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International audience; There is increasing evidence that elimination strategies have resulted in better outcomes for public health, the economy, and civil liberties than have mitigation strategies throughout the first year of the COVID-19 pandemic. With vaccines that offer high protection against severe forms of COVID-19, and increasing vaccination coverage, policy makers have had to reassess the trade-offs between different options. The desirability and feasibility of eliminating SARS-CoV-2 compared with other strategies should also be re-evaluated from the perspective of different fields, including epidemiology, public health, and economics. To end the pandemic as soon as possible-be it through elimination or reaching an acceptable endemic level-several key topics have emerged centring around coordination, both locally and internationally, and vaccine distribution. Without coordination it is difficult if not impossible to sustain elimination, which is particularly relevant in highly connected regions, such as Europe. Regarding vaccination, concerns remain with respect to equitable distribution, and the risk of the emergence of new variants of concern. Looking forward, it is crucial to overcome the dichotomy between elimination and mitigation, and to jointly define a long-term objective that can accommodate different political and societal realities.

Summary Background As with many Indigenous populations internationally, Māori in New Zealand suffer health inequity. We aimed to assess the rate of fall injuries at home with and without home modifications in houses with Māori occupants. Methods We did a single-blind randomised controlled trial in the Wellington and Taranaki regions of New Zealand and enrolled owner-occupied households with at least one Māori occupant. Only households who stated they intended to live at that address for the subsequent 3 years were eligible for participation. We randomly assigned (1:1) households to either the intervention group, who received home modifications (handrails for outside steps and internal stairs, grab rails for bathrooms, outside lighting, repairs to window catches, high-visibility and slip-resistant edging for outside steps, fixing of lifted edges of carpets and mats, non-slip bath mats, and slip-resistant surfacing for outside areas such as decks) immediately, or the control group, who received the modifications 3 years later. Data on home injuries were obtained from the Accident Compensation Corporation and coded by study team members, who were masked to study group allocation. The primary outcome was the rate of medically treated fall injuries at home per household per year, analysed according to intention to treat. This Māori Home Injury Prevention Intervention (MHIPI) trial is now completed, and is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613000148774. Findings Between Sept 3, 2013, and Oct 1, 2014, 824 households were assessed for eligibility and 254 were enrolled, of which 126 (50%) were assigned to the intervention group and 128 (50%) were assigned to the control group. After adjustment for previous falls and geographical region, there was an estimated 31% reduction in the rate of fall injuries at home per year exposed to the intervention compared with households in the control group (adjusted relative rate 0·69 [95% CI 0·47–1·00]). Interpretation Low-cost home modifications and repairs can be an effective means to reduce injury disparities. The high prevalence of modifiable safety issues in Māori homes merits considerable policy and community effort. Funding Health Research Council of New Zealand.

Acute rheumatic fever (ARF) and its sequela rheumatic heart disease (RHD) remain significant causes of morbidity and mortality. In New Zealand, ARF almost exclusively affects Indigenous Māori and Pacific children. This narrative review aims to present secondary interventions to improve early and accurate diagnosis of ARF and RHD, in order to minimise disease progression in New Zealand. Medline, EMBASE and Scopus databases were searched as well as other electronic publications. Included were 56 publications from 1980 onwards. Diagnosing ARF and RHD as early as possible is central to reducing disease progression. Recent identification of specific ARF biomarkers offer the opportunity to aid initial diagnosis and portable echocardiography has the potential to detect undiagnosed RHD in high-risk areas. However, further research into the benefits and risks to children with subclinical RHD is necessary, as well as an economic evaluation.

Public health lessons from one pandemic become the planning assumptions for the next one. Aotearoa New Zealand’s 2017 pandemic plan was derived from past experience of influenza. When Covid-19 emer...

Rheumatic fever is a serious post-infectious sequela of group A Streptococcus (GAS). Prior GAS exposures were mapped in sera using a large panel of M-type specific peptides. Rheumatic fever patients had serological evidence of significantly more GAS exposures than matched controls suggesting immune priming by repeat infections contributes to pathogenesis.

Background Six thousand children are hospitalized each year in New Zealand with housing sensitive conditions, and 86.2% of these children are rehospitalized during childhood. The Healthy Homes Initiative, set up by the Ministry of Health, and implemented in Wellington through Well Homes, carries out housing assessments and delivers a range of housing interventions. Method Housing assessments were carried out by trained community workers. Philanthropic funding was received for the interventions through a local charitable trust. Results Well Homes saw 895 families. Mold in the home was the most commonly recorded area of poor housing quality, in 836 homes (93%). Partial or complete lack of insulation was also common, with 452 records (51%) having a documented need for further assessment and either an upgrade or full installation. Eighty-three percent of homes had insufficient sources of heating. A total of 5,537 interventions were delivered. Bedding, heaters, and draft stopping were delivered over 90% of the time. In contrast, insulation and carpets were only delivered 40% of the time. Interventions were least likely to be delivered in private rental housing. Discussion Targeted interventions using social partnerships can deliver housing improvements for relatively little health spending. Well Homes provides immediate and practical interventions, education, connection with social agencies, and advocacy for more substantial structural home improvements to help families keep their home warmer, drier, and healthier. This approach will be strengthened when combined with a new regulatory framework to raise the standards of private rental housing.

Group A Streptococcus (GAS) pharyngitis is a key initiator of acute rheumatic fever (ARF). In New Zealand, ARF cases occur more frequently among persons of certain ethnic and socioeconomic groups. We compared GAS pharyngitis estimates (1,257,058 throat swab samples) with ARF incidence (792 hospitalizations) in Auckland during 2010–2016. Among children 5–14 years of age in primary healthcare clinics, GAS pharyngitis was detected in similar proportions across ethnic groups (≈19%). Relative risk for GAS pharyngitis was moderately elevated among children of Pacific Islander and Māori ethnicities compared with those of European/other ethnicities, but risk for ARF was highly elevated for children of Pacific Islander and Māori ethnicity compared with those of European/other ethnicity. That ethnic disparities are much higher among children with ARF than among those with GAS pharyngitis implies that ARF is driven by factors other than rate of GAS pharyngitis alone.

New Zealand responded to the COVID-19 pandemic with a combination of border restrictions and an Alert Level system that included strict stay-at-home orders. These interventions were successful in containing the outbreak and ultimately eliminating community transmission of COVID-19. The timing of interventions is crucial to their success. Delaying interventions for too long may both reduce their effectiveness and mean that they need to be maintained for a longer period of time. Here, we use a stochastic branching process model of COVID-19 transmission and control to simulate the epidemic trajectory in New Zealand and the effect of its interventions during its COVID-19 outbreak in March-April 2020. We use the model to calculate key outcomes, including the peak load on the contact tracing system, the total number of reported COVID-19 cases and deaths, and the probability of elimination within a specified time frame. We investigate the sensitivity of these outcomes to variations in the timing of the interventions. We find that a delay to the introduction of Alert Level 4 controls results in considerably worse outcomes. Changes in the timing of border measures have a smaller effect. We conclude that the rapid response in introducing stay-at-home orders was crucial in reducing the number of cases and deaths and increasing the probability of elimination. Executive Summary Evaluating the effectiveness of New Zealand’s COVID-19 response, relative to hypothetical response scenarios, is important for guiding future response strategies. We assess the importance of early implementation of interventions for controlling COVID-19. We model counterfactual (alternative ‘what-if’) scenarios in which the timings of three policy interventions are varied: border restrictions requiring 14-day quarantine of all international arrivals, border closure except to returning residents and citizens, and Alert Level 4 restrictions. Key measures describing the dynamics of a COVID-19 outbreak (notably peak load on the contact tracing system, the total number of reported COVID-19 cases and deaths, and the probability of elimination within a specified time frame), are used to compare outcomes from each scenario with New Zealand’s actual outcomes. Key measures were more sensitive to the timing of Alert Level 4, than to timing of border restrictions and border closure. Of the three counterfactual scenarios, an earlier start to Alert Level 4 would have resulted in the greatest reduction in numbers of cases and deaths. Delaying the start of Alert Level 4 by 20 days could have led to over 11,500 cases and 200 deaths, and would have substantially reduced the probability of eliminating community transmission of COVID-19, requring a longer period at Alert Level 4 to achieve control.

Acute rheumatic fever (ARF) and chronic rheumatic heart disease (RHD) are autoimmune sequelae of a Group A streptococcal infection with significant global mortality and poorly understood pathogenesis. Immunoglobulin and complement deposition were observed in ARF/RHD valve tissue over 50 years ago, yet contemporary investigations have been lacking. This study applied systems immunology to investigate the relationships between the complement system and immunoglobulin in ARF. Patients were stratified by C-reactive protein (CRP) concentration into high (≥10 μg mL-1 ) and low (

Background Severe influenza illness is presumed more common in adults with chronic medical conditions (CMCs), but evidence is sparse and often combined into broad CMC categories. Methods Residents (aged 18–80 years) of Central and South Auckland hospitalized for World Health Organization-defined severe acute respiratory illness (SARI) (2012–2015) underwent influenza virus polymerase chain reaction testing. The CMC statuses for Auckland residents were modeled using hospitalization International Classification of Diseases, Tenth Revision codes, pharmaceutical claims, and laboratory results. Population-level influenza rates in adults with congestive heart failure (CHF), coronary artery disease (CAD), cerebrovascular accidents (CVA), chronic obstructive pulmonary disease (COPD), asthma, diabetes mellitus (DM), and end-stage renal disease (ESRD) were calculated by Poisson regression stratified by age and adjusted for ethnicity. Results Among 891 276 adults, 2435 influenza-associated SARI hospitalizations occurred. Rates were significantly higher in those with CMCs compared with those without the respective CMC, except for older adults with DM or those aged Conclusions Our findings support the increased risk of severe, laboratory-confirmed influenza disease among adults with specific CMCs compared with those without these conditions.

Background Group A Streptococcal (GAS) infections cause the autoimmune disease acute rheumatic fever (ARF), which can progress to chronic rheumatic heart disease (RHD). Treating pharyngitis caused by GAS with antibiotics is important in preventing ARF. However, it is difficult to distinguish these infections from GAS carriers. There is growing evidence for GAS skin infections as a cause of ARF. This study will identify the incidence of true GAS pharyngitis and serological responses to GAS skin infections. The effectiveness of antibiotics for these conditions will be explored, and modifiable risk factors. Serum antibody titres indicating the upper limits of normal (ULN for ASO/ADB antibodies) will be established alongside carriage rates in asymptomatic children. Methods This is a prospective disease incidence study, with an associated case-control study. The study population includes 1000 children (5–14 years) from Auckland, New Zealand, 800 of whom have visited their healthcare professional, resulting in a throat or skin swab for GAS, and 200 who are asymptomatic. The conditions of interest are GAS throat swab positive pharyngitis (n = 200); GAS carriage (n = 200); GAS negative throat swab (n = 200); GAS skin infections (n = 200); and asymptomatic controls (n = 200). All participants, except asymptomatic controls, will have acute and convalescent serological testing for ASO/ADB titres (collected

Elimination and eradication of disease are among the ultimate goals of public health1 (for definitions see box 1). Vaccination has globally eradicated smallpox, rinderpest (a cattle disease that caused famines2) and two of the three serotypes of poliovirus.3 Three other vaccine-preventable diseases are eradicable globally with current technology,4 with measles the leading contender and with MMR vaccination potentially eradicating mumps and rubella at the same time. Some other diseases are close to being eradicated but without use of vaccines such as with the Guinea Worm Eradication Programme.5 Similarly, China has recently eliminated malaria with a range of non-vaccination tools, to become the 40th country to be certified malaria-free.6 Box 1 Definitions of key disease control terms from the Dahlem Workshop19 Control: The reduction of disease incidence, prevalence, morbidity or mortality to a locally acceptable level as a result of deliberate efforts; continued intervention measures are required to maintain the reduction. Example: diarrhoeal diseases. Elimination of disease: Reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts; continued intervention measures are required. Example: neonatal tetanus. Elimination of infections: Reduction to zero of the incidence of infection caused by a specific agent in a defined geographical area as a result of deliberate efforts; continued measures to prevent re-establishment of transmission are required. Example: measles, poliomyelitis. Eradication: Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed. Example: smallpox. Extinction: The specific infectious agent no longer exists in nature or in the laboratory. Example: none. Is COVID-19 also potentially eradicable? Or is it inevitably endemic having established itself across the world? Commentators have focused on the challenges of reaching population (herd) immunity,7 yet population immunity is not essential and was not achieved for smallpox, which was eradicated through ring vaccination. As proof of concept for COVID-19 eradication, several countries and jurisdictions have achieved elimination without vaccination, using new and established public health and social measures (PHSMs) (eg, border control, physical distancing, mask wearing, testing and contact tracing supported by genome sequencing).8 Successful jurisdictions have included those with vast land borders such as China, high population densities such as Hong Kong,9 but also island nations such as Iceland and New Zealand, although with occasional outbreaks from border control failures that have been brought under control.10

BackgroundAcute rheumatic fever (ARF) is a serious sequela of Group A Streptococcus (GAS) infection associated with significant global mortality. Pathogenesis remains poorly understood, with the current prevailing hypothesis based on molecular mimicry and the notion that antibodies generated in response to GAS infection cross-react with cardiac proteins such as myosin. Contemporary investigations of the broader autoantibody response in ARF are needed to both inform pathogenesis models and identify new biomarkers for the disease.MethodsThis study has utilised a multi-platform approach to profile circulating autoantibodies in ARF. Sera from patients with ARF, matched healthy controls and patients with uncomplicated GAS pharyngitis were initially analysed for autoreactivity using high content protein arrays (Protoarray, 9000 autoantigens), and further explored using a second protein array platform (HuProt Array, 16,000 autoantigens) and 2-D gel electrophoresis of heart tissue combined with mass spectrometry. Selected autoantigens were orthogonally validated using conventional immunoassays with sera from an ARF case-control study (n=79 cases and n=89 matched healthy controls) and a related study of GAS pharyngitis (n=39) conducted in New Zealand.ResultsGlobal analysis of the protein array data showed an increase in total autoantigen reactivity in ARF patients compared with controls, as well as marked heterogeneity in the autoantibody profiles between ARF patients. Autoantigens previously implicated in ARF pathogenesis, such as myosin and collagens were detected, as were novel candidates. Disease pathway analysis revealed several autoantigens within pathways linked to arthritic and myocardial disease. Orthogonal validation of three novel autoantigens (PTPN2, DMD and ANXA6) showed significant elevation of serum antibodies in ARF (p < 0.05), and further highlighted heterogeneity with patients reactive to different combinations of the three antigens.ConclusionsThe broad yet heterogenous elevation of autoantibodies observed suggests epitope spreading, and an expansion of the autoantibody repertoire, likely plays a key role in ARF pathogenesis and disease progression. Multiple autoantigens may be needed as diagnostic biomarkers to capture this heterogeneity.

Acute rheumatic fever (ARF) is a serious post-infectious immune sequelae of Group A streptococcus (GAS). Pathogenesis remains poorly understood, including the events associated with collagen autoantibody generation. GAS express streptococcal collagen-like proteins (Scl) that contain a collagenous domain resembling human collagen. Here, the relationship between antibody reactivity to GAS Scl proteins and human collagen in ARF was investigated. Serum IgG specific for a representative Scl protein (Scl1.1) together with collagen-I and collagen-IV mimetic peptides were quantified in ARF patients (n = 36) and healthy matched controls (n = 36). Reactivity to Scl1.1 was significantly elevated in ARF compared to controls (P < 0.0001) and this was mapped to the collagen-like region of the protein, rather than the N-terminal non-collagenous region. Reactivity to collagen-1 and collagen-IV peptides was also significantly elevated in ARF cases (P < 0.001). However, there was no correlation between Scl1.1 and collagen peptide antibody binding, and hierarchical clustering of ARF cases by IgG reactivity showed two distinct clusters, with Scl1.1 antigens in one and collagen peptides in the other, demonstrating that collagen autoantibodies are not immunologically related to those targeting Scl1.1. Thus, anti-collagen antibodies in ARF appear to be generated as part of the autoreactivity process, independent of any mimicry with GAS collagen-like proteins.

Objectives Rates of acute rheumatic fever, a sequelae of group A Streptococcal (GAS) infection, remain unacceptably high in Indigenous Māori and Pacific children in New Zealand. This prospective study aimed to describe GAS antibody titres in healthy children (5–14 years) by ethnicity, and to determine how paired titres vary with GAS culture positive and negative pharyngitis, and GAS skin infections. Methods Analysis included 887 children (32% Māori, 36% Pacific, 33% European/Other) from Auckland, New Zealand. Cases comprise 772 children who had a sore throat or skin infection, which resulted in a swab taken for culture. Healthy controls were asymptomatic (N = 154) and matched by age, ethnicity and region. All participants had a serum sample, with a second sample collected from cases only. Sera were analysed for anti-streptolysin O (ASO) and anti-DNase-B (ADB) antibodies. Results Healthy Māori and Pacific children had higher GAS antibody titres than healthy European/Other children. Children with GAS-positive sore throat had the highest mean ASO titres and children with GAS-positive skin infection had the highest mean ADB titres. When a two-fold increase or an upper limit of normal cut-off (ASO 450 IU/ml, ADB 400 U/ml) was applied to titres from children with GAS-positive sore throat, 62.1% were classified as having serologically confirmed GAS pharyngitis and 37.9% had GAS detected without serological response. Conclusions Elevated ASO titres were associated with GAS pharyngitis and elevated ADB titres were associated with GAS skin infections in New Zealand children. Higher ASO/ADB titres in healthy Māori and Pacific children could indicate a greater prior exposure to GAS infections.

New Zealand has a strategy of eliminating SARS-CoV-2 that has resulted in a low incidence of reported coronavirus-19 disease (COVID-19). The aim of this study was to describe the spread of SARS-CoV-2 in New Zealand via a nationwide serosurvey of blood donors. Samples (n = 9806) were collected over a month-long period (3 December 2020–6 January 2021) from donors aged 16–88 years. The sample population was geographically spread, covering 16 of 20 district health board regions. A series of Spike-based immunoassays were utilised, and the serological testing algorithm was optimised for specificity given New Zealand is a low prevalence setting. Eighteen samples were seropositive for SARS-CoV-2 antibodies, six of which were retrospectively matched to previously confirmed COVID-19 cases. A further four were from donors that travelled to settings with a high risk of SARS-CoV-2 exposure, suggesting likely infection outside New Zealand. The remaining eight seropositive samples were from seven different district health regions for a true seroprevalence estimate, adjusted for test sensitivity and specificity, of 0.103% (95% confidence interval, 0.09–0.12%). The very low seroprevalence is consistent with limited undetected community transmission and provides robust, serological evidence to support New Zealand's successful elimination strategy for COVID-19.

Rheumatic heart disease (RHD) is a large, preventable, global public health burden. In New Zealand (NZ), acute rheumatic fever (ARF) and RHD rates are highest for Māori and Pacific children. This structured review explores the evidence for primary prevention interventions to diagnose and effectively treat group A Streptococcus (GAS) pharyngitis and skin infections to reduce rates of ARF and RHD. Medline, EMBASE and Scopus databases were searched as well as other electronic publications. Included were 50 publications from 1980 onwards. This review has identified that there is little available evidence for effective primary prevention strategies to reduce ARF rates in NZ. However, two primary intervention strategies that should be considered by communities at high-risk of ARF are: the use of school-based clinics to identify and treat GAS pharyngitis and GAS skin infections; and intramuscular benzathine penicillin G with lignocaine analgesia in children who present with a GAS positive throat.

Objectives: To identify COVID-19 outbreaks and border control failures associated with quarantine systems in Australia and New Zealand and to estimate the failure risks. Design, setting, participants: Observational epidemiological study of travellers transiting quarantine in Australia and New Zealand up to 15 June 2021. Main outcome measures: The incidence of COVID-19 related failures arising from quarantine, and the failure risk for those transiting quarantine, estimated both per 100,000 travellers and per 1000 SARS-CoV-2 positive cases. Results: Australia and New Zealand had 32 COVID-19 related failures arising from quarantine systems up to 15 June 2021 (22 and 10, respectively). One resultant outbreak involved an estimated 800 deaths and quarantine failures instigated nine lockdowns. The failure risk for those transiting quarantine was estimated at 5.0 failures per 100,000 travellers and 6.1 failures (95%CI: 4.0 to 8.3) per 1000 SARS-CoV-2 positive cases. The latter risk was two-fold higher in New Zealand compared with Australia. The full vaccination of frontline border workers could likely have prevented a number of quarantine system failures. Conclusions: Quarantine system failures can be costly in terms of lives and economic impacts such as lockdowns. Ongoing improvements or alternatives to hotel-based quarantine are required.

Background Epidemiological evidence in multiple jurisdictions has shown an association between nitrate exposure in drinking water and an increased risk of colorectal cancer (CRC). Objective We aimed to review the extent of nitrate contamination in New Zealand drinking water and estimate the health and financial burden of nitrate-attributable CRC. Methods We collated data on nitrate concentrations in drinking water for an estimated 85% of the New Zealand population (∼4 million people) who were on registered supplies. We estimated nitrate levels for the remaining population (∼600,000 people) based on samples from 371 unregistered (private) supplies. We used the effective rate ratio from previous epidemiological studies to estimate CRC cases and deaths attributable to nitrate in drinking water. Results Three-quarters of New Zealanders are on water supplies with less than 1 mg/L NO3-N. The population weighted average for nitrate exposure for people on registered supplies was 0.49 mg/L NO3-N with 1.91% (95%CI 0.49, 3.30) of CRC cases attributable to nitrates. This correlates to 49.7 cases per year (95%CI 14.9, 101.5) at a cost of 21.3 million USD (95% 6.4, 43.5 million USD). When combining registered and unregistered supplies, we estimated 3.26% (95%CI 0.84, 5.57) of CRC cases were attributable to nitrates, resulting in 100 cases (95%CI 25.7, 171.3) and 41 deaths (95%CI 10.5, 69.7) at a cost of 43.2 million USD (95%CI 10.9, 73.4). Conclusion A substantial minority of New Zealanders are exposed to high or unknown levels of nitrates in their drinking water. Given the international epidemiological studies showing an association between cancer and nitrate ingestion from drinking water, this exposure may cause an important burden of preventable CRC cases, deaths, and economic costs. We consider there is sufficient evidence to justify a review of drinking water standards. Protecting public health adds to the strong environmental arguments to improve water management in New Zealand.

This chapter reviews what is known about the health and economic “burden” of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) worldwide. Evidence on the epidemiology of RHD has grown substantially over the last decade, but much less is known about ARF. The majority of disease risk is conferred by environmental and social factors, including poor-quality housing and household crowding, poor nutrition, and low use of preventive health services. In 2016, RHD accounted for an estimated 300,000 deaths and 10 million disability-adjusted life-years (a summary measure of premature mortality and disability) globally, and an estimated 30 million people were living with the condition. Disease rates have declined around the world, with the residual burden of disease concentrated in low-income countries and in middle-income countries like India with large subnational health inequalities. RHD results in significant economic consequences for affected individuals and households, especially those requiring costly surgical care.

ObjectivesThe aims of this study are to describe area deprivation levels and changes that occur during residential moves involving New Zealand children from birth to their fourth birthday, and to assess whether these changes vary by ethnicity.DesignLongitudinal administrative data.SettingChildren born in New Zealand from 2004 to 2018.ParticipantsAll (565 689) children born in New Zealand with at least one recorded residential move.Outcome measuresA longitudinal data set was created containing lifetime address histories for our cohort. This was linked to the New Zealand Deprivation Index, a measure of small area deprivation. Counts of moves from each deprivation level to each other deprivation level were used to construct transition matrices.ResultsChildren most commonly moved to an area with the same level of deprivation. This was especially pronounced in the most and least deprived areas. The number of moves observed also increased with deprivation. Māori and Pasifika children were less likely to move to, or remain in low-deprivation areas, and more likely to move to high-deprivation areas. They also had disproportionately high numbers of moves.ConclusionWhile there was evidence of mobility between deprivation levels, the most common outcome of a move was no change in area deprivation. The most deprived areas had the highest number of moves. Māori and Pasifika children were over-represented in high-deprivation areas and under-represented in low-deprivation areas. They also moved more frequently than the overall population of 0 to 3 year olds.

BackgroundExcess winter mortality (EWM) has been attributed to both seasonal cold exposure, and to infectious disease. In 2020, New Zealand’s border management and lockdown measures successfully eliminated community transmission of SARS-CoV-2, and also largely eliminated influenza and many other respiratory viruses. This study investigates the contribution of infections and temperature to EWM and typical extended winter (May to October) deaths in this natural experiment created by New Zealand’s COVID-19 pandemic response.MethodsWe used age-standardised weekly deaths to measure EWM 2011 to 2019, then used historical patterns to estimate high, medium and low scenario 2020 EWMs. We then modelled typical year and 2020 heating degree day: mortality relationships to estimate relative contributions of cold temperature and infection to typical EWEDs.ResultsEWM 2011 to 2019 averaged 14.7% (low 11.4%, high 20.9%). In contrast, 2020 EWM was estimated at 1.6%, 2.7%, or 3.8% under high, medium, and low spring-summer mortality scenarios. Between 2011 and 2019, temperature was estimated to explain 47% of extended winter deaths, and infection 27%, with the remaining 26% attributable to the interaction between infection and temperature.DiscussionThe society-wide response to COVID-19 in 2020 resulted in a major reduction of winter mortality in this high-income nation with a temperate climate. In addition to influenza, other respiratory pathogens likely also make a significant contribution to EWM. Low cost protection measures such as mask wearing (eg, in residential care facilities), discouragement of sick presenteeism, and increased influenza vaccine coverage, all have potential to reduce future winter mortality.Research in contextEvidence before this studyExcess winter mortality (EWM) is a widely observed phenomenon, commonly attributed to physiological responses to short and long-term outdoor and indoor cold exposure (and associated increased air pollution); other seasonal physiology changes; and higher incidence of some infectious diseases. Previous estimates of EWM in New Zealand range from 10.3% to 25.6%, with influenza estimated to make up roughly a third of that excess. Internationally, deaths attributable to cold temperatures are also found outside the traditional winter period, with influenza making a large contribution to cold temperature deaths.Added value of this studyThis study finds that following a successful COVID-19 elimination strategy, which simultaneously prevented the annual winter influenza season, and likely other winter respiratory infections, New Zealand is likely in 2020 to experience less than a third of the usual winter mortality excess. Further, this study for the first time estimates the relative contributions of cold temperature and infection, and the interaction between the two, to New Zealand winter deaths. We estimate that of the 9.5% fewer deaths than in typical years recorded between 1 May and 31 October 2020, 92.5% were prevented by infection control measures; 1.4% by the 1.14°C warmer than average winter; and 6.1% by the interaction between infection and low temperature.Implications of all the available evidenceInfluenza and other infectious respiratory pathogens appear to make a much larger contribution to winter mortality than previously recognised. Low cost protection measures such as mask wearing (eg, in residential care facilities), discouragement of sick presenteeism, and increased influenza vaccine coverage, all have potential to reduce future winter deaths, and lower overall annual mortality rates.

New Zealand has a long-running campylobacter infection (campylobacteriosis) epidemic with contaminated fresh chicken meat as the major source. This is both the highest impact zoonosis and the largest food safety problem in the country. Adding to this burden is the recent rapid emergence of antibiotic resistance in these campylobacter infections acquired from locally-produced chicken. Campylobacteriosis rates halved in 2008, as compared with the previous 5 years, following the introduction of regulatory limits on allowable contamination levels in fresh chicken meat, with large health and economic benefits resulting. In the following decade, disease rates do not appear to have declined further. The cumulative impact would equate to an estimated 539 000 cases, 5480 hospitalisations, 284 deaths and economic costs of approximately US$380 million during the last 10 years (2009–2018). Additional regulatory interventions, that build on previously successful regulations in this country, are urgently needed to control the source of this epidemic.

New Zealand, a geographically remote Pacific island with easily sealable borders, implemented a nationwide ‘lockdown’ of all non-essential services to curb the spread of COVID-19. Here, we generate 649 SARS-CoV-2 genome sequences from infected patients in New Zealand with samples collected during the ‘first wave’, representing 56% of all confirmed cases in this time period. Despite its remoteness, the viruses imported into New Zealand represented nearly all of the genomic diversity sequenced from the global virus population. These data helped to quantify the effectiveness of public health interventions. For example, the effective reproductive number, Re of New Zealand’s largest cluster decreased from 7 to 0.2 within the first week of lockdown. Similarly, only 19% of virus introductions into New Zealand resulted in ongoing transmission of more than one additional case. Overall, these results demonstrate the utility of genomic pathogen surveillance to inform public health and disease mitigation., New Zealand implemented stringent COVID-19 control measures early after identification of its first case. Here, the authors perform whole genome sequencing of samples taken until 22 May 2020 and find high viral diversity indicative of multiple separate introductions and limited community transmission.

Enterobacteriaceae that produce extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (ACBLs) are important pathogens and can cause community-acquired illnesses, such as urinary tract infections (UTIs). Fecal carriage of these resistant bacteria by companion animals may pose a risk for transmission to humans. Our work evaluated the sharing of ESBL- and ACBL-producing E. coli isolates between humans and companion animals. We found that in some households, dogs carried the same strain of ESBL-producing E. coli as the household member with a UTI. This suggests that transmission events between humans and animals (or vice versa) are likely occurring within the home environment and, therefore, the community as a whole. This is significant from a health perspective, when considering measures to minimize community transmission, and highlights that in order to manage community spread, we need to consider interventions at the household level., Extended-spectrum-beta-lactamase (ESBL)- or AmpC beta-lactamase (ACBL)-producing Escherichia coli bacteria are the most common cause of community-acquired multidrug-resistant urinary tract infections (UTIs) in New Zealand. The carriage of antimicrobial-resistant bacteria has been found in both people and pets from the same household; thus, the home environment may be a place where antimicrobial-resistant bacteria are shared between humans and pets. In this study, we sought to determine whether members (pets and people) of the households of human index cases with a UTI caused by an ESBL- or ACBL-producing E. coli strain also carried an ESBL- or ACBL-producing Enterobacteriaceae strain and, if so, whether it was a clonal match to the index case clinical strain. Index cases with a community-acquired UTI were recruited based on antimicrobial susceptibility testing of urine isolates. Fecal samples were collected from 18 non-index case people and 36 pets across 27 households. Eleven of the 27 households screened had non-index case household members (8/18 people and 5/36 animals) positive for ESBL- and/or ACBL-producing E. coli strains. Whole-genome sequence analysis of 125 E. coli isolates (including the clinical urine isolates) from these 11 households showed that within seven households, the same strain of ESBL-/ACBL-producing E. coli was cultured from both the index case and another person (5/11 households) or pet dog (2/11 households). These results suggest that transmission within the household may contribute to the community spread of ESBL- or ACBL-producing E. coli. IMPORTANCE Enterobacteriaceae that produce extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (ACBLs) are important pathogens and can cause community-acquired illnesses, such as urinary tract infections (UTIs). Fecal carriage of these resistant bacteria by companion animals may pose a risk for transmission to humans. Our work evaluated the sharing of ESBL- and ACBL-producing E. coli isolates between humans and companion animals. We found that in some households, dogs carried the same strain of ESBL-producing E. coli as the household member with a UTI. This suggests that transmission events between humans and animals (or vice versa) are likely occurring within the home environment and, therefore, the community as a whole. This is significant from a health perspective, when considering measures to minimize community transmission, and highlights that in order to manage community spread, we need to consider interventions at the household level.

Stringent nonpharmaceutical interventions (NPIs) such as lockdowns and border closures are not currently recommended for pandemic influenza control. New Zealand used these NPIs to eliminate coronavirus disease 2019 during its first wave. Using multiple surveillance systems, we observed a parallel and unprecedented reduction of influenza and other respiratory viral infections in 2020. This finding supports the use of these NPIs for controlling pandemic influenza and other severe respiratory viral threats., New Zealand has been relatively successful in controlling COVID-19 due to implementation of strict non-pharmaceutical interventions. Here, the authors demonstrate a striking decline in reports of influenza and other non-influenza respiratory pathogens over winter months in which the interventions have been in place.