Health problems related to the environment continue to be a major source of concern all over the world. Society needs to develop measures that will eliminate or considerably reduce hazardous factors from the environment that can result in health risk to humans.
There is scientific consensus worldwide through the Intergovernmental Panel on Climate Change, and National Academy of Sciences of USA, and other scientific professional associations, that the human modification of the global climate is occurring and that the climate is warming (Houghton et al., 2001; Oreskes 2004; Cicerone, 2005). Human activity is changing the climate by changing the chemical balance in the air. Certain gases in the atmosphere, called 'greenhouse gases,' absorb outgoing long wave radiation and re-emit back to the surface heat that would otherwise escape to space. The atmospheric concentrations of several greenhouse gases emitted by human activities, including carbon dioxide and methane, are increasing dramatically. Because these gases are causing the atmosphere to recycle heat and hold in more warmth, the average temperature at the surface of the planet is going up. The rate of increase has accelerated in the last 50 years, and significant further increases are expected in the next century and beyond. The global average surface temperature has increased over the twentieth century by about 0.6°C, and is projected to rise by an additional 1.4-5.8°C over the twenty-first century, depending on future emissions of greenhouse gases (Houghton et al., 2001).
A question that naturally arose is what effect will this have on human health, specifically on infectious diseases? This question has generated considerable public interest and stimulated the publication of numerous research and review papers. There is solid scientific evidence that increasing temperatures can lead to increased transmission of disease, through direct action on infectious agents (e.g., malarial parasites develop in the mosquito more rapidly in higher temperatures), effects on vectors (e.g., greater geographic range and longer active season for mosquitoes, ticks, etc.), or changes in host behavior (e.g., shifts in migratory bird patterns). As noted by several researchers, climate change is partly responsible for the recent resurgence and re-emergence of some diseases, especially vector-borne diseases. Warmer temperatures and changes in rainfall have created ideal conditions for vectors and the pathogens to survive in some areas that were previously inhospitable to them. Tropical Africa is not the only area where deadly viruses have recently emerged. In Southeast Asia severe epidemics of dengue hemorrhag-ic fever started in 1954 and flu pandemics have originated from China such as the Asian flu (H2N2) in 1957, the Hongkong flu (H3N2) in 1968, and the Russian flu (H1N1) in 1977. However, it is especially during the last 10 years that very dangerous viruses for mankind have repeatedly developed in Asia, with the occurrence of Alkhurma hemorrhagic fever in Saudi Arabia (1995), avian flu (H5N1) in Hongkong (1997), Nipah virus encephalitis in Malaysia (1998), and, above all, the SARS pandemic fever from southern China (2002). The evolution of these viral diseases was probably not directly affected by climate change. In fact, their emer-gential success may be better explained by the development of large industry poultry flocks increasing the risks of epizootics, dietary habits, economic and demographic constraints, and negligence in the surveillance and reporting of the first cases.
Research on climate and infectious disease linkages inherently requires interdisciplinary collaboration. Studies that consider the disease host, the disease agent, the environment, and society as an interactive system require more interdisciplinary collaboration among climate modelers, meteorologists, ecologists, social scientists, and a wide array of medical and public health professionals. Encouraging such efforts requires strengthening the infrastructure within universities and funding agencies for supporting interdisciplinary research and scientific training. In addition, educational programs in the medical and public health fields need to include interdisciplinary programs that explore the environmental and socioeconomic factors underlying the incidence of infectious diseases.
A more pressing issue for the World Health Organization is pandemic flu. With 329 cases of avian influenza in humans, including 206 deaths, reported officially to World Health Organization, the experts agree that the next influenza pandemic is inevitable.
According to the UN Food and Agriculture Organization (FAO, 2005) climate change and globalization could promote the spread of avian influenza and create a global pandemic. As the climate becomes more unstable, its role increases. There are many ways that global warming could conceivably impact influenza transmission. For instance, warming may change bird migration patterns and thus patterns of interaction between humans and infected animals.
Avian flu and climate warming are questions which involve not just remote countries but the whole planet and which impose on us new attitudes and a new way of finding solutions. This chapter will therefore first discuss how climate change may influence the spread of highly pathogenic influenza. On the other hand, the paper performs several key messages and advice for people living in areas affected by avian influenza to reduce its harm and to help limit the spread of a pandemic and prevent disease and death.
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