Disease ecology
[3] Parasitic infections, along with certain transmitted diseases, are present in wildlife which can have severe health effects on particular individuals and populations.
[4] Additionally, competition and predation dynamics in the ecosystem can influence the density of potential hosts which can either propagate or limit the spread of diseases.
[12] Biological factors that can determine the persistence of diseases include parameters pertaining at the level of the individual within the population (one single organism).
For example, male American minks are larger and travel wider distances, making them more prone to come into contact with parasites and diseases.
[13][14][15] Ecological disruption, including habitat fragmentation and road construction, degrade natural landscapes and have been studied as drivers of recent emergence and re-emergence of infectious diseases worldwide.
[14] Scientists have speculated that habitat destruction and biodiversity loss are some of the main reasons influencing the rapid spread of non-human, disease carrying vectors.
[14] Human anthropogenic induced climate change is becoming problematic, as parasites and their associated diseases, can move to higher latitudes with increasing global temperatures.
[13] Urbanization is considered one of the main land-use changes, defined as the growth in the area and number of people inhabiting cities and creates artificial landscapes of built-up structures for human use.
[16] With over 65% of the global human population living in cities by 2025, ecological impacts of urbanization focuses mainly on biodiversity loss defined as the decline in species richness.
[18] Research has shown that these smaller species are more likely the ones to carry and transmit pathogens (key examples include bats, rats, and mice).
[19] Encroachment on natural ecosystems and wildlife with rapid urbanization exposes humans to a wide variety of disease carrying animals.
[21] It is argued that between 2013 and 2015, the Ebola virus disease (EDB) outbreak in West Africa began due to deforestation and habitat degradation.
[22] Transmission of the Ebola virus is believed to have occurred through direct contact with bat species carrying the pathogen and humans, encroaching on natural ecosystems.
[24] With a warming climate, pathogens and parasites can begin shifting their native geographic ranges to higher latitudes and infect host species in which they have no prior interaction with.
[31] Additionally, this model can be used to find the population of mosquitoes that bite, allowing predictions of diseases such as dengue fever.
[26] An example of this type of model is CLIMEX, which maps vector species over geographical locations while accounting for climate factors.
[32][26] Malaria is a disease transferred by the female Anopheles mosquito, located predominantly in sub-Saharan Africa and is a long withstanding public health issue.
[38] Human infections of Lyme disease have been increasingly prominent in certain southern parts of Canadian provinces such as Ontario, Quebec, Manitoba, and Nova Scotia.
[37] According to Canadian published studies, other environmental factors are contributing to the expansion of the Ixodes scapularis home range which include the introduction of the vector through migratory birds and density of deer populations.
[37] West Nile virus is transferred between mosquitos and birds of prey including eagles, hawks, falcons, and owls.
[39] In the United States, West Nile Virus is being increasingly studied in New York and Connecticut due to the effects of climate change on two disease carrying vectors.
