Background: The NEIS CRE aims to determine the most effective immunisation program for prevention of invasive meningococcal disease (IMD) and gonorrhoea globally, using one vaccine (4CMenB). Vaccine effectiveness (VE) and impact (VI) against IMD and gonorrhoea were estimated 5-7 years post 4CMenB vaccine introduction in South Australia (SA) and the Northern Territory (NT)

Methods: Case-control and cohort studies in SA and NT. VE was estimated using notification data and controls from the Australian Immunisation Register for IMD and chlamydia controls for gonorrhoea. VI was estimated as adjusted incidence-rate-ratios (aIRR) in pre-vs-post-program-implementation years. Gonococcal isolates were sequenced.

Results: For IMD in SA at 5 years, VE=98.5% (95%CI 81.9-99.9%;p=0.001) for three-doses and VE=64.2% (95%CI 7.4%-86.1%;p=0.034) for two-doses in infants. In adolescents, two-dose VE=92.3% (95%CI 34.3%-99.1%;p=0.019). There was a 72.7% relative reduction in IMD B disease in infants <12 months old (aIRR=0.273 (95%CI 0.120-0.620);p=0.002) and 76.2% reduction in adolescents aged 15-18 years (aIRR=0.238 (95%CI 0.097-0.584);p=0.002).

At 7 years VE=57.2% (p=0.160) for infants and VE=85.3% (p=0.003) for adolescents.

Two-dose VE=40.2% (95%CI 33.7%-46.1%;p<0.001) against gonorrhoea in 2,168 cases and 9,625 controls in adolescents in SA. One-dose VE=27.1 (95%CI 10.6%-40.5%;p=0.002). The risk of a second gonococcal infection was lower in vaccinated gonococcal cases (adjusted Hazard Ratio (aHR)=0.671 (95%CI 0.513-0.878);p=0.004) but not for a third infection (aHR=0.701;p=0.130). In subgroup analyses, VE=4.1 (95%CI -17.8-21.9) at >60 months since vaccination.

In the NT cohort analysis VE=35% (aHR 0.646 (95%CI 0.508–0.821);p<0.001) in 34,413 individuals.

There were 1003 gonococcal isolates sequenced from 01/10/2021-01/01/2025 from SA (n=876) and the NT (n=127). For Neisseria-Heparin-Binding-Antigen (NHBA) there was a lower proportion of variant 542 in the vaccinated (28.9%) vs unvaccinated groups (38.7%).

Conclusions: 4CMenB demonstrated high effectiveness against IMD and moderate effectiveness against gonorrhoea up to 5years, with waning observed >5 years. The mechanism of cross-protection may relate to antibodies generated against outer-membrane-protein-NHBA.

Background and Aim
An infectious syphilis outbreak was declared in Perth in 2020. This was marked by increasing cases in priority populations including Aboriginal people, women of reproductive age and people experiencing homelessness. Over time, other priority groups emerged, such as people who use drugs, and culturally and linguistically diverse (CALD) people.

To address such threats, novel solutions and an ability to adapt to changing epidemiology are required.

Methods and Analysis
Data were extracted from Boorloo Public Health Unit’s (PHU) Syphilis Case Management Database to estimate the impact of infectious syphilis on priority populations.

A time series approach was undertaken to explore the evolving epidemiology, and targeted initiatives were developed and implemented as a result.

Outcomes
With dedicated funding from a state-wide public health response to syphilis, Boorloo PHU established a multidisciplinary team with nursing, midwifery, medical, epidemiologic and Aboriginal health expertise. Principles of team initiatives include:
• Embedding cultural safety for Aboriginal people and CALD populations.
• Collaborating with other healthcare providers to improve continuity of care, particularly in pregnancy. Since 2020, the Syphilis in Pregnancy multiagency program has supported 219 pregnant women and developed 149 Maternal Neonatal Management Plans.
• Addressing needs for people who face barriers accessing healthcare. In 2025, over 160 outreach services were conducted for syphilis cases and contacts.
• Expanding education and training offerings. In 2023-2025, 284 presentations were delivered to a range of consumer and professional settings, and eleven articles written for state-wide, national and international publications. 2026 has seen further innovation into CALD needs, including training for interpreters and education for the Adult Migrants English Program.

Conclusion and Future Actions
A multidisciplinary team including Aboriginal health workers enables adaptive responses to the syphilis outbreak.

In 2025, syphilis was declared a Communicable Disease Incident of National Significance. Our local successes may inform practice in other settings.

Aboriginal Governance
Boorloo PHU prioritises principles of cultural continuity, equity, respect, reciprocity and responsibility. As such, Aboriginal health liaison officers (AHLO) have been a part of Boorloo PHU’s multidisciplinary syphilis team from its inception. The team has four AHLOs – including at least one male and one female – who:
- Provide leadership on management planning of Aboriginal cases and contacts. Where Aboriginal cases and contacts are affected, Boorloo PHU also collaborates closely with Aboriginal health service providers.
- Co-design programs that involve Aboriginal community and Aboriginal controlled organisations.
- Author and contribute to policies that relate to Aboriginal people.
- Collect, access, manage and analyse information in the Syphilis Case Management Database (REDCap).
- Contribute to ongoing design and improvements of the REDCap.
- Give education to Aboriginal community groups, health service providers and other settings involved in the health of Aboriginal people.

In this presentation, Boorloo PHU’s Aboriginal Health Team Coordinator will describe the way Aboriginal governance has contributed towards optimising outcomes among Aboriginal people affected by syphilis.

Background and Aim
Beginning in 2022, sustained local transmission of mpox (clade IIb) was observed in multiple regions around the world where it had not previously circulated, including Australia. Clade IIb mpox is primarily transmitted through sexual contact and predominantly affects men who have sex with men (MSM). Following a small outbreak in 2023, Australia observed a significant epidemic from 2024 to early 2025, with more than 1,400 cases notified nationally. Levels of epidemic activity were lower in 2025 (approximately 80 cases from June to December), likely due to a combination of targeted public health responses, changes in behaviour, vaccination, and infection-induced immunity. Understanding the relative contributions of these factors to mpox transmission dynamics in Australia is essential for predicting if/when to expect possible resurgences and for planning public health responses.

Methods and Analysis
We developed a mathematical model of mpox transmission among MSM that incorporates sexual contact risk stratification, natural and vaccine-induced immune status, and age, and is calibrated to time series data of daily case incidence. We first estimated transmission parameters and MSM population susceptibility to mpox in Australia. We then explored potential outbreak response strategies and examined how vaccine effectiveness and behavioural changes may impact transmission conditions and expected intervention performance.

Outcomes
Using this model, we estimated the potential impact of alternate vaccination strategies on mpox transmission dynamics and health outcomes in Australia. As the long-term relationships between natural and vaccine-induced immunity have not yet been established empirically, we further considered these strategies across a range of plausible immunological scenarios.

Conclusion and Future Outcomes
In this work, we present a mathematical model for mpox transmission in a high-risk group in Australia that incorporates past transmission and immunisation patterns and can be adapted to reflect an updated understanding of risk behaviors and vaccine- and infection-induced immune dynamics.

Background and Aim
Infectious syphilis notifications in Australia have more than doubled in the last decade, reaching 5866 cases in 2024. Aboriginal and Torres Strait Islander notification rates are five times higher compared with non-Indigenous Australians. Between 2016-2024, 99 cases of congenital syphilis resulted in 33 infant deaths [1]. In August 2025, syphilis was declared a Communicable Disease Incident of National Significance (CDINS)[2]. Syphilis surveillance remains fragmented across state and territory systems, with only a fraction of data reported to the National Notifiable Diseases Surveillance System. This study maps data variations to inform nationally consistent surveillance requirements.
Methods and Analysis
We identified syphilis surveillance systems through literature review, document analysis and stakeholder consultation. We systematically analysed 15 syphilis surveillance databases across eight Australian states and territories, plus national and New Zealand systems. Variables were extracted using a structured matrix and categorized through an iterative process using the READ approach [3], [4]. Systems were compared examining both data content (which variables are collected) and process (how data are collected and managed).
Outcomes
Substantial heterogeneity exists across jurisdictions, with variation seen across sexual identity and details of sexual encounters, social vulnerability and partner notification. Operational challenges include reliance on fax, mail, or phone reporting, creating data entry delays. These variations can hinder capacity to identify transmission patterns and target interventions to particular populations. Furthermore, absence of standardised identifiers may preclude data linkage with other national datasets.

Conclusion and Future Actions
While Australia's National Notifiable Diseases Surveillance System provides minimum core data, jurisdictions independently collect substantially more detailed variables though in inconsistent ways. Harmonising surveillance data represents one critical component of a multi-pronged response to this CDINS, alongside clinical, public health, and social interventions. This study provides a first systematic, cross‑jurisdictional documentation of syphilis surveillance data variables in Australia, identifying specific areas where harmonisation could improve comparability, and support more effective public health action.

ADDITIONAL SECTION: ABORIGINAL AND TORRES STRAIT ISLANDER GOVERNANCE AND INDIGENOUS DATA SOVEREIGNTY
This research operates under a tailored, formal Aboriginal and Torres Strait Islander governance structure, chaired by Associate Professor Lisa Whop, to ensure cultural safety and Indigenous data sovereignty principles throughout all research phases. Our governance group includes Aboriginal and Torres Strait Islander co-investigators and representatives from Community Controlled Health Organisations, meeting bi-annually with oversight of research design, stakeholder engagement, data interpretation, and dissemination strategies.
We apply the Maiam nayri Wingara Indigenous Data Sovereignty Collective principles, emphasizing Aboriginal and Torres Strait Islander peoples' rights to govern the collection, ownership, and application of their own data. This is critical given syphilis disproportionately affects Aboriginal and Torres Strait Islander communities.
Current surveillance systems uniformly fail Indigenous Data Sovereignty principles. All jurisdictional databases are government-controlled across the entire data ecosystem—from collection through storage, analysis, and dissemination. Aboriginal Community Controlled Health Organisations face laborious, time-consuming processes to access aggregated data about their own communities. No jurisdiction provides Aboriginal and Torres Strait Islander peoples meaningful governance over how their data is collected, interpreted, or used, despite surveillance systems being ostensibly designed to improve health outcomes for affected communities.
Our research demonstrates that while individual jurisdictions collect different variables, none adequately embed Indigenous data sovereignty into surveillance infrastructure. A national syphilis register presents an opportunity to redesign data governance from inception, incorporating Aboriginal and Torres Strait Islander leadership in system design, community-controlled access protocols, and culturally safe data practices. Without addressing these fundamental governance failures, any national surveillance system risks perpetuating extractive research practices that have historically harmed Aboriginal and Torres Strait Islander peoples.

Background/Aim:
Congenital syphilis (CS) is a serious public health concern and can result in still births or babies with serious sequelae. In WA, CS notifications increased from three cases from 2008 to 2017 to 21 cases from 2018 to 2025.

Public health reviews of every CS and ‘near-miss’ case (baby born to an infected mother who did NOT receive treatment more than 30 days before delivery and did not contract CS) commenced in 2019 to identify health system changes required to prevent further cases.



Methods and Analysis:
We reviewed reports from 26 public health reviews covering 21 CS (13 live, eight stillbirths) and five near-miss cases from 2019 to 2025. Qualitative thematic analysis identified common issues contributing to vertical syphilis transmission.

Outcomes:
CS and near-miss cases occurred in both regional (12 cases) and metropolitan (14 cases) areas and 16 of the infants were Aboriginal.
Characteristics over-represented in mothers who had a baby with CS or a near miss included: identifying as Aboriginal, residing in a remote area, experiencing homelessness, alcohol use, drug use and/or other complex social issues.
Lack of access to culturally safe antenatal care and comprehensive primary healthcare was a factor frequently contributing to delayed syphilis diagnosis and treatment resulting in CS. Lack of awareness of the syphilis outbreak and the importance of syphilis testing in pregnancy among health care staff contributed to a small number of cases, mostly before 2022. The most recent cases involved mothers who had concealed pregnancy and/or limited health care related to social determinants of health.

Conclusions and Future actions:
It is important to explore alternative and co-designed models of care involving Aboriginal women, other affected communities, and key stakeholders. However, while background syphilis rates remain high, CS prevention requires social determinants to be addressed, community engagement and person-centred, culturally-safe healthcare.

Background and Aim

Western Public Health Unit (WPHU) analysed HIV surveillance data to understand HIV in Victoria and within our catchment.



Methods and Analysis

We analysed Victorian HIV cases confirmed between 1/1/2022 and 30/06/2025. We compared direct age-standardised rates of HIV between WPHU and other local public health units (LPHUs), using Victoria as a reference population. We then examined the demographics, pre-exposure prophylaxis (PrEP) usage, and CD4+ counts at diagnosis of WPHU cases.



Outcomes

Over the period, Victoria recorded 760 confirmed cases. Across LPHUs, WPHU recorded the highest age-standardised rate (WPHU: 17.4/100,000; Victoria: 11.2/100,000). Thirty-six percent of new HIV cases in Victoria lived in WPHU, 54% were aged 25-39 years, and 57% acquired HIV in Victoria.

Thirty-nine percent of WPHU cases (n=106) resided within Melbourne local government area (incidence: 50/100,000 population over the period of analysis). Of those, 96% (n=102) were male and 69% (n=73) aged 25-39. Fifty- nine percent (n=62) acquired infection in Victoria, and 24% (n=25) had ever used PrEP, whereas 7% (n=11) of cases outside Melbourne had ever used PrEP. Of Melbourne's cases, 57% (n=58) had CD4+ counts ≥ 250 cells/mm3 at diagnosis. The median age of Melbourne’s cases was 31 years; cases from other WPHU LGAs had a median age of 36 years.



Conclusion and Future actions

Prior use of PrEP among Melbourne cases indicates a degree of engagement with prevention initiatives in the locality with the highest incidence of infection. High CD4 counts at diagnosis suggest that most HIV in Melbourne is diagnosed early, indicating good access to testing. Nevertheless, a high proportion of Melbourne cases are thought to have been acquired locally among a relatively small community.



We identified an area with higher HIV rates among a defined cohort that is engaged with services, which will inform targeted prevention efforts.

Background/Aim:
Following the initial mpox outbreak in 2022, Western Australia (WA) experienced a resurgence of clade II in October 2024. Notifications increased from zero between October 2023 and September 2024 to three in October 2024, peaking at 27 between November 2024 and January 2025. Cases were predominantly metropolitan, gay, bisexual, and men who have sex with men (GBMSM) who attended sex-on-premises venues (SOPVs).

Methods and Analysis:
A collaborative mpox public health response was coordinated by the Communicable Disease Control Directorate in partnership with WAAC, communications directorate and public health units including:
• Establishment of WA Health’s mpox stakeholder advisory group enabling stakeholder access to notification data, thus facilitating collaborative evidence-informed initiatives.
• Targeted campaigns on social media, dating apps and at Perth airport.
• Resources for organisations and clinicians including a stakeholder toolkit, cleaning/infection control guideline for SOPVs, situational reports, web content, clinician alerts, and an mpox quick guide.
• Health sector partnerships with Perth metropolitan SOPVs.

Outcomes:
Cases of mpox dropped from 9 in January 2025 to 1 in February 2025; no notifications were received following Sydney Mardi Gras in March 2025.

Key achievements:
• Highly successful campaign.
o TikTok - 1.9 million impressions, and a click-through-rate of 0.2%.
o Meta - 447,359 impressions and a click-through-rate of 1.64%.
o Over 1.3 million visitors to Perth Airport in December 2024.
o Dating apps - over 170,000 impressions and click-through-rate of 1.4%.
• Providing infection prevention and control advice and resources to SOPVs
• Establishing a regular SOPV newsletter.
• Mpox vaccinations offered at a SOPV and Perth Pride events.

Challenges:
• Low vaccination uptake in GBMSM and other priority populations.
• Contact tracing limited due to anonymity of most sexual contacts.

Conclusions and Future actions:
A collaborative public health response, in partnership with SOPVs, can have a significant impact on the prevention, testing and management of emerging communicable diseases.