Effectiveness of adjunctive rifampicin for treatment of Staphylococcus aureus bacteraemia: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: To assess whether the addition of rifampicin to conventional treatment of Staphylococcus aureus bacteraemia (SAB) reduces bacteriological or clinical failure or death. DATA SOURCES: PubMed, Embase and Cochrane CENTRAL databases were searched from inception to 31 December 2022. Reference lists and PubMed citations of eligible studies were checked. REVIEW METHODS: Two study authors independently identified randomized controlled trials (RCTs) involving adult participants with SAB, in which an intervention group received adjunctive rifampicin and the control group received usual care with or without a placebo. Dichotomous data (bacteriological and clinical failure and deaths) were analysed and pooled across studies using risk ratio (RR) with 95% confidence intervals (CI) using a Mantel-Haenszel random-effect model. The key variable of interest being whether rifampicin was used. RESULTS: Six RCTs including 894 participants-of which 758 (85%) were from one trial-met the inclusion criteria. The addition of rifampicin to conventional treatment of SAB significantly reduced bacteriological failure by 59% (RR 0.41, 95% CI 0.21-0.81, I2 = 0%, number need to treat 27). However, it did not reduce clinical failure (RR 0.70, 95% CI 0.47-1.03, I2 = 0%) or deaths (RR 0.96, 95% CI 0.70-1.32, I2 = 0%). Further, it did not reduce the duration of bacteraemia, or the length of hospital stay. Adjunctive rifampicin reduced SAB recurrences (1% versus 4%, P = 0.01). Emergence of rifampicin resistance during treatment was uncommon (<1%). CONCLUSION: Although adjunctive rifampicin reduced the risk of bacteriological failure and recurrences, we found no mortality benefit to support its use in SAB.

Exploring the safety and quality of mobile X-ray imaging in a new infectious disease biocontainment unit: an in situ simulation and video-reflexive study.

OBJECTIVES: During a precommissioning inspection of a new biocontainment centre, radiographers noted structural features of quarantine rooms that could compromise staff and patient safety and the X-ray image quality, even after significant modifications had been made to an earlier radiography protocol. The aim of this study was to explore the safety and effectiveness of the modified protocol, in the new space, and identify improvements, if required. DESIGN: A qualitative study using in situ simulation and video-reflexive methods. SETTING: A newly built biocontainment centre, prior to its commissioning in 2021, in a large, tertiary hospital in Sydney, Australia. PARTICIPANTS: Five radiographers, and a nurse and a physician from the biocontainment centre, consented to participate. All completed the study. INTERVENTIONS: Two simulated mobile X-ray examinations were conducted in the unit prior to its commissioning; simulations were videoed. Participants and other stakeholders analysed video footage, collaboratively, and sessions were audio recorded, transcribed and analysed thematically. Problems and potential solutions identified were collated and communicated to the hospital executive, for endorsement and actioning, if possible. RESULTS: Four themes were identified from the data: infection exposure risks, occupational health and exposure risks, communication and X-ray image quality. Facilitated group reviews of video footage identified several important issues, across these four areas of risk, which had not been identified previously. CONCLUSIONS: In situ simulation is used, increasingly, to evaluate and improve healthcare practices. This study confirmed the added value of video-reflexive methods, which provided experienced participants with a richer view of a familiar protocol, in a new setting. Video footage can be examined immediately, or later if required, by a broader group of stakeholders, with diverse experience or expertise. Using video reflexivity, clinicians identified potential safety risks, which were collated and reported to the hospital executive, who agreed to implement modifications.

Laboratory surveillance of invasive pneumococcal disease in New South Wales, Australia, before and after introduction of 7-valent conjugate vaccine: reduced disease, but not antibiotic resistance rates.

We compared serotype distributions of Streptococcus pneumoniae isolates from patients aged <5 and o5 years with invasive pneumococcal disease in New South Wales, Australia, and antibiotic susceptibilities of isolates from the <5 years age group only, before (2002­2004) and after(2005­2009) introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). Overall, there were significant decreases in the mean annual number of referred isolates (770 vs. 515) and the proportion belonging to PCV7 serotypes (74% vs. 38%), but non-PCV7 serotypes, particularly 19A, increased (5% vs. 18%). All changes were more marked in the <5 years age group.Susceptibility testing of isolates from the <5 years age group showed variation in resistance between serotypes, but significant overall increases in penicillin non-susceptibility (23% vs. 31%),ceftriaxone resistance (2% vs. 12%) and multidrug resistance (4% vs. 7%) rates ; erythromycin resistance fell (32% vs. 25%). Continued surveillance is needed to monitor changes following the introduction of 13-valent PCV in 2012.

Understanding routine (non-outbreak) respiratory protective equipment behaviour of hospital workers in different clinical settings - lessons for the future post-COVID-19.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has drawn attention to the importance of facial (respiratory and eye) protective equipment (FPE). Optimal use of FPE in non-outbreak situations will enable front-line staff, such as emergency department (ED) clinicians, to adapt more rapidly and safely to the increased demands and skills required during an infectious disease outbreak. METHODS: A survey, designed to determine the attitudes, beliefs and knowledge of healthcare workers around the use of FPE for protection against respiratory infections, was distributed to staff in a respiratory ward, an adult ED and a paediatric ED in Sydney, Australia prior to COVID-19. RESULTS: The survey revealed differences between the respiratory ward and the EDs, and between professional groups. ED staff, particularly paediatric clinicians, were less likely than ward staff to use FPE appropriately during routine care. Medical staff were more likely to work outside of infection prevention and control policies. DISCUSSION: The busy, relatively chaotic ED environment presents unique challenges for optimal compliance with safe use of FPE when caring for patients with respiratory symptoms. CONCLUSIONS: Building upon the lessons of the pandemic, it is timely to address the specific infection prevention and control needs of the ED environment to improve compliance with the use of FPE during non-outbreak situations.

Natural outbreak of Streptococcus agalactiae (GBS) infection in wild giant Queensland grouper, Epinephelus lanceolatus (Bloch), and other wild fish in northern Queensland, Australia.

Ninety-three giant Queensland grouper, Epinephelus lanceolatus (Bloch), were found dead in Queensland, Australia, from 2007 to 2011. Most dead fish occurred in northern Queensland, with a peak of mortalities in Cairns in June 2008. In 2009, sick wild fish including giant sea catfish, Arius thalassinus (Rüppell), and javelin grunter, Pomadasys kaakan (Cuvier), also occurred in Cairns. In 2009 and 2010, two disease epizootics involving wild stingrays occurred at Sea World marine aquarium. Necropsy, histopathology, bacteriology and PCR determined that the cause of deaths of 12 giant Queensland grouper, three wild fish, six estuary rays, Dasyatis fluviorum (Ogilby), one mangrove whipray, Himantura granulata (Macleay), and one eastern shovelnose ray, Aptychotrema rostrata (Shaw), was Streptococcus agalactiae septicaemia. Biochemical testing of 34 S. agalactiae isolates from giant Queensland grouper, wild fish and stingrays showed all had identical biochemical profiles. The 16S rRNA gene sequences of isolates confirmed all isolates were S. agalactiae; genotyping of selected S. agalactiae isolates showed the isolates from giant Queensland grouper were serotype Ib, whereas isolates from wild fish and stingrays closely resembled serotype II. This is the first report of S. agalactiae from wild giant Queensland grouper and other wild tropical fish and stingray species in Queensland, Australia.

Experiences of the SARS-CoV-2 pandemic amongst Australian healthcare workers: from stressors to protective factors.

BACKGROUND: The SARS-CoV-2 pandemic has critically challenged healthcare systems globally. Examining the experiences of healthcare workers (HCWs) is important for optimizing ongoing and future pandemic responses. OBJECTIVES: In-depth exploration of Australian HCWs' experiences of the SARS-CoV-2 pandemic, with a focus on reported stressors vis-à-vis protective factors. METHODS: Individual interviews were performed with 63 HCWs in Australia. A range of professional streams and operational staff were included. Thematic analysis was performed. RESULTS: Thematic analysis identified stressors centred on paucity of, or changing, evidence, leading to absence of, or mistrust in, guidelines; unprecedented alterations to the autonomy and sense of control of clinicians; and deficiencies in communication and support. Key protective factors included: the development of clear guidance from respected clinical leaders or recognized clinical bodies, interpersonal support, and strong teamwork, leadership, and a sense of organizational preparedness. CONCLUSIONS: This study provides insights into the key organizational sources of emotional stress for HCWs within pandemic responses and describes experiences of protective factors. HCWs experiencing unprecedented uncertainty, fear, and rapid change, rely on clear communication, strong leadership, guidelines endorsed by recognized expert groups or individuals, and have increased reliance on interpersonal support. Structured strategies for leadership and communication at team, service group and organizational levels, provision of psychological support, and consideration of the potential negative effects of centralizing control, would assist in ameliorating the extreme pressures of working within a pandemic environment.

Testing the efficacy and acceptability of video-reflexive methods in personal protective equipment training for medical interns: a mixed methods study.

OBJECTIVES: To test the efficacy and acceptability of video-reflexive methods for training medical interns in the use of personal protective equipment (PPE). DESIGN: Mixed methods study. SETTING: A tertiary-care teaching hospital, Sydney, January 2018-February 2019. PARTICIPANTS: 72 of 90 medical interns consented to participate. Of these, 39 completed all three time points. INTERVENTIONS: Participants received a standard infection prevention and control (IPC) education module during their hospital orientation. They were then allocated alternately to a control or video group. At three time points (TPs) over the year, participants were asked to don/doff PPE items based on hospital protocol. At the first two TPs, all participants also participated in a reflexive discussion. At the second and third TPs, all participants were audited on their performance. The only difference between groups was that the video group was videoed while donning/doffing PPE, and they watched this footage as a stimulus for reflexive discussion. PRIMARY AND SECONDARY OUTCOME MEASURES: The efficacy and acceptability of the intervention were assessed using: (1) comparisons of audit performance between and within groups over time, (2) comparisons between groups on survey responses for evaluation of training and self-efficacy and (3) thematic analysis of reflexive discussions. RESULTS: Both groups improved in their PPE competence over time, although there was no consistent pattern of significant differences within and between groups. No significant differences were found between groups on reported acceptability of training, or self-efficacy for PPE use. However, analysis of reflexive discussions shows that the effects of the video-reflexive intervention were tangible and different in important respects from standard training. CONCLUSIONS: Video reflexivity in group-based training can assist new clinicians in engagement with, and better understanding of, IPC in their clinical practice. Our study also highlights the need for ongoing and targeted IPC training during medical undergraduate studies as well as regular workplace refresher training.

Priority allocation of pandemic influenza vaccines in Australia - Recommendations of 3 community juries.

BACKGROUND: Pandemic planning has historically been oriented to respond to an influenza virus, with vaccination strategy being a key focus. As the current COVID-19 pandemic plays out, the Australian government is closely monitoring progress towards development of SARS-CoV2 vaccines as a definitive intervention. However, as in any pandemic, initial supply will likely be exceeded by demand due to limited manufacturing output. METHODS: We convened community juries in three Australian locations in 2019 to assess public acceptability and perceived legitimacy of influenza pandemic vaccination distribution strategies. Preparatory work included literature reviews on pandemic vaccine allocation strategies and on vaccine allocation ethics, and simulation modelling studies. We assumed vaccine would be provided to predefined priority groups. Jurors were then asked to recommend one of two strategies for distributing remaining early doses of vaccine: directly vaccinate people at higher risk of adverse outcomes from influenza; or indirectly protect the general population by vaccinating primary school students, who are most likely to spread infection. RESULTS: Thirty-four participants of diverse backgrounds and ages were recruited through random digit dialling and topic-blinded social media advertising. Juries heard evidence and arguments supporting different vaccine distribution strategies, and questioned expert presenters. All three community juries supported prioritising school children for influenza vaccination (aiming for indirect protection), one by 10-2 majority and two by consensus. Justifications included that indirect protection benefits more people and is likely to be more publicly acceptable. CONCLUSIONS: In the context of an influenza pandemic, informed citizens were not opposed to prioritising groups at higher risks of adverse outcomes, but if resources and epidemiological conditions allow, achieving population benefits should be a strategic priority. These insights may inform future SARS-CoV-2 vaccination strategies.

Constructing an ethical framework for priority allocation of pandemic vaccines.

BACKGROUND: Allocation of scarce resources during a pandemic extends to the allocation of vaccines when they eventually become available. We describe a framework for priority vaccine allocation that employed a cross-disciplinary approach, guided by ethical considerations and informed by local risk assessment. METHODS: Published and grey literature was reviewed, and augmented by consultation with key informants, to collate past experience, existing guidelines and emerging strategies for pandemic vaccine deployment. Identified ethical issues and decision-making processes were also included. Concurrently, simulation modelling studies estimated the likely impacts of alternative vaccine allocation approaches. Assembled evidence was presented to a workshop of national experts in pandemic preparedness, vaccine strategy, implementation and ethics. All of this evidence was then used to generate a proposed ethical framework for vaccine priorities best suited to the Australian context. FINDINGS: Published and emerging guidance for priority pandemic vaccine distribution differed widely with respect to strategic objectives, specification of target groups, and explicit discussion of ethical considerations and decision-making processes. Flexibility in response was universally emphasised, informed by real-time assessment of the pandemic impact level, and identification of disproportionately affected groups. Model outputs aided identification of vaccine approaches most likely to achieve overarching goals in pandemics of varying transmissibility and severity. Pandemic response aims deemed most relevant for an Australian framework were: creating and maintaining trust, promoting equity, and reducing harmful outcomes. INTERPRETATION: Defining clear and ethically-defendable objectives for pandemic response in context aids development of flexible and adaptive decision support frameworks and facilitates clear communication and engagement activities.

The nonserotypeable pneumococcus: phenotypic dynamics in the era of anticapsular vaccines.

Nonserotypeable pneumococci (NSP) are commonly carried by Australian Indigenous children in remote communities. The purpose of this study was to characterize carriage isolates of NSP from Indigenous children vaccinated with the seven-valent pneumococcal conjugate vaccine (PCV7) and to use these data to guide decisions on reporting of NSP. A total of 182 NSP were characterized by BOX typing, antibiogram analysis, and multilocus sequence typing (MLST) of common BOX types. NSP positive for the wzg capsule gene were analyzed by a multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB-H) targeting capsule genes to determine the serotype. Among 182 NSP, 49 BOX types were identified. MLST of 10 representative isolates found 7 STs, including ST448 (which accounted for 11% of NSP). Non-penicillin susceptibility was evident in 51% of the isolates. Pneumococcal wzg sequences were detected in only 23 (13%) NSP, including 10 that contained an approximately 1.2-kb insert in the region. mPCR/RLB-H identified serotype 14 wzy sequences in all 10 NSP, and 1 also contained a serotype 3-specific wze sequence. Among the remaining 13 wzg-positive NSP, few belonged to the serotypes represented in PCV7. It appears that most NSP identified in Australian Indigenous children are from a true nonencapsulated lineage. Few NSP represented serotypes in PCV7 that suppress capsular expression. High rates of carriage and penicillin resistance and the occasional presence of capsule genes suggest a role for NSP in the maintenance and survival of capsulated pneumococci. To avoid the inflation of pneumococcal carriage and antibiotic resistance rates, in clinical trials, we recommend separate reporting of rates of capsular strains and NSP and the exclusion of data for NSP from primary analyses.

The utility of seroepidemiology for tracking trends in pertussis infection.

Comparing pertussis epidemiology over time and between countries is confounded by differences in diagnostic and notification practices. Standardized serological methods applied to population-based samples enhance comparability. Population prevalence of different levels of pertussis toxin IgG (PT IgG) antibody, measured by standardized methods, were compared by age group and region of Australia between 1997/1998 and 2002. The proportion of 5- to 9-year-olds with presumptive recent pertussis infection (based on IgG levels >or=62.5 ELISA units/ml) significantly decreased in 2002, consistent with notification data for the same period and improved uptake of booster vaccines following the schedule change from whole-cell to acellular vaccine. In contrast, recent presumptive infection significantly increased in adults aged 35-49 years. Population-based serosurveillance using standardized PT IgG antibody assays has the potential to aid interpretation of trends in pertussis incidence in relation to vaccine programmes and between countries.

Multiplex polymerase chain reaction-based reverse line blot hybridization assay to detect common genital pathogens.

The objective of the present paper is to develop and apply a multiplex polymerase chain reaction (mPCR) based reverse line blot (RLB) hybridization assay to facilitate the diagnosis of genital infections by detection of seven recognized or putative genital pathogens (Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum, Ureaplasma parvum, Mycoplasma genitalium, Mycoplasma hominis and Trichomonas vaginalis). Species-specific biotin-labelled primer pairs were used in a single mPCR to amplify target regions in each of seven pathogens. The amplified biotin-labelled PCR products were hybridized with membrane-bound-specific oligonucleotide probes and were detected by chemiluminescence. Two hundred and eleven specimens (104 male urethral and 107 female vaginal swabs), collected from patients with suspected genital infections attending the Wuhan First Hospital Sexually Transmitted Diseases (STD) clinic, were tested by mPCR/RLB and results were confirmed by single PCR using different species-specific targets. The sensitivity of the assay was assessed using dilutions of positive DNA controls with known copy numbers, for each target. The assay correctly identified all reference strains and detected potential pathogens in a high proportion of clinical specimens. There was no cross-reaction between the seven pathogens. The mPCR/RLB can detect

Differentiation of Chlamydia trachomatis lymphogranuloma venereum-related serovars from other serovars using multiplex allele-specific polymerase chain reaction and high-resolution melting analysis.

Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by Chlamydia trachomatis serovars L1, L2 and L3. Consequently, more specific and sensitive detection methods that are rapid and inexpensive are necessary to differentiate between C. trachomatis serovars. The purpose of this study was to identify and differentiate LGV-related C. trachomatis serovars from rectal swabs using high-resolution melting analysis (HRMA) and multiplex allele-specific polymerase chain reaction (MAS-PCR). Fifteen clinical samples from patients in Sydney were first screened and confirmed as C. trachomatis by using the COBAS AMPLICOR PCR analyser. The same samples were assayed for C. trachomatis and LGV by HRMA and MAS-PCR of the polymorphic membrane protein H (pmpH) gene. Both methods indicated that two of 15 samples were serovar L2 and the remainder (13/15) other C. trachomatis serovars. Both HRMA and MAS-PCR are inexpensive, rapid, easy methods that are useful tools for the identification of LGV in clinical and research laboratories.

Ureaplasma urealyticum is significantly associated with non-gonococcal urethritis in heterosexual Sydney men.

We investigated the prevalence of various genital organisms in 268 men with (cases) and 237 men without (controls) urethral symptoms/signs (urethral discharge, dysuria and/or urethral irritation) from two sexual health clinics in Sydney between April 2006 and November 2007. The presence of urethral symptoms/signs was defined as non-gonococcal urethritis (NGU) for this study. Specific aims were to investigate the role of Ureaplasma urealyticum in NGU and the prevalence of Mycoplasma genitalium in our population. Multiplex polymerase chain reaction-based reverse line blot (mPCR/RLB) assay was performed to detect 14 recognized or putative genital pathogens, including Chlamydia trachomatis, M. genitalium, U. urealyticum and U. parvum. U. urealyticum was associated with NGU in men without another urethral pathogen (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.1-3.8; P = 0.04); this association remained after controlling for potential confounding by age and history of unprotected vaginal sex in the last four weeks (OR 2.0, 95% CI: 1.1-3.9; P = 0.03). C. trachomatis (OR 7.5, P < 0.001) and M. genitalium (OR 5.5, P = 0.027) were significantly associated with NGU. The prevalence of M. genitalium was low (4.5% cases, 0.8% controls). U. urealyticum is independently associated with NGU in men without other recognized urethral pathogens. Further research should investigate the role of U. urealyticum subtypes among heterosexual men with NGU.

Citizens' juries give verdict on whether private practice veterinarians should attend unvaccinated Hendra virus suspect horses.

BACKGROUND: Hendra virus (HeV) is endemic in Australian flying foxes, posing a threat to equine and human health. Equine vaccination remains the most effective risk mitigation strategy. Many horses remain unvaccinated - even in higher-risk regions. Debate surrounding the vaccine's use is characterised by conflicting perspectives, misunderstanding and mistrust. Private veterinary practitioners are critical to early identification of public health risk through recognition, sampling and management of suspect-equine-HeV-cases. However, managing such cases can be burdensome, with some veterinarians opting not to attend unvaccinated horses or to abandon equine practice because of risk posed by HeV disease and liability. OBJECTIVE: Ascertain the perspectives of informed citizens on what obligations (if any) private veterinarians have to attend unvaccinated horses with HeV or HeV-like disease. METHODS: Three citizens' juries were tasked with considering approaches to managing HeV risk in Australia, including (reported here) roles and obligations of private veterinarians in responding to HeV-suspect-cases. RESULTS: Jurors acknowledged that HeV management posed an important challenge for private veterinarians. A clear majority (27 of 31 jurors) voted that veterinarians should not be obliged to attend unvaccinated horses. All recognised that greater support for veterinarians should be a priority. CONCLUSIONS: When informed of HeV risks and strategies for control and management, citizens appreciated the need to support veterinarians performing this critical 'One Health' role for public benefit. The current governance framework within which zoonotic disease recognition and response operates limits the contingency and scope for increasing support and efficacy of these important veterinary public health practices.

Recurrence of tuberculosis in a low-incidence setting.

Recurrence of active tuberculosis following treatment of an initial disease episode can occur due to endogenous re-activation or exogenous re-infection. Cases of recurrent tuberculosis in the Australian state of New South Wales between 1994 and 2006 were identified by data linkage analysis with confirmatory review of case notes. Patients with more than one culture-positive disease episode during that time period who had completed treatment for the initial disease episode were included. Genotyping of Mycobacterium tuberculosis was used to determine whether recurrence was likely to be due to re-activation or re-infection. There were 5,723 tuberculosis notifications between 1994 and 2006, 3,731 of which were culture-positive. Fifteen (0.4%) patients had recurrent culture-positive disease over a mean 5.7 yrs of follow-up (crude annual incidence 71 per 100,000 population). Recurrent tuberculosis was attributable to re-activation (indistinguishable strains) in 11 (73%) cases and to re-infection (different strains) in four (27%). In a low-incidence setting of tuberculosis, a control programme incorporating directly observed therapy for active disease resulted in a very low rate of recurrent tuberculosis over a long period of follow-up. Re-infection is less likely than re-activation, but still contributes significantly to the number of cases with recurrent disease.

Use of a multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay for the rapid identification of bacterial pathogens.

The aim of this study was to develop a sensitive and reliable method for the molecular identification of pathogenic bacteria. A multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay was developed and evaluated for the rapid identification of 24 systemic and respiratory bacterial pathogens in routine diagnosis. All species-specific probes designed for the RLB hybridised with amplified DNA only from the corresponding species. Sensitivity limits of the mPCR/RLB assay varied among the 24 target organisms from 0.05 pg to 0.5 ng of genomic DNA. The sensitivity of the assay was 2 x 10(2) CFU/mL for Streptococcus pneumoniae and 6 x 10(2) CFU/mL for Escherichia coli. The specificity of each probe was tested against 24 species. There were no cross-reactions among any of the 43 probes. The mPCR/RLB assay appeared to be a useful alternative tool for the molecular identification of common pathogens.

Distribution of genotypes and antibiotic resistance genes among invasive Streptococcus agalactiae (group B streptococcus) isolates from Australasian patients belonging to different age groups.

Serotype distribution and antibiotic resistance (AR) among group B streptococci (GBS) affect GBS disease prevention strategies, but vary among patient groups. A multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay was used to compare the distributions of GBS serotypes, serotype III subtypes and AR-associated genes among 666 invasive isolates from 663 patients, divided into five age groups: infants, early-onset (EO; 0-6 days) and late-onset (LO; 7-90 days); children (aged 3 months to 14 years); women of childbearing age (WCBA; aged 15-45 years); and other adults (males aged >15 years; females aged >45 years). Serotypes Ia and V and serosubtype III-1 accounted for 60% of infections. Serosubtype III-2, which corresponds to a virulent clone belonging to sequence type (ST)17, was relatively uncommon overall (7%), but was associated strongly with LO infant infections, in which it was significantly more common than in adult infections (25/104 (24%) vs. 9/392 (2%), p <0.0001) or in EO infections (25/104 (24%) vs. 14/155 (9%), p <0.005). Erythromycin resistance genes were found in 8% of all isolates (ermB 3%, ermA 2.5% and mefA/E 2%), in 11-15% of isolates of serotypes II and V and subtype III-1, but in none of the isolates of serosubtype III-2 (III-2, 0/49 vs. all others, 54/618 (9%), p <0.04). In summary, the virulent serosubtype III-2 was associated strongly with LO infant GBS infection, but was less likely than other serotypes or serosubtype III-1 to carry AR genes.

The seroepidemiology of Helicobacter pylori infection in Australia.

BACKGROUND: Infection with Helicobacter pylori is common worldwide and a significant cause of upper gastrointestinal disease. Prevalence of this infection varies in different population groups internationally. Because of the invasiveness of specimen collection for bacteriologic diagnosis and the expense of tests such as labeled urea breath tests, serology is the most feasible means of determining the population epidemiology of H. pylori. The aim of this study was to describe the seroepidemiology of H. pylori infection in Australia. METHODS: H. pylori-specific ELISA for the presence of IgG antibodies was performed on a representative sample of 2413 sera from Australia in 2002, using validated serosurveillance methods. RESULTS: The overall seroprevalence of H. pylori infection in Australia was 15.1% in 2002, with no statistical difference between genders. Seropositivity rates increased progressively with age, ranging between 4.0% in the 1-4-year-olds and 23.3% in the 50-59-year-olds. CONCLUSIONS: The prevalence of infection with H. pylori in Australia was lower than rates reported in other developed countries, at 15.4%. This study provides important baseline measurements for future preventive measures including vaccine research and development. Further studies to determine subgroups at higher risk of infection may help target the more susceptible populations.

Sensitivity of human gamma interferon assay and tuberculin skin testing for detecting infection with Mycobacterium tuberculosis in patients with culture positive tuberculosis.

SETTING: Nine university-affiliated chest clinics in Australia. OBJECTIVE: To evaluate the sensitivity of a whole blood human gamma-interferon assay (HGIA, QuantiFERON-TB) for specific T lymphocyte responses and Tuberculin skin testing (TST) for the detection of Mycobacterium tuberculosis infection in subjects with culture-proven M. tuberculosis disease (TBCP). DESIGN: Prospective testing of 129 patients with recent TBCP and 100 patients with non-tuberculosis lung disease (NTBLD). RESULTS: Using a defined level of specific IFN-gamma production and TST 10mm as positive cut-offs, the sensitivity of HGIA was 81% compared to 89% for TST (p=0.06). When positive responses in both TST and HGIA were combined, 96% of TB patients were detected. For the NTBLD group, 43% of whom were born overseas, 73% were negative for both the HGIA and TST. Prior immunization with M. bovis (bacille Calmette-Guerin) (BCG) or the type of TB had no effect on the sensitivities of the assays. For those treated for <2 months, the sensitivities for both assays were 84%, but for those treated for >2 months the sensitivity of TST (90%) tended to be higher than for HGIA (81%) (p=0.07). The distribution of TST results in TB patients showed a broad peak between 10 and 25 mm, while the results in the HGIA were bimodal in both TB and NTBLD patients. CONCLUSION: HGIA may prove an alternative to skin testing for detecting M. tuberculosis infection in certain settings.