Search

Most of the 233 worldwide cases of variant Creutzfeldt-Jakob disease (vCJD) have been reported in the United Kingdom and 3 have been associated with transfusion-transmission. To mitigate the potential vCJD risk to blood safety, Australian Red Cross Lifeblood imposes restrictions on blood donation from people with prior residency in, or extended travel to, the United Kingdom during the risk period 1980-1996. We have modified a previously published methodology to estimate the transfusion-transmission risk of vCJD associated with fresh component transfusion in Australia if the UK residence deferral was removed.The prevalence of current pre-symptomatic vCJD infection in the United Kingdom by age at infection and genotype was estimated based on risk of exposure to the bovine spongiform encephalopathy agent for the period 1980-1996. These results were used to estimate the age-specific prevalence of undiagnosed, pre-symptomatic vCJD in the Australian population in the current year due to prior UK residency or travel. The primary model outputs were the 2020 vCJD risks/unit of vCJD contamination, transfusion-transmission (infections) and clinical cases.The overall (prior UK residency in and travel to United Kingdom, 1980-1996) mean risk of contamination per unit was 1 in 29,900,000. The risks of resulting vCJD transmission (infection) and clinical case were 1 in 389,000,000 and 1 in 1,450,000,000, respectively.Our modelling suggests that removing the Lifeblood donation deferral for travel to, or UK residence, would result in virtually no increased risk of vCJD transfusion-transmission and would be a safe and effective strategy for increasing the donor base.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus first identified in late 2019 and subsequently declared a worldwide pandemic in March 2020. In this review, we provide an overview of the implications of SARS-CoV-2 for blood safety and sufficiency. Summary: Approximately one-third of SARS-CoV-2 infections are asymptomatic. The reported mean incubation period typically varies from 2 to 11 days, but longer periods up to 22 days have been reported. The blood phase of SARS-CoV-2 appears to be brief and low level, with RNAaemia detectable in only a small proportion of patients, typically associated with more severe disease and not demonstrated to be infectious virus. A small number of presymptomatic and asymptomatic blood phase cases have been reported. Transfusion-transmission (TT) of SARS-CoV-2 has not been reported. Therefore, the TT risk associated with SARS-CoV-2 is currently theoretical. To mitigate any potential TT risk, but more importantly to prevent respiratory transmission in donor centers, blood services can implement donor deferral policies based on travel, disease status, or potential risk of exposure and encourage staff vaccination. Key Messages: The TT risk of SARS-CoV-2 appears to be low. The biggest risk to blood services in the current COVID-19 pandemic is to maintain the sufficiency of the blood supply while minimizing respiratory transmission of SARS-CoV-2 to donors and staff while donating blood.

Several studies have described associations between ABO blood group and SARS-CoV-2 infection severity in hospitalized patients where group A individuals are over-represented and group O individuals may have a lower infection rate. In convalescent individuals, group B blood donors have higher neutralizing SARS-CoV-2 antibody titers. We analyzed whether there was any correlation of ABO Rh(D) blood group with SARS-CoV-2 infection and with neutralizing antibodies in Australian convalescent plasma (CP) donors.ABO Rh(D) distribution and demographics of CP donors (n = 765) were compared with the total blood donor panel (n = 488,028), plasmapheresis donors (n = 203,176) and whole blood donors (n = 282,437) from 2020. The presence of neutralizing antibodies in CP donors was measured using the Vero E6 cell microneutralization assay.The distribution of ABO group in CP donors compared to the total donor panel was not significantly different (p = .177). There were significantly more group AB donors in the plasmapheresis subset (p = .005) and group O individuals were over-represented in the whole blood donor subset (p .0001). There was no significant difference in neutralizing antibody levels among CP donors with differing ABO blood groups (p = .872).ABO Rh(D) blood group distribution was not found to be significantly different between convalescent plasma donors and general blood donors in our large sample group. Inherent blood donor selection biases associated with clinical demand accounted for some differences within CP donors. The levels of SARS-CoV-2 neutralizing antibodies were also not significantly associated with ABO Rh(D) group.

Australian Red Cross Lifeblood supplies pasteurised donor human milk (PDHM) to more than 30 partner hospitals across Australia. Preterm infants who receive PDHM are a highly vulnerable population but formal biovigilance programs are rare in human milk banking. Lifeblood Milk performs ongoing surveillance for both donor and recipient adverse events. This study aimed to formally review adverse events reported to Lifeblood Milk since 2018.Milk donor infectious diseases testing outcomes and donor adverse events (DAEs) are prospectively recorded at Lifeblood. Infant recipient adverse events are contractually reported back to Lifeblood Milk by hospitals and assessed according to severity and likelihood of relationship to PDHM administration. Donor and recipient adverse events over a 3.5-year period (July 2018 to December 2021) were reviewed.There were three DAEs (3/976 = 0.31%) related to phlebotomy; these included two vasovagal reactions and one phlebotomy site haematoma. Eight (8/976 = 0.81%) additional donors had biological false reactive (BFR) infectious diseases serology results. There were 10 reported suspected adverse events in recipients. Six were infection-related; other events included milk curd obstruction, high urinary iodine levels, sudden cardiac death and nasogastric tube obstruction. All reported suspected adverse events in recipients were classified as unlikely to be related, or definitely not related, to PDHM administration.Milk donor adverse events were rare but biological false reactive serology results were not uncommon. There were no recipient adverse events considered causally related to pasteurised donor human milk, which is generally a low-risk biological product. Ongoing biovigilance remains essential.

Objectives To estimate SARS‐CoV‐2‐specific antibody seroprevalence after the first epidemic wave of coronavirus disease 2019 (COVID‐19) in Sydney. Setting, participants People of any age who had provided blood for testing at selected diagnostic pathology services (general pathology); pregnant women aged 20–39 years who had received routine antenatal screening; and Australian Red Cross Lifeblood plasmapheresis donors aged 20–69 years. Design Cross‐sectional study; testing of de‐identified residual blood specimens collected during 20 April – 2 June 2020. Main outcome measure Estimated proportions of people seropositive for anti‐SARS‐CoV‐2‐specific IgG, adjusted for test sensitivity and specificity. Results Thirty‐eight of 5339 specimens were IgG‐positive (general pathology, 19 of 3231; antenatal screening, 7 of 560; plasmapheresis donors, 12 of 1548); there were no clear patterns by age group, sex, or location of residence. Adjusted estimated seroprevalence among people who had had general pathology blood tests (all ages) was 0.15% (95% credible interval [CrI], 0.04–0.41%), and 0.29% (95% CrI, 0.04–0.75%) for plasmapheresis donors (20–69 years). Among 20–39‐year‐old people, the age group common to all three collection groups, adjusted estimated seroprevalence was 0.24% (95% CrI, 0.04–0.80%) for the general pathology group, 0.79% (95% CrI, 0.04–1.88%) for the antenatal screening group, and 0.69% (95% CrI, 0.04–1.59%) for plasmapheresis donors. Conclusions Estimated SARS‐CoV‐2 seroprevalence was below 1%, indicating that community transmission was low during the first COVID‐19 epidemic wave in Sydney. These findings suggest that early control of the spread of COVID‐19 was successful, but efforts to reduce further transmission remain important.

Objectives: To determine the motivators and barriers to COVID-19 convalescent plasma donation by those in the United Kingdom who have been diagnosed with or who have had symptoms of SARS-CoV-2 (COVID-19) but who have not donated. Background: Convalescent plasma from people recovered from COVID-19 with sufficient antibody titres is a potential option for the treatment and prevention of COVID-19. However, to date, recruiting and retaining COVID-19 convalescent plasma donors has been challenging. Understanding why those eligible to donate COVID-19 convalescent plasma have not donated is critical to developing recruitment campaigns. Methods/Materials: A total of 419 UK residents who indicated that they had been infected with COVID-19 and who lived within 50 km of sites collecting COVID-19 convalescent plasma completed an online survey between 25th June and 5th July 2020. Respondents completed items assessing their awareness of convalescent plasma, motivations and barriers to donation and intention to donate COVID-19 convalescent plasma. Results: Awareness of COVID-19 convalescent plasma was low. Exploratory factor analysis identified six motivations and seven barriers to donating. A stronger sense of altruism through adversity and moral and civic duty were positively related to intention to donate, whereas generic donation fears was negatively related. Conclusions: Once potential donors are aware of convalescent plasma, interventions should focus on the gratitude and reciprocity that those eligible to donate feel, along with a focus on (potentially) helping family and norms of what people ought to do. Fears associated with donation should not be neglected, and strategies that have been successfully used tor recruit whole-blood donors should be adapted and deployed to recruit COVID-19 convalescent plasma donors.

Background As of mid-2021, Australia’s only nationwide coronavirus disease 2019 (COVID-19) epidemic occurred in the first 6 months of the pandemic. Subsequently, there has been limited transmission in most states and territories. Understanding community spread during the first wave was hampered by initial limitations on testing and surveillance. To characterize the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody seroprevalence generated during this time, we undertook Australia’s largest national SARS-CoV-2 serosurvey. Methods Between June 19 and August 6, 2020, residual specimens were sampled from people undergoing general pathology testing (all ages), women attending antenatal screening (20–39 years), and blood donors (20–69 years) based on the Australian population’s age and geographic distributions. Specimens were tested by Wantai total SARS-CoV-2-antibody assay. Seroprevalence estimates adjusted for test performance were produced. The SARS-CoV-2 antibody-positive specimens were characterized with microneutralization assays. Results Of 11 317 specimens (5132 general pathology; 2972 antenatal; 3213 blood-donors), 71 were positive for SARS-CoV-2-specific antibodies. Seroprevalence estimates were 0.47% (95% credible interval [CrI], 0.04%–0.89%), 0.25% (CrI, 0.03%–0.54%), and 0.23% (CrI, 0.04%–0.54%), respectively. No seropositive specimens had neutralizing antibodies. Conclusions Australia’s seroprevalence was extremely low (

A widespread outbreak of Japanese encephalitis virus (JEV) was detected in mainland Australia in 2022 in a previous non-endemic area. Given JEV is known to be transfusion-transmissible, a rapid blood-safety risk assessment was performed using a simple deterministic model to estimate the risk to blood safety over a 3-month outbreak period during which 234,212 donors attended. The cumulative estimated incidence in donors was 82 infections with an estimated 4.26 viraemic components issued, 1.58 resulting in transfusion-transmission and an estimated risk of encephalitis of 1 in 4.3 million per component transfused over the risk period. Australia has initiated a robust public health response, including vector control, animal control and movement, and surveillance. Unlike West Nile virus, there is an effective vaccine that is being rolled-out to those at higher risk. Risk evaluation considered options such as restricting those potentially at risk to plasma for fractionation, which incorporates additional pathogen reduction, introducing a screening test, physicochemical pathogen reduction, quarantine, post donation illness policy changes and a new donor deferral. However, except for introducing a new deferral to potentially cover rare flavivirus risks, no option resulted in a clear risk reduction benefit but all posed threats to blood sufficiency or cost. Therefore, the blood safety risk was concluded to be tolerable without specific mitigations.

Endoscopic procedures are vital to gastrointestinal disease diagnosis and management, but risk infection transmission. In Australia, endoscopes undergo monthly-to-quarterly microbiological testing, to prevent patient infection. Endoscopes are used more frequently, meaning contamination may not be detected by this surveillance before infection transmission occurs.To evaluate the use of adenosine triphosphate (ATP) measurement, alongside standard microbiological cultures, in detecting endoscope contamination before high-level disinfection. Using these results, we also aimed to confirm the efficacy of manual cleaning in reducing levels of ATP and cfu/mL.Seventeen in-clinical-use gastroscopes and 24 in-clinical-use colonoscopes from the Liverpool Hospital Endoscopy unit were sampled across three separate cleaning stages before high-level disinfection. Colony counts and ATP measurements were then performed on these samples.The correlation between the cfu/mL and RLU of samples collected from colonoscopes was 0.497 (95% confidence interval: 0.28-0.66; P 0.0001). The correlation between cfu/mL and RLU for samples collected from gastroscopes was 0.377 (0.08-0.61; P = 0.0138). RLU and cfu/mL values were shown to fall significantly (P 0.005) following precleaning and manual cleaning.There was a significant correlation between ATP and cfu/mL measured from samples collected before high-level disinfection. Precleaning and manual cleaning were shown to reduce ATP and microbiological load significantly. ATP measurement can be performed within minutes with little training and produces results that are easy to interpret. These findings warrant further research on the utility of ATP measurement as a screening tool for detecting endoscope contamination after high-level disinfection.

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antibody neutralization response and its evasion by emerging viral variants and variant of concern (VOC) are unknown, but critical to understand reinfection risk and breakthrough infection following vaccination. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus–cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 reverse transcription polymerase chain reaction (RT-PCR)–confirmed Coronavirus Disease 2019 (COVID-19) individuals with detailed demographics and followed up to 7 months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization, was associated with COVID-19 severity. A subgroup of “high responders” maintained high neutralizing responses over time, representing ideal convalescent plasma donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants and VOC. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal responders and vaccine monitoring and design.

Serological testing for SARS-CoV-2-specific antibodies provides important research and diagnostic information relating to COVID-19 prevalence, incidence and host immune response. A greater understanding of the relationship between functionally neutralising antibodies detected using microneutralisation assays and binding antibodies detected using scalable enzyme immunoassays (EIA) is needed in order to address protective immunity post-infection or vaccination, and assess EIA suitability as a surrogate test for screening of convalescent plasma donors. We assessed whether neutralising antibody titres correlated with signal cut-off ratios in five commercially available EIAs, and one in-house assay based on expressed spike protein targets. Sera from recovered patients or convalescent plasma donors who reported laboratory-confirmed SARS-CoV-2 infection (n = 200), and negative control sera collected prior to the COVID-19 pandemic (n = 100), were assessed in parallel. Performance was assessed by calculating EIA sensitivity and specificity with reference to microneutralisation. Neutralising antibodies were detected in 166 (83%) samples. Compared with this, the most sensitive EIAs were the Cobas Elecsys Anti-SARS-CoV-2 (98%) and Vitros Immunodiagnostic Anti-SARS-CoV-2 (100%), which detect total antibody targeting the N and S1 antigens, respectively. The assay with the best quantitative relationship with microneutralisation was the Euroimmun IgG. These results suggest the marker used (total Ab vs. IgG vs. IgA) and the target antigen are important determinants of assay performance. The strong correlation between microneutralisation and some commercially available assays demonstrates their potential for clinical and research use in assessing protection following infection or vaccination, and use as a surrogate test to assess donor suitability for convalescent plasma donation.

Background Total hip and total knee replacement (THR/TKR) are common and effective surgeries to reduce the pain and disability associated with arthritis but are associated with small but significant risks of preventable complications such as surgical site infection (SSI) and venous-thrombo-embolism (VTE). This study aims to determine the degree to which hospital care was compliant with clinical guidelines for the prevention of SSI and VTE after THR/TKR; and whether non-compliant prophylaxis is associated with increased risk of complications. Methods and findings A prospective multi-centre cohort study was undertaken in consenting adults with osteoarthritis undergoing elective primary TKR/THR at one of 19 high-volume Australian public or private hospitals. Data were collected prior to surgery and for one-year post-surgery. Four adjusted logistic regression analyses were undertaken to explore associations between binary non-compliance and the risk of surgical complications: (1) composite (simultaneous) non-compliance with both (VTE and antibiotic) guidelines and composite complications [all-cause mortality, VTE, readmission/reoperation for joint-related reasons (one-year) and non-joint-related reasons (35-days)], (2) VTE non-compliance and VTE outcomes, (3) antibiotic non-compliance and any SSI, and (4) antibiotic non-compliance and deep SSI. Data were analysed for 1875 participants. Guideline non-compliance rates were high: 65% (VTE), 87% (antibiotics) and 95% (composite guideline). Composite non-compliance was not associated with composite complication (12.8% vs 8.3%, adjusted odds ratio [AOR] = 1.41, 95%CI 0.68–3.45, p = 0.40). Non-compliance with VTE guidelines was associated with VTE outcomes (5% vs 2.4%, AOR = 2.83, 95%CI 1.59–5.28,p < 0.001). Non-compliance with antibiotic guidelines was associated with any SSI (14.8% vs 6.1%, AOR = 1.98, 95%CI 1.17–3.62,p = 0.02) but not deep infection (3.7% vs 1.2%,AOR = 2.39, 95%CI 0.85–10.00, p = 0.15). Conclusions We found high rates of clinical variation and statistically significant associations between non-compliance with VTE and antibiotic guidelines and increased risk of VTE and SSI, respectively. Complications after THR/TKR surgery may be decreased by improving compliance with clinical guidelines.

The SARS-CoV-2 antibody neutralization response and its evasion by emerging viral variants are unknown. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus-cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 RT-PCR-confirmed COVID-19 individuals with detailed demographics and followed up to seven months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization were associated with COVID-19 severity. A subgroup of ‘high responders’ maintained high neutralizing responses over time, representing ideal convalescent plasma therapy donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal plasma donors and vaccine monitoring and design.One Sentence SummaryNeutralizing antibody responses to SARS-CoV-2 are sustained, associated with COVID19 severity, and evaded by emerging viral variants

BackgroundSerological testing for SARS-CoV-2 specific antibodies provides important research and diagnostic information relating to COVID-19 prevalence, incidence, and host immune response. A greater understanding of the relationship between functionally neutralising antibodies detected using microneutralisation assays and binding antibodies detected using scalable enzyme immunoassays (EIA) is needed in order to address protective immunity post-infection or vaccination, and assess EIA suitability as a surrogate test for screening of convalescent plasma donors. We assessed whether neutralising antibody titres correlated with signal cut-off ratios in five commercially available EIAs, and one in-house assay based on expressed spike protein targets.MethodsSera from individuals recovered from patients or convalescent plasma donors who reported laboratory-confirmed SARS-CoV-2 infection (n=200), and negative control sera collected prior to the COVID-19 pandemic (n=100) were assessed in parallel. Performance was assessed by calculating EIA sensitivity and specificity with reference to microneutralisation.ResultsNeutralising antibodies were detected in 166 (83%) samples. Compared with this, the most sensitive EIAs were the Cobas Elecsys Anti-SARS-CoV-2 (98%) and Vitros Immunodiagnostic Anti-SARS-CoV-2 (100%), which detect total antibody targeting the N and S1 antigens, respectively. The assay with the best quantitative relationship with microneutralisation was the Euroimmun IgG.ConclusionsThese results suggest the marker used (total Ab vs IgG vs IgA), and the target antigen are important determinants of assay performance. The strong correlation between microneutralisation and some commercially available assays demonstrate their potential for clinical and research use in assessing protection following infection or vaccination, and use as a surrogate test to assess donor suitability for convalescent plasma donation.

Background and objective Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel coronavirus, first identified in China at the end of 2019 and has now caused a worldwide pandemic. In this review, we provide an overview of the implications of SARS-CoV-2 for blood safety and sufficiency. Material and method We searched the PubMed database, the preprint sites bioRxiv and medRxiv, the websites of the World Health Organization, European Centre for Disease Prevention and Control, the US Communicable Diseases Center and monitored ProMed updates. Results An estimated 15%-46% of SARS-CoV-2 infections are asymptomatic. The reported mean incubation period is 3 to 7 days with a range of 1-14 days. The blood phase of SARS-CoV-2 appears to be brief and low level, with RNAaemia detectable in only a small proportion of patients, typically associated with more severe disease and not demonstrated to be infectious virus. An asymptomatic blood phase has not been demonstrated. Given these characteristics of SARS-CoV-2 infection and the absence of reported transfusion transmission (TT), the TT risk is currently theoretical. To mitigate any potential TT risk, but more importantly to prevent respiratory transmission in donor centres, blood centres can implement donor deferral policies based on travel, disease status or potential risk of exposure. Conclusion The TT risk of SARS-CoV-2 appears to be low. The biggest risk to blood services in the current COVID-19 pandemic is to maintain the sufficiency of the blood supply while minimizing respiratory transmission of SARS-CoV-19 to donors and staff while donating blood.

Background and objectives Based on the Council of Europe directive which dictates regulatory requirements in Australia, blood donors are currently deferred from donating for 4 months after an endoscopic procedure if either polyps were removed or a biopsy sample was taken. We aimed to assess the incidence of blood-borne viruses (BBVs) (HIV, hepatitis B and C) in blood donors who donated after an endoscopic procedure and evaluate the risk to blood safety through risk modelling. Materials and methods Donors from 1/1/2013 to 31/12/2017 with an endoscopy deferral on their blood donor file with pre- and post-BBV testing were analysed to determine an incidence of BBVs using standard methods. The standard blood donor cohort was used as a comparator group. Using the incidence of endoscopies and BBV risk, the total residual risk estimate of allowing donors to return postendoscopy without restriction was calculated. Results The incidence of a BBV postendoscopy in this large cohort of 16,283 where testing has been confirmed postendoscopy was zero (95% CI 0-0·000105). The upper confidence interval of the zero events is 10·5 per 100 000 donations. Total positive donations from 2017 repeat donors were 1·87 per 100 000 (95% CI 0·0000117-0·0000277). Sensitivity analysis demonstrated that the residual risk remained negligible under realistic worst-case scenarios. Conclusion A BBV endoscopy deferral is not required for blood safety in Australia. The presented data has enabled us to submit a request for an exemption to our regulator, which has been approved and the policy change subsequently implemented by Lifeblood on 4/4/2020.

Summary Background The importance of biofilms to clinical practice is being increasingly realized. Biofilm tolerance to antibiotics is well described but limited work has been conducted on the efficacy of heat disinfection and sterilization against biofilms. Aim To test the susceptibility of planktonic, hydrated biofilm and dry-surface biofilm forms of Staphylococcus aureus, to dry-heat and wet-heat treatments. Methods S. aureus was grown as both hydrated biofilm and dry-surface biofilm in the CDC biofilm generator. Biofilm was subjected to a range of temperatures in a hot-air oven (dry heat), water bath or autoclave (wet heat). Findings Dry-surface biofilms remained culture positive even when treated with the harshest dry-heat condition of 100°C for 60 min. Following autoclaving samples were culture negative but 62–74% of bacteria in dry-surface biofilms remained alive as demonstrated by live/dead staining and confocal microscopy. Dry-surface biofilms subjected to autoclaving at 121°C for up to 30 min recovered and released planktonic cells. Recovery did not occur following autoclaving for longer or at 134°C, at least during the time-period tested. Hydrated biofilm recovered following dry-heat treatment up to 100°C for 10 min but failed to recover following autoclaving despite the presence of 43–60% live cells as demonstrated by live/dead staining. Conclusion S. aureus dry-surface biofilms are less susceptible to killing by dry heat and steam autoclaving than hydrated biofilms, which are less susceptible to heat treatment than planktonic suspensions.

Objectives Test the performance of topical antimicrobial wound solutions against microbial biofilms using in vitro, ex vivo and in vivo model systems at clinically relevant exposure times. Methods Topical antimicrobial wound solutions were tested under three different conditions: (in vitro) 4% w/v Melaleuca oil, polyhexamethylene biguanide, chlorhexidine, povidone iodine and hypochlorous acid were tested at short duration exposure times for 15 min against 3 day mature biofilms of Staphylococcus aureus and Pseudomonas aeruginosa; (ex vivo) hypochlorous acid was tested in a porcine skin explant model with 12 cycles of 10 min exposure, over 24 h, against 3 day mature P. aeruginosa biofilms; and (in vivo) 4% w/v Melaleuca oil was applied for 15 min exposure, daily, for 7 days, in 10 patients with chronic non-healing diabetic foot ulcers complicated by biofilm. Results In vitro assessment demonstrated variable efficacy in reducing biofilms ranging from 0.5 log10 reductions to full eradication. Repeated instillation of hypochlorous acid in a porcine model achieved

Increasing evidence within the literature has identified the presence of biofilms in chronic wounds and proposed that they contribute to delayed wound healing. This research aimed to investigate the presence of biofilm in diabetic foot ulcers (DFUs) using microscopy and molecular approaches and define if these are predominantly mono- or multi-species. Secondary objectives were to correlate wound observations against microscopy results in ascertaining if clinical cues are useful in detecting wound biofilm. DFU tissue specimens were obtained from 65 subjects. Scanning electron microscopy (SEM) and peptide nucleic acid fluorescent in situ hybridisation (PNA-FISH) techniques with confocal laser scanning microscopy (CLSM) were used to visualise biofilm structures. Next-generation DNA sequencing was performed to explore the microbial diversity. Clinical cues that included the presence of slough, excessive exudate, a gel material on the wound bed that reforms quickly following debridement, poor granulation and pyocyanin were correlated to microscopy results. Of the 65 DFU specimens evaluated by microscopy, all were characterised as containing biofilm (100%, P < 0·001). The presence of both mono-species and multi-species biofilms within the same tissue sections were detected, even when DNA sequencing analysis of DFU specimens revealed diverse polymicrobial communities. No clinical correlations were identified to aid clinicians in identifying wound biofilm. Microscopy visualisation, when combined with molecular approaches, confirms biofilms are ubiquitous in DFUs and form either mono- or multi-species biofilms. Clinical cues to aid clinicians in detecting wound biofilm are not accurate for use in DFUs. A paradigm shift of managing DFUs needs to consider anti-biofilm strategies.

Summary Background Broad-range 16S rRNA PCR can be used for the detection and identification of bacteria from clinical specimens in patients for whom there is a high suspicion of infection and cultures are negative. The aims of this study were (1) to compare 16S rRNA PCR results with microbiological culture results, (2) to assess the utility of 16S rRNA PCR with regard to antimicrobial therapy, and (3) to compare the yield of 16S rRNA PCR for different types of clinical specimen and to perform a cost analysis of the test. Methods A retrospective study was performed on different clinical specimens which had 16S performed over 3 years (2012–2015). Standard microbiological cultures were performed on appropriate media, as per the laboratory protocol. Patient clinical and microbiological data were obtained from the electronic medical records and laboratory information system, respectively. 16S rRNA PCR was performed in a reference laboratory using a validated method for amplification and sequencing. The outcomes assessed were the performance of 16S rRNA PCR, change of antimicrobials (rationalization, cessation, or addition), and duration of therapy. Concordance of 16S rRNA PCR with bacterial cultures was also determined for tissue specimens. Results Thirty-two patients were included in the study, for whom an equal number of specimens ( n =32) were sent for 16S rRNA PCR. 16S rRNA PCR could identify an organism in 10 of 32 cases (31.2%), of which seven were culture-positive and three were culture-negative. The sensitivity was 58% (confidence interval (CI) 28.59–83.5%) and specificity was 85% (CI 61.13–96%), with a positive predictive value of 70% (CI 35.3–91.9%) and negative predictive value of 77.2% (CI 54.17–91.3%). Antimicrobial therapy was rationalized after 16S rRNA PCR results in five patients (15.6%) and was ceased in four based on negative results (12.5%). Overall the 16S rRNA PCR result had an impact on antimicrobial therapy in 28% of patients (9/32). The highest concordance of 16S rRNA PCR with bacterial culture was found for heart valve tissue (80%), followed by joint fluid/tissue (50%). Conclusions Despite the low diagnostic yield, results of 16S rRNA PCR can still have a significant impact on patient management due to rationalization or cessation of the antimicrobial therapy. The yield of 16S rRNA PCR was highest for heart valves.

Objectives: The performance of cadexomer iodine was determined against microbial populations from chronic non-healing diabetic foot ulcers (DFUs) complicated by biofilm in vivo, using molecular, microscopy and zymography methods. Methods: Chronic non-healing DFUs due to suspected biofilm involvement were eligible for enrolment. DNA sequencing and real-time quantitative PCR was used to determine the microbial load and diversity of tissue punch biopsies obtained pre- and post-treatment. Scanning electron microscopy and/or fluorescence in situ hybridization confirmed the presence or absence of biofilm. Zymography was used to determine levels of wound proteases. Results: Seventeen participants were recruited over a 6 month period. Scanning electron microscopy and or fluorescence in situ hybridization confirmed the presence of biofilm in all samples. Eleven participants exhibited log10 reductions in microbial load after treatment (range 1–2 log10) in comparison with six patients who experienced

BACKGROUND Foodborne hepatitis A virus (HAV) outbreaks are becoming more common in high-income countries with low HAV incidence, and the associated blood safety risk may not be adequately mitigated by routine HAV risk mitigation strategies. This study describes the rapid risk modeling undertaken in response to a 2018 HAV outbreak in Australia associated with imported frozen pomegranate arils. STUDY DESIGN AND METHODS The input parameters used in the modeling were the outbreak-associated HAV incidence, duration of viremia, population seroprevalence, and rate of symptomatic infection in adults. The number and risk of viremic components issued, cases of transfusion transmission, and symptomatic infections among recipients were estimated. RESULTS The incidence of pomegranate-associated HAV infection among donors was very low, with fewer than 0.1 viremic fresh components estimated to have been released during the risk period. The risk of this event was less than one in 500,000, and the risks of transfusion transmission and symptomatic illness in recipients were less than one in one million. When considering only donors who had consumed the pomegranate product, the risk was much higher, with approximately one in 1000 components estimated to be viremic. CONCLUSION Rapid risk assessment indicated that the overall risk to blood safety associated with a small foodborne outbreak of HAV was negligible. Because fresh components collected from donors known to have consumed the affected product were at high risk, these donors were identified via signage in donor centers and deferred. The contribution of factors other than outbreak size to risk management decisions is discussed.

Pyrexia of unknown origin (PUO) is a syndrome that has long tested the skills of physicians to achieve a diagnosis in affected patients. By definition, patients included in this syndrome will be more difficult to diagnose as they have already resisted classification during baseline investigations. Furthermore, investigation of PUO requires knowledge of many diseases across a range of clinical specialties, as well as knowledge of less commonly used investigative tools. As both society and medicine continue to change, the aetiology and epidemiology of the diseases that cause PUO also change. For these reasons, it is important for physicians to approach PUO in a logical manner, and for the causes and approach to PUO to be continuously reviewed. In this article, we review the aetiology of PUO and the diagnostic strategies that may be used to investigate it.

Summary Background Dry hospital environments are contaminated with pathogenic bacteria in biofilms, which suggests that current cleaning practices and disinfectants are failing. Aim To test the efficacy of sodium hypochlorite solution against Staphylococcus aureus dry-surface biofilms. Methods The Centers for Disease Control and Prevention Biofilm Reactor was adapted to create a dry-surface biofilm, containing 1.36 × 10 7 S. aureus /coupon, by alternating cycles of growth and dehydration over 12 days. Biofilm was detected qualitatively using live/dead stain confocal laser scanning microscopy (CLSM), and quantitatively with sonicated viable plate counts and crystal violet assay. Sodium hypochlorite (1000–20,000parts per million) was applied to the dry-surface biofilm for 10min, coupons were rinsed three times, and residual biofilm viability was determined by CLSM, plate counts and prolonged culture up to 16 days. Isolates before and after exposure underwent minimum inhibitory concentration (MIC) and minimum eradication concentration (MEC) testing, and one pair underwent whole-genome sequencing. Findings Hypochlorite exposure reduced plate counts by a factor of 7 log 10 , and reduced biofilm biomass by a factor of 100; however, staining of residual biofilm showed that live S. aureus cells remained. On prolonged incubation, S. aureus regrew and formed biofilms. Post-exposure S. aureus isolates had MICs and MECs that were not significantly different from the parent strains. Whole-genome sequencing of one pre- and post-exposure pair found that they were virtually identical. Conclusions Hypochlorite exposure led to a 7-log kill but the organisms regrew. No resistance mutations occurred, implying that hypochlorite resistance is an intrinsic property of S. aureus biofilms. The clinical significance of this warrants further study.

Background The persistence of multidrug-resistant organisms (MDROs) within an intensive care unit (ICU) possibly contained within dry surface biofilms, remains a perplexing confounder and is a threat to patient safety. Identification of residential locations of MDRO within the ICU is an intervention for which new scientific approaches may assist in finding potential MDRO reservoirs. Method This study investigated a new approach to sampling using a more aggressive environmental swabbing technique of high-touch objects (HTOs) and surfaces, aided by 2 commercially available adenosine triphosphate (ATP) bioluminometers. Results A total of 13 individual MDRO locations identified in this pilot study. The use of ATP bioluminometers was significantly associated with the identification of 12 of the 13 individual MDRO locations. The MDRO recovery and readings from the 2 ATP bioluminometers were not significantly correlated with distinct cutoffs for each ATP device, and there was no correlation between the 2 ATP devices. Conclusion The specific MDRO locations were not limited to the immediate patient surroundings or to any specific HTO or type of surface. The use of ATP testing helped rapidly identify the soiled locations for MDRO sampling. The greatest density of positive MDRO locations was around and within the clinical staff work station.

Introduction During clinical use, gastrointestinal endoscopes are grossly contaminated with patient’s native flora. These endoscopes undergo reprocessing to prevent infectious transmission upon future use. Endoscopy-associated infections and outbreaks have been reported, with a recent focus on the transmission of multi-drug resistant organisms. This review aims to provide an update on endoscopy-associated infections, and the factors contributing to their occurrence. Methods PubMed, ScienceDirect, and CINAHL were searched for articles describing gastrointestinal endoscopy-associated infections and outbreaks published from 2008 to 2018. Factors contributing to their occurrence, and the outcomes of each outbreak were also examined. Results This review found 18 articles, 16 of which described duodenoscope-associated infections, and the remaining two described colonoscope- and gastroscope-associated infection respectively. Outbreaks were reported from the United States, France, China, Germany, the Netherlands and the United Kingdom. The causative organisms reported were Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella enteritidis. Conclusions A number of factors, including lapses in reprocessing, biofilm formation, endoscope design issues and endoscope damage, contribute to gastrointestinal endoscopy associated infection. Methods of improving endoscope reprocessing, screening for contamination and evaluating endoscope damage may be vital to preventing future infections and outbreaks.

Summary Background Hospital-associated infections cause considerable morbidity and mortality, and are expensive to treat. Organisms causing these infections can be sourced from the inanimate environment around a patient. Could the difficulty in eradicating these organisms from the environment be because they reside in dry surface biofilms? Aim The intensive care unit (ICU) of a tertiary referral hospital was decommissioned and the opportunity to destructively sample clinical surfaces was taken in order to investigate whether multidrug-resistant organisms (MDROs) had survived the decommissioning process and whether they were present in biofilms. Methods The ICU had two ‘terminal cleans' with 500ppm free chlorine solution; items from bedding, surrounds, and furnishings were then sampled with cutting implements. Sections were sonicated in tryptone soya broth and inoculated on to chromogenic plates to demonstrate MDROs, which were confirmed with the Vitek2 system. Genomic DNA was extracted directly from ICU samples, and subjected to polymerase chain reaction (PCR) for femA to detect Staphylococcus aureus and the microbiome by bacterial tag-encoded FLX amplicon pyrosequencing. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were performed on environmental samples. Findings Multidrug-resistant bacteria were cultured from 52% (23/44) of samples cultured. S. aureus PCR was positive in 50%. Biofilm was demonstrated in 93% (41/44) of samples by CLSM and/or SEM. Pyrosequencing demonstrated that the biofilms were polymicrobial and contained species that had multidrug-resistant strains. Conclusion Dry surface biofilms containing MDROs are found on ICU surfaces despite terminal cleaning with chlorine solution. How these arise and how they might be removed requires further study.

Background Aggregatibacter actinomycetemcomitans most commonly causes periodontitis but has been reported to infect heart valves, soft tissue, brain and lungs, and distal bones. Osteomyelitis distal to the jaw is rarely described. Case presentation We report an unusual and rare case of chronic osteomyelitis caused by A. actinomycetemcomitans in the toe of a paediatric patient, and review the available literature. The infection was managed with intravenous antibiotics followed by oral antibiotics. Conclusion This is an unusual presentation of A. actinomycetemcomitans causing chronic osteomyelitis presumed due to nidation in a minimally damaged bone, associated with bacteraemia of an oral commensal. It occurred in the toe, without obvious dental predisposition; associated with minimal clinical disturbance and with muted immune response.

Introduction: The concept of biofilms in human health and disease is now widely accepted as cause of chronic infection. Typically, biofilms show remarkable tolerance to many forms of treatments and the host immune response. This has led to vast increase in research to identify new (and sometimes old) anti-biofilm strategies that demonstrate effectiveness against these tolerant phenotypes.Areas covered: Unfortunately, a standardized methodological approach of biofilm models has not been adopted leading to a large disparity between testing conditions. This has made it almost impossible to compare data across multiple laboratories, leaving large gaps in the evidence. Furthermore, many biofilm models testing anti-biofilm strategies aimed at the medical arena have not considered the matter of relevance to an intended application. This may explain why some in vitro models based on methodological designs that do not consider relevance to an intended application fail when applied in vivo at the clinical level.Expert commentary: This review will explore the issues that need to be considered in developing performance standards for anti-biofilm therapeutics and provide a rationale for the need to standardize models/methods that are clinically relevant. We also provide some rational as to why no standards currently exist.

Objectives: To investigate the genetic context associated with the emergence of vanA VRE in Australia. Methods: The whole genomes of 18 randomly selected vanA-positive Enterococcus faecium patient isolates, collected between 2011 and 2013 from hospitals in four Australian capitals, were sequenced and analysed. Results: In silico typing and transposon/plasmid assembly revealed that the sequenced isolates represented (in most cases) different hospital-adapted STs and were associated with a variety of different Tn1546 variants and plasmid backbone structures. Conclusions: The recent emergence of vanA VRE in Australia was polyclonal and not associatedwith the dissemination of a single 'dominant' ST or vanA-encoding plasmid. Interestingly, the factors contributing to this epidemiological change are not known and future studies may need to consider investigation of potential community sources.

Approximately 39% of methicillin-resistant Staphylococcus aureus (MRSA) sequence type 239 (ST239)-like bloodstream isolates from Liverpool Hospital (obtained between 1997 and 2008) carry an arginine catabolic mobile element (ACME). Whole-genome sequencing revealed that an ACME II variant is located between orfX and SCC mec III, and based on pulsed-field gel electrophoresis patterns and temporal relationships of all ST239-like isolates ( n = 360), ACME carriage may have contributed to subpulsotype strain replacement.

Staphylococcus aureus is an important pathogen involved in infections in both the community and hospital setting. Strains that are resistant to multiple classes of antibiotics, particularly methicillin-resistant strains (MRSA), are prevalent in nosocomial infections and are associated with high morbidity and mortality rates. Such antibiotic-resistant strains limit the therapeutic options and place a burden on the health care system. In the hospital setting, horizontal gene transfer plays an important role in disseminating antibiotic resistant determinants among S. aureus. However, resistance to all known classes of antibiotics have been attributed to genes found within the S. aureus chromosome or to due to mutation as a result of selection pressure. Spontaneous mutations, in particular, are pivotal in the emergence of novel resistances. Consequently, newer drugs with better activity and/or antibacterial agents with novel targets need to be developed to combat and control the further spread of antibiotic resistance.

Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was evaluated prospectively in a diagnostic laboratory. Nine hundred twenty-seven organisms were tested in triplicate; 2,351/2,781 (85%) species and 2,681/2,781 (96%) genus identifications were correct. Known issues such as the misidentification of alpha-hemolytic streptococci as Streptococcus pneumoniae were easily corrected. Identifications cost AUD$0.45 per isolate and were available in minutes. MALDI-TOF MS is rapid, accurate, and inexpensive. Matrix-assisted laser desorption–ionization time of flight mass spectrometry (MALDI-TOF MS) has been shown to be both accurate in the identification of bacteria (1, 8, 9) and rapid (5, 10, 11, 13, 14), which is of proven benefit to patient care (2, 4). New technology is never able to completely replace conventional methods; rather, these tests form part of the overall diagnostic algorithms. We therefore undertook this prospective study to determine the utility of the MALDI-TOF MS in a routine diagnostic laboratory for bacterial identification. All bacteria isolated within one calendar month from any site or specimen type that would normally undergo identification were tested in parallel with our routine methods and in triplicate (to assess the reproducibility of the results) using the microflex MALDI Biotyper 2.0 (Bruker Daltonics, GmbH, Bremen, Germany) according to the manufacturer’s instructions (software version 3.1.1.0). As specified by the manufacturer, identification scores of 2 and between 1.7 and 1.9 were required for a reliable identification to the species and genus level, respectively, while identification scores of 1.7 were considered unreliable. MALDI-TOF MS identifications were compared to identifications by current methods, which in

To determine the correlation between various vancomycin MIC testing methodologies and explore the phenomenon of MIC creep.A total of 417 consecutive non-duplicate methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from Liverpool Hospital between 1997 and 2008 were retrieved. All isolates were classified using PFGE and underwent susceptibility testing for vancomycin using a standard Etest (AB bioMérieux, Solna, Sweden), Vitek2(®) (AST-P612; bioMérieux, Inc., Durham, NC, USA) and broth microdilution (BMD) performed as per the CLSI method.Over the 12 years, 78% (n = 326) of the isolates were multiresistant MRSA (ST239-like by PFGE, where ST stands for sequence type). The correlation between MIC testing methods was moderate with Spearman's correlation coefficients of 0.50 for BMD versus Etest (P 0.001), 0.33 for BMD versus Vitek2(®) (P 0.001) and 0.42 for Etest versus Vitek2(®) (P 0.001). In general, Etest results were 1 dilution higher while the Vitek2(®) results were 1 dilution lower than the BMD MIC result. MIC creep was dependent on the MIC testing method and the measurement used for analysis (geometric mean MIC versus modal MIC versus frequency analysis), with creep detected for Etest regression analysis only. In contrast, the proportion of isolates with a BMD MIC ≥2 mg/L decreased from 16% to 9% in the latter half of the study. Modal MIC was stable over the 12 years at 1 mg/L irrespective of MIC method used.Correlation between vancomycin MIC methodologies remains suboptimal. Temporal MIC trends should be interpreted with caution as these are dependent on the testing methodology and the measurement used for analysis.

The best screening method for detecting heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) remains unclear. Using population analysis profiling utilizing the area under the concentration-time curve (PAP-AUC) as the gold standard, we screened 458 consecutive methicillin-resistant S. aureus (MRSA) bloodstream isolates to determine the most accurate and cost-effective testing strategy to detect the presence of heteroresistance. All isolates were also tested using the macromethod Etest (MET) and glycopeptide resistance detection (GRD) Etest. The MIC was determined by several methods, including standard vancomycin Etest, vancomycin broth microdilution (BMD), and Vitek2 testing. Fifty-five (12%) hVISA and 4 (1%) VISA isolates were detected by PAP-AUC. Compared to PAP-AUC, the sensitivities and specificities of MET, GRD Etest, BMD (using a MIC cutoff of ≥2 mg/liter), and standard vancomycin Etest (using a MIC cutoff of ≥2 mg/liter) were 89 and 55%, 71 and 94%, 82 and 97%, and 71 and 94%, respectively. Combination testing increased the overall testing accuracy by reducing the number of false-positive results. Cost was determined predominately by the number of PAP-AUC runs required following a screening assay. The most cost-effective strategy was BMD (using a MIC cutoff of ≥2 μg/ml) as a standalone assay or in combination with PAP-AUC, provided that BMD testing was batched. GRD Etest remained an alternative, with 71% of hVISA isolates detected. Prevalence influenced both cost and test accuracy, with results remaining unchanged for hVISA prevalences of up to 25%. Implementation of any testing strategy would therefore be dependent on balancing cost with accuracy in a given population and clinical context.

A patient developed a daptomycin-resistant methicillin-resistant Staphylococcus aureus (MRSA) infection, despite being daptomycin-naïve, in the setting of persistent bacteraemia secondary to vertebral osteomyelitis. Modified population analysis profiling of sequential MRSA blood culture isolates revealed transition from a vancomycin-susceptible phenotype to a vancomycin-intermediate S. aureus (VISA) phenotype through a vancomycin-heteroresistant S. aureus (hVISA) intermediary. Increased cell wall thickening, determined by transmission electron microscopy, correlated with the emergence of daptomycin resistance. This case supports the current hypothesis that MRSA with reduced glycopeptide susceptibility are less susceptible to daptomycin because of a thickened cell wall. This may have significance for the use of daptomycin in salvage therapy. Other predictors of daptomycin resistance include bacteraemic persistence and the presence of high inoculum infections. As resistance may appear de novo and be unstable in vivo, all isolates should have daptomycin susceptibility testing performed. The optimal antibiotic option for salvage therapy of these daptomycin-resistant infections is unknown. However, these findings emphasise the importance of optimising management, including the consideration of early surgical intervention to avoid the emergence of daptomycin resistance, especially in high inoculum infections.

Aim To examine factors associated with testing and detection of influenza A in patients admitted to hospital for acute care during the winter 2009 pandemic influenza outbreak. Design, setting and participants Retrospective observational study of patients who were tested for influenza A after being admitted to hospital through emergency departments of the Sydney South West Area Health Service from 15 June to 30 August 2009. Main outcome measures The association of factors such as age, diagnosis at admission, hospital and week of admission with rates of testing and detection of influenza A. Results 17,681 patients were admitted through nine emergency departments; 1344 (7.6%) were tested for influenza A, of whom 356 (26.5%) tested positive for pandemic influenza. Testing rates were highest in 0-4-year-old children, in the peak period of the outbreak, and in patients presenting with a febrile or respiratory illness. Positive influenza test results were common across a range of diagnoses, but occurred most frequently in children aged 10-14 years (64.3%) and in patients with a diagnosis at admission of influenza-like illness (59.1%). Using multivariate logistic regression, patients with a diagnosis at admission of fever or a respiratory illness at admission were most likely to be tested (odds ratios [ORs], 15 [95% CI, 11-21] and 17 [95% CI, 15-19], respectively). These diagnoses were stronger predictors of influenza testing than the peak testing week (Week 4; OR, 7.0 [95% CI, 3.8-13]) or any age group. However, diagnosis at admission and age were significant but weak predictors of a positive test result, and the strongest predictor of a positive test result was the peak epidemic week (Week 3; OR, 120 [95% CI, 27-490]). Conclusion The strongest predictor of a clinician's decision to test for influenza was the diagnosis at admission, but the strongest predictor of a positive test was the week of admission. A rational approach to influenza testing for patients who are admitted to hospital for acute care could include active tracking of influenza testing and detection rates, testing patients with a strong indication for antiviral treatment, and admitting only those who test negative to "clean" wards during the peak of an outbreak.