The impact of pneumococcal serotype replacement on the effectiveness of a national immunization program: a population-based active surveillance cohort study in New Zealand.

Background: In Aotearoa New Zealand (NZ) PCV7 was introduced in 2008, then PCV10 in 2011 and PCV13 in 2014. In 2017 PCV10 was re-introduced, replacing PCV13. In the present study, we investigate the resultant rapidly changing invasive pneumococcal disease (IPD) epidemiology. Methods: We compare the IPD incidence rate ratio (IRR) in NZ (2022 versus 2020) with other countries, and describe the IPD epidemiology (including trends in overall IPD and serotype 19A, and antimicrobial resistance) within NZ. Additionally, we performed a genomic-epidemiology investigation identifying the most common 19A sequence types and associated risk factors. Findings: Though IPD incidence rates have increased in the US and Australia (2021-22) after declines in 2020, in NZ the incidence rate is the highest since 2011 with a significantly higher IRR than US (p < 0.01). Incidence rates among children <2 and adults 65 or over in 2022 are the highest since 2009, driven by significant increases of serotype 19A (p = 0.01). Maori and Pacific peoples are experiencing the highest rates since 2009. Further, penicillin resistance among 19A isolates has increased from 39% (2012) to 84% (2021) (p = 0.02). Genomic sequencing identified the more virulent ST-2062 as most common among 19A isolates sequenced, increasing from 5% (2010) to 55% (2022). Interpretation: With very high incidence rates of IPD in NZ, inadequate protection against 19A, increasing resistance, and a more virulent 19A clade, targeted public health campaigns and increased PCV13 availability are needed. Funding: The NZ Ministry of Health funds IPD surveillance and typing in NZ.

Sexually Transmitted Infections and the Risk of Reinfection Within 12 Months: A Population-Based Cohort.

BACKGROUND: Chlamydia, gonorrhea, and syphilis are common sexually transmitted infections that disproportionately affect specific groups in New Zealand (NZ). Predictors of reinfection are not well studied in NZ but could inform public health strategies to decrease sexually transmitted infection (STI) incidence. METHODS: New Zealand-wide chlamydia, gonorrhea, and syphilis cases during 2019 were identified using nationally collected data. Cases were followed-up to identify reinfection with the same STI within 12 months of initial infections. Logistic regression models were used to identify predictors for each STI reinfection. RESULTS: Determinants identified for increased odds of chlamydia reinfection were age groups 16-19 and 20-24 years, females, Maori and Pacific peoples, cases in the Northern region, and cases with at least one test before the initial infection. Age 40 years and older was associated with lower odds of gonorrhea reinfection, as was being of Asian ethnicity, living in Midland or Southern regions, and reporting heterosexual behavior. Region was the only statistically significant predictor for syphilis reinfection, with higher odds of reinfection for people living in the Central region. CONCLUSIONS: Our findings reflect disproportionate STI rates for some groups in NZ, with younger age groups, Maori and Pacific peoples, men who have sex with men, and people living in the Northern region experiencing higher odds of reinfection. Groups identified with higher odds for reinfection require increased access to culturally responsive health services to treat, understand, and prevent possible reinfection. Changes to current public health strategies could include culturally specific behavioral counseling, and improvements to and adherence to effective contract tracing.

Comparison of the epidemiology of invasive pneumococcal disease between Australia and New Zealand in 2017-2021: an observational study based on surveillance data.

Background: The Australian immunisation schedule uses 13-valent pneumococcal conjugate vaccine (PCV13), while New Zealand (NZ) changed from PCV13 to 10-valent PCV (PCV10) in 2017. In NZ, cases of serotype 19A (not in PCV10) have been increasing since 2017. We compared invasive pneumococcal disease (IPD) epidemiology between Australia and NZ in 2017-2021. Methods: We collated IPD notification data from national surveillance systems. Between Australia and NZ, we compared IPD incidence rates and assessed the proportion of serotype 19A, and stratified for ethnicity and age. Findings: Between 2017 and 2021, the crude IPD incidence per 100,000 in Australia ranged from 4.3 to 8.4, and ranged from 6.9 to 11.4 in NZ. The highest age-adjusted IPD rates were observed in Australian Indigenous people (range: 27.3-35.5) followed by NZ Maori/Pacific peoples (range 19.7-30.4). For children <2 years, ethnicity-adjusted IPD rates were similar between Australia and NZ in 2017-2020. In 2021, however, the ethnicity-adjusted incidence in children <2 years was higher in NZ (30.2; 95% CI 21.1-39.4) than in Australia (23.3 95% CI: 19.5-27.1) (p < 0.01). In Australia, the proportion of serotype 19A remained 5%, whereas in NZ serotype 19A increased from 11.5% to 29.5% with the largest increase in children <2 years and 2-4 years. Interpretation: Despite higher risks in Indigenous populations in Australia compared to all other groups, the overall IPD rate in NZ is increasing, particularly among children. The numbers and proportions of IPD due to serotype 19A are increasing in NZ especially in children. These data support the NZ decision from December 2022 to change to PCV13. Funding: This research received no specific funding.

Comparison of Clinical Prediction Rules in Pre-school Aged Children With Septic Hip Arthritis Due to Different Pathogens.

BACKGROUND: Although differentiating between transient synovitis and septic hip arthritis is challenging, clinical prediction rules such as the Kocher criteria (KC) have been shown to help with the diagnosis of septic hip arthritis in children. Their performance in septic arthritis due to less virulent pathogens such as Kingella Kingae , however is unknown. We aimed to describe the performance of these clinical prediction rules in pre-school children with septic hip arthritis due to different pathogens. We hypothesised that the number of KC or modified KC met would be lower in children with septic hip arthritis caused by K. kingae , compared to those caused by Staphylococcus aureus . METHODS: In this retrospective multicentre study conducted in Australia and New Zealand between 2012-2016, we included children with confirmed septic hip arthritis due to S. aureus (n=29), K. kingae (n=20), other pathogens (n=32), and no pathogen identified (n=48). We applied the KC (temperature, weight-bearing, erythrocyte sedimentation rate, white blood cell count) and the modified KC (C-reactive protein added) and assessed their sensitivity for septic hip arthritis, using cut offs of KC ≥ 3 and modified KC ≥ 4. RESULTS: The score of the KC and the modified KC was not lower in K. kingae compared to S. aureus ( P =0.27, P =0.21). In addition, both the sensitivity for the KC ( S. aureus 18/29 (62.1%); K. kingae 12/20 (60.0%)), and for the modified KC ( S. aureus 18/29 (62.1%); K. kingae 12/20 (60.0%)) did not differ between K. kingae and S. aureus . Of all children with septic hip arthritis, the sensitivity of both the KC and modified KC were 56.6% (95%CI 47.6-65.3). CONCLUSIONS: The clinical prediction rules had comparable performance in K. kingae infections to those caused by S. aureus . Concerningly, less than 60% of the children with confirmed septic hip arthritis met the cut-off values. These prediction rules lack sensitivity to rule-out septic hip arthritis in the early assessment of pre-school aged children with acute hip pain. LEVEL OF EVIDENCE: Level III Diagnostic.

Multisystem Inflammatory Syndrome in New Zealand Children.

New Zealand (NZ) initially adopted an elimination approach to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pre-Omicron variant, the NZ pediatric population was immunologically naïve to SARS-CoV-2. This study, utilizing national data sources, describes the NZ incidence of multisystem inflammatory syndrome in children (MIS-C) following infection with the Omicron variant. MIS-C incidence was 1.03 of 100,000 age-specific population and 0.04 of 1000 recorded SARS-CoV-2 infections.

Gaps in measles immunisation coverage for pre-school children in Aotearoa New Zealand: a cross-sectional study.

AIMS: To evaluate gaps in measles immunisation coverage for children <5 years in Aotearoa New Zealand. METHODS: In this cross-sectional study, we extracted coverage rates for the first measles, mumps and rubella (MMR1) vaccine and second MMR vaccine (MMR2) from the National Immunisation Register for birth cohorts 2017 to 2020. We described measles coverage rates per birth cohort, and stratified per district health board (DHB), ethnicity and deprivation quintile. RESULTS: Coverage for MMR1 declined from 95.1% for those born in 2017 to 88.9% for those born in 2020. The coverage for MMR2 was below 90% for all the birth cohorts, with the lowest MMR2 coverage in the birth cohort of 2018 (61.6%). MMR1 coverage was lowest for children of Maori ethnicity and coverage declined over time: 92.8% for those born in 2017 to 78.4% for those born in 2020. Six DHBs had average MMR1 coverage <90% including Bay of Plenty, Lakes, Northland, Tairawhiti, West Coast and Whanganui. CONCLUSIONS: Immunisation coverage rates for measles are insufficient to prevent a potential measles outbreak in children <5 years. Concerningly, the coverage for MMR1 is declining, especially in Maori children. Catch-up immunisation programmes are urgently needed to improve immunisation coverage.

Congenital Syphilis: a Review of Global Epidemiology.

In 2007, the World Health Organization (WHO) launched a global health initiative for the elimination of mother-to-child transmission (MTCT) of syphilis. This condition is highly preventable through antenatal identification of syphilis infection and treatment with penicillin during pregnancy. This review summarizes the global status of MTCT of syphilis and concludes that this condition remains a significant issue worldwide. There are large variations in case rates by region, with the highest numbers of cases in the African and Eastern Mediterranean regions, where there are also the least data available. There are also pockets of high-incidence areas within the other regions. Although the general trend is of decreasing rates over time, there are concerning indications of consistently increasing congenital syphilis cases in some areas, particularly in areas which have previously had very low case numbers. A concerted effort will be required to achieve the 2007 WHO goal of worldwide elimination of MTCT of syphilis in the near future.

Longitudinal trends in community antibiotic consumption in the Waitaha Canterbury Region of Aotearoa New Zealand over 10 years (2012-2021): an observational study.

AIMS: To investigate community antibiotic consumption in the Waitaha Canterbury Region of Aotearoa New Zealand across 2012-2021. METHODS: This observational study was based on antibiotic dispensing data from Waitaha Canterbury. Outcome measures included number of dispensings/1,000 inhabitants per year and defined daily doses/1,000 inhabitants per day (DIDs), expressed as average annual change (AAC). We stratified antibiotic dispensing per antibiotic group, and per the World Health Organization (WHO) AWaRE (Access, Watch, Reserve) classification. RESULTS: Across 2012-2021, antibiotic dispensing decreased from 867 to 601 dispensings/1,000 inhabitants (AAC -4.2% [95%CI -4.3 to -4.2]). In the pre-COVID period of 2012 to 2019, antibiotic dispensings decreased with AAC of -3.5% (95%CI -3.6 to -3.5). Considering number of dispensings, the largest reductions were observed in quinolones (-14.6%), macrolides/lincosamides (-8.5%) and penicillins with extended spectrum (-4.8%). The number of dispensings increased for nitrofurans (6.0%) and first generation cephalosporins (28.1%), of which 98% comprised cefalexin dispensing. The proportion of Watch antibiotics decreased from 22.0% to 11.9%. CONCLUSIONS: Community antibiotic consumption decreased in Waitaha Canterbury Aotearoa New Zealand from 2012 to 2021, as did use of Watch antibiotics. These changes concord with increasing antimicrobial stewardship guidance for more judicious use of antibiotics. Further research should investigate the factors driving the observed 10-fold rise in cefalexin dispensing.

E-cigarette use patterns, brand preference and knowledge about vaping among teenagers (13-16 years) and parents of children attending Christchurch Hospital.

AIM: Parents attending hospital with children in New Zealand are routinely asked about tobacco use, but information about vaping is lacking. We assessed e-cigarette use, brand preferences, and knowledge during paediatric outpatient attendance at Christchurch Hospital. METHOD: We undertook an anonymous online survey of teenagers and parents attending paediatric outpatient clinic in December 2021 to February 2022. The sample (n=95) were 16% Maori and 8.4% currently smoked (4.8% teenagers, 11.3% parents). We used descriptive and contingency table analysis. RESULTS: Ever vaping was reported in 33.3% of teenagers and 30.8% of parents, and current use in 7.1% vs 15.1%, respectively. Most teenagers selected "curiosity/just wanted to try them" as their reason for vaping, whereas parents selected vaping to quit or reduce/avoid smoking. More teenagers than parents used nicotine-containing e-cigarettes (100% vs 86.7%) and more parents vaped indoors (in home or car) when other people were present. The most important reasons for choosing particular e-cigarette brands among teenagers were price and flavours, with fruit flavours preferred. No teenagers obtained their e-cigarettes from vape shops versus 40% of parents. The primary source of information about vaping for teenagers and parents was friends/peers. CONCLUSION: Vaping was common among teenagers and parents; teenagers vaped for curiosity and flavours and obtained vape products from sources other than vape shops.

The epidemiology of aseptic meningitis in New Zealand children from 1991 to 2020.

AIM: Aseptic meningitis, including culture negative and viral meningitis, contributes a significant health-care burden, including unnecessary antibiotic use and hospitalisation to treat possible bacterial meningitis. This study analysed aseptic meningitis hospitalisations in New Zealand (NZ) children over 29 years. METHODS: In this population-based study, aseptic meningitis hospitalisations in NZ children <15 years old were analysed from 1991 to 2020. Incident rate ratios were calculated using Poisson regression models. Variations in hospitalisations by age, year, sex, ethnicity, geographical region and socio-economic deprivation were analysed. RESULTS: There were 5142 paediatric aseptic meningitis hospitalisations from 1991 to 2020. Most were unspecified viral meningitis (64%), followed by enterovirus (29%). Hospitalisation rates varied annually with a median of 18.4/100 000 children including a peak in 2001 of 56.4/100 000 (51.7-61.6). From 2002 to 2019, rates increased by 8.4%/year (7.2-9.5%) in infants <90 days old but decreased in all other age groups. In 2020, a reduction in hospitalisations to 9.6/100 000 (7.9-11.8) occurred, and in infants <90 days old were 0.37 times expected. Hospitalisations were 1.50 times (1.49-1.68) higher in males than females; higher in children of Maori (P < 0.001) and Pacific (P < 0.001) versus European ethnicity; and higher for children living in the most (2.44 times, (2.16-2.75)) versus least deprived households; and in northern versus southern NZ. CONCLUSIONS: Aseptic meningitis hospitalisations increased in young infants during 29 years of surveillance, apart from 2020 when admissions reduced during the COVID-19 pandemic. In contrast, hospitalisations decreased in children aged >1 year. Further investigation into reasons for higher admissions by ethnic group, geographical location and increased deprivation are required.

Kingella kingae Spondylodiscitis: Treatment Failure With Flucloxacillin.

Kingella kingae infections generally respond well to most beta-lactam antibiotics. We investigated an antibiotic treatment failure in a 3-year-old with K. kingae L3-4 spondylodiscitis. Her disease progressed even after 19 days of high-dose intravenous flucloxacillin. The clinical isolate did not produce a beta-lactamase and despite phenotypic testing and whole-genome sequencing, the mechanism of flucloxacillin resistance remains unknown.

Invasive Pneumococcal Disease: Concerning Trends in Serotype 19A Notifications in New Zealand.

New Zealand (NZ) is one of few countries to shift from PCV13 to PCV10. The number of serotype 19A cases in young children and the proportions of isolates that are penicillin-resistant have been steadily increasing since. It is time for NZ to reconsider its choice of pneumococcal vaccine.

High Incidence of Congenital Syphilis in New Zealand: A New Zealand Pediatric Surveillance Unit Study.

BACKGROUND: Syphilis, a disease once in decline, has made a resurgence worldwide. New Zealand has had increasing syphilis rates since enhanced syphilis surveillance was initiated in 2013. This study reports epidemiologic, descriptive and treatment data on management of infants prenatally exposed or vertically infected with syphilis across New Zealand as reported by pediatricians. METHODS: Over a 26-month period from April 2018 to May 2020 (inclusive), pediatricians throughout New Zealand notified potential, probable and confirmed cases of congenital syphilis to the New Zealand Pediatric Surveillance Unit. National reporting numbers were concurrently ascertained to demonstrate reporting accuracy. RESULTS: Thirty-two cases were notified, comprised of 25 infants born to women with positive antenatal syphilis serology (5 whom developed congenital syphilis), and 7 infants diagnosed with congenital syphilis after birth where syphilis was not diagnosed in pregnancy. There were 12 cases of congenital syphilis; an incidence rate of 9.4 cases per 100,000 live births. Nine of the 12 infants had clinical features of congenital syphilis. One-third of maternal infections were early syphilis, and the women who gave birth to infected infants were less likely to have received antenatal care, adequate treatment and follow-up monitoring of treatment for syphilis during pregnancy. CONCLUSIONS: This study quantifies an important burden of disease from congenital syphilis in our population. Case finding and treatment of syphilis in pregnancy are critical to prevent this. Our findings support the urgent need for measures such as repeat maternal syphilis screening in early third trimester; whether by affected region or instituted for all, in the context of rising cases.

Comparison of influenza surveillance systems in Australia, China, Malaysia and expert recommendations for influenza control.

BACKGROUND: The Western Pacific Region (WPR) is exposed each year to seasonal influenza and is often the source of new influenza virus variants and novel pathogen emergence. National influenza surveillance systems play a critical role in detecting emerging viruses, monitoring influenza epidemics, improving public disease awareness and promoting pandemic preparedness, but vary widely across WPR countries. The aim of this study is to improve existing influenza surveillance systems by systematically comparing selected WPR influenza surveillance systems. METHODS: Three national influenza surveillance systems with different levels of development (Australia, China and Malaysia) were compared and their adherence to World Health Organization (WHO) guidance was evaluated using a structured framework previously tested in several European countries consisting of seven surveillance sub-systems, 19 comparable outcomes and five evaluation criteria. Based on the results, experts from the Asia-Pacific Alliance for the Control of Influenza (APACI) issued recommendations for the improvement of existing surveillance systems. RESULTS: Australia demonstrated the broadest scope of influenza surveillance followed by China and Malaysia. In Australia, surveillance tools covered all sub-systems. In China, surveillance did not cover non-medically attended respiratory events, primary care consultations, and excess mortality modelling. In Malaysia, surveillance consisted of primary care and hospital sentinel schemes. There were disparities between the countries across the 5 evaluation criteria, particularly regarding data granularity from health authorities, information on data representativeness, and data communication, especially the absence of publicly available influenza epidemiological reports in Malaysia. This dual approach describing the scope of surveillance and evaluating the adherence to WHO guidance enabled APACI experts to make a number of recommendations for each country that included but were not limited to introducing new surveillance tools, broadening the use of specific existing surveillance tools, collecting and sharing data on virus characteristics, developing immunization status registries, and improving public health communication. CONCLUSIONS: Influenza monitoring in Australia, China, and Malaysia could benefit from the expansion of existing surveillance sentinel schemes, the broadened use of laboratory confirmation and the introduction of excess-mortality modelling. The results from the evaluation can be used as a basis to support expert recommendations and to enhance influenza surveillance capabilities.