Biodiversity is essential for survival of many living organisms on the earth (Duffy 438). Disturbance of the ecosystems on the earth results in many changes, some of which could contribute to human diseases. Pathogens and disease vectors are the major causes of infectious diseases in human beings.
Diseases lead to poor health outcomes and unhealthy people who cannot be productive in the process of economic development (Chivian and Bernstein 287). The pathogens that cause infectious diseases include parasites, viruses, fungi, and bacteria. Diseases spread at high rates from one person to another.
In some cases, infectious diseases may originate from animals; zoonotic diseases. The World Health Organization (WHO) focuses on seeking remedies to clear the infectious diseases. WHO funds numerous projects dealing with infectious diseases, especially in regions of high pandemics and epidemics.
African countries and other third world countries within the tropics are at high risk of infectious diseases (Chivian and Bernstein 296). The ongoing programs and research studies aim at reducing disruptions, mortality, and morbidity rates resulting from epidemics of infectious diseases.
Research studies in major higher learning institutions and research institutes develop mechanisms of preparedness, prevention, recovery, and response with regard to infectious diseases.
Some of the approaches have succeeded while others have stagnated due to limited funds and/or complexity of projects. However, there is hope that continued efforts will bear fruits in the long run (Chivian and Bernstein 289).
The ecosystem of the vectors is complex and is influenced by human activities (Bradshaw, Sodhi and Brook 79). In fact, human activities like farming, fishing and deforestation have been shown to greatly impact natural ecosystems.
Agriculture, being a major economic activity in African and other third world countries, may encourage breeding of vectors such as mosquitoes, snails, and tsetse flies.
The chemical method of controlling the vectors may not be efficient because it results in the destruction of the ecosystem causing imbalance and destruction of useful resources for human survival.
The diversity of the life cycle of the vectors is a protective mechanism for proliferation and increase in numbers (Chivian and Bernstein 300).
The mode of transmission also varies among different vectors and infectious agents. The major route of transmission is penetration through the skin, ingestion, inhalation, and sexual intercourse.
The vectors and infectious agents develop mechanisms of evading the human immune system in order to proliferate (Chivian and Bernstein 302).
The ecosystem of infectious agents changes due to human disturbances (Duffy 440). The major human activities on the ecosystem are deforestation, agricultural activities, mining, and water management. The human activities cause degradation of land, which leads to soil erosion, droughts, and global warming.
Pollution is rapidly increasing across the world due to the presence of nitrogenous fertilizers, pesticides and disposal of industrial wastes. The urbanization process is contributing to changing ecosystems, leading to variation of breeding seasons of the vectors and infectious agents (Bradshaw et al 83).
Some governments such as in Argentina are conserving plains, grasslands and forests. The presence of forests and grasslands creates good breeding grounds for vectors such as mosquitoes. Destruction of natural ecosystem encourages vectors in changing habitat to human homesteads.
The control mechanism of the vectors within the homestead results in the development of resistant strains that act as reservoirs of the infectious agents.
The resistant strains of the vectors make the elimination process of infectious agents difficult in eradication from the human population. The existing mechanisms of controlling vectors and infectious agents are useful because they control the breeding of the vectors.
The disturbance of the ecosystem has some effects on the dynamics of vectors and infectious diseases. For example, altering forest ecosystem results in the destruction of mosquitoes, sandflies, blackflies, and tsetse fly species. The affected vectors seek new habitats in homesteads and they cause infections in human beings.
Human settlement increases the changes of transmission of infectious diseases. Individuals living in overcrowded places have a high likelihood of transmitting malaria at a faster rate than the individuals in sparsely populated locations (Chivian and Bernstein 204).
Deforestation may also make human beings to have multiple infectious diseases due to different types of vectors. Mosquito bites cause transmission of plasmodium species in the human blood circulatory system. Deforestation may lead to change of vectors from resilient to resistant strains (Chivian and Bernstein 304).
The presence of streams and stagnant water bodies provides an array of habitats for mosquitoes both in the forests and around the homesteads. Presence of tall grass and bushes around the homestead enhances development and proliferation of the vectors that transmit infectious diseases.
Paddy areas such as rice growing regions have a high likelihood of obtaining schistosomiasis due to the presence of snails. Snails breed in marshy areas and in forested parts. The leading causes of death of all infectious diseases are lower respiratory infections due to bacterial infections (Chivian and Bernstein 310).
According to WHO records, infectious diseases cause more than 100,000 deaths every year. Previous research successfully eliminated some infectious diseases, but some are re-emerging in the 21st century (Chivian and Bernstein 312).
The re-emerging phenomenon of infectious diseases is due to mutual interaction of the pathogenic parasites resulting in new species. The new pathogenic species have different genetic make-up that results in resistance with regard to the available preventive approaches.
In summary, human activities disrupt the natural ecosystem resulting in the loss of diversity of the infectious agents. The loss of diversity results in complexity of infectious agents’ life cycle and the methods of prevention. In addition, there exists a complex interaction among the vectors, infectious agents and human being.
Scholars and researchers are developing different preventive approaches that target the vector, infectious agent or the lifecycle of pathogenic agents in human beings. Change of climate is a contributing factor in the emergence of new species and infectious diseases.
For example, Ebola re-emergence is due to changes in genetic diversity of human beings, vectors, and pathogens. Vector-borne infectious diseases are on the increase due to urbanization, settlement, and global warming. Infectious diseases are the leading causes of death in the tropical countries, especially Africa.
Third world countries have high levels of poverty and lack of jobs. These lead to poor health, malnutrition and death. Research on infectious diseases is undergoing in the African countries in order to develop the best mechanisms of eliminating infectious diseases.
The major challenge that scientists face in the field of research is a change of climate. Change of climate correlates with the change of pathogens, change of vectors, and change of patterns of infections.
An infectious disease that has affected human beings
AIDS is an example of infectious disease mainly that is transmitted through sexual intercourse. HIV attacks and destroys the CD4 cells responsible for boosting the human immune system.
Individuals with AIDS have a high likelihood of obtaining opportunist infections such as oral thrush, tuberculosis, Pneumosytis carni, Herpes zooster, and protozoal infections.
An infected individual becomes malnourished, resulting in general body weakness. HIV has diverse methods of evading human immune system through shedding its coat. Also, HIV/AIDS has a history of a vicious cycle of disease, malnutrition, and poverty.
Works Cited
Bradshaw, Corey JA, Navjot S. Sodhi, and Barry W. Brook. “Tropical turmoil: a biodiversity tragedy in progress.” Frontiers in Ecology and the Environment 7.2 (2008): 79-87. Print.
Chivian, Eric, and Aaron Bernstein, eds. Sustaining life: how human health depends on biodiversity. Oxford University Press, United Kingdom, 2008. Print.
Duffy, J. Emmett. “Why biodiversity is important to the functioning of real-world ecosystems.” Frontiers in Ecology and the Environment 7.8 (2008): 437-444. Print.