|Human Populations are at Risk from outbreaks of New Diseases|
Diseases are the disturbance of body processes impacting homeostasis, the emergence and resurgence of diseases is majorly dependent on social, ecological and geographical change rather than the molecular or microbiological aspects (Mayer, 2000). This essay will cover the growing evidence that climate change poses health concerns for the future decade’s thus increasing morbidity and mortality in many continents. Climate changes and the extremities of weather events have profound impacts on infectious diseases for example viruses and protozoa and vectors such as mosquitoes and ticks, their reproduction patterns are disturbed by the extremities of the weather (Gubler et al., 2001). This paper will also explore the ways in which technology such as aeroplanes and aircraft produces new initiatives to prevent transmission of diseases among different countries. The population density is measurable during a fixed time period where the average contact with susceptible individuals by each person explores the rate of spreading diseases among communities.
Climate change and global warming has serious implications to human life involving the human regions and their interactions with the causative disease agent (Khasnis & Nettleman, 2005). Climate change is a key determinant of health as the weather affects the timing and concentration whereas climate constrains the range of infectious diseases of the outbreaks (Dobson & Carper, 1993). Global warming is encouraging the spread of infectious diseases geographically as extreme weather can also bring sparks of different diseases (Epstein et al., 1998).The meteorological conditions and climate change are unpredictable as they constantly redistribute and spread infectious diseases, examples include AIDS, Lyme disease, toxic Escherichia Coli. The increase of greenhouse gases is due to the correlation between population size and global warming. The rising temperatures are predicted to continue and precipitation is likely to increase however rainfall may be erratic, leading to floods and droughts. Some scientists have hypothesised that the increase in temperatures will kill of the plants and therefore reduce surface area for evaporation making it adaptable areas for new diseases and pathogens to arise. The most striking example of health risks from climate change is shown in the summer of 2003 where Europe’s temperatures were 3.5C above normal temperatures and 22,000 to 45,000 heat-related deaths occurred (Campbell-Lendrum, Holloway, & Foley, 2005). However results comparing the weather outcomes that year show that with or without anthropogenic drivers the weather doubled as a result from human induced climate changes (Stott, Stone, & Allen, 2004).
Global warming is known to bring about change and some conclude that diseases will come more abundant when the earth warms up, however it majorly depends on the magnitude and the speed of these changes. When communities exhaust the environmental resources and infrastructures they allow for infectious disease to cascade across continents and populations. The extremities in the weather cycle can destabilise the biological and physical systems of our world. Due to changes in the weather patterns and the repeated winter thawing and refreezing, reduction in forest mechanisms and defences and thus the human population becomes vulnerable to disease and pest infestations, and the shifts in seasons also alter rhythms of predators, and the natural biological controls (Lindgren, Tälleklint, & Polfeldt, 2000). The increase in mortality and morbidity is due to extremes in both hot and cold weathers.The WHO organisation estamated that around 800 million people are undernorished due to living in areas and countries of drought and other climate extremes which thus affects their crops and food supplies hence leading to alterations in plant pathogens leading to new diseases or the reintorduction of old diseases.
The constant changes in urbanisation, human activities along with biological factors such as mutation, genetics factors and changes in the genetic pool affect the rate of emergence of new infectious diseases. Importantly the economic and political stresses may destroy the health system infrastructure, leaving the population unprepared for any sudden epidemics. The interaction between the human population and the environment can be disturbed by various changes including land usage; migration and population pressure and thus reflect the significant mal-adaptation through the appearance or diffusion of new diseases (Mayer, 2000). The lack of disequlibrium in the economy is shown in an example of the incidence of schistosomiasis following the construction of the Aswan Dam, and the increase in schistosomiasis, malaria and other infectious diseases following the Volta River project in Africa.Water sources and its various contaminations and the insufficiency of it can enhance the process of transmitting diseases among a population. Deforestation and changes in land use patterns have been shown to spread transmission of diseases between the animal world and the humans, especially when forests are destroyed to make way for residential and commercial usage.
Water is a huge necessity, yet 1.1 billion people in the world do not have access to it and 2.4 billion people do not have access to sanitation (Cairncross, 2003). In order to ensure supply various approaches have already been used such as polices to eliminate profiteering, efficient management of available water, improved technology and integrating agricultural policies. Contaminated water is the source of epidemics such as cholera, typhoid and other similar diseases. Esrey, Potash, Roberts, & Shiff, in 1991 conducted research and found that it is possible to reduce diseases by clean water and sanitations some of his statistics show this: “diarrhoea (26%), ascariasis (29%), guinea worm infection (78%), schistosomiasis (77%), trachoma (27%) and a median reduction of 65% in diarrhoea-specific mortality and 55% in general child mortality.” Emerging diseases are hard to define as they may have been present at one time in a community in either low of high levels for example a disease like dengue fever is emerging in the US but has been known for many years in Latin America. Travelling from one country to another can assist the diffusion of diseases in several manners; firstly human can act as vectors and carry around diseases from one region to another. Also transportation vehicles can act as mechanical vectors such as the dengue case where it was transported from Asia to the US by automobile tires and ships as it provided for ideal surviving conditions such as a damp and wet environment.
Modern transport systems are efficient and fast thus placing people in danger from emerging new disease or new strands of known diseases and pathogens (Guimerà, Mossa, Turtschi, & Amaral, 2005). Spatial diffusion involves the changes in travel patterns that have dramatically changed the ecology of infectious diseases. Garrett in 1996, estimated that approximately one million people travel internationally a day and one million travel from developed to non-developed countries per week therefore disease can be transmitted in a matter of a day. And as diffusion is rapid such as with influenza where viral replication takes place in the epithelial cells of the respiratory tract and then transmitted through airborne route. This reflects how spatial diffusion is the main cause of diffuses of HIV/AIDS. Pathogens have relatively simple DNA/RNA and any minor changes in the nucleotides can mutate to make a new disease that humans lack immunity for. The development of antimicrobial-resistant agents is also a major problem for populations around both the developed and undeveloped world. Social factors such as homelessness, poverty and migration make it hard to control specific diseases as there are a limited number of antimicrobials available. The emergence of aeroplanes is notably the one that increased the speed of travel and over time introduced ‘new’ diseases and re-surfaced ‘old’ diseases, and therefore the national borders are not very secure in terms of quarantine. Other modes of transport includes rail travel which also have surveillance on both departure and arrival routes (Budd, Bell, & Brown, 2009).
The mobility of infectious diseases is on the rise and several public health interventions have tried to limit this by focusing on the increase in international air travel around the world (Avila, Saïd, & Ojcius, 2008). The aircraft passenger cabin transmits diseases consistently; although the cabin is ventilated it exposes individuals to hypobaric and dry humidity between travellers. The close spaces allows for disease to be re-circulated throughout the cabin. One technique of reducing this transmission is through supplying fresh air to cabins in a circulation pattern (Mangili & Gendreau, 2005). Specific use of technological filters in aeroplanes such as HEAP filters have the efficiency rate of 99.97% of removing particles in the cabins such as dust, vapours and fungi, these are effective as viruses spread by droplets of nuclei. There is four different methods of the spread of microorganisms, these include direct contact or with a contaminated object, airborne, common vehicle (usually through foods and drinks) and vector-borne diseases by insects or vermin. Many are concerned that the airborne particles on an aeroplane is transported throughout the cabins due to the ventilation systems and therefore this has been the focus media investigations throughout the last few centuries and criticism from many special interest organisations (Withers & Christopher, 2000). Tuberculosis has been a threat for many years and is estimated that a third of the world’s population have it. Mycobacterium Tuberculosis is the most spread in airborne pathogens abroad plans. An example is shown in Kenyon, Valway, Ihle, Onorato, & Castro, 1996 papers “travelling from Baltimore to Chicago and then on to Honolulu. Four of 15 fellow passengers seated within two rows of the index passenger had positive tuberculin skin test conversion”. There has also been evidence that human hygiene plays a big role therefore all aircraft now have guidelines for hand hygiene in bathrooms and kitchens. Appropriate quarantine levels must be taken to reduce the exposure of these diseases among passengers, thus the governments and international laws have provided specific legal laws that control the movement of travellers and this can include issuing travel alerts to quarantine of passenger’s upon departure and arrival.
Climate change, social and ecological factors play an ever-increasing role in the resurgence and redistribution of infectious diseases. The increase in mobility of air and rail transport is increasing the transmission of diseases from passenger to passenger and also after and before the flights. The transmission of diseases probably happens a lot more than reported due to numerous reasons including reporting bias and the fact that various diseases have a longer incubation period than that of air travel. Further research and assessments of risk must be taken in order to reflect insights of disease transmissions with transportation and thus control the increase in transmitted diseases from one individual to another. The government and the medical industry are educating the general public about health issues whether they relate to travel or any other human life aspects. Dynamic diseases are increased due to the increase of population density of human who facilitate for the transmission of diseases and infectious organisms (Lindgren, Tälleklint, & Polfeldt, 2000). The widespread of environment degradation also contributes to the increase of diseases along with the rapid increase in population numbers. Rapid demographic, technological, social and environmental changes in lifestyles can introduce new diseases due to the changes made to lifestyles. Climate change is an example, as it brings about an epidemic of diseases and microorganisms to societies due to the extremities of its changes in weather conditions altering lifestyles.
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