Australian vaccine preventable disease epidemiological review series: Hepatitis B, 2000-2019.

Introduction: Hepatitis B vaccination was nationally funded for adolescents in 1996, with inclusion of universal infant immunisation under the National Immunisation Program (NIP) in May 2000. This study describes hepatitis B epidemiology in Australia in the two decades since 2000. Methods: This article analyses newly-acquired (within the prior 24 months) and unspecified (all other) hepatitis B notifications (2000-2019) from the National Notifiable Diseases Surveillance System; acute hepatitis B hospitalisations (2001-2019) from the National Hospital Morbidity Database; and acute (2000-2019) and chronic (2006-2019) hepatitis B deaths from the Australian Bureau of Statistics and Australian Coordinating Registry. Rates over the reporting period were described overall, and by age group, sex, and Aboriginal and Torres Strait Islander status (Aboriginal and/or Torres Strait Islander versus other [neither Aboriginal nor Torres Strait Islander, unknown or not stated]). Trend analyses were performed using Poisson or negative binomial regression. Additional analyses were performed for the cohort born after May 2000. Results and discussion: The annual all-age notification rate per 100,000 per year declined (p < 0.001) from 2.13 in 2000 to 0.65 in 2019 for newly-acquired hepatitis B and from 38.3 to 22.3 for unspecified hepatitis B (likely to predominantly represent chronic hepatitis B). Newly-acquired and unspecified hepatitis B notification rates were lowest among children aged < 15 years. The most substantial reductions in notification rates of newly-acquired hepatitis B were among adolescents aged 15-19 years and young adults aged 20-24 and 25-29 years (respectively 17-, 11-, and 7-fold); these age groups also recorded the most substantial reductions in unspecified hepatitis B notifications (respectively 5-, 3.5-, and 2-fold). Newly-acquired hepatitis B notification and acute hepatitis B mortality rates were two- to threefold higher in males than females. The all-age newly-acquired hepatitis B notification rate in Aboriginal and Torres Strait Islander people decreased twofold between 2000 and 2019, but remained threefold higher than in other people. Acute hepatitis B hospitalisations also declined over the study period (p < 0.001) and followed similar patterns. There were no acute or chronic hepatitis B deaths among people born after May 2000; this cohort featured 52 newly-acquired and 887 unspecified hepatitis B notifications. Due to lack of data on country of birth (and hence eligibility for infant vaccination under the NIP or overseas programs), vaccination status and likely transmission routes, we were unable to assess factors contributing to these potentially preventable infections. Conclusion: Adolescent and infant immunisation under the NIP has led to significant reductions in notification rates of newly-acquired hepatitis B, and in acute hepatitis B hospitalisation rates, both overall and in Aboriginal and Torres Strait Islander people. Unspecified hepatitis B notification rates have also greatly decreased in children and young adults, likely largely due to the impact of overseas infant immunisation programs on prevalence in child and adolescent migrants. Work to improve completeness of variables within national datasets is crucial, along with enhanced surveillance of both newly-acquired and unspecified hepatitis B cases to investigate transmission routes, vaccination status and factors contributing to acquisition of hepatitis B, in order to optimise the impact of immunisation programs and ensure linkage with care.

Longitudinal tracking of intrabreath respiratory impedance in preschool children.

BACKGROUND: Longitudinal measurements of intrabreath respiratory impedance (Zrs) in preschool-aged children may be able to distinguish abnormal lung function trajectories in children with a history of wheezing compared to healthy ones. METHODS: Children from a prospective, longitudinal community-based cohort performed annual intrabreath oscillometry (IB-OSC) measurements from age 3- to 7-years. IB-OSC was performed using a single 10 Hz sinusoid while clinically asymptomatic. Linear mixed-effects models were developed to explore the effects of wheezing phenotypes, growth, and sex on seven IB-OSC outcome variables over time: resistance at end-expiration (ReE), resistance at end-inspiration (ReI), the tidal change in resistance (∆R=ReE-ReI), reactance at end-expiration (XeE), reactance at end-inspiration (XeI), the tidal change in reactance (∆X=XeE-XeI), and ∆X normalized by tidal volume (∆X/VT). RESULTS: Eighty-five children produced 374 acceptable IB-OSC measurements. Subjects were classified into one of three wheeze groups: never (n = 36), transient (n = 34), or persistent (n = 15). After adjusting for height, children with persistent wheezing, compared to those who never wheezed, had +0.814 hPa s L-1 ReE (95% confidence interval [CI] +0.178 to +1.451, p = 0.015), -0.792 hPa s L-1 XeE (95% CI -1.203 to -0.381, p = 0.003), -0.538 hPa s L-1 ∆X (95% CI -0.834 to -0.242, p = 0.007) and -1.672 hPa s L-2 ∆X/VT (95% CI -2.567 to -0.777, p < 0.001). Increasing height had a significant effect on all IB-OSC resistance and reactance variables when adjusted for the effect of preschool wheezing. CONCLUSIONS: IB-OSC is feasible for tracking lung function growth in preschool-aged children and may allow abnormal lung function to be identified early in asymptomatic preschoolers with a history of persistent wheezing.

Exploring the infectious contribution to intussusception causality using the effects of COVID-19 lockdowns in Australia: An ecological study.

INTRODUCTION: Intussusception is the primary cause of acute bowel obstruction in infants. The majority of cases under 2 years of age are classed as idiopathic with viral infection implicated as one of the causes. COVID-19 public health measures led to significant decreases in communicable disease prevalence. During these times, reductions in intussusception frequency were reported - reductions greater than would be expected with our previous understanding of its infectious aetiology. METHODS: We conducted a retrospective, multi-state, ecological study over a twelve-year period. Monthly case numbers of ICD-10-AM K56.1 'Intussusception' coded admissions were acquired from state-wide admissions datasets from New South Wales (NSW), Victoria and Queensland, representing 77.62% of the eligible Australian population. These counts within differing jurisdictional lockdowns were compared to non-lockdown periods in order to investigate a correlation between intussusception frequency and lockdown periods. RESULTS: We found a negative association between intussusception frequency and lockdown periods in both eligible states. The largest reductions were seen in the under 2 year age groups with Victoria experiencing a 62.7% reduction (Rate ratio (RR) = 0.37, p < 0.0001) and NSW a 40.1% reduction (RR = 0.599, p = 0.006) during lockdown times. Controls for variations in lockdown restrictions between both regional and metropolitan areas also showed expected decreases. CONCLUSION: Our ecological study demonstrates significant decreases in the frequency of paediatric intussusception admissions during the COVID-19 lockdown periods. The unexpected magnitude of the reductions suggests that the true proportion of infectious disease-caused idiopathic intussusception is greatly underestimated.

Association of antenatal and early childhood air pollution and greenspace exposures with respiratory pathogen upper airway acquisitions and respiratory health outcomes.

The association of air pollution and greenspace with respiratory pathogen acquisition and respiratory health was investigated in a community-based birth-cohort of 158 Australian children. Weekly nasal swabs and daily symptom-diaries were collected for 2-years, with annual reviews from ages 3-7-years. Annual exposure to fine-particulate-matter (PM2.5), nitrogen-dioxide (NO2), and normalised-difference-vegetation-index (NDVI) was estimated for pregnancy and the first 2-years-of-life. We examined rhinovirus, any respiratory virus, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae detections in the first 3-months-of-life, age at initial pathogen detection, wheezing in the first 2-years, and asthma at ages 5-7-years. Our findings suggest that higher NDVI was associated with fewer viral and M. catarrhalis detections in the first 3-months, while increased PM2.5 and NO2 were linked to earlier symptomatic rhinovirus and H. influenzae detections, respectively. However, no associations were observed with wheezing or asthma. Early-life exposure to air pollution and greenspace may influence early-life respiratory pathogen acquisition and illness. .

Shiga Toxin‒Producing Escherichia coli Diagnoses from Health Practitioners, Queensland, Australia.

In Queensland, Australia, 31 of 96 Shiga toxin‒producing Escherichia coli cases during 2020-2022 were reported by a specialty pathology laboratory servicing alternative health practitioners. Those new cases were more likely to be asymptomatic or paucisymptomatic, prompting a review of the standard public health response.

A five-year analysis of latent tuberculosis infection in Queensland, 2016-2020.

Background Australia is aiming to reach tuberculosis pre-elimination targets by 2035. As a low-incidence setting, control efforts will increasingly rely on the management of latent tuberculosis infection (LTBI). We undertook this descriptive analysis to assess the recent trends of LTBI testing in Queensland. Methods Our objective was to describe the features of LTBI testing in Queensland, and to estimate the range of possible annual notifications were it to be made a notifiable condition. We collated both state-wide and region-specific data on tuberculin skin testing (TST) and interferon gamma release assays (IGRA) conducted in Queensland during the five-year period 1 January 2016 - 31 December 2020. We used reports on Medicare-funded TST and IGRA testing in Queensland, as well as tuberculosis notification data, to understand the representativeness of our data and to derive state-wide estimates. Results We analysed 3,899 public TST, 5,463 private TST, 37,802 public pathology IGRA, and 31,656 private pathology IGRA results. The median age of people tested was 31 years; 57% of those tested were female. From our data sources, an annual average of 1,067 positive IGRA and 354 positive TST results occurred in Queensland. Building on this minimum value, we estimate possible latent tuberculosis notifications in Queensland could range from 2,901 to 6,995 per annum. Private laboratory TSTs are estimated to contribute the lowest number of potential notifications (range: 170-340), followed by private laboratory IGRA testing (range: 354-922), public laboratory IGRA testing (range: 706-1,138), and public setting TSTs (range: 1,671-4,595). Conclusion If LTBI were to be made notifiable, these estimates would place it among the ten most notified conditions in Queensland. This has implications for potential surveillance methods and goals, and their associated system and resource requirements.

Assessing the impact of chickenpox and shingles vaccination using intermittent enhanced surveillance in Queensland, Australia.

INTRODUCTION: Chickenpox and shingles are vaccine preventable diseases caused by varicella-zoster virus (VZV). Chickenpox is more common in children before adolescence and shingles among ≥50 years of age. With this study we aimed to determine changes in VZV epidemiology following chickenpox and shingles vaccine introduction in Queensland. METHODS: This case series study used notified cases of VZV infection in Queensland from January 2010 to December 2021. In Queensland, VZV notifications are received as mostly clinically unspecified cases from pathology laboratories. Intermittent enhanced surveillance was conducted using clinician follow up to determine chickenpox and shingles clinical presentation, and we then analysed these by age-group, time period, and within vaccine eligible cohorts. RESULTS: Of the 87,759 VZV notifications received, 70 % (n = 61,298) were notified as unspecified, followed by 23 % shingles (n = 19,927), and 7 % chickenpox (n = 6,534). Over the study period, the percent change in total notifications adjusted by age and sex was estimated to be an increase of 5.7 % (95 % CI 4.9-6.4) each year. The chickenpox notifications fell sharply at 18 months of age (eligible for chickenpox vaccine) with the rate being 57 % and 36 % lower among those aged 18-23 months compared to <12 and 12-17 months of age, respectively. Assuming all cases aged 60 years and older were shingles, notification rates of shingles decreased by 12-22 % among 70-79 years old (eligible for shingles vaccination) over the years 2017-2021 after vaccine introduction in 2016. CONCLUSION: The VZV notification rate has increased over time in Queensland. Impact of chickenpox and shingles vaccines funded under National Immunisation Program is seen with a decline in notification rates among age-specific cohorts eligible to receive the vaccines under the program. Introduction of a second childhood dose chickenpox vaccine and more effective recombinant shingles vaccine may further improve the impact of the vaccination program.

Enhanced surveillance of notifications of hepatitis C to Queensland Health up to 19 years previously.

In this study we aimed to assess the utility of following up historical hepatitis C notifications for enhanced surveillance and linking cases to further testing and treatment. Queensland hepatitis C notifications from June 2018, 2013, 2008 and 2003 who were not incarcerated at the time of testing were followed up. The most recent identified clinicians for cases were contacted by telephone. When no information about a current clinician was available, the case was contacted via a letter or text message. Clinicians and cases were encouraged to pursue further testing and treatment and provide information about management. Following notification but prior to this study's follow-up, a majority of cases (309/532; 58%) had a negative polymerase chain reaction (PCR) test or underwent treatment.Clinician follow-up was successful in 21% of eligible cases, with the proportion decreasing with increasing time since notification. In conclusion, contacting clinicians to link notified cases to further testing and treatment may increase testing and treatment in a small proportion of cases notified up to nine years post-notification. From our experience, the follow-up of notifications before this time is unlikely to result in improved outcomes.

Using notifications data to increase hepatitis C testing and treatment rates in Queensland.

Australia's goal of eliminating hepatitis C by 2030 requires increases in uptake of and access to testing and treatment. As hepatitis C is a notifiable condition, health departments have access to information about people exposed to the hepatitis C virus (HCV), including the details of notifying clinicians who ordered their diagnostic pathology tests. Hepatitis C RNA testing confirms active infection that requires treatment, whereas a positive antibody test result only indicates prior exposure to the virus. We undertook a pilot project in Queensland to follow up hepatitis C notifications with clinicians, aiming to increase HCV-RNA testing and treatment uptake. For all individuals with a first-time hepatitis C notification in Queensland between 3 November 2020 and 28 May 2021, we sought information regarding hepatitis C RNA testing from laboratories, excluding those cases diagnosed in prisons. Cases who did not have RNA testing identified as part of or after their initial diagnostic tests were followed up via their notifying clinician. Interviews with selected clinicians were undertaken to improve our understanding of the follow-up process. There were 769 new hepatitis C notifications during our study period: 244 had no subsequent RNA test identified and were followed up for this study. Of these, 134 cases were lost to follow-up; 26 were already being effectively case managed; 22 reported previous treatment and no further risk; and 62 were eligible for HCV-RNA testing. Twenty-six cases subsequently started hepatitis C treatment. Thirty-four percent of notifications that required follow-up resulted from testing initially requested in hospital settings. Following up hepatitis C notifications can result in increased treatment rates; however, the process was resource-intensive and often failed to result in further contact between clinicians and patients. Our findings also highlight the importance of supporting better continuity of care between hospitals and community settings.

Maternal Pertussis Vaccination, Infant Immunization, and Risk of Pertussis.

OBJECTIVES: Following the introduction of jurisdictional maternal pertussis vaccination programs in Australia, we estimated maternal vaccine effectiveness (VE) and whether maternal pertussis vaccination modified the effectiveness of the first 3 primary doses of pertussis-containing vaccines. METHODS: We conducted a population-based cohort study of 279 418 mother-infant pairs using probabilistic linkage of administrative health records in 3 Australian jurisdictions. Infants were maternally vaccinated if their mother had a documented pertussis vaccination ≥14 days before birth. Jurisdictional immunization records were used to identify receipt of the first 3 infant doses of pertussis-containing vaccines. Infant pertussis infections were identified using notifiable disease records. VE was estimated using Cox proportional hazard models. RESULTS: Pertussis was administered during 51.7% (n = 144 429/279 418) of pregnancies, predominantly at 28-31 weeks' gestation. VE of maternal pertussis vaccination declined from 70.4% (95% confidence interval [CI], 50.5-82.3) among infants <2 months old to 43.3% (95% CI, 6.8-65.6) among infants 7-8 months old and was not significant after 8 months of age. Although we observed slightly lower VE point estimates for the third dose of infant pertussis vaccine among maternally vaccinated compared with unvaccinated infants (76.5% vs 92.9%, P = .002), we did not observe higher rates of pertussis infection (hazard ratio, 0.70; 95% CI, 0.61-3.39). CONCLUSIONS: Pertussis vaccination near 28 weeks' gestation was associated with lower risk of infection among infants through 8 months of age. Although there was some evidence of lower effectiveness of infant vaccination among maternally vaccinated infants, this did not appear to translate to greater risk of disease.

Association of rhinovirus and potentially pathogenic bacterial detections in the first 3 months of life with subsequent wheezing in childhood.

OBJECTIVE: Airway interactions between viruses, especially rhinoviruses, and potentially pathogenic bacteria (PPB; Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis) in early infancy may increase the risk of subsequent wheezing and asthma. We evaluated the association between rhinovirus and PPB in the first 3 months of life and wheezing episodes before age 2 years and asthma at age 5-7 years. METHODS: An Australian community-based birth cohort of healthy children involved parents collecting nasal swabs weekly and completing symptom diaries daily until age 2 years. In a follow-up subset, asthma diagnosis was assessed annually until age 7 years. Swabs were analyzed by real-time polymerase chain reaction assays. Children were included if they returned symptom diaries beyond age 3 months (wheeze) or were reviewed at age 5-7 years (asthma). RESULTS: 1440 swabs were returned by 146 children in the first 3 months of life. Wheeze and asthma outcomes were recorded for 146 and 84 children, respectively. Each additional week of rhinovirus detection increased the incidence of wheezing before age 2 years by 1.16 times (95% confidence interval [CI]: 0.99-1.35). There were no significant associations between bacteria and wheeze. Each additional week with H. influenzae increased the odds of asthma at age 5-7 years by 135% (odds ratio: 2.35, 95% CI: 0.99-5.58). No significant interaction was observed between rhinovirus and PPB for wheezing or asthma. CONCLUSION: Early life rhinovirus infection was associated with wheezing before age 2 years and H. influenzae with asthma by age 5-7 years. Microbes may play an etiologic role in wheezing and asthma, warranting further study.

"They said we're all in it together, but we were kind of separated": barriers to access, and suggestions for improving access to official information about COVID-19 vaccines for migrants in Australia.

BACKGROUND: Vaccination is a cornerstone of public health measures to mitigate the burden of COVID-19 infection. Equitable access to information is necessary to ensure all members of society can make an informed decision about COVID-19 vaccines. We sought to investigate barriers that migrants living in Australia faced in accessing official information about COVID-19 vaccines and identify potential solutions. METHODS: This study used a descriptive qualitative study design. Seventeen adults living in Australia and born in the World Health Organization's Eastern Mediterranean Region participated in a semi-structured interview conducted via telephone. Participants were recruited using advertising through social media platforms. The interviews were conducted between December 2021 and February 2022. All interviews were audio-recorded and transcribed verbatim. Data were analysed using inductive thematic analysis. In this study official information was defined as information provided by Australian Health system. RESULTS: Barriers to accessing official information about COVID-19 vaccines were related to unmet language needs, methods of dissemination, and mistrust in official sources of information. To overcome barriers, participants suggested improving the quality and timeliness of language support, using diverse modes of dissemination, working with members of migrant communities, providing opportunities for two-way communication, communicating uncertainty, and building a broader foundation of trust. CONCLUSION: Information about COVID-19 vaccines during different stages of the vaccination program should be provided in migrants' languages at the same time that it is available in English using a variety of methods for dissemination. The acceptability of official information can be improved by communicating uncertainty, acknowledging people's concerns about the safety and effectiveness of COVID-19 vaccines and providing opportunities for two-way communication. People's trust in official sources of health information can be improved by working with migrant communities and recognising migrants' contributions to society. The findings of this study may improve managing the response to COVID-19 and other health emergencies in Australia and in other similar societies.

Interference Between Enteric Viruses and Live-Attenuated Rotavirus Vaccine Virus in a Healthy Australian Birth Cohort.

BACKGROUND: Rotavirus vaccines have reduced effectiveness in high-mortality settings. Interference between enteric viruses and live-attenuated oral vaccine strains may be a factor. METHODS: In a birth cohort of healthy Australian infants, parents collected weekly stool samples. Three hundred eighty-one paired swabs collected within 10-days of RotaTeq vaccination from 140 infants were tested for 10 enteric viruses and RotaTeq strains. RESULTS: Collectively, both ribonucleic acid and deoxyribonucleic acid viruses were negatively associated with RotaTeq shedding (adjusted odds ratio = 0.29, 95% confidence interval = 0.14-0.58 and adjusted odds ratio = 0.30, 95% confidence interval = 0.11-0.78, respectively). CONCLUSIONS: Enteric viruses may interfere with RotaTeq replication in the gut and thus RotaTeq stool shedding.

Effect of COVID-19 pandemic restrictions on chlamydia and gonorrhoea notifications and testing in Queensland, Australia: an interrupted time series analysis.

OBJECTIVE: To investigate trends in testing and notifications of chlamydia and gonorrhoea during the COVID-19 pandemic in Queensland, Australia. METHODS: Statewide disease notification and testing data between 1 January 2015 and 31 December 2021 were modelled using interrupted time series. A segmented regression model estimated the pre-pandemic trend and observed effect of the COVID-19 pandemic response on weekly chlamydia notifications, monthly gonorrhoea notifications and monthly testing figures. The intervention time point was 29 March 2020, when key COVID-19 public health restrictions were introduced. RESULTS: There were 158 064 chlamydia and 33 404 gonorrhoea notifications and 2 107 057 combined chlamydia and gonorrhoea tests across the 72-month study period. All three studied outcomes were increasing prior to the COVID-19 pandemic. Immediate declines were observed for all studied outcomes. Directly after COVID-19 restrictions were introduced, declines were observed for all chlamydia notifications (mean decrease 48.4 notifications/week, 95% CI -77.1 to -19.6), gonorrhoea notifications among males (mean decrease 39.1 notifications/month, 95% CI -73.9 to -4.3) and combined testing (mean decrease 4262 tests/month, 95% CI -6646 to -1877). The immediate decline was more pronounced among males for both conditions. By the end of the study period, only monthly gonorrhoea notifications showed a continuing decline (mean decrease 3.3 notifications/month, p<0.001). CONCLUSION: There is a difference between the immediate and sustained impact of the COVID-19 pandemic on reported chlamydia and gonorrhoea notifications and testing in Queensland, Australia. This prompts considerations for disease surveillance and management in future pandemics. Possible explanations for our findings are an interruption or change to healthcare services during the pandemic, reduced or changed sexual practices or changed disease transmission patterns due to international travel restrictions. As pandemic priorities shift, STIs remain an important public health priority to be addressed.

Human bocavirus-1 infections in Australian children aged < 2 years: a birth cohort study.

To determine human bocavirus-1 (HBoV1) infection characteristics in young Australian children. Data were from the Observational Research in Childhood Infectious Diseases (ORChID) study, a Brisbane, Australia-based birth cohort of healthy, term, newborns followed prospectively for 2 years. Parents recorded daily symptoms, maintained an illness-burden diary, and collected weekly nasal swabs, which were tested for 17 respiratory viruses, including HBoV1, by real-time polymerase chain reaction (PCR) assays. Main outcomes measured were infection incidence, risk factors, symptoms, and healthcare use. One hundred fifty-eight children in the ORChID cohort provided 11,126 weekly swabs, of which 157 swabs were HBoV1 positive involving 107 incident episodes. Co-detections were observed in 65/157 (41.4%) HBoV1-positive swabs (or 41/107 [38.3%] infection episodes), principally with rhinovirus. Shedding duration was 1 week in 64.5% of episodes. The incidence of HBoV1 infections in the first 2 years of life was 0.58 episodes per child-year (95% confidence interval [CI] 0.47-0.71), including 0.38 episodes per child-year (95% CI 0.30-0.49) associated with respiratory symptoms. Recurrent episodes occurred in 18/87 (20.7%) children following their primary infection. In the first 2 years of life, incidence of HBoV1 episodes increased with age, during winter and with childcare attendance. Overall, 64.2% of HBoV1 episodes were symptomatic, with 26.4% having healthcare contact. Viral load estimates were higher when children were symptomatic than when asymptomatic (mean difference = 3.4; 95% CI 1.0-5.7 PCR cycle threshold units). After age 6 months, HBoV1 is detected frequently in the first 2 years of life, especially during winter. Symptoms are usually mild and associated with higher viral loads.

Real world impact of 13vPCV in preventing invasive pneumococcal pneumonia in Australian children: A national study.

BACKGROUND: We aimed to assess the direct protective effect of 13 valent pneumococcal conjugate vaccine (13vPCV) against invasive pneumococcal pneumonia (IPP; including pneumonia and empyema) in children using a nation-wide case-control study across 11 paediatric tertiary hospitals in Australia. METHODS: Children < 18 years old admitted with pneumonia were eligible for enrolment. IPP was defined as Streptococcus pneumoniae (SP) cultured or detected by polymerase chain reaction (PCR) from blood or pleural fluid. Causative SP serotype (ST) was determined from blood or pleural fluid SP isolates by molecular methods in PCR positive specimens or else inferred from nasopharyngeal isolates. For each IPP case, 20 population controls matched by age and socio-economic status were sampled from the Australian Immunisation Register. Conditional logistic regression was used to estimate the adjusted odds ratio (aOR) of being fully vaccinated with 13vPCV (≥3 doses versus < 3 doses) among IPP cases compared to controls, adjusted for sex and Indigenous status. RESULTS: From February 2015 to September 2018, we enrolled 1,168 children with pneumonia; 779 were 13vPCV-eligible and were individually matched to 15,580 controls. SP was confirmed in 195 IPP cases, 181 of whom had empyema. ST3 and ST19A were identified in 52% (102/195) and 11% (21/195) of IPP cases respectively. The aOR of being fully vaccinated with 13vPCV was 0.8 (95% CI 0.6-1.0) among IPP cases compared to matched controls. CONCLUSION: We failed to identify a strong direct protective effect of 13vPCV against IPP among Australian children, where disease was largely driven by ST3.

Assessing the Prevalence of Trachoma: Lessons from Community Screening with Laboratory Testing in Australia's Torres Strait Islands.

PURPOSE: We undertook a screening program between 2016 and 2019 to determine if trachoma was endemic in the Torres Strait Islands of Queensland, Australia. METHODS: Eleven screening surveys assessing trachoma prevalence were undertaken in seven communities using the World Health Organization (WHO) simplified grading tool. Additionally, an ophthalmologist performed a detailed clinical assessment including examination for Herbert's pits and corneal pannus and, where clinically indicated, collection of conjunctival specimens to investigate the presence of Chlamydia trachomatis nucleic acid. RESULTS: Prevalence of trachomatous inflammation-follicular (TF) in children aged 5-9 years for the aggregated first survey across all communities was 6% (17/284). No child had trachomatous inflammation-intense, trachomatous scarring, corneal pannus, or Herbert's pits. Of the 66 times any child was tested for C. trachomatis by polymerase chain reaction (PCR), the result was negative. No cicatricial trachoma was identified amongst the adults (n = 186) who were opportunistically offered examination. CONCLUSION: Whilst TF was present, the lack of intense inflammatory thickening in any child examined, the lack of end-stage trachomatous disease, and the lack of ocular C. trachomatis detection by PCR indicate trachoma is not endemic in the Torres Strait Islands, and no ongoing public health intervention is required. These findings add to a growing body of evidence suggesting that use of the WHO simplified grading tool alone in the peri-elimination setting may overestimate the community burden of trachoma.

Novel Human Parechovirus 3 Diversity, Recombination, and Clinical Impact Across 7 Years: An Australian Story.

BACKGROUND: A novel human parechovirus 3 Australian recombinant (HPeV3-AR) strain emerged in 2013 and coincided with biennial outbreaks of sepsis-like illnesses in infants. We evaluated the molecular evolution of the HPeV3-AR strain and its association with severe HPeV infections. METHODS: HPeV3-positive samples collected from hospitalized infants aged 5-252 days in 2 Australian states (2013-2020) and from a community-based birth cohort (2010-2014) were sequenced. Coding regions were used to conduct phylogenetic and evolutionary analyses. A recombinant-specific polymerase chain reaction was designed and utilized to screen all clinical and community HPeV3-positive samples. RESULTS: Complete coding regions of 54 cases were obtained, which showed the HPeV3-AR strain progressively evolving, particularly in the 3' end of the nonstructural genes. The HPeV3-AR strain was not detected in the community birth cohort until the initial outbreak in late 2013. High-throughput screening showed that most (>75%) hospitalized HPeV3 cases involved the AR strain in the first 3 clinical outbreaks, with declining prevalence in the 2019-2020 season. The AR strain was not statistically associated with increased clinical severity among hospitalized infants. CONCLUSIONS: HPeV3-AR was the dominant strain during the study period. Increased hospital admissions may have been from a temporary fitness advantage and/or increased virulence.