Search tips
Search criteria

Results 1-25 (33)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
1.  Estimating influenza-associated mortality in New Zealand from 1990 to 2008 
This study used Poisson regression modelling to estimate influenza-associated mortality in New Zealand for 1990–2008. Inputs were weekly numbers of deaths and influenza and RSV isolates. Seasonal influenza was associated with an average of 401 medical deaths annually from 1990 to 2008, a rate of 10·6 (95% CI: 7·9, 13·3) per 100 000 persons per year, which is 17 times higher than recorded influenza deaths. The majority (86%) of deaths occurred in those 65 years and over. There was no clear decline in influenza-associated mortality in this age group over the course of the study period.
PMCID: PMC4280813  PMID: 25346370
Mortality; influenza; statistical regression
2.  Declining Guillain-Barré Syndrome after Campylobacteriosis Control, New Zealand, 1988–2010 
Emerging Infectious Diseases  2012;18(2):226-233.
Food safety measures that lower incidence of campylobacteriosis might also prevent Guillain-Barré syndrome.
PMCID: PMC3310455  PMID: 22304786
Guillain-Barré syndrome; Campylobacter infection; camplyobacteriosis; food safety; poultry; government regulations; public health surveillance; epidemiology; New Zealand
3.  Staphylococcus aureus Infections in New Zealand, 2000–2011 
Emerging Infectious Diseases  2014;20(7):1157-1162.
Skin and soft tissue infections increased significantly; sociodemographic disparity was noted.
The incidence rate for invasive and noninvasive Staphylococcus aureus infections in New Zealand is among the highest reported in the developed world. Using nationally collated hospital discharge data, we analyzed the epidemiology of serious S. aureus infections in New Zealand during 2000–2011. During this period, incidence of S. aureus skin and soft tissue infections increased significantly while incidence of staphylococcal sepsis and pneumonia remained stable. We observed marked ethnic and sociodemographic inequality across all S. aureus infections; incidence rates for all forms of S. aureus infections were highest among Māori and Pacific Peoples and among patients residing in areas of high socioeconomic deprivation. The increased incidence of S. aureus skin and soft tissue infections, coupled with the demographic disparities, is of considerable concern. Future work should aim to reduce this disturbing national trend.
PMCID: PMC4073854  PMID: 24960446
Infectious disease epidemiology; skin infections; inequality; sepsis; New Zealand; Staphylococcus aureus; bacteria
4.  Improving rheumatic fever surveillance in New Zealand: results of a surveillance sector review 
BMC Public Health  2014;14:528.
The New Zealand (NZ) Government has made a strong commitment to reduce the incidence of rheumatic fever (RF) by two thirds, to 1.4 cases per 100,000, by mid-2017. We reviewed the NZ RF surveillance sector, aiming to identify potential improvements which would support optimal RF control and prevention activities.
This review used a recently developed surveillance sector review method. Interviews with 36 key informants were used to describe the sector, assess it and identify its gaps. Priorities for improvement and implementation strategies were determined following discussion with these key informants, with policy advisors and within the research team.
Key improvements identified included the need for a comprehensive RF surveillance strategy, integrated reporting and an online national RF register. At a managerial level this review provided evidence for system change and built support for this across the surveillance sector.
The surveillance sector review approach can be added to the small set of tools currently available for developing and evaluating surveillance systems. This new approach is likely to prove useful as we confront the challenges of combating new emerging infectious diseases, responding to global environmental changes, and reducing health inequalities.
PMCID: PMC4049392  PMID: 24885018
Public health surveillance; Epidemiological surveillance; Acute rheumatic fever; Rheumatic heart disease
5.  Risk factors for death from pandemic influenza in 1918–1919: a case–control study 
Despite the persisting threat from future influenza pandemics, much is still unknown about the risk factors for death from such events, and especially for the 1918–1919 influenza pandemic.
A case–control study was performed to explore possible risk factors for death from pandemic influenza among New Zealand military personnel in the Northern Hemisphere in 1918–1919 (n = 218 cases, n = 221 controls). Data were compiled from a Roll-of-Honour dataset, a dataset of nearly all military personnel involved in the war and archived individual records.
In the fully adjusted multivariable model, the following were significantly associated with increased risk of death from pandemic influenza: age (25–29 years), pre-pandemic hospitalisations for a chronic condition (e.g. tuberculosis), relatively early year of military deployment, a relatively short time from enlistment to foreign service, and having a larger chest size (e.g. adjusted odds ratio for 90–99 cm versus <90 cm was 2·45; 95% CI=1·47–4·10). There were no significant associations in the fully adjusted model with military rank, occupational class at enlistment, and rurality at enlistment.
This is one of the first published case–control studies of mortality risk factors for the 1918–1919 influenza pandemic. Some of the findings are consistent with previous research on risk factors (such as chronic conditions and age groups), but others appear more novel (e.g., larger chest size). As all such historical analyses have limitations, there is a need for additional studies in other settings as archival World War One records become digitalised.
PMCID: PMC4181481  PMID: 24490663
1918–1919 Influenza pandemic; infectious disease; influenza; military; pandemic
6.  Sero-Prevalence and Risk Factors for Leptospirosis in Abattoir Workers in New Zealand 
Leptospirosis is an important occupational disease in New Zealand. The objectives of this study were to determine risk factors for sero-prevalence of leptospiral antibodies in abattoir workers. Sera were collected from 567 abattoir workers and tested by microscopic agglutination for Leptospira interrogans sv. Pomona and Leptospira borgpetersenii sv. Hardjobovis. Association between prevalence and risk factors were determined by species specific multivariable analysis. Eleven percent of workers had antibodies against Hardjobovis or/and Pomona. Workers from the four sheep abattoirs had an average sero-prevalence of 10%–31%, from the two deer abattoirs 17%–19% and the two beef abattoirs 5%. The strongest risk factor for sero-positivity in sheep and deer abattoirs was work position. In sheep abattoirs, prevalence was highest at stunning and hide removal, followed by removal of the bladder and kidneys. Wearing personal protective equipment such as gloves and facemasks did not appear to protect against infection. Home slaughtering, farming or hunting were not significantly associated with sero-prevalence. There is substantial risk of exposure to leptospires in sheep and deer abattoirs in New Zealand and a persisting, but lower risk, in beef abattoirs. Interventions, such as animal vaccination, appear necessary to control leptospirosis as an occupational disease in New Zealand.
PMCID: PMC3945566  PMID: 24503973
abattoir; leptospirosis; Leptospira borgpetersenii sv. Hardjobovis; Leptospira interrogans sv. Pomona; microscopic agglutination test; sero-prevalence
7.  Climate Variability, Weather and Enteric Disease Incidence in New Zealand: Time Series Analysis 
PLoS ONE  2013;8(12):e83484.
Evaluating the influence of climate variability on enteric disease incidence may improve our ability to predict how climate change may affect these diseases.
To examine the associations between regional climate variability and enteric disease incidence in New Zealand.
Associations between monthly climate and enteric diseases (campylobacteriosis, salmonellosis, cryptosporidiosis, giardiasis) were investigated using Seasonal Auto Regressive Integrated Moving Average (SARIMA) models.
No climatic factors were significantly associated with campylobacteriosis and giardiasis, with similar predictive power for univariate and multivariate models. Cryptosporidiosis was positively associated with average temperature of the previous month (β =  0.130, SE =  0.060, p <0.01) and inversely related to the Southern Oscillation Index (SOI) two months previously (β =  −0.008, SE =  0.004, p <0.05). By contrast, salmonellosis was positively associated with temperature (β  = 0.110, SE = 0.020, p<0.001) of the current month and SOI of the current (β  = 0.005, SE = 0.002, p<0.050) and previous month (β  = 0.005, SE = 0.002, p<0.05). Forecasting accuracy of the multivariate models for cryptosporidiosis and salmonellosis were significantly higher.
Although spatial heterogeneity in the observed patterns could not be assessed, these results suggest that temporally lagged relationships between climate variables and national communicable disease incidence data can contribute to disease prediction models and early warning systems.
PMCID: PMC3871872  PMID: 24376707
8.  Incidence, trends and demographics of Staphylococcus aureus infections in Auckland, New Zealand, 2001–2011 
BMC Infectious Diseases  2013;13:569.
New Zealand has a higher incidence of Staphylococcus aureus disease than other developed countries, with significant sociodemographic variation in incidence rates. In contrast to North America, the majority of disease is due to methicillin-susceptible S. aureus (MSSA), although relatively little is known about the comparative demographics of MSSA and methicillin-resistant S. aureus (MRSA) infections in New Zealand.
Our objectives were to describe the trends, incidence and patient demographics of all S. aureus infections in patients presenting to our institution between 2001 and 2011, and compare the epidemiology of MSSA and MRSA infections. We identified all patients with S. aureus infections over the study period. A unique S. aureus infection was defined as the first positive S. aureus culture taken from the same patient within a thirty-day period. Standard definitions were used to classify episodes into community- or healthcare-associated S. aureus infection.
There were 16,249 S. aureus infections over the study period. The incidence increased significantly over the study period from 360 to 412 per 100,000 population (P < 0.001), largely driven by an increase in community-associated non-invasive MSSA infections. When compared with MSSA infections, patients with non-multiresistant MRSA infections were more likely to be older, have hospital-onset infections and be Māori or Pacific Peoples.
Our work provides valuable baseline data on the epidemiology and trends of S. aureus infections in New Zealand. The significant increase in community-associated S. aureus infections is of public health importance. Future studies should investigate the reasons underlying this concerning trend.
PMCID: PMC4219404  PMID: 24299298
Staphylococcus aureus; Epidemiology; Healthcare-associated infection; Ethnicity; Methicillin-susceptible
9.  A prospective case–control and molecular epidemiological study of human cases of Shiga toxin-producing Escherichia coli in New Zealand 
BMC Infectious Diseases  2013;13:450.
Shiga toxin-producing Escherichia coli (STEC) O157:H7 and related non-O157 STEC strains are enteric pathogens of public health concern worldwide, causing life-threatening diseases. Cattle are considered the principal hosts and have been shown to be a source of infection for both foodborne and environmental outbreaks in humans. The aims of this study were to investigate risk factors associated with sporadic STEC infections in humans in New Zealand and to provide epidemiological information about the source and exposure pathways.
During a national prospective case–control study from July 2011 to July 2012, any confirmed case of STEC infection notified to regional public health units, together with a random selection of controls intended to be representative of the national demography, were interviewed for risk factor evaluation. Isolates from each case were genotyped using pulsed-field gel electrophoresis (PFGE) and Shiga toxin-encoding bacteriophage insertion (SBI) typing.
Questionnaire data from 113 eligible cases and 506 controls were analysed using multivariate logistic regression. Statistically significant animal and environmental risk factors for human STEC infections were identified, notably 'Cattle livestock present in meshblock’ (the smallest geographical unit) (odds ratio 1.89, 95% CI 1.04–3.42), 'Contact with animal manure’ (OR 2.09, 95% CI 1.12–3.90), and 'Contact with recreational waters’ (OR 2.95, 95% CI 1.30–6.70). No food-associated risk factors were identified as sources of STEC infection. E. coli O157:H7 caused 100/113 (88.5%) of clinical STEC infections in this study, and 97/100 isolates were available for molecular analysis. PFGE profiles of isolates revealed three distinctive clusters of genotypes, and these were strongly correlated with SBI type. The variable 'Island of residence’ (North or South Island of New Zealand) was significantly associated with PFGE genotype (p = 0.012).
Our findings implicate environmental and animal contact, but not food, as significant exposure pathways for sporadic STEC infections in humans in New Zealand. Risk factors associated with beef and dairy cattle suggest that ruminants are the most important sources of STEC infection. Notably, outbreaks of STEC infections are rare in New Zealand and this further suggests that food is not a significant exposure pathway.
PMCID: PMC3854066  PMID: 24079470
Prospective case–control study; Sporadic STEC infections; New Zealand; Risk factors; Source attribution; Cattle; Molecular epidemiology; Pathways of infection; Population attributable fractions
10.  Marked Campylobacteriosis Decline after Interventions Aimed at Poultry, New Zealand 
Emerging Infectious Diseases  2011;17(6):1007-1015.
A population-level food safety response successfully reduced disease incidence.
Beginning in the 1980s, New Zealand experienced rising annual rates of campylobacteriosis that peaked in 2006. We analyzed notification, hospitalization, and other data to explore the 2007–2008 drop in campylobacteriosis incidence. Source attribution techniques based on genotyping of Campylobacter jejuni isolates from patients and environmental sources were also used to examine the decline. In 2008, the annual campylobacteriosis notification rate was 161.5/100,000 population, representing a 54% decline compared with the average annual rate of 353.8/100,000 for 2002–2006. A similar decline was seen for hospitalizations. Source attribution findings demonstrated a 74% (95% credible interval 49%–94%) reduction in the number of cases attributed to poultry. These reductions coincided with the introduction of a range of voluntary and regulatory interventions to reduce Campylobacter spp. contamination of poultry. The apparent success of these interventions may inform approaches other countries could consider to help control foodborne campylobacteriosis.
PMCID: PMC3358198  PMID: 21749761
bacteria; foodborne infections; Campylobacter; epidemiology; surveillance; poultry; food supply; bacterial typing; research; New Zealand
11.  Foods and Dietary Patterns That Are Healthy, Low-Cost, and Environmentally Sustainable: A Case Study of Optimization Modeling for New Zealand 
PLoS ONE  2013;8(3):e59648.
Global health challenges include non-communicable disease burdens, ensuring food security in the context of rising food prices, and environmental constraints around food production, e.g., greenhouse gas [GHG] emissions. We therefore aimed to consider optimized solutions to the mix of food items in daily diets for a developed country population: New Zealand (NZ).
We conducted scenario development and linear programming to model 16 diets (some with uncertainty). Data inputs included nutrients in foods, food prices, food wastage and food-specific GHG emissions.
This study identified daily dietary patterns that met key nutrient requirements for as little as a median of NZ$ 3.17 per day (US$ 2.41/d) (95% simulation interval [SI] = NZ$ 2.86 to 3.50/d). Diets that included “more familiar meals” for New Zealanders, increased the cost. The optimized diets also had low GHG emission profiles compared with the estimate for the ‘typical NZ diet’ e.g., 1.62 kg CO2e/d for one scenario (95%SI = 1.39 to 1.85 kg CO2e) compared with 10.1 kg CO2e/d, respectively. All of the optimized low-cost and low-GHG dietary patterns had likely health advantages over the current NZ dietary pattern, i.e., lower cardiovascular disease and cancer risk.
We identified optimal foods and dietary patterns that would lower the risk of non-communicable diseases at low cost and with low greenhouse gas emission profiles. These results could help guide central and local government decisions around which foods to focus policies on. That is which foods are most suitable for: food taxes (additions and exemptions); healthy food vouchers and subsidies; and for increased use by public institutions involved in food preparation.
PMCID: PMC3609827  PMID: 23544082
12.  Risk factors, microbiological findings and outcomes of necrotizing fasciitis in New Zealand: a retrospective chart review 
BMC Infectious Diseases  2012;12:348.
The incidence and mortality from necrotizing fasciitis (NF) are increasing in New Zealand (NZ). Triggered by a media report that traditional Samoan tattooing was causing NF, we conducted a chart review to investigate the role of this and other predisposing and precipitating factors and to document NF microbiology, complications and interventions in NZ.
We conducted a retrospective review of 299 hospital charts of patients discharged with NF diagnosis codes in eight hospitals in NZ between 2000 and 2006. We documented and compared by ethnicity the prevalence of predisposing and precipitating conditions, bacteria isolated, complications and interventions used.
Out of 299 charts, 247 fulfilled the case definition. NF was most common in elderly males. Diabetes was the most frequent co-morbid condition, followed by obesity. Nearly a quarter of patients were taking non-steroidal anti-inflammatory drugs (NSAID). Traditional Samoan tattooing was an uncommon cause. Streptococcus pyogenes and Staphylococcus aureus were the two commonly isolated bacteria. Methicillin-resistant Staphylococcus aureus was implicated in a relatively small number of cases. Shock, renal failure, coagulation abnormality and multi-organ dysfunction were common complications. More than 90% of patients underwent surgical debridement, 56% were admitted to an intensive care unit (ICU) and slightly less than half of all patients had blood product transfusion. One in six NF cases had amputations and 23.5% died.
This chart review found that the highest proportion of NF cases was elderly males with co-morbidities, particularly diabetes and obesity. Tattooing was an uncommon precipitating event. The role of NSAID needs further exploration. NF is a serious disease with severe complications, high case fatality and considerable use of health care resources.
PMCID: PMC3538518  PMID: 23234429
Bacterial infection; Ethnicity; Necrotizing fasciitis; New Zealand; Traditional Samoan tattooing
13.  Seasonality, incidence and prognosis in atrial fibrillation and stroke in Denmark and New Zealand 
BMJ Open  2012;2(4):e001210.
There are relatively few large studies of seasonal variation in the occurrence of stroke in patients with atrial fibrillation (AF). We investigated the seasonal variation in incidence rates of hospitalisation with stroke in patients from Denmark and New Zealand.
Cohort study.
Nationwide hospital discharge data from Denmark and New Zealand.
243 381 (median age 75) subjects having a first-time hospitalisation with AF in Denmark and 51 480 (median age 76) subjects in New Zealand constituted the study population. Subjects with previous hospitalisation with stroke were excluded.
Primary and secondary effect measures
Peak-to-trough ratio of the seasonal variation in incidence rates of stroke in AF patients adjusted for an overall trend was primary effect measure and was assessed using a log-linear Poisson regression model. Secondary effect measures were incidence rate ratios of AF and 30-day case fatality for stroke patients.
Incidence rates of AF per 1000 person-years in Denmark increased by 5.4% (95% CI 5.3% to 5.7%) for patients aged <65 and 5% (95% CI 4.9% to 5.1%) for patients aged ≥65, whereas the increase was 0.2% (95% CI −0.2% to 0.6%) for patients aged <65 and 2.6% (95% CI 2.4% to 2.8%) for patients aged ≥65 in New Zealand. In Denmark 36 088 subjects were hospitalised with stroke, and 7518 subjects in New Zealand, both showing peaks during winter with peak-to-trough ratios of 1.22 and 1.27, respectively and a decreasing trend. The 30-day case fatality risk for stroke patients having AF is now (2000–2008) about 20% in both countries.
Although incidence rates of hospitalisation with stroke in patients with AF have decreased in recent years, stroke remains a common AF complication with a high case fatality risk. The marked winter peak in incidence rates of hospitalisation with stroke in AF patients suggests that there are opportunities to reduce this complication. Further studies are necessary to identify how to optimise treatment of AF and prevention of stroke.
PMCID: PMC3432837  PMID: 22923628
Neurology; Stroke; Atrial fibrillation; Seasonal variation; Epidemiology; Internal Medicine; Cardiology; Poisson regression
14.  Searching for Sharp Drops in the Incidence of Pandemic A/H1N1 Influenza by Single Year of Age 
PLoS ONE  2012;7(8):e42328.
During the 2009 H1N1 pandemic (pH1N1), morbidity and mortality sparing was observed among the elderly population; it was hypothesized that this age group benefited from immunity to pH1N1 due to cross-reactive antibodies generated from prior infection with antigenically similar influenza viruses. Evidence from serologic studies and genetic similarities between pH1N1 and historical influenza viruses suggest that the incidence of pH1N1 cases should drop markedly in age cohorts born prior to the disappearance of H1N1 in 1957, namely those at least 52–53 years old in 2009, but the precise range of ages affected has not been delineated.
Methods and Findings
To test for any age-associated discontinuities in pH1N1 incidence, we aggregated laboratory-confirmed pH1N1 case data from 8 jurisdictions in 7 countries, stratified by single year of age, sex (when available), and hospitalization status. Using single year of age population denominators, we generated smoothed curves of the weighted risk ratio of pH1N1 incidence, and looked for sharp drops at varying age bandwidths, defined as a significantly negative second derivative. Analyses stratified by hospitalization status and sex were used to test alternative explanations for observed discontinuities. We found that the risk of laboratory-confirmed infection with pH1N1 declines with age, but that there was a statistically significant leveling off or increase in risk from about 45 to 50 years of age, after which a sharp drop in risk occurs until the late fifties. This trend was more pronounced in hospitalized cases and in women and was independent of the choice in smoothing parameters. The age range at which the decline in risk accelerates corresponds to the cohort born between 1951–1959 (hospitalized) and 1953–1960 (not hospitalized).
The reduced incidence of pH1N1 disease in older individuals shows a detailed age-specific pattern consistent with protection conferred by exposure to influenza A/H1N1 viruses circulating before 1957.
PMCID: PMC3410923  PMID: 22876316
15.  Global Public Health Surveillance under New International Health Regulations 
Emerging Infectious Diseases  2006;12(7):1058-1065.
IHR 2005 establishes a global surveillance system for public health emergencies of international concern.
The new International Health Regulations adopted by the World Health Assembly in May 2005 (IHR 2005) represents a major development in the use of international law for public health purposes. One of the most important aspects of IHR 2005 is the establishment of a global surveillance system for public health emergencies of international concern. This article assesses the surveillance system in IHR 2005 by applying well-established frameworks for evaluating public health surveillance. The assessment shows that IHR 2005 constitutes a major advance in global surveillance from what has prevailed in the past. Effectively implementing the IHR 2005 surveillance objectives requires surmounting technical, resource, governance, legal, and political obstacles. Although IHR 2005 contains some provisions that directly address these obstacles, active support by the World Health Organization and its member states is required to strengthen national and global surveillance capabilities.
PMCID: PMC3291053  PMID: 16836821
Disease surveillance; International law; Infectious disease; Emergence; Health law; International Health Regulations; Outbreaks; World Health Organization
16.  A measure for quantifying the impact of housing quality on respiratory health: a cross-sectional study 
Environmental Health  2012;11:33.
Damp and mould in homes have been established as risk factors for respiratory health. There is a need for a relatively straightforward assessment of the home that quantifies this risk.
Using data from 891 New Zealand houses, the utility of a Respiratory Hazard Index quantifying key attributes related to damp and mould was tested by studying its associations with self-reported respiratory symptoms.
A dose–response relationship was found whereby each unit increase in the Respiratory Hazard Index was associated with an 11% increase in the odds of at least one episode of wheezing/whistling in the chest over the last 12 months (relative odds of 1.11 with a 95% CI 1.04%–1.20%). An 11% increase in the odds of an asthma attack over the last 12 months was estimated (relative odds of 1.11 with a 95% CI 1.01%–1.22%). These estimates were adjusted for household crowding levels, age, sex and smoking status. There was suggestive evidence of more steeply increasing odds of respiratory symptoms with increasing levels of the Respiratory Hazard Index for children aged under 7. In the worst performing houses according to the Index, a 33% reduction in the number of people experiencing respiratory symptoms (relative risk 0.67 with 95% CI 0.53 to 0.85) could be expected if people were housed in the best performing houses.
This study showed that increased evidence of housing conditions supporting dampness and mould was associated with increased odds of respiratory symptoms. A valid housing assessment tool can provide a rational basis for investment in improved housing quality to improve respiratory health.
PMCID: PMC3410778  PMID: 22583775
Respiratory health; Home environment; Asthma symptoms
17.  Screening for Influenza A(H1N1)pdm09, Auckland International Airport, New Zealand 
Emerging Infectious Diseases  2012;18(5):866-868.
Entry screening for influenza A(H1N1)pdm09 at Auckland International Airport, New Zealand, detected 4 cases, which were later confirmed, among 456,518 passengers arriving April 27–June 22, 2009. On the basis of national influenza surveillance data, which suggest that ≈69 infected travelers passed through the airport, sensitivity for screening was only 5.8%.
PMCID: PMC3358051  PMID: 22516105
pandemic; communicable diseases; influenza; viruses; emigration and immigration; mass screening; sensitivity; program evaluation; airport; influenza; New Zealand; influenza A(H1N1)pdm09; pandemic (H1N1) 2009; H1N1; pH1N1
18.  Seasonality in Human Zoonotic Enteric Diseases: A Systematic Review 
PLoS ONE  2012;7(4):e31883.
Although seasonality is a defining characteristic of many infectious diseases, few studies have described and compared seasonal patterns across diseases globally, impeding our understanding of putative mechanisms. Here, we review seasonal patterns across five enteric zoonotic diseases: campylobacteriosis, salmonellosis, vero-cytotoxigenic Escherichia coli (VTEC), cryptosporidiosis and giardiasis in the context of two primary drivers of seasonality: (i) environmental effects on pathogen occurrence and pathogen-host associations and (ii) population characteristics/behaviour.
Methodology/Principal Findings
We systematically reviewed published literature from 1960–2010, resulting in the review of 86 studies across the five diseases. The Gini coefficient compared temporal variations in incidence across diseases and the monthly seasonality index characterised timing of seasonal peaks. Consistent seasonal patterns across transnational boundaries, albeit with regional variations was observed. The bacterial diseases all had a distinct summer peak, with identical Gini values for campylobacteriosis and salmonellosis (0.22) and a higher index for VTEC (Gini = 0.36). Cryptosporidiosis displayed a bi-modal peak with spring and summer highs and the most marked temporal variation (Gini = 0.39). Giardiasis showed a relatively small summer increase and was the least variable (Gini = 0.18).
Seasonal variation in enteric zoonotic diseases is ubiquitous, with regional variations highlighting complex environment-pathogen-host interactions. Results suggest that proximal environmental influences and host population dynamics, together with distal, longer-term climatic variability could have important direct and indirect consequences for future enteric disease risk. Additional understanding of the concerted influence of these factors on disease patterns may improve assessment and prediction of enteric disease burden in temperate, developed countries.
PMCID: PMC3317665  PMID: 22485127
19.  Community responses to communication campaigns for influenza A (H1N1): a focus group study 
BMC Public Health  2012;12:205.
This research was a part of a contestable rapid response initiative launched by the Health Research Council of New Zealand and the Ministry of Health in response to the 2009 influenza A pandemic. The aim was to provide health authorities in New Zealand with evidence-based practical information to guide the development and delivery of effective health messages for H1N1 and other health campaigns. This study contributed to the initiative by providing qualitative data about community responses to key health messages in the 2009 and 2010 H1N1 campaigns, the impact of messages on behavioural change and the differential impact on vulnerable groups in New Zealand.
Qualitative data were collected on community responses to key health messages in the 2009 and 2010 Ministry of Health H1N1 campaigns, the impact of messages on behaviour and the differential impact on vulnerable groups. Eight focus groups were held in the winter of 2010 with 80 participants from groups identified by the Ministry of Health as vulnerable to the H1N1 virus, such as people with chronic health conditions, pregnant women, children, Pacific Peoples and Māori. Because this study was part of a rapid response initiative, focus groups were selected as the most efficient means of data collection in the time available. For Māori, focus group discussion (hui) is a culturally appropriate methodology.
Thematic analysis of data identified four major themes: personal and community risk, building community strategies, responsibility and information sources. People wanted messages about specific actions that they could take to protect themselves and their families and to mitigate any consequences. They wanted transparent and factual communication where both good and bad news is conveyed by people who they could trust.
The responses from all groups endorsed the need for community based risk management including information dissemination. Engaging with communities will be essential to facilitate preparedness and build community resilience to future pandemic events. This research provides an illustration of the complexities of how people understand and respond to health messages related to the H1N1 pandemic. The importance of the differences identified in the analysis is not the differences per se but highlight problems with a "one size fits all" pandemic warning strategy.
PMCID: PMC3324376  PMID: 22429559
20.  Differential Mortality Rates by Ethnicity in 3 Influenza Pandemics Over a Century, New Zealand 
Emerging Infectious Diseases  2012;18(1):71-77.
The persistent excess in adverse outcomes by ethnicity highlights the need for improved public health responses.
Evidence suggests that indigenous populations have suffered disproportionately from past influenza pandemics. To examine any such patterns for Māori in New Zealand, we searched the literature and performed new analyses by using additional datasets. The Māori death rate in the 1918 pandemic (4,230/100,000 population) was 7.3× the European rate. In the 1957 pandemic, the Māori death rate (40/100,000) was 6.2× the European rate. In the 2009 pandemic, the Māori rate was higher than the European rate (rate ratio 2.6, 95% confidence interval 1.3–5.3). These findings suggest some decline in pandemic-related ethnic inequalities in death rates over the past century. Nevertheless, the persistent excess in adverse outcomes for Māori, and for Pacific persons residing in New Zealand, highlights the need for improved public health responses.
PMCID: PMC3310086  PMID: 22257434
influenza pandemic; virus; historical; Maori; Pacific
21.  Injuries associated with housing conditions in Europe: a burden of disease study based on 2004 injury data 
Environmental Health  2011;10:98.
The authors recently undertook a study for the World Health Organization estimating the European burden of injuries that can be attributed to remediable structural hazards in the home. Such estimates are essential for motivating injury prevention efforts as they quantify potential health gains, in terms of injuries prevented, via specific environmental interventions.
We combined exposure estimates from existing surveys and scenarios with estimates of the exposure-risk relationship obtained from a structured review of the literature on injury in the home and housing conditions. The resulting attributable fractions were applied to burden of injury data for the WHO European Region.
This analysis estimated that two specific hazards, lack of window guards at second level and higher, and lack of domestic smoke detectors resulted in an estimated 7,500 deaths and 200,000 disability adjusted life years (DALYs) per year. In estimating the environmental burden of injury associated with housing, important deficiencies in injury surveillance data and related limitations in studies of injury risk attributable to the home environment were apparent. The ability to attribute proportions of the home injury burden to features of the home were correspondingly limited, leading to probable severe underestimates of the burden.
The burden of injury from modifiable home injury exposures is substantial. Estimating this burden in a comprehensive and accurate manner requires improvements to the scope of injury surveillance data and the evidence base regarding the effectiveness of interventions.
PMCID: PMC3305900  PMID: 22074463
Injury burden; housing injury hazards; attributable risk; Europe
22.  Self-diagnosis of influenza during a pandemic: a cross-sectional survey 
BMJ Open  2011;1(2):e000234.
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.
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).
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).
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.
PMCID: PMC3191601  PMID: 22021887
23.  A pilot study of medical student attitudes to, and use of, commercial movies that address public health issues 
BMC Research Notes  2011;4:111.
An innovative approach to learning public health by using feature-length commercial movies was piloted in the fourth year of a medical degree. We aimed to explore how students responded to this approach and the relative effectiveness of two promotional strategies. Firstly we placed DVDs of 15 movies (with public health-related content) in the medical school library. Then alternating groups of students (total n = 82 students) were exposed to either a brief promotional intervention or a more intensive intervention involving a class presentation. The response rates were 99% at baseline and 85% at follow-up.
The level and strength of support for using movies in public health training increased after exposure to the public health module with significantly more students "strongly agreeing". Student behaviour, in terms of movies viewed or accessed from the library, also suggested student interest. While there were no statistically significant differences in median viewing or library access rates between the two intervention groups, the distribution of viewing patterns was shifted favourably. Those exposed to the more intensive intervention (class presentation) were significantly more likely to have reported watching at least one movie (97% vs. 81%; p = 0.033) or to having accessed at least one movie from the library (100% vs. 70%, p = 0.0001).
This pilot study found that the students had very positive attitudes towards viewing public health-related commercial movies. Movie access rates from the library were also favourable.
PMCID: PMC3090335  PMID: 21473773
24.  Thermal Image Scanning for Influenza Border Screening: Results of an Airport Screening Study 
PLoS ONE  2011;6(1):e14490.
Infrared thermal image scanners (ITIS) appear an attractive option for the mass screening of travellers for influenza, but there are no published data on their performance in airports.
ITIS was used to measure cutaneous temperature in 1275 airline travellers who had agreed to tympanic temperature measurement and respiratory sampling. The prediction by ITIS of tympanic temperature (37.8°C and 37.5°C) and of influenza infection was assessed using Receiver Operating Characteristic (ROC) curves and estimated sensitivity, specificity and positive predictive value (PPV).
Using front of face ITIS for prediction of tympanic temperature ≥37.8°C, the area under the ROC curve was 0.86 (95%CI 0.75–0.97) and setting sensitivity at 86% gave specificity of 71%. The PPV in this population of travellers, of whom 0.5% were febrile using this definition, was 1.5%. We identified influenza virus infection in 30 travellers (3 Type A and 27 Type B). For ITIS prediction of influenza infection the area under the ROC curve was 0.66 (0.56–0.75), a sensitivity of 87% gave specificity of 39%, and PPV of 2.8%. None of the 30 influenza-positive travellers had tympanic temperature ≥37.8°C at screening (95%CI 0% to 12%); three had no influenza symptoms.
ITIS performed moderately well in detecting fever but in this study, during a seasonal epidemic of predominantly influenza type B, the proportion of influenza-infected travellers who were febrile was low and ITIS were not much better than chance at identifying travellers likely to be influenza-infected. Although febrile illness is more common in influenza A infections than influenza B infections, many influenza A infections are afebrile. Our findings therefore suggest that ITIS is unlikely to be effective for entry screening of travellers to detect influenza infection with the intention of preventing entry of the virus into a country.
PMCID: PMC3016318  PMID: 21245928
25.  Mortality Risk Factors for Pandemic Influenza on New Zealand Troop Ship, 1918 
Emerging Infectious Diseases  2010;16(12):1931-1937.
TOC summary: Crowding and ventilation problems contributed to an increased risk of death.
We describe the epidemiology and risk factors for death in an outbreak of pandemic influenza on a troop ship. Mortality and descriptive data for military personnel on His Majesty’s New Zealand Transport troop ship Tahiti in July 1918 were analyzed, along with archival information. Mortality risk was increased among persons 25–34 years of age. Accommodations in cabins rather than sleeping in hammocks in other areas were also associated with increased mortality risk (rate ratio 4.28, 95% confidence interval 2.69–6.81). Assignment to a particular military unit, the field artillery (probably housed in cabins), also made a significant difference (adjusted odds ratio in logistic regression 3.04, 95% confidence interval 1.59–5.82). There were no significant differences by assigned rurality (rural residence) or socioeconomic status. Results suggest that the virulent nature of the 1918 influenza strain, a crowded environment, and inadequate isolation measures contributed to the high influenza mortality rate onboard this ship.
PMCID: PMC3294590  PMID: 21122224
Influenza; pandemic; viruses; New Zealand; infectious disease outbreak; troop ship; mortality; risk factors; military; historical review

Results 1-25 (33)