Communicable diseases intelligence (2018)最新文献

An editorial by Christina Bareja, CDI's Editor and the Director of the Antimicrobial Resistance Policy and Surveillance Section, marking the start of World AMR Awareness Week 2025. The editorial highlights the several surveillance reports of the Australian Group on Antimicrobial Resistance, and of the National Neisseria Network, Australia, which accompany the editorial in a special CDI 'issue' on AMR.

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 the delineation of new disease subtypes; and in 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 2024. Since the ANCJDR began offering diagnostic cerebrospinal fluid (CSF) 14-3-3 protein testing in Australia in September 1997, the annual number of referrals has steadily increased. In 2024, a total of 760 domestic CSF specimens were referred for diagnostic testing and 88 persons with suspected human prion disease were formally added to the national register. As of 31 December 2024, approximately half (42) of the 83 initial case notifications for 2024 remain classified as 'incomplete'; 21 cases were classified as 'definite' and 17 as 'probable' prion disease; three cases were excluded through neuropathological examination. For 2024, seventy-two percent of all suspected human-prion-disease-related deaths in Australia underwent neuropathological examination. No cases of variant or iatrogenic CJD were identified in Australia during 2024.

In Australia, there were 1,552 cases (6.7 per 100,000 population per year) of invasive pneumococcal disease (IPD) notified to the National Notifiable Diseases Surveillance System (NNDSS) in 2013, and 1,564 cases (6.7 per 100,000 population per year) in 2014. The non-age standardised rate of IPD in Indigenous Australians was six times the rate of IPD in non-Indigenous Australians in both 2013 and 2014. Following the July 2011 introduction of the 13-valent pneumococcal conjugate vaccine (13vPCV) to the National Immunisation Program (NIP), the overall rate of IPD in children aged less than 5 years decreased from 19.8 per 100,000 population per year in 2011 to 12.5 per 100,000 population per year in 2013. In 2014 there was a slight increase in the overall rate of IPD in children aged less than 5 years to 14.1 per 100,000 population per year in 2014. In both 2013 and 2014, the rate of IPD caused by serotypes included 23-valent pneumococcal polysaccharide vaccine (23vPPV) declined in Indigenous adults aged 50 years or older (40.5 per 100,000 population per year and 35.2 per 100,000 population per year, respectively) after displaying a gradual increase between 2002 and 2012. Rates of IPD in non-Indigenous adults aged 65 years or older caused by serotypes included in the 23vPPV also declined in both 2013 and 2014 (9.5 per 100,000 population per year and 8.3 per 100,000 population per year, respectively) compared to 2011 (11.8 per 100,000 population per year). There were 134 deaths attributable to IPD in 2013 (a case fatality rate of 8.6%) and 118 in 2014 (a case fatality rate of 7.5%).

This report from the Australian Rotavirus Surveillance Program describes the circulating rotavirus genotypes identified in children and adults during the period 1 January to 31 December 2024. In 2024, we saw a continuation of a high burden of rotavirus disease in the Australian population. During this period, 2,118 faecal specimens were referred to the National Rotavirus Reference Centre (NRRC), for rotavirus G- and P-genotype analysis; of these samples, 1,880 were confirmed as rotavirus positive. This is the second highest number of samples referred to the NRRC over the past 20+ years of operation. Of the 1,880 samples confirmed rotavirus positive, 1,610 (85.6%) were identified as wildtype rotavirus; 268 (14.3%) were identified as the Rotarix vaccine-like strain; and two G1P[8] samples could not be confirmed as wildtype or vaccine-like due to inadequate sequence quality. The equine-like G3P[8] variant was the dominant genotype nationally (n = 1,297/1,610; 80.6%). Other genotypes were identified at low frequencies including G1P[8] (n = 9/1,610; 0.6%); G2P[4] (n = 34/1,610; 2.1%); G3P[8] (n = 77/1,610; 4.8%); G8P[8] (n = 46/1,610; 2.9%); G9P[4] (n = 9/1,610; 0.6%); G9P[8] (n = 6/1,610; 0.4%); and G12P[8] (n = 8/1,610; 0.5%). Genotype distribution was consistent nationally, with equine-like G3P[8] the dominant genotype in all jurisdictions. Consistent with observations in recent years, a small number of samples with unusual genotypes were identified (n = 70/1,610; 4.3%). Of these unusual genotypes, the most frequently detected was G2P[8], which accounted for 52.9% of unusual samples (n = 37/70) and 2.3% of all positive wildtype samples (n = 37/1,610). The high number of rotavirus positive samples received by the program reflected the notifications for rotavirus disease reported to the National Notifiable Disease Surveillance Service (NNDSS). Across Australia, there were 10,108 notifications recorded, the highest reported in any year since establishment of the national rotavirus notification. The ability to monitor the genotypes of rotavirus strains causing disease across ages and across jurisdictions provides important data to aid in assessing the performance of the national rotavirus vaccination program and to inform public health interventions during outbreaks. The Australian Rotavirus Surveillance Program also provides important data to monitor annual variations in genotypes circulating in the population. Understanding the diversity of genotypes in circulation, and the emergence of variants, provides important context for any changes observed in disease epidemiology in the community. The Australian Rotavirus Surveillance Program provides diagnostic laboratories with valuable feedback on laboratory data quality, by reporting incidences of wildtype, vaccine-like, and/or false positive rotavirus results.

Foodborne listeriosis outbreaks occur occasionally in Australia and can lead to severe outcomes for at-risk populations. Outbreaks also have the potential to cause illness in a large number of people in a short period. We identified invasive listeriosis outbreaks investigated in Australia from 2012 to 2022. We summarised the key features of these outbreaks and assessed the implications for food safety and future outbreak investigations. Outbreak data were extracted from the national OzFoodNet Outbreak Register and described by year reported; size; severity; type of evidence; food implicated; setting in which the food was prepared and eaten; and likely cause of contamination. Twelve listeriosis outbreaks were identified. These outbreaks involved a total of 94 cases, with 20 deaths reported (an overall case fatality rate of 21.3%). The median number of cases per outbreak was three (range: 2-34) and the median number of deaths was one (range: 0-7). Except for one outbreak with a median age of 32 years, the median age per outbreak ranged within 62-92 years. The most common food type implicated was pre-prepared composite foods (25%), including frozen meals and sandwiches. Ten outbreak investigations (83.3%) identified microbiological evidence of the same aetiological agent in the cases and the suspected food vehicle, including using whole genome sequencing as an emerging laboratory method. Most outbreaks (ten outbreaks, 83.3%) were caused by contamination of the product in the production environment, with one outbreak associated with extreme weather events. Use of novel microbiologic techniques has increased listeriosis outbreak detection and has also improved the ability to identify causes of outbreaks. It is important that public health communication emphasises the risks of consuming high-risk ingredients in composite foods, not just as standalone products. Food safety protocols should undergo ongoing review to ensure they are responsive to a changing climate.

Amoebiasis is an important parasitic cause of morbidity and mortality worldwide and is known to be endemic in Northern Australia. The Northern Territory is the only jurisdiction in Australia where amoebiasis is notifiable. The epidemiology of amoebiasis across Australia is not well described. We undertook this retrospective study to describe the epidemiology of amoebiasis in the Northern Territory from 1 January 2005 to 30 June 2024. Data were obtained from the Northern Territory Notifiable Disease System. Of the 26 cases identified, most were men (81%), non-Indigenous (88%) and with infection overseas acquired (69%). Most had extra-intestinal manifestations (65%), and most required hospitalisation (54%). There was one death related to amoebic splenic abscess. Of the seven locally acquired cases, all resided in the Top End and Katherine regions, and two were children. The highest annual incidence occurred in 2024, all of whom were returned travellers. This study highlights that amoebiasis in the Northern Territory is both endemic and overseas acquired, and that clinicians should consider this differential diagnosis in people presenting with gastrointestinal symptoms and initiate timely testing and appropriate treatment.

FluTracking Australia, an online respiratory illness surveillance system, monitors self-reported symptoms, care-seeking, absence from normal duties, and testing and vaccination for influenza and coronavirus disease 2019 (COVID-19). From 2022 to 2023, the number of participants who completed at least one survey decreased by 16.8%, possibly due to participation fatigue and additional survey questions. In 2023, FluTracking identified a 22% reduction in the peak weekly incidence of fever and cough (FC) compared to the 2022 season. The 2023 FC peak was similar in timing to the 2022 FC influenza peak but smaller in magnitude compared to most previous years documented by FluTracking. From 2022 to 2023, FluTracking observed: • A 36% decrease in influenza polymerase chain reaction (PCR) testing among participants reporting incident FC symptoms, largely influenced by a 57% decrease in New South Wales. • A 25% decrease in SARS-CoV-2 testing, by PCR and/or rapid antigen test (RAT), among participants reporting incident runny nose and sore throat (RNST) symptoms. • An 11% decrease in SARS-CoV-2 testing (PCR and/or RAT) among participants reporting incident FC symptoms. Reduced testing accessibility coupled with modified testing practices likely contributed to these decreases. By June 2023, SARS-CoV-2 PCR testing rates among participants with incident FC symptoms aligned with influenza PCR testing rates. Period cumulative incidence of RNST symptoms showed minimal variation across age groups in 2023. In contrast, FC period cumulative incidence inversely correlated with age, suggesting young individuals experience a higher cumulative incidence of FC symptoms.

FluTracking, an online participatory respiratory surveillance system, revealed that the coronavirus disease 2019 (COVID-19) pandemic led to historically low levels of fever and cough (FC) in the 2020-2021 influenza seasons in Australia. In 2022, the influenza peak occurred earlier and was shorter compared to pre-pandemic seasons. Based on weekly percentages of participants reporting FC, FluTracking identified four Omicron waves (BA.1, BA.2, BA.4/BA.5 and a mixed Omicron variant wave). These waves, while consistent with laboratory-confirmed COVID-19 trends, showed higher FC incidences in the BA.4/BA.5 and mixed variant waves. During the Omicron waves in 2022, up to 60% of FluTracking participants with FC reported positive SARS-CoV-2 tests, a significant increase from the less than 10% positivity rate for most of 2020-2021. These trends mirrored the timing of rises in National Notifiable Disease Surveillance System (NNDSS) COVID-19 notifications, although peak magnitudes varied between the two systems. Before November 2021, fewer than half (49.9% weekly mean) of participants with FC, and fewer than a third (27.7% weekly mean) with runny nose and sore throat reported being tested for SARS-CoV-2. Following the introduction of rapid antigen tests (RATs) in November 2021 and the spread of the Omicron variant of SARS-CoV-2 in early 2022, testing rates increased for both symptom profiles in 2022. Additionally, the reopening of international borders and the resurgence of influenza led to expanded respiratory panel testing in drive-through clinics, marked by a 36% increase in the mean weekly percentage of participants reporting an influenza polymerase chain reaction (PCR) test. FluTracking's participation grew by 107% in 2020 compared to 2019, then declined by 17.7% in 2021, likely due to participation and pandemic fatigue. However, participation stabilised with a 0.2% increase in 2022 compared to 2021. FluTracking offers valuable insights into respiratory illness trends, changes in testing behaviours, and positivity rates for influenza and SARS-CoV-2.

Background: Australia is largely dependent on immigrant workers to bridge the employment gap in the agricultural sector and in agriculture-related food production; this poses a potential risk of the introduction and transmission of non-endemic vaccine preventable disease. We report the response to a Salmonella Typhi (S. Typhi) outbreak amongst workers from the Pacific Australia Labour Mobility (PALM) scheme in regional Queensland.

Methods: A cluster of invasive Salmonella infections was investigated in accordance with the Communicable Diseases Network Australia guidelines. Active case finding of the at-risk group was undertaken to identify potential causal links and further transmission.

Results: Three confirmed cases of S. Typhi were reported, all male, with a median age of 31 years (range: 29-33 years). All cases were hospitalised and were managed with antibiotics and supportive care, with a median illness duration of nine days. Full recovery was reported for all cases, without complications. No recent travel history or contact with a recent typhoid case were reported. We identified 310 individuals in the exposed cohort, with a median age of 31 years (range: 22-55 years), all males. Of the exposed cohort, 305/310 individuals (98·4%) provided a faecal sample for S. Typhi testing; all returned a negative result. Genomic sequencing concluded the likely source of infection in this outbreak was chronic carriage of S. Typhi.

Conclusion: Australia has had a significant increase in the number of PALM workers in regional areas, particularly within the agricultural sector, to mitigate employment gaps. A greater emphasis on culturally appropriate and linguistically sound hand hygiene education, and consideration of pre-employment health checks and vaccinations in these workers, would be beneficial in the reduction of communicable disease outbreaks.

Background: Mumps is a highly contagious acute viral disease. We describe Australian mumps epidemiology, 2013-2021.

Methods: National mumps notification, hospitalisation and death data were analysed by age group, Indigenous status, state/territory and vaccination status.

Results: There were 3,643 mumps notifications between 2013-2021 (average annual rate 1.65 per 100,000 population), with highest annual rates 2015-2018 (2.71-3.32 per 100,000 population). Average annual rates per 100,000 population for 2013-2021 and 2015-2018 were highest in the Northern Territory (15.8 and 35.2), Western Australia (4.7 and 9.5) and Queensland (2.6 and 5.0). Average annual rates per 100,000 population were higher in Indigenous people than other Australians in 2013-2021 (25.65 vs 0.82) and 2015-2018 (57.53 vs 1.10). Highest age-specific average annual rates per 100,000 population were in adolescents aged 10-19 years (overall 3.66, Indigenous 48.24 for 2013-2021; 7.60 and 108.52 for 2015-2018), followed by adults aged 20-29 years. Among mumps notifications with vaccination status recorded (n = 2,295 notifications), 64.2% had received ≥ 2 doses of mumps-containing vaccine and 18.1% had received one dose, with 17.7% unvaccinated. Between 2013-2021, 719 hospitalisations had mumps recorded as principal diagnosis (average annual rate, 0.34 per 100,000 population). There were 1-5 deaths coded with mumps as underlying cause of death.

Conclusion: Mumps epidemiology was dominated by large outbreaks predominantly in fully vaccinated Indigenous adolescents/young adults. Mumps outbreaks among highly vaccinated adolescent/young adult populations have occurred overseas related to waning of vaccine-induced immunity, reduced boosting from wild-type virus circulation and high force of infection in close contact settings. A third dose of mumps-containing vaccine is not warranted routinely, but should be considered in the context of outbreaks occurring in high two-dose coverage settings.