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Michael Baker and colleagues argue that aiming for elimination of community transmission of the SARS-CoV-2 virus could offer important advantages over a suppression or mitigation strategy with ongoing transmission

Many of the arguments made by Thornley and colleagues against taking an elimination approach to covid-19 are misleading and incorrect1—in particular, their assertion that the infection fatality risk (IFR) for covid-19 is “similar to that for seasonal flu.” Research conducted in New Zealand and internationally suggests that the IFR for covid-19 is typically …

Background Injuries due to falls in the home amongst the general population impose a huge social and economic cost on society. We previously found important safety benefits of home modifications such as handrails for steps and stairs, grab rails for bathrooms, outside lighting, edging for outside steps and slip-resistant surfacing for outside surfaces such as decks. Methods Following a single-blinded cluster randomised controlled trial (the HIPI trial), we analysed insurance payments for medically-treated home fall injuries. The benefits in terms of the value of DALYs averted and social costs of injuries were extrapolated to a national level and compared with the costs of the intervention. Results Costs per injury per time exposed to the modified homes compared to the unmodified homes showed a reduction in the insurer costs of home fall injuries of 36% (95% CI: 5%–59%). The social benefits of injuries prevented were estimated to be at least 9 times the costs of the intervention. The benefit cost ratio can be at least doubled for older people and those with a prior history of fall injuries. Conclusions This is the first randomised controlled trial to our knowledge to examine the benefits of home modification for reducing fall injury costs in the general population. The results show a convincing economic justification for undertaking relatively low-cost home repairs and installation of safety features.

To prevent cervical cancer, a government-funded vaccination programme against human papillomavirus (HPV) infection started in New Zealand in 2008. After an initial catch-up phase, vaccination with a quadrivalent vaccine was routinely offered from year 2011 onwards to girls in school year 8 (typically age 12 years) or in primary care settings at age 12. To better understand the impact of this vaccination programme, we examined national prescription data from the government's pharmaceutical purchasing agency (PHARMAC). From this agency, we obtained national data for both imiquimod cream (ie, Aldara) and for podophyllum resin-based products …

Background Despite the large mortality burden of World War One (WW1) on New Zealand (NZ) military forces, no analysis using modern epidemiological methods has ever been conducted. Aims To study injury-related mortality amongst NZ military forces for WW1 and consider issues around preventability. Methods An electronic version of the Roll-of-Honour for NZ Expeditionary Force (NZEF) personnel was supplemented with further coding and analysed statistically. We also performed literature searches to provide context. Results Out of a total of 16 703 deaths occurring during the war (28 July 1914 to 11 November 1918), injury deaths predominated: 65.1% were 'killed in action' (KIA)', 23.4% 'died of wounds' (DOW), 1.0% were other injuries ('accidents', drownings, and executions), and 10.5% were other causes (mainly disease). During the course of the war the annual mortality rate from injury (for KIA+DOW) per 10 000 NZEF personnel in the North Hemisphere peaked at 1335 in 1915 (Gallipoli campaign) and then peaked again in 1917 at 937 (largely the Battle of Passchendaele). Cumulative injury mortality proportions for WW1 differed by ethnicity which reflected differing roles in the military: European/Other (1245/10 000); Māori (906); and Pacific soldiers (83). While historical interpretations differ, there are many plausible preventive measures that could have reduced mortality eg: better diplomacy (to prevent the war); better military planning to avoid failed campaigns (eg, Gallipoli); and improved design and resourcing of medical services. Significance WW1 was by far the worst mass injury event in New Zealand's history. Many of these injury deaths could have been prevented. This is an abstract of a presentation at Safety 2012, the 11th World Conference on Injury Prevention and Safety Promotion, 1-4 October 2012, Michael Fowler Center, Wellington, New Zealand. Full text does not seem to be available for this abstract.

Background Although the home is a major setting for injury morbidity and mortality, there are few proven effective interventions for reducing home injury risk. Aims To develop measurement protocols for assessing home injury hazards and practical procedures for making targeted repairs to these hazards. Methods We developed the Healthy Housing Index as a protocol for systematically quantifying the degree of risk posed by housing to the health and safety of the occupants. We studied in detail a large number of home injuries to identify likely preventive measures focused on structural aspects of the home environment. Results Approximately 38% of the 1328 home injuries studied were potentially associated with modifiable features of the home environment. We also found a statistically significant association between increasing numbers of home injury hazards and the occurrence of home injury, providing qualified evidence for the potential effectiveness of home injury hazard remediation as an effective injury prevention measure. Significance The current study potentially provides a path to an effective means to prevent home injury. The expense of making repairs to home injury hazards places greater demands on reliable evidence of the effectiveness of this intervention. This is currently the subject of a large randomised controlled trial, currently in progress.

Background Self-diagnosis of influenza is an important component of pandemic control and management as it may support self-management practices and reduce visits to healthcare facilities, thus helping contain viral spread. However, little is known about the accuracy of self-diagnosis of influenza, particularly during pandemics. Methods We used cross-sectional survey data to correlate self-diagnosis of influenza with serological evidence of 2009 pandemic influenza A(H1N1) infection (haemagglutination inhibition titres of ≥1:40) and to determine what symptoms were more likely to be present in accurate self-diagnosis. The sera and risk factor data were collected for the national A(H1N1) seroprevalence survey from November 2009 to March 2010, 3 months after the first pandemic wave in New Zealand (NZ). Results The samples consisted of 318 children, 413 adults and 423 healthcare workers. The likelihood of being seropositive was no different in those who believed they had influenza from those who believed they did not have influenza in all groups. Among adults, 23.3% (95% CI 11.9% to 34.7%) of those who reported having had influenza were seropositive for H1N1, but among those reporting no influenza, 21.3% (95% CI 13% to 29.7%) were also seropositive. Those meeting NZ surveillance or Ministry of Health influenza case definitions were more likely to believe they had the flu (surveillance data adult sample OR 27.1, 95% CI 13.6 to 53.6), but these symptom profiles were not associated with a higher likelihood of H1N1 seropositivity (surveillance data adult sample OR 0.93, 95% CI 0.5 to 1.7). Conclusions Self-diagnosis does not accurately predict influenza seropositivity. The symptoms promoted by many public health campaigns are linked with self-diagnosis of influenza but not with seropositivity. These findings raise challenges for public health initiatives that depend on accurate self-diagnosis by members of the public and appropriate self-management action., Article summary Article focus To determine whether lay people can accurately recognise influenza infection. Key messages Individuals meeting influenza case definitions were more likely to believe they had influenza. Self-diagnosis, whether by a lay person or a healthcare worker, did not accurately predict influenza seropositivity. Strengths and limitations of this study This is the first published study of the effectiveness of self-diagnosis of influenza compared with laboratory evidence of infection in a broad population-based sample during a pandemic. Some of the participants who believed they had the flu may have had a seasonal influenza or other respiratory pathogens (although H1N1 was the dominant influenza strain). This survey was based on symptom recall rather than symptom reports, which may reflect the participants' enduring perceptions of influenza, likely to guide their behaviour in future influenza epidemics.

Introduction Seasonality of disease has been long recognised in epidemiology. More recently, researchers have established standard ways of measuring seasonality. In temperate countries there has been a particular interest in excess winter mortality (EWM), and, to a lesser degree, excess winter hospitalisations (EWH). Understanding the aetiology of seasonality is important for identifying interventions and potential future climate change effects. Method We measured EWM and EWH in 60–95 year olds between 2000 and 2008, by ICD-10 chapter, and the contribution of each chapter to all-cause winter excess. We then compared indices and percentage contributions for mortality to those for hospitalisation. Results Indices do not lie in the same direction for all ICD-10 chapters. Excesses lay within the same range only for respiratory deaths and hospitalisations. Circulatory illness showed an excess for both hospitalisation and death, but the excess was higher for mortality than for morbidity. However, neoplasms, digestive diseases, and genitourinary diseases all showed a winter mortality excess but a non-winter hospitalisation index. Other chapters also lacked a relationship between indices for hospitalisation and death. Similarly, there was a difference in contribution to winter excess by chapter. Conclusion The comparison of EWM and EWH indicates that caution may be needed in extrapolating causal results from one to the other. As their disease and excess distribution is different, factors which contribute to EWH may play a different role in EWM, and vice versa. Research that can identify the reasons for these differences would improve our understanding of the mechanisms causing disease seasonality.

Background The New Zealand epidemic of campylobacteriosis increased steadily from 1989 onwards, peaking in 2006 with a national rate of over 380 notified cases per 100 000 population. At the peak there were an estimated 120 000 cases a year in the community, and 800 hospitalisations. This rate was markedly higher than that reported by other developed countries. Interventions were introduced to lower contamination levels in fresh chicken meat, notably mandatory monitoring and reporting of Campylobacter in broiler flocks and carcass rinsates, and mandatory Campylobacter carcass performance targets. Methods National notification and hospitalisation data for the period 1997 to 2008 were analysed to describe disease incidence and distribution. Source attribution techniques based on bacterial typing of Campylobacter isolates from human cases and environmental sources were also used to examine the decline. Results Directly following implementation of the regulatory measures, the 2008 campylobacteriosis notification rate declined by 54% and the hospitalisation rate by 56% (compared to the average annual rates for 2002–2006). Source attribution studies suggested an approximate 70% decline in human disease with chicken meat as the source. Conclusions These marked reductions in disease incidence directly followed the introduction of regulatory interventions to reduce Campylobacter contamination of chicken meat. Measures aimed at lowering contamination of raw food appeared far more effective than educational approaches aimed at improving food handling by consumers. Changes to established food production and processing methods may initially be resisted by the food industry, highlighting the need for science-based public health advocacy and regulation. High quality public health surveillance of disease and hazards can also help drive improvements in food safety.

Introduction The aim of border screening for influenza is to prevent or delay the entry of a new pandemic strain, but the evidence base for this strategy is limited. This study aimed to assess the test characteristics of a health questionnaire and temperature measurement for predicting influenza infection in arriving international travellers. Methods A questionnaire was distributed on board flights from Australia to Christchurch, New Zealand during 12 weeks in June–September 2008. It included questions on demographics, symptoms, contacts, and countries visited. All symptomatic travellers and a random sample of asymptomatic travellers were asked to provide a throat swab and have their temperature measured. Results 175/307 (57%) flights were screened according to protocol, and 15 618/22 192 (70%) travellers on screened flights returned questionnaires. 48% of symptomatic travellers and 35% of sampled asymptomatic travellers agreed to provide a swab. The overall prevalence of influenza infection was 1%. The sensitivity for influenza infection of ‘any symptom’ was 85%, for cough 58%, sore throat 26%, self reported fever 15%, and for measured temperature >37.8°C it was 8%. The highest PPV was for self-reported fever, at 23%. Conclusion The poor sensitivity of most screening questions or tests and low prevalence of influenza infection among travellers means that border screening would be resource-intensive yet would fail to identify all, or possibly even most, influenza infected travellers entering the country.

Objectives To assess the risk of transmission of pandemic A/H1N1 2009 influenza (pandemic A/H1N1) from an infected high school group to other passengers on an airline flight and the effectiveness of screening and follow-up of exposed passengers. Design Retrospective cohort investigation using a questionnaire administered to passengers and laboratory investigation of those with symptoms. Setting Auckland, New Zealand, with national and international follow-up of passengers. Participants Passengers seated in the rear section of a Boeing 747-400 long haul flight that arrived on 25 April 2009, including a group of 24 students and teachers and 97 (out of 102) other passengers in the same section of the plane who agreed to be interviewed. Main outcome measures Laboratory confirmed pandemic A/H1N1 infection in susceptible passengers within 3.2 days of arrival; sensitivity and specificity of influenza symptoms for confirmed infection; and completeness and timeliness of contact tracing. Results Nine members of the school group were laboratory confirmed cases of pandemic A/H1N1 infection and had symptoms during the flight. Two other passengers developed confirmed pandemic A/H1N1 infection, 12 and 48 hours after the flight. They reported no other potential sources of infection. Their seating was within two rows of infected passengers, implying a risk of infection of about 3.5% for the 57 passengers in those rows. All but one of the confirmed pandemic A/H1N1 infected travellers reported cough, but more complex definitions of influenza cases had relatively low sensitivity. Rigorous follow-up by public health workers located 93% of passengers, but only 52% were contacted within 72 hours of arrival. Conclusions A low but measurable risk of transmission of pandemic A/H1N1 exists during modern commercial air travel. This risk is concentrated close to infected passengers with symptoms. Follow-up and screening of exposed passengers is slow and difficult once they have left the airport.