Health Impacts of Climate Change in Pacific Island Countries: A Regional Assessment of Vulnerabilities and Adaptation Priorities.

BACKGROUND: Between 2010 and 2012, the World Health Organization Division of Pacific Technical Support led a regional climate change and health vulnerability assessment and adaptation planning project, in collaboration with health sector partners, in 13 Pacific island countries-Cook Islands, Federated States of Micronesia, Fiji, Kiribati, Marshall Islands, Nauru, Niue, Palau, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu. OBJECTIVE: We assessed the vulnerabilities of Pacific island countries to the health impacts of climate change and planned adaptation strategies to minimize such threats to health. METHODS: This assessment involved a combination of quantitative and qualitative techniques. The former included descriptive epidemiology, time series analyses, Poisson regression, and spatial modeling of climate and climate-sensitive disease data, in the few instances where this was possible; the latter included wide stakeholder consultations, iterative consensus building, and expert opinion. Vulnerabilities were ranked using a "likelihood versus impact" matrix, and adaptation strategies were prioritized and planned accordingly. RESULTS: The highest-priority climate-sensitive health risks in Pacific island countries included trauma from extreme weather events, heat-related illnesses, compromised safety and security of water and food, vector-borne diseases, zoonoses, respiratory illnesses, psychosocial ill-health, non-communicable diseases, population pressures, and health system deficiencies. Adaptation strategies relating to these climate change and health risks could be clustered according to categories common to many countries in the Pacific region. CONCLUSION: Pacific island countries are among the most vulnerable in the world to the health impacts of climate change. This vulnerability is a function of their unique geographic, demographic, and socioeconomic characteristics combined with their exposure to changing weather patterns associated with climate change, the health risks entailed, and the limited capacity of the countries to manage and adapt in the face of such risks. Citation: McIver L, Kim R, Woodward A, Hales S, Spickett J, Katscherian D, Hashizume M, Honda Y, Kim H, Iddings S, Naicker J, Bambrick H, McMichael AJ, Ebi KL. 2016. Health impacts of climate change in Pacific island countries: a regional assessment of vulnerabilities and adaptation priorities. Environ Health Perspect 124:1707-1714; http://dx.doi.org/10.1289/ehp.1509756.

Extreme weather events and infectious disease outbreaks.

Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental conditions of extreme weather events. This review article examines infectious disease risks associated with extreme weather events; it draws on recent experiences including Hurricane Katrina in 2005 and the 2010 Pakistan mega-floods, and historical examples from previous centuries of epidemics and 'pestilence' associated with extreme weather disasters and climatic changes. A fuller understanding of climatic change, the precursors and triggers of extreme weather events and health consequences is needed in order to anticipate and respond to the infectious disease risks associated with human-driven climate change. Post-event risks to human health can be constrained, nonetheless, by reducing background rates of persistent infection, preparatory action such as coordinated disease surveillance and vaccination coverage, and strengthened disaster response. In the face of changing climate and weather conditions, it is critically important to think in ecological terms about the determinants of health, disease and death in human populations.

Comparative assessment of the effects of climate change on heat- and cold-related mortality in the United Kingdom and Australia.

BACKGROUND: High and low ambient temperatures are associated with increased mortality in temperate and subtropical climates. Temperature-related mortality patterns are expected to change throughout this century because of climate change. OBJECTIVES: We compared mortality associated with heat and cold in UK regions and Australian cities for current and projected climates and populations. METHODS: Time-series regression analyses were carried out on daily mortality in relation to ambient temperatures for UK regions and Australian cities to estimate relative risk functions for heat and cold and variations in risk parameters by age. Excess deaths due to heat and cold were estimated for future climates. RESULTS: In UK regions, cold-related mortality currently accounts for more than one order of magnitude more deaths than heat-related mortality (around 61 and 3 deaths per 100,000 population per year, respectively). In Australian cities, approximately 33 and 2 deaths per 100,000 population are associated every year with cold and heat, respectively. Although cold-related mortality is projected to decrease due to climate change to approximately 42 and 19 deaths per 100,000 population per year in UK regions and Australian cities, heat-related mortality is projected to increase to around 9 and 8 deaths per 100,000 population per year, respectively, by the 2080s, assuming no changes in susceptibility and structure of the population. CONCLUSIONS: Projected changes in climate are likely to lead to an increase in heat-related mortality in the United Kingdom and Australia over this century, but also to a decrease in cold-related deaths. Future temperature-related mortality will be amplified by aging populations. Health protection from hot weather will become increasingly necessary in both countries, while protection from cold weather will be still needed.

Keyhole limpet haemocyanin - a model antigen for human immunotoxicological studies.

Immunization with a T-cell dependent antigen has been promoted as a reliable and sensitive tool for assessing the influence of putative immunotoxic exposures or agents on immune function. Keyhole limpet haemocyanin (KLH) is a very large, copper-containing protein molecule derived from the haemolymph of the inedible mollusc, Megathura crenulata. KLH is a highly immunogenic T-cell dependent antigen that is used increasingly in immunotoxicological studies, particularly in those involving animals. This report systematically reviews the human clinical studies that have used trans-cutaneous KLH immunization for assessment of the influence of various physiological and disease states and exposures on immune function over the last 20 years (1994-2013). These studies varied in their immunization protocols, formulation of KLH, dose, site and route of administration and immunoassay platforms developed to assess KLH-specific responses. KLH immunization has been well tolerated with only mild to moderate adverse effects reported. Though very promising as a model antigen candidate in immunotoxicology research, more work on standardizing immunization and immunoassay protocols is required.

Analysis and prediction of Ross River virus transmission in New South Wales, Australia.

BACKGROUND: Ross River virus (RRV) disease is the most widespread mosquito-borne disease in Australia. The disease is maintained in enzootic cycles between mosquitoes and reservoir hosts. During outbreaks and in endemic regions, RRV transmission can be sustained between vectors and reservoir hosts in zoonotic cycles with spillover to humans. Symptoms include arthritis, rash, fever and fatigue and can persist for several months. The prevalence and associated morbidity make this disease a medically and economically important mosquito-borne disease in Australia. METHODS: Climate, environment, and RRV vector and reservoir host information were used to develop predictive models in four regions in NSW over a 13-year period (1991-2004). Polynomial distributed lag (PDL) models were used to explore long-term influences of up to 2 years ago that could be related to RRV activity. RESULTS: Each regional model consisted of a unique combination of predictors for RRV disease highlighting the differences in the disease ecology and epidemiology in New South Wales (NSW). Events up to 2 years before were found to influence RRV activity. The shorter-term associations may reflect conditions that promote virus amplification in RRV vectors whereas long-term associations may reflect RRV reservoir host breeding and herd immunity. The models indicate an association between host populations and RRV disease, lagged by 24 months, suggesting two or more generations of susceptible juveniles may be necessary for an outbreak. Model sensitivities ranged from 60.4% to 73.1%, and model specificities ranged from 57.9% to 90.7%. This was the first study to include reservoir host data into statistical RRV models; the inclusion of host parameters was found to improve model fit significantly. CONCLUSION: The research presents the novel use of a combination of climate, environment, and RRV vector and reservoir host information in statistical predictive models. The models have potential for public health decision-making.

Earth as humans' habitat: global climate change and the health of populations.

Human-induced climate change, with such rapid and continuing global-scale warming, is historically unprecedented and signifies that human pressures on Earth's life-supporting natural systems now exceed the planet's bio-geo-capacity. The risks from climate change to health and survival in populations are diverse, as are the social and political ramifications. Although attributing observed health changes in a population to the recent climatic change is difficult, a coherent pattern of climate- and weather-associated changes is now evident in many regions of the world. The risks impinge unevenly, especially on poorer and vulnerable regions, and are amplified by pre-existing high rates of climate-sensitive diseases and conditions. If, as now appears likely, the world warms by 3-5oC by 2100, the health consequences, directly and via massive social and economic disruption, will be severe. The health sector has an important message to convey, comparing the health risks and benefits of enlightened action to avert climate change and to achieve sustainable ways of living versus the self-interested or complacent inaction.

In an interconnected world: joint research priorities for the environment, agriculture and infectious disease.

In 2008 the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) commissioned ten think-tanks to work on disease-specific and thematic reference groups to identify top research priorities that would advance the research agenda on infectious diseases of poverty, thus contributing to improvements in human health. The first of the thematic reference group reports - on environment, agriculture and infectious diseases of poverty - was recently released. In this article we review, from an insider perspective, the strengths and weaknesses of this thematic reference group report and highlight key messages for policy-makers, funders and researchers.

Shifts in the seasonal distribution of deaths in Australia, 1968-2007.

Studies in temperate countries have shown that both hot weather in summer and cold weather in winter increase short-term (daily) mortality. The gradual warming, decade on decade, that Australia has experienced since the 1960s, might therefore be expected to have differentially affected mortality in the two seasons, and thus indicate an early impact of climate change on human health. Failure to detect such a signal would challenge the widespread assumption that the effect of weather on mortality implies a similar effect of a change from the present to projected future climate. We examine the ratio of summer to winter deaths against a background of rising average annual temperatures over four decades: the ratio has increased from 0.71 to 0.86 since 1968. The same trend, albeit of varying strength, is evident in all states of Australia, in four age groups (aged 55 years and above) and in both sexes. Analysis of cause-specific mortality suggests that the change has so far been driven more by reduced winter mortality than by increased summer mortality. Furthermore, comparisons of this seasonal mortality ratio calculated in the warmest subsets of seasons in each decade, with that calculated in the coldest seasons, show that particularly warm annual conditions, which mimic the expected temperatures of future climate change, increase the likelihood of higher ratios (approaching 1:1). Overall, our results indicate that gradual climate change, as well as short-term weather variations, affect patterns of mortality.

Climate Change and Children: Health Risks of Abatement Inaction, Health Gains from Action.

As human-driven climate change advances, many adults fret about the losses of livelihoods, houses and farms that may result. Children fret about their parents' worries and about information they hear, but do not really understand about the world's climate and perhaps about their own futures. In chronically worried or anxious children, blood cortisol levels rise and adverse changes accrue in various organ systems that prefigure adult-life diseases. Meanwhile, for many millions of children in poor countries who hear little news and live with day-to-day fatalism, climate change threatens the fundamentals of life-food sufficiency, safe drinking water and physical security-and heightens the risks of diarrhoeal disease, malaria and other climate-sensitive infections. Poor and disadvantaged populations, and especially their children, will bear the brunt of climate-related trauma, disease and premature death over the next few decades and, less directly, from social disruption, impoverishment and displacement. The recent droughts in Somalia as the Indian Ocean warmed and monsoonal rains failed, on top of chronic civil war, forced hundreds of thousands of Somali families into north-eastern Kenya's vast Dadaab refugee camps, where, for children, shortages of food, water, hygiene and schooling has endangered physical, emotional and mental health. Children warrant special concern, both as children per se and as the coming generation likely to face ever more extreme climate conditions later this century. As children, they face diverse risks, from violent weather, proliferating aeroallergens, heat extremes and mobilised microbes, through to reduced recreational facilities, chronic anxieties about the future and health hazards of displacement and local resource conflict. Many will come to regard their parents' generation and complacency as culpable.

Will Global Climate Change Alter Fundamental Human Immune Reactivity: Implications for Child Health?

The human immune system is an interface across which many climate change sensitive exposures can affect health outcomes. Gaining an understanding of the range of potential effects that climate change could have on immune function will be of considerable importance, particularly for child health, but has, as yet, received minimal research attention. We postulate several mechanisms whereby climate change sensitive exposures and conditions will subtly impair aspects of the human immune response, thereby altering the distribution of vulnerability within populations-particularly for children-to infection and disease. Key climate change-sensitive pathways include under-nutrition, psychological stress and exposure to ambient ultraviolet radiation, with effects on susceptibility to infection, allergy and autoimmune diseases. Other climate change sensitive exposures may also be important and interact, either additively or synergistically, to alter health risks. Conducting directed research in this area is imperative as the potential public health implications of climate change-induced weakening of the immune system at both individual and population levels are profound. This is particularly relevant for the already vulnerable children of the developing world, who will bear a disproportionate burden of future adverse environmental and geopolitical consequences of climate change.

Impediments to comprehensive research on climate change and health.

During every climatic era Life on Earth is constrained by a limited range of climatic conditions, outside which thriving and then surviving becomes difficult. This applies at both planetary and organism (species) levels. Further, many causal influences of climate change on human health entail changes-often disruptive, sometimes irreversible-in complex system functioning. Understanding the diverse health risks from climate change, and their influence pathways, presents a challenge to environmental health researchers whose prior work has been in a more definable, specific and quantitative milieu. Extension of the research agenda and conceptual framework to assess present and future health risks from climate change may be constrained by three factors: (i) lack of historically-informed understanding of population-health sensitivity to climatic changes; (ii) an instinctual 'epidemiologising' tendency to choose research topics amenable to conventional epidemiological analysis and risk estimation; and (iii) under-confidence in relation to interdisciplinary collaborative scenario-based modeling of future health risks. These constraints must be recognized and remedied. And environmental researchers must argue for heightened public attention to today's macro-environmental threats to present and future population health-emphasising the ecological dimension of these determinants of long-term health that apply to whole populations and communities, not just to individuals and social groupings.

A multi-layered governance framework for incorporating social science insights into adapting to the health impacts of climate change.

BACKGROUND: Addressing climate change and its associated effects is a multi-dimensional and ongoing challenge. This includes recognizing that climate change will affect the health and wellbeing of all populations over short and longer terms, albeit in varied ways and intensities. That recognition has drawn attention to the need to take adaptive actions to lessen adverse impacts over the next few decades from unavoidable climate change, particularly in developing country settings. A range of sectors is responsible for appropriate adaptive policies and measures to address the health risks of climate change, including health services, water and sanitation, trade, agriculture, disaster management, and development. OBJECTIVES: To broaden the framing of governance and decision-making processes by using innovative methods and assessments to illustrate the multi-sectoral nature of health-related adaptation to climate change. This is a shift from sector-specific to multi-level systems encompassing sectors and actors, across temporal and spatial scales. DESIGN: A review and synthesis of the current knowledge in the areas of health and climate change adaptation governance and decision-making processes. RESULTS: A novel framework is presented that incorporates social science insights into the formulation and implementation of adaptation activities and policies to lessen the health risks posed by climate change. CONCLUSION: Clarification of the roles that different sectors, organizations, and individuals occupy in relation to the development of health-related adaptation strategies will facilitate the inclusion of health and wellbeing within multi-sector adaptation policies, thereby strengthening the overall set of responses to minimize the adverse health effects of climate change.

Land-use change and emerging infectious disease on an island continent.

A more rigorous and nuanced understanding of land-use change (LUC) as a driver of emerging infectious disease (EID) is required. Here we examine post hunter-gatherer LUC as a driver of infectious disease in one biogeographical region with a compressed and documented history--continental Australia. We do this by examining land-use and native vegetation change (LUCC) associations with infectious disease emergence identified through a systematic (1973-2010) and historical (1788-1973) review of infectious disease literature of humans and animals. We find that 22% (20) of the systematically reviewed EIDs are associated with LUCC, most frequently where natural landscapes have been removed or replaced with agriculture, plantations, livestock or urban development. Historical clustering of vector-borne, zoonotic and environmental disease emergence also follows major periods of extensive land clearing. These advanced stages of LUCC are accompanied by changes in the distribution and density of hosts and vectors, at varying scales and chronology. This review of infectious disease emergence in one continent provides valuable insight into the association between accelerated global LUC and concurrent accelerated infectious disease emergence.

The physical anthropometry, lifestyle habits and blood pressure of people presenting with a first clinical demyelinating event compared to controls: the Ausimmune study.

INTRODUCTION: Lifestyle factors prior to a first clinical demyelinating event (FCD), a disorder often preceding the development of clinically definite multiple sclerosis (MS), have not previously been examined in detail. Past tobacco smoking has been consistently associated with MS. METHODS: This was a multicentre incident case-control study. Cases (n = 282) were aged 18-59 years with an FCD and resident within one of four Australian centres (from latitudes 27°S to 43°S), from 1 November 2003 to 31 December 2006. Controls (n = 558) were matched to cases on age, sex and study region, without CNS demyelination. Exposures measured included current and past tobacco and marijuana, alcohol and beverage use, physical activity patterns, blood pressure and physical anthropometry. RESULTS: A history of smoking ever was associated with FCD risk (AOR 1.89 (95%CL 1.82, 3.52)). Marijuana use was not associated with FCD risk after adjusting for confounders such as smoking ever but the estimates were imprecise because of a low prevalence of use. Alcohol consumption was common and not associated with FCD risk. No case-control differences in blood pressure or physical anthropometry were observed. CONCLUSIONS: Past tobacco smoking was positively associated with a risk of FCD but most other lifestyle factors were not. Prevention efforts against type 2 diabetes and cardiovascular disease by increasing physical activity and reducing obesity are unlikely to alter MS incidence, and more targeted campaigns will be required.

Climate change threats to population health and well-being: the imperative of protective solutions that will last.

BACKGROUND: The observational evidence of the impacts of climate conditions on human health is accumulating. A variety of direct, indirect, and systemically mediated health effects have been identified. Excessive daily heat exposures create direct effects, such as heat stroke (and possibly death), reduce work productivity, and interfere with daily household activities. Extreme weather events, including storms, floods, and droughts, create direct injury risks and follow-on outbreaks of infectious diseases, lack of nutrition, and mental stress. Climate change will increase these direct health effects. Indirect effects include malnutrition and under-nutrition due to failing local agriculture, spread of vector-borne diseases and other infectious diseases, and mental health and other problems caused by forced migration from affected homes and workplaces. Examples of systemically mediated impacts on population health include famine, conflicts, and the consequences of large-scale adverse economic effects due to reduced human and environmental productivity. This article highlights links between climate change and non-communicable health problems, a major concern for global health beyond 2015. DISCUSSION: Detailed regional analysis of climate conditions clearly shows increasing temperatures in many parts of the world. Climate modelling indicates that by the year 2100 the global average temperature may have increased by 34°C unless fundamental reductions in current global trends for greenhouse gas emissions are achieved. Given other unforeseeable environmental, social, demographic, and geopolitical changes that may occur in a plus-4-degree world, that scenario may comprise a largely uninhabitable world for millions of people and great social and military tensions. CONCLUSION: It is imperative that we identify actions and strategies that are effective in reducing these increasingly likely threats to health and well-being. The fundamental preventive strategy is, of course, climate change mitigation by significantly reducing global greenhouse gas emissions, especially long-acting carbon dioxide (CO(2)), and by increasing the uptake of CO(2) at the earth's surface. This involves urgent shifts in energy production from fossil fuels to renewable energy sources, energy conservation in building design and urban planning, and reduced waste of energy for transport, building heating/cooling, and agriculture. It would also involve shifts in agricultural production and food systems to reduce energy and water use particularly in meat production. There is also potential for prevention via mitigation, adaptation, or resilience building actions, but for the large populations in tropical countries, mitigation of climate change is required to achieve health protection solutions that will last.