Incidence of cerebrovascular accident following head and neck free tissue transfer surgery

The aim of this study was to determine the incidence of postoperative cerebrovascular accident (CVA) following head and neck free tissue transfer and to identify predictive risk factors. A retrospective audit was performed of patients who underwent head and neck reconstructive surgery at Queen Elizabeth University Hospital between 2009 and 2020. The patient records were analysed to identify those who developed CVA within 30 days after surgery. A total of 1109 patients underwent head and neck free tissue transfer surgery, including 1048 neck dissection procedures. Of these, 78.6% had one or more identified risk factors for perioperative stroke. Five patients (0.45%) developed postoperative CVA. The results showed that CVA correlated to patients with hypercholesterolemia (P = 0.007). This study demonstrates the safety of free tissue transfer. Despite underlying co-morbidities and risk factors, the incidence of CVA is low following surgery and manipulation of the major vasculature of the neck.

Locally acquired lymphocytic choriomeningitis virus infections in South-East Queensland: an outbreak of a pathogen rarely described in Australia

Lymphocytic choriomeningitis virus (LCMV) is a zoonotic virus that can cause clinically significant illnesses in humans. Although cases of LCMV infection are well described globally, and there is evidence that the virus is present in Australian rodent populations, there has been only one case of domestically acquired LCMV infection published previously. Here, we describe a cluster of LCMV infections in South-East Queensland identified in early 2021, and the diagnostic testing processes implemented. This identifies LCMV as an under-recognised human pathogen in Australia.

Detection of the Omicron (B.1.1.529) variant of SARS-CoV-2 in aircraft wastewater

On the 26th of November 2021, the World Health Organization (WHO) designated the newly detected B.1.1.529 lineage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) the Omicron Variant of Concern (VOC). The genome of the Omicron VOC contains more than 50 mutations, many of which have been associated with increased transmissibility, differing disease severity, and potential to evade immune responses developed for previous VOCs such as Alpha and Delta. In the days since the designation of B.1.1.529 as a VOC, infections with the lineage have been reported in countries around the globe and many countries have implemented travel restrictions and increased border controls in response. We putatively detected the Omicron variant in an aircraft wastewater sample from a flight arriving to Darwin, Australia from Johannesburg, South Africa on the 25th of November 2021 via positive results on the CDC N1, CDC N2, and del(69-70) RT-qPCR assays per guidance from the WHO. The Australian Northern Territory Health Department detected one passenger onboard the flight who was infected with SARS-CoV-2, which was determined to be the Omicron VOC by sequencing of a nasopharyngeal swab sample. Subsequent sequencing of the aircraft wastewater sample using the ARTIC V3 protocol with Nanopore and ATOPlex confirmed the presence of the Omicron variant with a consensus genome that clustered with the B.1.1.529 BA.1 sub-lineage. Our detection and confirmation of a single onboard Omicron infection via aircraft wastewater further bolsters the important role that aircraft wastewater can play as an independent and unintrusive surveillance point for infectious diseases, particularly coronavirus disease 2019.

Genomic Characterisation Reveals a Dominant Lineage of SARS-CoV-2 in Papua New Guinea

The coronavirus disease pandemic has highlighted the utility of pathogen genomics as a key part of comprehensive public health response to emerging infectious diseases threats, however, the ability to generate, analyse, and respond to pathogen genomic data varies around the world. Papua New Guinea (PNG), which has limited in-country capacity for genomics, has experienced significant outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with initial genomics data indicating a large proportion of cases were from lineages that are not well defined within the current nomenclature. Through a partnership between in-country public health agencies and academic organisations, industry, and a public health genomics reference laboratory in Australia a system for routine SARS-CoV-2 genomics from PNG was established. Here we aim to characterise and describe the genomics of PNG’s second wave and examine the sudden expansion of a lineage that is not well defined but very prevalent in the Western Pacific region. We generated 1797 sequences from cases in PNG and performed phylogenetic and phylodynamic analyses to examine the outbreak and characterise the circulating lineages and clusters present. Our results reveal the rapid expansion of the B.1.466.2 and related lineages within PNG, from multiple introductions into the country. We also highlight the difficulties that unstable lineage assignment causes when using genomics to assist with rapid cluster definitions.

A norovirus gastroenteritis outbreak in an Australian child-care center: A household-level analysis

There is a large burden of norovirus disease in child-care centers in Australia and around the world. Despite the ubiquity of norovirus outbreaks in child-care centers, little is known about the extent of this burden within the child-care center and the surrounding household clusters. Therefore, we performed an in-depth analysis of a gastroenteritis outbreak to examine the patterns of transmissions, household attack rates and the basic reproduction number (R₀) for Norovirus in a child-care facility. We used data from parental interviews of suspected cases sent home with gastroenteritis at a child-care center between 24^th of August and 18^th of September 2020. A total of 52 persons in 19 household clusters were symptomatic in this outbreak investigation. Of all transmissions, 23 (46.9%) occurred in the child-care center, the rest occurring in households. We found a household attack rate of 36.5% (95% CI 27.3, 47.1%). Serial intervals were estimated as mean 2.5 ± SD1.45 days. The R₀, using time-dependent methods during the growth phase of the outbreak (days 2 to 8) was 2.4 (95% CI 1.50, 3.50). The count of affected persons of a child-care center norovirus outbreak is approximately double the count of the total symptomatic staff and attending children. In the study setting, each symptomatic child-care attendee likely infected one other child-care attendee or staff and just over one household contact on average.

Tracking the international spread of SARS-CoV-2 lineages B.1.1.7 and B.1.351/501Y-V2 with grinch

Late in 2020, two genetically-distinct clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with mutations of biological concern were reported, one in the United Kingdom and one in South Africa. Using a combination of data from routine surveillance, genomic sequencing and international travel we track the international dispersal of lineages B.1.1.7 and B.1.351 (variant 501Y-V2). We account for potential biases in genomic surveillance efforts by including passenger volumes from location of where the lineage was first reported, London and South Africa respectively. Using the software tool grinch (global report investigating novel coronavirus haplotypes), we track the international spread of lineages of concern with automated daily reports, Further, we have built a custom tracking website (cov-lineages.org/global_report.html) which hosts this daily report and will continue to include novel SARS-CoV-2 lineages of concern as they are detected.

Genomics-informed responses in the elimination of COVID-19 in Victoria, Australia: an observational, genomic epidemiological study

BACKGROUND

A cornerstone of Australia's ability to control COVID-19 has been effective border control with an extensive supervised quarantine programme. However, a rapid recrudescence of COVID-19 was observed in the state of Victoria in June, 2020. We aim to describe the genomic findings that located the source of this second wave and show the role of genomic epidemiology in the successful elimination of COVID-19 for a second time in Australia.

METHODS

In this observational, genomic epidemiological study, we did genomic sequencing of all laboratory-confirmed cases of COVID-19 diagnosed in Victoria, Australia between Jan 25, 2020, and Jan 31, 2021. We did phylogenetic analyses, genomic cluster discovery, and integrated results with epidemiological data (detailed information on demographics, risk factors, and exposure) collected via interview by the Victorian Government Department of Health. Genomic transmission networks were used to group multiple genomic clusters when epidemiological and genomic data suggested they arose from a single importation event and diversified within Victoria. To identify transmission of emergent lineages between Victoria and other states or territories in Australia, all publicly available SARS-CoV-2 sequences uploaded before Feb 11, 2021, were obtained from the national sequence sharing programme AusTrakka, and epidemiological data were obtained from the submitting laboratories. We did phylodynamic analyses to estimate the growth rate, doubling time, and number of days from the first local infection to the collection of the first sequenced genome for the dominant local cluster, and compared our growth estimates to previously published estimates from a similar growth phase of lineage B.1.1.7 (also known as the Alpha variant) in the UK.

FINDINGS

Between Jan 25, 2020, and Jan 31, 2021, there were 20 451 laboratory-confirmed cases of COVID-19 in Victoria, Australia, of which 15 431 were submitted for sequencing, and 11 711 met all quality control metrics and were included in our analysis. We identified 595 genomic clusters, with a median of five cases per cluster (IQR 2-11). Overall, samples from 11 503 (98·2%) of 11 711 cases clustered with another sample in Victoria, either within a genomic cluster or transmission network. Genomic analysis revealed that 10 426 cases, including 10 416 (98·4%) of 10 584 locally acquired cases, diagnosed during the second wave (between June and October, 2020) were derived from a single incursion from hotel quarantine, with the outbreak lineage (transmission network G, lineage D.2) rapidly detected in other Australian states and territories. Phylodynamic analyses indicated that the epidemic growth rate of the outbreak lineage in Victoria during the initial growth phase (samples collected between June 4 and July 9, 2020; 47·4 putative transmission events, per branch, per year [1/years; 95% credible interval 26·0-85·0]), was similar to that of other reported variants, such as B.1.1.7 in the UK (mean approximately 71·5 1/years). Strict interventions were implemented, and the outbreak lineage has not been detected in Australia since Oct 29, 2020. Subsequent cases represented independent international or interstate introductions, with limited local spread.

INTERPRETATION

Our study highlights how rapid escalation of clonal outbreaks can occur from a single incursion. However, strict quarantine measures and decisive public health responses to emergent cases are effective, even with high epidemic growth rates. Real-time genomic surveillance can alter the way in which public health agencies view and respond to COVID-19 outbreaks.

FUNDING

The Victorian Government, the National Health and Medical Research Council Australia, and the Medical Research Future Fund.

Applying the British Association of Oral and Maxillofacial Surgeons quality outcomes metrics to a UK oncology and reconstructive surgery service - benchmarking the data

The British Association of Oral and Maxillofacial Surgery is soon to implement the Quality Outcomes in Oral in Maxillofacial Surgery (QOMS) to provide a platform for quality management across the specialty in the UK. The initial oncology and reconstruction audits for QOMS involves data collection on specific procedures and metrics. The aim of this report is to determine their appropriateness using extant audit datasets in our institution that overlap substantially with the QOMS audits. Pre-existing datasets comprising information on patients treated for oral cavity SCC with curative intent were analysed. Data on surgical margins, lymphadenectomy lymph node yield, delay between surgery and adjuvant radiotherapy, duration of hospital stay, and complications including flap failures were analysed. All statistical analyses were performed with SPSS 25. Run charts describing longitudinal data were generated using SPC for Excel version 6. Twenty three patients (3.1%) of 701 resections had a positive surgical margin reported. Seventeen (4.3%) of patients had less than 18 LNs in the ND specimen analysed. Mean time to start date of adjuvant therapy was 62 days. Only 9% of patients commenced adjuvant therapy within 6 weeks. The median duration of stay was 18 days. In 1153 free flaps a failure rate of 4.3% was identified. A total of 1349 complications (CD I-V) were recorded in the 1111 patients undergoing major surgery with free flap reconstruction. The QOMS selected metrics for oncology and reconstruction are clinically relevant, readily measurable, and likely to be actionable by the surgical team.

Replication Kinetics of B.1.351 and B.1.1.7 SARS-CoV-2 Variants of Concern Including Assessment of a B.1.1.7 Mutant Carrying a Defective ORF7a Gene

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, is a readily transmissible and potentially deadly pathogen which is currently re-defining human susceptibility to pandemic viruses in the modern world. The recent emergence of several genetically distinct descendants known as variants of concern (VOCs) is further challenging public health disease management, due to increased rates of virus transmission and potential constraints on vaccine effectiveness. We report the isolation of SARS-CoV-2 VOCs imported into Australia belonging to the B.1.351 lineage, first described in the Republic of South Africa (RSA), and the B.1.1.7 lineage originally reported in the United Kingdom, and directly compare the replication kinetics of these two VOCs in Vero E6 cells. In this analysis, we also investigated a B.1.1.7 VOC (QLD1516/2021) carrying a 7-nucleotide deletion in the open reading frame 7a (ORF7a) gene, likely truncating and rendering the ORF7a protein of this virus defective. We demonstrate that the replication of the B.1.351 VOC (QLD1520/2020) in Vero E6 cells can be detected earlier than the B.1.1.7 VOCs (QLD1516/2021 and QLD1517/2021), before peaking at 48 h post infection (p.i.), with significantly higher levels of virus progeny. Whilst replication of the ORF7a defective isolate QLD1516/2021 was delayed longer than the other viruses, slightly more viral progeny was produced by the mutant compared to the unmutated isolate QLD1517/2021 at 72 h p.i. Collectively, these findings contribute to our understanding of SARS-CoV-2 replication and evolutionary dynamics, which have important implications in the development of future vaccination, antiviral therapies, and epidemiological control strategies for COVID-19.

Tracking the international spread of SARS-CoV-2 lineages B.1.1.7 and B.1.351/501Y-V2

Late in 2020, two genetically-distinct clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with mutations of biological concern were reported, one in the United Kingdom and one in South Africa. Using a combination of data from routine surveillance, genomic sequencing and international travel we track the international dispersal of lineages B.1.1.7 and B.1.351 (variant 501Y-V2). We account for potential biases in genomic surveillance efforts by including passenger volumes from location of where the lineage was first reported, London and South Africa respectively. Using the software tool grinch (global report investigating novel coronavirus haplotypes), we track the international spread of lineages of concern with automated daily reports, Further, we have built a custom tracking website (cov-lineages.org/global_report.html) which hosts this daily report and will continue to include novel SARS-CoV-2 lineages of concern as they are detected.

Infection, Dissemination, and Replication of Urban and Sylvatic Strains of Dengue Virus Type 2 (Flaviviridae: Flavivirus) in Australian Aedes aegypti (Diptera: Culicidae)

The dengue viruses (DENVs) occur throughout tropical and subtropical regions of the world where they infect 100s of millions of people annually. In Australia, the dengue receptive zone is confined to the northern state of Queensland where the principal vector Aedes aegypti (L.) is present. In the current study, two populations of Ae. aegypti from north Queensland were exposed to two urban outbreak strains and one sylvatic strain of dengue virus type 2 (DENV-2). The titer of virus required to infect 50% of mosquitoes was between 105 and 106 50% tissue culture infectious dose (TCID)50/ml and was influenced by the combination of the origin of Ae. aegypti population and virus strain. When exposed to infectious bloodmeal titers > 106 TCID50/ml, infection and dissemination rates were all > 50% and were significantly affected by the origin of the mosquito population but not by the strain of DENV-2. Replication of DENV-2 was also significantly affected by the mosquito population and the titer of the infectious bloodmeal that mosquitoes were exposed to. The results of this study are discussed in the context of DENV transmission dynamics in northern Australia and the relative fitness of the sylvatic virus strain in urban Ae. aegypti populations.

COVID-19 in Australia: our national response to the first cases of SARS-CoV-2 infection during the early biocontainment phase

BACKGROUND

On 31 December 2019, the World Health Organization recognised clusters of pneumonia-like cases due to a novel coronavirus disease (COVID-19). COVID-19 became a pandemic 71 days later.

AIM

To report the clinical and epidemiological features, laboratory data and outcomes of the first group of 11 returned travellers with COVID-19 in Australia.

METHODS

This is a retrospective, multi-centre case series. All patients with confirmed COVID-19 infection were admitted to tertiary referral hospitals in New South Wales, Queensland, Victoria and South Australia.

RESULTS

The median age of the patient cohort was 42 years (interquartile range (IQR), 24-53 years) with six men and five women. Eight (72.7%) patients had returned from Wuhan, one from Shenzhen, one from Japan and one from Europe. Possible human-to-human transmission from close family contacts in gatherings overseas occurred in two cases. Symptoms on admission were fever, cough and sore throat (n = 9, 81.8%). Co-morbidities included hypertension (n = 3, 27.3%) and hypercholesterolaemia (n = 2, 18.2%). No patients developed severe acute respiratory distress nor required intensive care unit admission or mechanical ventilation. After a median hospital stay of 14.5 days (IQR, 6.75-21), all patients were discharged.

CONCLUSIONS

This is a historical record of the first COVID-19 cases in Australia during the early biocontainment phase of the national response. These findings were invaluable for establishing early inpatient and outpatient COVID-19 models of care and informing the management of COVID-19 over time as the outbreak evolved. Future research should extend this Australian case series to examine global epidemiological variation of this novel infection.

Operative tactics in floor of mouth and tongue cancer resection - the importance of imaging and planning

Complete tumour resection (R0 margin) is an axiom of surgical oncology. Oral cancer ablation is challenging, due to anatomical, functional, and aesthetic considerations. R0 margin is strongly linked to better survival outcomes with great variation in the R0 % across units. This is commonly attributed to disease biology. Without disputing the importance of biological characteristics, we contend that image-based anatomical surgical planning has an important role to play in achieving complete resection. Here, we present our approach utilising cross-sectional imaging, anatomical characteristics and spatial awareness in planning resections for floor of mouth (FOM) and oral tongue cancers. We highlight the challenge of controlling the deep tumour margin lingual to mandible due to anterior vector constraints and emphasise the importance of resecting the genial muscles in a planned fashion and that any rim resection should be obliquely sagittal. In resecting lateral FOM tumours, assessing extension to the parapharyngeal fat is crucial; and mandibular rim resection at a sagittal plane below the mylohyoid line is often required. Assessing the proximity of the contralateral neurovascular pedicle, pre-epiglottic space and hyoid bone are crucial parameters to determine the extent of tongue tumour resection. Our cohort included 173 patients with FOM SCC and 299 patients with tongue SCC. Six patients (3.5%) from the FOM group and eight patients (3%) from the tongue group had involved (R1) margins following surgery. This was associated with local relapse (p<0.05). In conclusion, we demonstrate that image-based planning can aid achieving R0 resections and reduce disease relapse.

External validation of OroGrams as a predictive model for overall and progression-free survival in Scottish patients with oropharyngeal squamous cell carcinoma: a retrospective cohort study

The aims of this study were to externally validate the OroGrams (oropharyngeal cancer survival calculator) nomogram in a Scottish cohort with high endemic smoking rates, and to compare survival rates with the original validation cohort. A retrospective cohort study in Greater Glasgow and Clyde ENT and OMFS departments was performed to investigate survival outcomes of patients with oropharyngeal squamous cell carcinoma (OPSCC) from January 2012 - December 2017. The main outcome measures were progression-free (PFS) and overall survival (OS), and Kaplan Meier curves. The predictive accuracy of OroGrams was investigated for survival probabilities at one, three, and five years. Smoking and HPV-negative cancer rates were significantly higher in Scottish patients than in the UK consortium cohort. A greater proportion of Scottish patients had advanced UICC8 stages. PFS in patients with HPV-negative cancer appeared better in the Scottish cohort than in the original cohort. Calculated mean standardised Brier scores for PFS and OS were below 0.2 at all three follow-up points, suggesting good overall prognostic accuracy, but there was wide variation between predictive accuracy in individual patients. OroGrams shows prognostic accuracy at one-year follow up in Scotland. The accuracy decreases with longer follow-up periods.

A Case of Japanese Encephalitis with a Fatal Outcome in an Australian Who Traveled from Bali in 2019

A severe case of Japanese encephalitis virus (JEV) infection, resulting in fatality, occurred in an unvaccinated Australian male traveler from Bali, Indonesia, in 2019. During hospitalisation in Australia, patient cerebrospinal fluid (CSF) yielded JEV-specific IgM antibodies and RNA, and an isolate of the virus. Ongoing transmission of JEV in Bali underscores this pathogen as a public health risk and the importance of appropriate health, vaccination and mosquito avoidance advice to prospective travelers to the region.

Staging and treatment outcomes in oropharyngeal squamous cell carcinoma: a single-centre UK cohort

The 8^th edition of the UICC TNM (UICC 8) staging rules for oropharyngeal squamous cell carcinoma (OPSCC) acknowledges dichotomous disease biology based on the human papillomavirus (HPV) tumour status. This retrospective study was undertaken to validate those staging rules in a single UK treatment centre. Given a recent resurgence of interest in primary surgery for OPSCC, a secondary objective was to identify subsets of patients who might benefit. Patients presenting with OPSCC between 2010 and 2017 to the South Glasgow head and neck multidisciplinary team were identified from a prospective database. Only patients managed with curative intent were included (n=272). Stage group allocation according to the UICC 8 resulted in appropriate hazard discrimination, in contradistinction to the UICC 7 staging rules. Locally advanced (cT3-4) disease had a relatively poor prognosis irrespective of HPV status. No clear benefit for primary surgery in any subgroup was demonstrated. A dichotomous disease biology based on the HPV status of tumour is confirmed in this cohort. Patients with HPV-positive T1 and T2 primary tumours have an excellent prognosis when treated with non-surgical treatment regimens. The use of surgery as the primary management for categories of patients presenting with OPSCC should be in the context of clinical trials.

Broadband, millimeter-wave antireflection coatings for large-format, cryogenic aluminum oxide optics

We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements-in our case, 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly, while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions, then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves $ (97 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance.

Mosquito-Independent Transmission of West Nile virus in Farmed Saltwater Crocodiles (Crocodylus porosus)

West Nile virus, Kunjin strain (WNV_KUN) is endemic in Northern Australia, but rarely causes clinical disease in humans and horses. Recently, WNV_KUN genomic material was detected in cutaneous lesions of farmed saltwater crocodiles (Crocodylus porosus), but live virus could not be isolated, begging the question of the pathogenesis of these lesions. Crocodile hatchlings were experimentally infected with either 10⁵ (n = 10) or 10⁴ (n = 11) TCID₅₀-doses of WNV_KUN and each group co-housed with six uninfected hatchlings in a mosquito-free facility. Seven hatchlings were mock-infected and housed separately. Each crocodile was rotationally examined and blood-sampled every third day over a 3-week period. Eleven animals, including three crocodiles developing typical skin lesions, were culled and sampled 21 days post-infection (dpi). The remaining hatchlings were blood-sampled fortnightly until experimental endpoint 87 dpi. All hatchlings remained free of overt clinical disease, apart from skin lesions, throughout the experiment. Viremia was detected by qRT-PCR in infected animals during 2–17 dpi and in-contact animals 11–21 dpi, indicating horizontal mosquito-independent transmission. Detection of viral genome in tank-water as well as oral and cloacal swabs, collected on multiple days, suggests that shedding into pen-water and subsequent mucosal infection is the most likely route. All inoculated animals and some in-contact animals developed virus-neutralizing antibodies detectable from 17 dpi. Virus-neutralizing antibody titers continued to increase in exposed animals until the experimental endpoint, suggestive of persisting viral antigen. However, no viral antigen was detected by immunohistochemistry in any tissue sample, including from skin and intestine. While this study confirmed that infection of saltwater crocodiles with WNV_KUN was associated with the formation of skin lesions, we were unable to elucidate the pathogenesis of these lesions or the nidus of viral persistence. Our results nevertheless suggest that prevention of WNV_KUN infection and induction of skin lesions in farmed crocodiles may require management of both mosquito-borne and water-borne viral transmission in addition to vaccination strategies.

Measles Vaccine Virus RNA in Children More Than 100 Days after Vaccination

Measles vaccines have been in use since the 1960s with excellent safety and effectiveness profiles. Limited data are available on detection of measles vaccine virus (MeVV) RNA in human subjects following vaccination. Available evidence suggests MeVV RNA can be identified up to 14 days after vaccination, with detection beyond this rare. In routine diagnostic testing, we used two real-time reverse transcription-polymerase chain reaction (RT-rPCR) assays targeting M and F genes to identify measles virus (MeV) and MeVV RNA. Confirmatory testing was performed with an N gene RT-rPCR, followed by sequence confirmation of RT-rPCR positives by semi-nested conventional RT-PCR assays targeting portions of the N, H, and L genes. We report detection and confirmation of MeVV RNA from the respiratory tract of 11 children between 100 and 800 days after most recent receipt of measles-containing vaccine. These novel findings emphasize the importance of genotyping all MeV detections and highlight the need for further work to assess whether persistent MeVV RNA represents viable virus and if transmission to close contacts can occur.

Shape of (101955) Bennu indicative of a rubble pile with internal stiffness

The shapes of asteroids reflect interplay between their interior properties and the processes responsible for their formation and evolution as they journey through the Solar System. Prior to the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) mission, Earth-based radar imaging gave an overview of (101955) Bennu's shape. Here, we construct a high-resolution shape model from OSIRIS-REx images. We find that Bennu's top-like shape, considerable macroporosity, and prominent surface boulders suggest that it is a rubble pile. High-standing, north-south ridges that extend from pole to pole, many long grooves, and surface mass wasting indicate some low levels of internal friction and/or cohesion. Our shape model indicates that, similar to other top-shaped asteroids, Bennu formed by reaccumulation and underwent past periods of fast spin leading to its current shape. Today, Bennu might follow a different evolutionary pathway, with interior stiffness permitting surface cracking and mass wasting.

Illumina sequencing of clinical samples for virus detection in a public health laboratory

High-throughput sequencing (HTS) provides the opportunity, once a diagnostic result is obtained, to extract additional information from a virus-containing sample. Hence, it offers advantages over established quantitative amplification technology, such as quantitative PCR, particularly in a public health environment. At this early stage of its clinical application, there have been limited studies comparing HTS performance to that of the more established quantitative PCR technology for direct detection of viruses. In this pilot-scale study, we tested HTS with a range of viruses and sample types routinely encountered in a public health virology laboratory. In comparison with quantitative PCR, our HTS method was able to sensitively (92%) detect all viruses in any sample type with the exception of certain tissues. Moreover, sufficient nucleotide sequence information was obtained to enable genotyping of strains detected, thus providing additional useful epidemiological information. While HTS sensitivity may not yet match that of PCR, the added value through enhanced epidemiological data has considerable potential to enable real-time surveillance of circulating strains so as to facilitate rapid and appropriate response to outbreaks and virus zoonotic spillover events.

On the Home Front: Specialised Reference Testing for Dengue in the Australasian Region

Reference laboratories are vital for disease control and interpreting the complexities and impact of emerging pathogens. The role of these centralized facilities extends beyond routine screening capabilities to provide rapid, specific, and accurate diagnoses, advanced data analysis, consultation services, and sophisticated disease surveillance and monitoring. Within the Australasian region, the Public Health Virology Laboratory (PHV), Forensic and Scientific Services, Department of Health, Queensland Government, Australia, and the Institute of Environmental Science and Research Limited (ESR), New Zealand (NZ) perform specialised reference testing and surveillance for dengue viruses (DENVs) and other emerging arthropod-borne viruses (arboviruses), including chikungunya virus (CHIKV) and Zika virus (ZIKV). With a focus on DENV, we review the reference testing performed by PHV (2005 to 2017) and ESR (2008 to 2017). We also describe how the evolution and expansion of reference-based methodologies and the adoption of new technologies have provided the critical elements of preparedness and early detection that complement frontline public health control efforts and limit the spread of arboviruses within Australasia.

Detection of Spotted Fever Group Rickettsia DNA by Deep Sequencing

After conventional molecular and serologic testing failed to diagnose the cause of illness, deep sequencing identified spotted fever group Rickettsia DNA in a patient’s blood sample. Sequences belonged to R. honei, the causative agent of Flinders Island spotted fever. Next-generation sequencing is proving to be a useful tool for clinical diagnostics.

Sentinel lymph node biopsy for oral squamous cell carcinoma. Where are we now?

Recent data have confirmed that elective surgical management of the cN0 neck improves survival in patients with early (T1-T2) oral squamous cell carcinoma (SCC), and is better than watchful waiting. However, elective neck dissection (END) may not always be necessary. Sentinel node biopsy (SNB), which is a reliable staging test for patients with early disease and a radiologically N0 neck, can detect occult metastases with a sensitivity of 86%-94%. Patients with no sign of metastases on SNB could avoid neck dissection, and individual treatment should reduce both morbidity and cost. Currently, SNB for oral SCC is available at a limited number of centres in the UK, but this is likely to change as national guidelines have recommended that it is incorporated into the standard treatment pathway. It is therefore important to understand the current evidence that supports its use, its limitations and related controversies, and to plan for a validated training programme.

Genetic Characterization of Archived Bunyaviruses and their Potential for Emergence in Australia

Genetic relationships between bunyaviruses from Australia and pathogenic bunyaviruses from elsewhere indicate emergence potential.

To better understand the diversity of bunyaviruses and their circulation in Australia, we sequenced 5 viruses (Gan Gan, Trubanaman, Kowanyama, Yacaaba, and Taggert) isolated and serologically identified 4 decades ago as members of the family Bunyaviridae. Gan Gan and Trubanaman viruses almost perfectly matched 2 recently isolated, purportedly novel viruses, Salt Ash and Murrumbidgee viruses, respectively. Kowanyama and Yacaaba viruses were identified as being related to members of a large clade containing pathogenic viruses. Taggert virus was confirmed as being a nairovirus; several viruses of this genus are pathogenic to humans. The genetic relationships and historical experimental infections in mice reveal the potential for these viruses to lead to disease emergence.

A longitudinal cohort study of HIV 'treatment as prevention' in gay, bisexual and other men who have sex with men: the Treatment with Antiretrovirals and their Impact on Positive And Negative men (TAIPAN) study protocol

BACKGROUND

Australia has increased coverage of antiretroviral treatment (ART) over the past decade, reaching 73% uptake in 2014. While ART reduces AIDS-related deaths, accumulating evidence suggests that it could also bolster prevention efforts by reducing the risk of HIV transmission ('treatment as prevention'). While promising, evidence of community-level impact of treatment as prevention on reducing HIV incidence among gay and bisexual men is limited. We describe a study protocol that aims to determine if scale up of testing and treatment for HIV leads to a reduction in community viraemia and, in turn, if this reduction is temporally associated with a reduction in HIV incidence among gay and bisexual men in Australia's two most populous states.

METHODS

Over the period 2009 to 2017, we will establish two cohorts making use of clinical and laboratory data electronically extracted retrospectively and prospectively from 73 health services and laboratories in the states of New South Wales and Victoria. The 'positive cohort' will consist of approximately 13,000 gay and bisexual men (>90% of all people living with HIV). The 'negative cohort' will consist of at least 40,000 HIV-negative gay and bisexual men (approximately half of the total population). Within the negative cohort we will use standard repeat-testing methods to calculate annual HIV incidence. Community prevalence of viraemia will be defined as the proportion of men with a viral load ≥200RNA copies/mm³, which will combine viral load data from the positive cohort and viraemia estimates among those with an undiagnosed HIV infection. Using regression analyses and adjusting for behavioural and demographic factors associated with infection, we will assess the temporal association between the community prevalence of viraemia and the incidence of HIV infection. Further analyses will make use of these cohorts to assess incidence and predictors of treatment initiation, repeat HIV testing, and viral suppression.

DISCUSSION

This study will provide important information on whether 'treatment as prevention' is associated with a reduction in HIV incidence at a community level among gay and bisexual men.

Experiences of care by Australians with a diagnosis of borderline personality disorder

Borderline personality disorder (BPD) is a complex and challenging mental health condition for the person and service providers who support them. This paper reports on the results of a survey of 153 people with a diagnosis of BPD about their experiences of attempting to receive support in managing this mental health condition. It provides their perceptions of a range of experiences not reported in the existing literature, including general practitioner roles, urban and rural differences, public and private hospital differences, and comparison of usefulness of support across multiple support types. People with a diagnosis of BPD continue to experience significant discrimination when attempting to get their needs met within both public and private health services. Further education for nurses and other health professionals is indicated to address pervasive negative attitudes towards people with a diagnosis of BPD. There is limited understanding of the experience of seeking and receiving treatment and care by people with a diagnosis of borderline personality disorder (BPD), their perceptions of barriers to care and the quality of services they receive. This study aimed to explore these experiences from the perspective of Australians with this diagnosis. An invitation to participate in an online survey was distributed across multiple consumer and carer organizations and mental health services, by the Private Mental Health Consumer Carer Network (Australia) in 2011. Responses from 153 people with a diagnosis of BPD showed that they experience significant challenges and discrimination when attempting to get their needs met within both public and private health services, including general practice. Seeking help from hospital emergency departments during crises was particularly challenging. Metropolitan and rural differences, and gender differences, were also apparent. Community supports were perceived as inadequate to meet their needs. This study provides data on a range of experiences not reported in existing literature, including general practitioner roles, urban and rural differences, public and private hospital differences, and comparison of usefulness of support across multiple support types. Its findings can help inform better training for health professionals and better care for this population.

Experiences of family carers of people diagnosed with borderline personality disorder

There is limited understanding of the experience of family carers of people diagnosed with borderline personality disorder (BPD). This study aimed to explore their experiences of being carers, their attempts to seek help for the person diagnosed with BPD and their own carer needs. An invitation to participate in an online survey was distributed to carers across multiple consumer and carer organizations and mental health services, by the Private Mental Health Consumer Carer Network (Australia) in 2011. Responses from 121 carers showed that they experience significant challenges and discrimination when attempting to engage with and seek support from health services. Comparison with consumers' experiences (reported elsewhere) showed that these carers have a clear understanding of the discrimination faced by people with this diagnosis, largely because they also experience exclusion and discrimination. Community carer support services were perceived as inadequate. General practitioners were an important source of support; however, they and other service providers need more education and training to support attitudinal change to address discrimination, recognize carers' needs and provide more effective support. This study provides the first detailed account of BPD carers' experiences across a broad range of support needs and interactions with community support and health services.

No evidence of prolonged Hendra virus shedding by 2 patients, Australia

To better understand the natural history of Hendra virus infection and its tendency to relapse, 2 humans infected with this virus were monitored after acute infection. Virus was not detected in blood samples when patients were followed-up at 2 and 6 years. Thus, no evidence was found for prolonged virus shedding.