultures. Six (45%) of these 13 patients were infected with methicillin-resistant S. aureus (MRSA). Nosocomial infection occurred in 12 (60%) of the patients studied, including all patients with MRSA infections. Vertebral osteomyelitis may be largely preventable if infection-control aspects of intravenous cannulation are improved, attempts at reducing and preventing MRSA colonization are made, and therapy for bacteremias is optimized.