
This report describes influenza surveillance activities in Australia in 2020 to 2021 and the impact which coronavirus disease 2019 (COVID-19) related public health and social measures (PHSMs) had on influenza notifications. Data were extracted from several sources constituting the National Influenza Surveillance Scheme. In 2020 and 2021, a range of PHSMs were instituted across Australia to reduce the spread of COVID-19. These measures had a substantial impact on influenza circulation during this time. Laboratory-confirmed influenza notifications in these years were the lowest reported to the National Notifiable Diseases Surveillance System (NNDSS) since influenza became nationally notifiable in 2001. Laboratory-confirmed influenza notification rates varied greatly between states and territories in the two-year reporting period, likely influenced by differences in the PHSMs instituted across the country. Higher influenza notification rates were observed in the 0-4 and 5-9 year age groups in 2020, while the notification rates in 2021 were very low across all age groups. In 2020, eighty-seven percent of laboratory-confirmed influenza notifications were influenza A (91.1% influenza A(unsubtyped); 7.7% A(H1N1)pdm09; 1.2% A(H3N2)) and 12.6% were influenza B. In 2021, seventy-two percent of laboratory-confirmed influenza notifications were influenza A (91.1% influenza A(unsubtyped); 8.3% A(H3N2); 1.3% A(H1N1)pdm09) and 17.3% were influenza B. Very low influenza activity was also observed in community sentinel surveillance systems. However, slight increases in influenza-like illness, still at very low rates compared to previous years, were reported by sentinel general practices, with rises observed in mid-June in both 2020 and 2021. Very few laboratory-confirmed influenza sentinel hospital admissions and deaths were reported in 2020 and 2021.
Background:As most Salmonella Typhi (S. Typhi) cases notified to public health units in Australia are acquired overseas, a case without recent travel raises concerns of local transmission. We describe a case of S. Typhi in a hospital inpatient without recent travel, where early use of genomic sequencing suggested remote acquisition from Chile in the 1980s, with chronic asymptomatic carriage. This facilitated the stand-down of a complex acquisition investigation. Case:A notification of S. Typhi on stool culture was received for a female aged over 90 years living in Melbourne, Australia in October 2023. She had been hospitalised for three weeks (unrelated illness) and transferred into a residential aged care facility (RACF) six days prior to the result being known. She was asymptomatic and the sample was collected due to a recent ward gastroenteritis outbreak. Investigation:Epidemiological investigation identified the case had emigrated to Australia in 1981 from Chile. Recent typhoid-like illness, overseas travel or contact with travellers from endemic areas were excluded. Subsequent genomic sequencing identified the isolate was multilocus sequence type 2 and did not cluster with any strains isolated in Victorian or international databases, most closely clustering with historical South American strains, with potential in-host changes over time. Management:The case was presumed infectious throughout their hospital stay, with chronic carriage. There were 18 contacts, of whom 14 provided screening samples and were negative. Antibiotic case clearance was not recommended by the treating clinician due to patient comorbidity, treatment toxicity risks and unlikely treatment success without gallbladder removal. Enhanced infection control measures were instituted in the RACF (e.g. private bathroom, contact precautions for personal care, no food preparation). No additional cases were reported after two incubation periods (60 days). Conclusion:Early genomic sequencing enhanced the efficiency of the public health investigation by rapidly confirming overseas acquisition and chronic carriage, obviating the need for extensive local upstream investigation.
Two incursions of high pathogenicity avian influenza (HPAI) A(H5N1) clade 2.3.4.4b in vagrant birds were identified in the Hunter New England region of New South Wales, Australia on 28 June 2026 and 10 July 2026. These were the first detections of the virus in New South Wales and occurred shortly after the first Australian detection in June 2026. The Hunter New England Population Health Unit managed human contacts of the infected birds using a contact management system designed and purpose-built by the Unit. We report on the public health response and opportunities for improvement.
Vaccination plays a pivotal role in protecting people who are immunocompromised, and who may therefore be at increased risk of infectious diseases, including vaccine preventable diseases (VPDs). However, there are special challenges in clinical practice and the development of immunisation policies to accurately address the vaccination needs of this heterogeneous population. This review aims to highlight the immunisation needs and challenges of immunocompromised populations, and to summarise the rationale behind the immunisation recommendations for these populations in Australia. The chapter Vaccination for people who are immunocompromised, in the Australian Immunisation Handbook, was recently updated by the Australian Technical Advisory Group on Immunisation (ATAGI). The updated chapter introduces new categorisation and risk classification for various types of immunocompromise, alongside the principles of immunisation. When planning immunisation for immunocompromised people, it is crucial to consider their underlying diagnoses, exposure to immunosuppressive therapies, susceptibility to VPDs, and their immune response to vaccination. Strategies to improve protection for immunocompromised persons include booster doses or altered schedules of routine vaccines; additional vaccines to prevent specific VPDs; and complete revaccination following immune reconstitution. Several national and jurisdictional vaccination programs have been implemented for immunocompromised populations (alongside other priority populations); however, monitoring vaccine coverage in these groups is challenging, and strategies to improve coverage are needed. There are significant evidence gaps in vaccine research for immunocompromised people, particularly regarding the optimal timing and scheduling of vaccinations to ensure maximum efficacy and safety. Future research should prioritise the inclusion of immunocompromised people in clinical trials and should integrate evidence from post-licensure use through data linkage. Emerging vaccine technologies may enable the development of more immunogenic vaccines or may offer more effective vaccination strategies for better protection against VPDs in immunocompromised people.
This report describes influenza surveillance activities in Australia in 2019. Data were extracted from several sources constituting the National Influenza Surveillance Scheme. The 2019 influenza season in Australia was characterised by high activity overall, with 2.8 times as many laboratory-confirmed influenza notifications as the five-year mean value. There were an unusually high number of notifications reported in the 2018-2019 interseasonal period; an earlier peak in influenza notifications; and prolonged activity after the peak of the season compared to previous years. There was considerable variation in the timing of peak influenza activity between states and territories; however, this was not unexpected given climatic differences. Notification rates were highest in the 0-4 and 5-9 year age groups, and about 2.1 times higher in these age groups than the overall notification rate. The age-specific notification rates of influenza A were higher than the corresponding rates of influenza B in all age groups in 2019; however, the age-specific notification rate of influenza B was considerably higher among those aged 0-15 years compared to other age groups. In 2019, of laboratory-confirmed influenza notifications, 76.6% were influenza A (71.6% influenza A(unsubtyped), 3.9% A(H3N2) and 1.1% A(H1N1)pdm09) and 23.2% were influenza B. Similar trends were observed across many sentinel surveillance systems for influenza, with each sentinel system showing increased activity during the interseasonal period and earlier peak activity in 2019. High notification rates were reflected in an increase in sentinel hospital admissions with confirmed influenza. The burden placed on hospitals due to people admitted with influenza was high; however, severity (measured through the proportion of patients admitted directly to intensive care units) was moderate. Influenza was recorded as the underlying cause of death for fewer than 1% of all deaths that occurred in 2019.
The reference laboratories of the Australian Meningococcal Surveillance Programme (AMSP) report data on the number of cases of invasive meningococcal disease (IMD) confirmed by laboratory testing using culture and molecular based techniques. Data contained in quarterly reports are restricted to a description of case numbers of IMD by jurisdiction and serogroup, where known and expanded in 2024 to include antimicrobial resistance data for ceftriaxone, penicillin, ciprofloxacin and rifampicin. A full analysis of laboratory confirmations of IMD in each calendar year are contained in the AMSP annual reports.
As part of its role in the World Health Organization (WHO) Global Influenza Surveillance and Response System (GISRS), the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne (the Centre) received 13,817 human influenza-positive samples during 2025. Viruses were analysed for their antigenic, genetic, and antiviral susceptibility properties. Selected viruses were propagated in qualified cells or embryonated hens' eggs for potential use in seasonal influenza virus vaccines. Of the 13,817 samples received or processed, influenza A(H1N1)pdm09 viruses predominated, accounting for 46.1% of samples, compared to 21.2% for A(H3N2) viruses and 19.5% for influenza B viruses; one influenza C virus was received. Among viruses analysed at the Centre, the majority of A(H1N1)pdm09 (> 99%) and influenza B (98%) viruses were antigenically similar to their respective WHO recommended vaccine strains for the Southern Hemisphere in 2025. In contrast, only 43% of A(H3N2) viruses were antigenically similar to their respective WHO recommended vaccine strains. Of 3,307 samples tested for susceptibility to the neuraminidase inhibitors oseltamivir and zanamivir, 37 A(H1N1)pdm09 viruses showed highly reduced inhibition by oseltamivir and no influenza viruses tested showed highly reduced inhibition by zanamivir. Of 5,080 samples with sequencing of the polymerase acidic (PA) gene, no genetic markers associated with highly reduced susceptibility to baloxavir marboxil were identified.
This article, as originally published, contained a mis-compiled tabulation of the notified measles clusters within Australia for the period 2014–2024, inadvertently misrepresenting the distribution of measles clusters across the country during this period. The revised text passages and the revised table presented on the following pages correct these errors. Australia has maintained endemic measles elimination since verification was first achieved in 2014. To support sustained elimination, and strengthen national preparedness, we conducted a ten-year review of measles epidemiology from 1 January 2014 to 31 December 2024. Measles notifications to the National Notifiable Disease Surveillance System were analysed by sex, age, seasonality, state/territory, country of acquisition, vaccination status, genotype, and cluster characteristics.
For over 30 years, the Australian Paediatric Surveillance Unit (APSU) has conducted national prospective surveillance of rare conditions in children, including communicable diseases and complications, providing data that has informed changes to policy and clinical practice. In 2025, the APSU monitored seven rare communicable diseases and complications: acute flaccid paralysis (AFP); perinatal exposure to human immunodeficiency virus (HIV); paediatric HIV infection; juvenile-onset recurrent respiratory papillomatosis (JoRRP); congenital rubella infection/syndrome; congenital varicella syndrome (CVS); and neonatal varicella infection (NVI). An average of 1,313 paediatricians and other relevant clinical specialists received a report card each month listing rare conditions under APSU surveillance (including the seven described in this report), and completed a case report form for any child(ren) seen with one or more of these conditions, detailing demographics, clinical features, treatment/management, risk factors and short-term outcomes. There were 134 notifications, of which 105 were confirmed as cases, after excluding duplicate reports or errors. The annual response rate to the report card was 78.4%. The non-polio AFP incidence of 1.58 per 100,000 children aged < 15 years exceeded the World Health Organization requirement to maintain Australia's polio-free status. Incidence of perinatal exposure to HIV remained stable, but new paediatric HIV infections increased. While there were no cases of congenital rubella or CVS, three cases of NVI and one case of JoRRP were reported, indicating ongoing gaps in vaccination despite two decades of universal vaccination in Australia. Continued APSU surveillance remains essential to assess the prevention of disease occurrence and adverse outcomes.
Background:An outbreak of gastrointestinal illness was notified, affecting attendees at a private function in the Australian Capital Territory (ACT) in 2024. Investigations were conducted to determine the infectious agent, source of illness and mode of transmission, as well as to determine any public health actions required to prevent further illness. Methods:Function attendees were surveyed using a modified standard gastroenteritis questionnaire. A confirmed outbreak case was defined as an individual who was unwell after attending the event and had a norovirus-positive clinical sample; a probable outbreak case was defined as an individual who was unwell with clinically compatible symptoms after attending the event. A case-control study was conducted to identify food items associated with illness. Food safety inspections were performed, and food samples were tested at the ACT Government Analytical Laboratory. Clinical samples were collected from unwell attendees and from an asymptomatic food handler. Results:There were approximately 250-500 attendees at the function; 224 attendees completed the questionnaire and there were 65 cases (5 confirmed and 60 probable). A food handler who had previously been unwell, and who prepared fruit and meat platters for the function more than 96 hours after their symptoms had resolved, subsequently tested positive for norovirus. Environmental Health investigations showed the venue had good food practices and handwashing; the investigation identified no ongoing risks to the public. Testing of food samples did not detect any bacterial foodborne pathogens. Epidemiological investigations identified consumption of fresh fruit (odds ratio [OR]: 5.3; 95% confidence interval [95% CI]: 2.4-12.6; p < 0.001) and cured meat (OR: 2.7; 95% CI: 1.2-6.2; p = 0.02) as significantly associated with disease. Conclusion:Epidemiological and clinical evidence indicates that norovirus was transmitted via contaminated fresh fruit and cured meat platters. Despite the venue having good food handling and handwashing practices, it was likely due to a food handler who had been unwell in the week prior to the function and prepared the implicated foods more than 96 hours after their symptoms resolved. This outbreak investigation shows that safe food practices and exclusion periods reduce but do not eliminate risk completely. Our findings highlight the need for continued education on effective hand hygiene in food preparation settings, especially following gastrointestinal illness.
Nationwide surveillance of Creutzfeldt-Jakob disease (CJD) and other human prion diseases is performed by the Australian National Creutzfeldt-Jakob Disease Registry (ANCJDR). National surveillance encompasses the period since 1 January 1970, with prospective surveillance occurring from 1 October 1993. Over this prospective surveillance period, considerable improvements have been developed in pre-mortem diagnostics in parallel with the delineation of new disease subtypes and heightened awareness of prion diseases in healthcare settings. Surveillance practices of the ANCJDR have evolved and adapted accordingly. This report summarises the activities of the ANCJDR during 2025. Since the ANCJDR began offering diagnostic cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of diagnostic test referrals has steadily increased. In 2025, there were 788 domestic CSF specimens referred for diagnostic testing; 92 persons with suspected human prion disease were formally added to the national register. As of 31 December 2025, more than half of the 84 initial case notifications for 2025 (44/84) remain classified as 'incomplete'; 35 cases have been confirmed as 'definite' or 'probable' prion disease; five cases were excluded. In 2025, most suspected human-prion-disease-related deaths in Australia (56%) underwent neuropathological examination. No cases of variant or iatrogenic CJD were identified in Australia during 2025.
Trachoma is the world's leading infectious cause of preventable blindness and is linked to poor living conditions. In Australia, trachoma has remained a public health problem in remote Indigenous communities in northern, central, and western regions. To seek formal validation by the World Health Organization (WHO) of the elimination of trachoma as a public health problem, Australia has needed to maintain levels of overall trachoma prevalence below 5% in children for at least two years in each formerly endemic state or territory. Australia must also demonstrate that the prevalence of previously undiagnosed trachomatous trichiasis (TT), the severe advanced blinding stage caused by repeated infection, remains below 0.2% in people aged 15 years and over. Australia first reached elimination thresholds in 2022, with 2024 the final year of pre-validation monitoring. In 2024, screening staff assessed trachoma according to WHO grading criteria in 86 communities. Overall prevalence of trachoma was 2.1% in the Northern Territory; 0% in South Australia; and 1.3% in Western Australia. Only nine previously unknown TT cases were reported throughout the Northern Territory, Queensland, South Australia and Western Australia. Based on 2024 surveillance data, Australia is eligible to apply for validation of elimination as a public health problem. Maintaining this achievement will require ongoing improvements to remote housing and environmental conditions; supporting communities to manage remaining disease pockets or risk of resurgence; and continuing accessible TT diagnosis and surgery pathways to address long-term disease impacts. Indigenous leadership is critical to ensure local ownership and accountability to communities.
In 2020, the National Notifiable Diseases Surveillance System received 1,618 tuberculosis (TB) notifications, representing a notification rate of 6.3 per 100,0000 population. In 2019, there were 1,505 TB notifications, with a rate of 5.9 per 100,000 population. Australia has achieved and maintained good TB control since the mid-1980s, sustaining a low annual TB incidence rate of approximately five to six cases per 100,000 population. The number of multi-drug-resistant TB (MDR-TB) cases notified in Australia is lower than global rates, with approximately 2% of TB notifications per year classified as MDR-TB. In Australia, overseas-born people represent the majority of TB cases, accounting for 92% and 90% of TB notifications in 2020 and 2019, respectively. In 2020 and 2019, Aboriginal and Torres Strait Islander people recorded TB rates approximately four times higher than the Australian-born non-Indigenous population. Whilst Australia has achieved and maintained excellent control of TB, sustained effort is required to reduce local rates further, especially among Aboriginal and Torres Strait Islander populations, and to contribute to the World Health Organization's goal to end the global TB epidemic by 2035.
Background:In October 2024, Pilbara treatment guidance for uncomplicated urogenital gonorrhoea shifted from routine ZAP pack (amoxicillin 3 g and probenecid 1 g and azithromycin 1 g oral as a single treatment) to ceftriaxone-based LAC pack (ceftriaxone 500 mg in 2 mL 1% lignocaine intramuscularly and azithromycin 1 g oral, as a single treatment) in response to rising penicillinase-producing N. gonorrhoeae (PPNG) and the threat of imported ciprofloxacin resistance. Design:A retrospective clinical audit to describe demographics, compare treatment and resistance data collected for N. gonorrhoeae notifications for Pilbara health region residents meeting the surveillance case definitions in the Western Australian Notifiable Infectious Diseases Database (WANIDD) against clinical guidelines. Setting:All Pilbara health region resident N. gonorrhoeae notifications in the Western Australian Notifiable Infectious Diseases Database (WANIDD) from 1 July 2023 to 30 June 2024. Main outcome measures:The proportion of notifications that reported treatment with a ZAP pack or LAC pack as per Western Australian and national clinical guidelines. Secondary outcomes included the proportion of notifications undertaken by the WA Country Health Service that reported test of cure at 1-2 weeks; the proportion that reported rescreening at 3 months post notification; and the proportion of notifications that reported PPNG and ciprofloxacin resistance. Results:A total of 188 N. gonorrhoeae notifications were received over the audit time frame. One hundred and twenty-seven notifications of a total of 156 N. gonorrhoeae notifications (81%) reported receiving treatment consistent with WA and National STI treatment guidelines, i.e. ZAP or LAC pack. Fifteen notifications of a total of 188 notifications (8%) reported detection of PPNG and 20 notifications of a total of 188 notifications (11%) reported ciprofloxacin resistance. For WA Country Health service notifications, 9 of 27 (33%) reported re-testing at 1-2 weeks or 3 months. Conclusions:The majority of notifications (81%) reported N. gonorrhoeae treatment consistent with guidelines. A significant proportion of notifications (8%) indicated likely penicillin resistance due to the detection of PPNG. Reinforcing treatment consistent with the updated treatment guidelines of October 2024 for the Pilbara region will reduce the risk of ineffective treatment. Improving the rate of test of cure and test for reinfection (33%) would improve the likelihood of detecting treatment failure and detecting resistance.
Background:There are known gaps in care uptake for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, and public health surveillance represents an opportunity to support health service engagement for cases; however, specific data are lacking regarding follow-up after diagnosis. We assessed outcomes of a Victorian initiative to enhance data availability and to support linkage to care. Methods:Notified cases of HBV and HCV within Victoria during 2023-2024 were analysed to determine post-diagnosis follow-up, including variation by demographics and setting, and reported reasons for lack of linkage to care. Results:Information was available for two-thirds of cases. For HBV, 37.7% reported current treatment or management, while 53.6% reported referral or assessment in progress; for HCV, these proportions were 33.3% and 54.7%. Reasons for gaps included loss to follow-up, cost barriers, and misapplication of HBV treatment criteria. Discussion:Cascade of care information can be effectively collected via public health surveillance, and these systems represent an opportunity to support prioritisation of public health follow-up.
The Australian National Neisseria Network (NNN) comprises reference laboratories in each state and territory that report data on antimicrobial susceptibility testing to an agreed group of antimicrobial agents for the Australian Gonococcal Surveillance Programme (AGSP). The AGSP data are presented quarterly in tabulated form, as well as in the AGSP annual report. This report presents national gonococcal antimicrobial resistance surveillance data from 1 October to 31 December 2025.
The Strategic Plan for Tuberculosis Elimination and Equity in Australia, 2026-2030 provides the framework for Australia's tuberculosis (TB) programmatic response over the next five years. The Strategic Plan upholds a focus on achieving TB elimination, and equitable outcomes for all people affected by TB.
This article, as originally published, contained a mis-compiled tabulation of the notified measles clusters within Australia for the period 2014-2024, inadvertently misrepresenting the distribution of measles clusters across the country during this period. The revised text passages and the revised table presented on the following pages correct these errors. Australia has maintained endemic measles elimination since verification was first achieved in 2014. To support sustained elimination, and strengthen national preparedness, we conducted a ten-year review of measles epidemiology from 1 January 2014 to 31 December 2024. Measles notifications to the National Notifiable Disease Surveillance System were analysed by sex, age, seasonality, state/territory, country of acquisition, vaccination status, genotype, and cluster characteristics.
This report outlines a localised cluster of mpox detected in July 2024, in Canberra, Australian Capital Territory. Investigation identified nine cases, including likely presymptomatic transmission by a vaccinated primary case with a high-contact profile. Five of the nine cluster cases had breakthrough infections and had received two mpox vaccinations more than 18 months earlier. The public health response involved targeted community engagement and a pop-up vaccination clinic, although a high proportion of anonymous sexual partners made contact tracing challenging. These findings underscore the potential for presymptomatic transmission and the importance of ongoing preventive measures, even with vaccination, in high-contact environments.
The reference laboratories of the Australian Meningococcal Surveillance Programme (AMSP) report data on the number of cases of invasive meningococcal disease (IMD) confirmed by laboratory testing using culture and molecular based techniques. Data contained in quarterly reports are restricted to a description of case numbers of IMD by jurisdiction and serogroup, where known and expanded in 2024 to include antimicrobial resistance data for ceftriaxone, penicillin, ciprofloxacin and rifampicin. A full analysis of laboratory confirmations of IMD in each calendar year are contained in the AMSP annual reports.