Communicable diseases intelligence (2018)最新文献

Between January 2022 and December 2023, there were 1,827 bloodstream infection (BSI) isolates in 1,745 children and adolescents reported to the Australian Group on Antimicrobial Resistance (AGAR) surveillance outcome programs, with 40% of episodes in children aged < 12 months. Two-thirds of BSIs were community-onset. Of 1,034 gram-negative isolates, 932 (90%) were Enterobacterales. Gram-negative BSI episodes were more commonly community-onset and in children < 12 months of age. Of Enterobacterales isolates, 17.9% were ciprofloxacin resistant; 14.0% were ceftriaxone and/or ceftazidime resistant; 9.5% were gentamicin and/or tobramycin resistant; and 8.9% were piperacillin-tazobactam resistant. Increasing ciprofloxacin resistance was noted, primarily due to the increase in Salmonella Typhi BSI. Overall, 13% of Enterobacterales were extended spectrum β-lactamase producers, and 18.5% were multi-drug resistant (MDR). Of 601 Staphylococcus aureus isolates, 13.6% were methicillin-resistant (MRSA), and 5.5% were MDR. Overall, 14.4% of S. aureus isolates were erythromycin resistant; 10.3% were clindamycin resistant; and 5.0% were ciprofloxacin resistant. Erythromycin, clindamycin, and ciprofloxacin resistance in MRSA were significantly higher than in methicillin-sensitive isolates. No co-trimoxazole resistant S. aureus was isolated. There were 192 enterococcal isolates reported; 70.8% were E. faecalis and 17.2% were E. faecium. All ampicillin-resistant, vancomycin-resistant, and MDR enterococci were E. faecium. The 2022-2023 AGAR Kids Biennial Report shows relative stability in the antimicrobial resistance landscape within the Australian paediatric population, with few significant differences detected when compared to the 2020-2021 report. Small increases in the proportion of resistant Enterobacterales and Enterococcus spp. isolates highlight the importance of ongoing surveillance to inform stewardship and infection prevention interventions.

In Australia, both probable and laboratory-confirmed cases of invasive meningococcal disease (IMD) are reported to the National Notifiable Diseases Surveillance System (NNDSS). When compared to 2023, the number of IMD notifications in 2024 decreased by 5% to 136. IMD was confirmed by laboratory testing in 136/136 (100%) of 2024 IMD cases, with 63% (86/136) diagnosed by bacterial culture and 37% (50/136) by nucleic acid amplification testing. The serogroup was determined for 96% of laboratory-confirmed cases (130/136): serogroup B (MenB) accounted for 84% of infections (109/130); MenY for 14% (18/130); MenW for 1.5% (2/130) and MenC for 0.8% (1/130). Finetyping was available on 71% of the cases for which the serogroup was determined (92/130). In MenB isolates, 21 porA types were detected, the most prevalent of which were P1.7-2,4 (38%; 29/76) and P1.7,16-26 (11%; 8/76). In MenY infections, 6 porA types were detected, with P1.5-1,10-1 the dominant porA type (60%; 9/15); where typed, this was of multilocus sequence type MLST (ST) 1655 and from clonal complex 23 (8/9). One of the two MenW isolates in 2024 was finetyped and identified as porA type P1.5,2, MLST (ST) 11 and belonging to the clonal complex 11, the hypervirulent strain reported in outbreaks in Australia and overseas. The MenC isolate was not typed. Peaks of IMD occurred in children aged less than 5 years, and in those aged 15-24 years, accounting for 20% (27/136) and 28% (38/136) of laboratory-confirmed cases respectively. In children aged under 5 years, 92% (24/26) of IMD was MenB; in those aged 15-24 years, 94% (33/35) of IMD was MenB, with serogroup not determined for one case in those aged < 5 years and three cases aged 15-24 years. IMD was reported in all age groups: < 5 years (20%; 27/136); 5-9 years (6%; 8/136); 10-14 years (5%; 7/136); 15-24 years (28%; 38/136); 25-44 years (12%; 16/136); 45-64 years (18%; 25/136); and in those aged 65 years and older (11%; 15/136). Whilst MenB predominated in all age groups, the majority of MenY IMD cases were reported in adults aged 45 years and older (14/18; 78%). All cultured IMD isolates (n = 86) had antimicrobial susceptibility testing performed with ceftriaxone and penicillin. Minimum inhibitory concentration (MIC) values were reported using Clinical Laboratory Standards Institute (CLSI) interpretative criteria: 7% (6/86) were defined as penicillin resistant (MIC value, ≥ 0.5mg/L); 60% (52/86) had intermediate susceptibility to penicillin (MIC values, 0.125 and 0.25 mg/L); and 33% (28/86) were susceptible to penicillin (MIC values, ≤ 0.064 mg/L). All isolates tested susceptible to ceftriaxone, ciprofloxacin and rifampicin.

From 1 January to 31 December 2024, fifty-five institutions across Australia participated in the Australian Staphylococcus aureus Surveillance Outcome Program (ASSOP). The aim of ASSOP 2024 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that were antimicrobial resistant, with particular emphasis on methicillin resistance, and to characterise the molecular epidemiology of methicillin-resistant S. aureus (MRSA). A total of 3,358 SAB episodes were reported, of which 78.5% were community-onset. Overall, 14.9% of S. aureus were methicillin resistant. The 30-day all-cause mortality associated with methicillin-resistant SAB was 13.7%, which was not significantly different to the 14.1% 30-day all-cause mortality associated with methicillin-susceptible SAB (p = 0.9). With the exception of the β-lactams and erythromycin, antimicrobial resistance in methicillin-susceptible S. aureus (MSSA) was infrequent. However, in addition to the β-lactams, 34.8% of MRSA were resistant to erythromycin; 28.9% to ciprofloxacin; 13.1% to gentamicin; 11.0% to tetracycline; and 2.7% to cotrimoxazole. A daptomycin-resistant MRSA from New South Wales was identified. The isolate had a daptomycin minimum inhibitory concentration (MIC) of 6.0 mg/L, and was identified as ST5-V, with a S337L MprF mutation. When applying the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, teicoplanin resistance was detected in three MSSA isolates. Linezolid or vancomycin resistance was not detected. Resistance to the non-β-lactam antimicrobials was largely attributable to the predominant healthcare-associated MRSA (HA-MRSA) clone ST22-IV [2B] (EMRSA-15), and to the community-associated MRSA (CA-MRSA) clone ST45-V [5C2&5], which has acquired resistance to multiple antimicrobials including ciprofloxacin, clindamycin, erythromycin, gentamicin, and tetracycline. Overall, 89.6% of methicillin-resistant SAB episodes were caused by CA-MRSA clones. Although polyclonal, approximately 72% of CA-MRSA clones were characterised as ST93-IV [2B] (Queensland clone), ST5-IV [2B], ST45-V [5C2&5], ST8-IV [2B], ST30-IV [2B], ST1-IV [2B], ST6-IV [2B], ST97-IV [2B] and Panton-Valentine leucocidin positive ST22-IV [2B]. As CA-MRSA is well established in the Australian community, it is important to monitor antimicrobial resistance patterns in community- and healthcare-associated SAB, as this information will guide therapeutic practices in treating S. aureus bacteraemia.

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.