Climate Change and Vector-Borne Diseases (Research Paper Sample)

Climate Change and Vector-Borne Diseases
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Climate Change and Vector-Borne Diseases
Introduction
Climate change has lately emerged as one of the serious environmental issues facing the entire world. From the scientific point of view, studies indicate that climate change is evident in various parts of the globe, and it is taking place at an alarming pace (McMichael and Woodruff, 2006). According to Sining (2011), climate change creates threats of severe social disturbance, displacement of population, environmental degradation, as well as economic hardships. Lately, the impact of climate change on human health is one of the areas of interest. Particularly, it is argued that climate change is likely to influence or affect vector-borne diseases. Martin (2002), in his study argued that, temperature, humidity, precipitation, as well as other climatic factors affects the reproduction of vectors such as mosquitoes, that are responsible for the transmission of these diseases.
The main focus of this paper is to review studies, statistics, and scholarly articles which analyze the link between climate change and transmission of vector-borne diseases. Diseases of interest in this case include dengue fever, malaria, and chagas. Specifically, paper is aimed at establishing the trends of vector-borne diseases and to create a direct connection the change in climate change as it relates to the spread of vector-borne diseases. Moreover, the interaction of climate and human behaviors, demographic factors, and land use will be discussed, with an objective of establishing the real weight of vector-borne diseases among humans. Finally, the paper will highlight some of the strategies of adapting to climate change in relation to vector-borne diseases.
Climate change
Although climate change has become a common phenomenon not only among the scientists and environmentalists, but other parties as well, a concise and clear definition of what “climate change” means is yet to be established. Perhaps, this can be attributed to the different perceptions of this issue, depending on the objective of whoever is interested in the issue (Jacob, Jai and Nalini, 2011). However, climate change can be generally described as the continuous human-induced sequence of transformations or changes in the environment, which includes loss of biodiversity, global warming, rising sea levels, as well as a rise in natural disaster incidences. Some of the identifiable effects of climate change that have been experienced in various parts of the globe include hurricanes, landslides, floods, vanishing of islands in the pacific as a result of sea level increase. Besides, it is recently argued that the patterns of vector-borne diseases are like to change as a result of climate change.
Vector-borne diseases
Vector-borne diseases are generally described as diseases that arise from infections transmitted via a bite of contaminated arthropod specie. Such arthropods include blackflies, sandflies, triatomine bugs, ticks, and mosquitoes. The term ‘vector’ is universally used in describing arthropods that transmit infections. It is worth noting that spread of these diseases depends on the features and needs of about three major organisms; namely, pathogenic agent, vector, and the human host. Besides, in some cases intermediary hosts act as a reservoir (Mills, Gage and Ali, 2010). It is estimated that a good percentage of the population of the world are infected with these diseases, which have been responsible for the increasing rates of mortality and morbidity. In terms of distribution incidence, vector-borne diseases have been observed to have a considerable impact in the growing counties within the subtropical and tropical regions.
Impacts of climate change on vector-borne diseases
The impact of environment and climate in general has been a subject of intensive research, discussion, and speculation for decades (Githeko, et al, 2007). Climate change impacts have both direct and indirect impacts on the transmission of vector-borne diseases. Although the root causes of various vector-borne diseases are well known, it is not easy to forecast climate change’s effect on these diseases, as a result of the multifaceted disease process. Nevertheless, in order to establish or determine the effects of change of climate regarding the incidence of these diseases, focus should be placed on the individual disease’s life cycle, as well as the environmental considerations connected to each phase. The following are some of the ways in which a change of climate impacts vector-borne diseases.
Distribution of vectors
It has been established that climate is one of the determining factors in distribution of vector-borne diseases, based on the argument that vectors particularly flourish in under certain climate conditions. Thus, these diseases are likely to be common in areas that support the survivor of the vectors as compared to areas that are not fit for the survival of the vectors (Gage, et al. 2008). For instance, studies have shown that mosquitoes are well adapted to warm and wet habitats, which also supports their breeding. In case there is an infected population and the breeding mosquitoes are the species responsible for transmission of diseases, then there is likely to be an outbreak of the disease in the region.
It has been observed that the distribution of vectors has been modified with climate change. As a result, some areas which rarely experienced certain vector-borne diseases are now experiencing these diseases while areas that were well known for such diseases are no longer experiencing certain vector-borne diseases. For instance, it has been observed that the geographical range of disease carrying mosquitoes and ticks has changed, and these changes are in response to the changing climate conditions. For example, it has been established that in Canada and Sweden, the range of ticks has increased to cover higher altitudes (Rogers and Randolph, 2006).
Additionally, the range of mosquitoes has considerably widened lately. Initially, disease spreading mosquitoes were very common in the most of East and Central Africa regions, explaining why malaria was very common in these areas. However, as a result of climate change, malaria has become common not only in other parts of the African continent, but also in other parts of the world such as in Australia (Sutherst, 2004). This is a good indicator that climate change has enhanced the distribution of vectors, such as mosquitoes and ticks, leading to spread of vector-borne diseases across regions.
However, it is also important to note that there are also other factors which could be responsible for a shift in the distribution of vectors, and the degree of infection. Perhaps, this factors points out the biasness of studies regarding the role of climate change in the increasing distribution of disease vectors, due to the fact that it is difficult to clearly differentiate the impact of the two causes of disease vector distribution (McMichael and Woodruff, 2006). One of the common factors which are likely to enhance disease vector distribution is the change in the use of land. Other factors include human behavior and population density. Nonetheless, the environmentalists argue that the mentioned factors are part of the major causes of climate change; hence, the changing distribution of diseases vectors could has well be attributed to climate change in general (Martin, 2002).
Changes in population density
It has been observed that climate change is responsible for provisions that vary ecosystem’s carrying capacity for some animal or plant populations (Sining, 2011). As such, these changes can contribute to spectacular increase or decrease of the vector or host densities. For instance, following period of high rainfall, the population of mosquitoes increases dramatically. Besides, prolonged periods of high temperatures reduce the development period of mosquitoes, facilitating an increase in population density. In a study that was carried out in East African countries, specifically in Kenya, to establish the causes of high incidence of malaria that was experienced between 1998 and 1999, it was established that the increase in incidence was associated with high rainfall and higher temperatures experienced in the region during that particular period (Rogers and Randolph, 2006).This is one of the implications of the impacts of climate change regarding a change in population density of vectors.
Environmental extremes’ effect on intermediary hosts can also be well-defined. For example, it has been observed that high temperatures during the summer period are usually responsible high mortality rates of hosts, particularly in the subtropical and tropical regions, or higher survivorship of certain species in temperate regions (McMichael and Woodruff, 2006). In a study that was carried out in North America at the end of the heavy rains that were experienced in 1997, investigators showed that the population density of hosts, such as that of the North America deer mice, increased significantly; perhaps as a result of improved vegetation quality. The increase of population density of such hosts was associated to the various vector-borne diseases that were experienced in the region later on (Sining, 2011).
Extended transmission
According to research, there is a link between climate change and the transmission duration of vector borne diseases. For instance, increase in temperature is likely to extend the transmission season, in the case of malaria and dengue, based on various reasons. First, this change changes the vulnerability to some pathogens, more especially those responsible for malaria and dengue. Secondly, the high temperatures, as mentioned above, are conducive for reproduction of the vectors,...