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Climate change may trigger spread of disease from animals to people Jeremy Hance, mongabay.com October 7, 2008 The Deadly Dozen: diseases most likely to spread due to climate change
The impact of climate change on global diseases has been largely drowned out by news of diminishing glaciers, cannibalizing polar bears, and conflicts due to drought. Dr. Steven Sanderson, President and CEO of WCS, points out that "the term 'climate change' conjures images of melting ice caps and rising sea levels... but just as important is how increasing temperatures and fluctuating precipitation levels will change the distribution of dangerous pathogens." The list of a dozen pathogens includes some infamous diseases, like bird flu and Ebola, while others are little known outside of the region in which they occur (see below). The researchers believe that the best way to stay on top of the diseases is continual monitoring of wildlife health in risk areas.
In addition, monitoring of wildlife health can grant greater insight our knowledge of environmental changes. Dr. William Karesh, director of WCS's Global Health Programs, describes wildlife health monitoring as "a new lens to see what is changing around us and will help governments, agencies, and communities detect and mitigate threats before they become disasters." If an outbreak becomes a 'disaster', as Karesh described it, the incident could affect more than just immediate human and wildlife populations. Past outbreaks have caused significant economic damage. It is estimated that livestock diseases alone have caused $100 billion in losses for the global economy since the mid-1990s. The Wildlife Conservation Society's "Deadly Dozen"
1. Babesiosis: This disease is tick-borne, affecting both wildlife and human populations. The disease, not fatal in itself, causes greater susceptibility to other infections. For example, after dry conditions spawned a heavy infestation of ticks in East Africa, large numbers of lions died from canine distemper after first being weakened by Babesiosis. The disease is becoming more common in Europe and North America, also in relation with shifting tick distributions. 2. Bird flu: Changes in climate may disrupt natural movements and migrations of wild birds, possibly bringing them into contact with greater numbers of domestic birds, thereby further spreading bird flu. A particular pathogenic strain of bird flu, labeled H5NI, can be contracted by humans. This strain has caused grave concern among medical experts who worry it will evolve to become contagious from human to human. 3. Bovine tuberculosis: As cattle move globally, so does bovine tuberculosis. As climate change affects water availability worldwide, it is reasonable to assume that cattle distribution will change, bringing bovine tuberculosis to new regions. The disease can spread from cattle to wildlife and humans, greatly affecting natural environments and human settlements.
5. Ebola: A deadly virus that targets people, gorillas, and chimpanzees. There is no known cure. The virus appears to be linked to variations in precipitation, leading experts to believe that changing climate will allow outbreaks in new locations. 6. Parasites: Widespread, parasites are expected to shift ranges with temperature and precipitation changes. Some parasites affect many species, including humans. Others, like the Baylisascaris schroederi, are fatal only to one species, in this case the giant panda. A study from last year showed that 50 percent of panda mortalities in the past five years were due to the parasite. 7. Lyme disease: Like Babesiosis, Lyme disease is tick-borne. Where climate change shifts tick populations, the disease will follow. The disease can cause grave illness to humans who have been bitten by carrier ticks. 8: The plague: Infamous due to its ravages across Europe in the 14th Century, the plague still causes mortality in wildlife, domestic animals, and even humans. Spread by fleas carried from place-to-place by rodents. As climate changes, rodent populations are expected to shift worldwide perhaps bringing the plague to new regions.
10. Rift Valley Fever: This fever is having great impact in the Middle East and Africa on both livestock and people. Infected livestock have high abortion and death rates. In addition, the disease is often fatal to humans. Mosquitoes transmit the disease and as water increases in some areas and lessens in others, there is little question that the range of the disease will change. 11. Sleeping sickness: Transmitted by the tsetse fly, this disease affects both humans and animals. Sleeping sickness is known in 36 countries in Sub-Saharan Africa and leads to 40,000 human deaths every year. The tsetse fly's habitat may shift, like mosquitoes' and ticks', due to climate change. 12. Yellow Fever: Like Rift Valley Fever, Yellow Fever depends on mosquitoes for transportation. As mosquitoes shift due to changes in water availability, it is likely that Yellow Fever will appear in new places. The fever affects primates as well as humans. Recently, Brazil and Argentina have seen sudden drops in primate populations due to Yellow Fever. SHARE THIS ARTICLE:
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