In the photo: Ebola Vibrio under a microscope.
Scientists have nicknamed them the "deadly dozen". 12 diseases that are fatal to humans and wildlife are expanding the geography of their distribution
Ebola, cholera, plague and sleeping sickness - these and other diseases, according to veterinarians from the Wildlife Conservation Society (WCS), are spreading across the planet due to climate change. Scientists argue that the state of wild animals can detect early signs of an impending epidemic and save millions of people.
Researchers are calling for wildlife surveillance agencies around the world to track disease symptoms in animals before the disease spreads to humans. Observing networks have already been established in some regions of the world and are successfully saving lives.
William Karesh of WCS noted, speaking at a conference of the International Union for Conservation of Nature (IUCN) in Barcelona, that the potential impact of climate change on the spread of disease is of growing concern. At the presentation of the report on this topic - it is called the "Deadly Dozen" - Karesh noted that changes in temperature and precipitation volumes affect the spread of diseases, although the reasons are not always clear.
Observing the spread of disease among animal populations will allow action to be taken to protect both people and the local economy. “Today we are calling for a comprehensive approach to disease on a global scale. Our long-term goal is to create a comprehensive wildlife health surveillance network around the globe,”said Karesh.
The success of the idea has already been proven by experiments - for example, a network of hunters and other local residents who visit the forests in the Republic of Congo. They report the corpses of gorillas and chimpanzees that have died from outbreaks of Ebola, and as a result, in northern Congo, outbreaks of this infection in humans have been prevented for three years.
Until the hunters were involved in this project, they brought dead animals from the forest to their villages, thereby accelerating the spread of Ebola among people.
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Similar projects are underway in South America, where data collection on the impact of climate change on diseases like yellow fever is just beginning. Vaccination programs are now underway in areas with outbreaks of disease in primates.
Scientists regard animals as a valuable indicator of climate change, as fauna rarely adapts quickly enough to go unnoticed. New forms of disease affecting animals or unusual patterns of infection are often driven by climate change.
How does climate change affect the spread of disease? Climate warming increases the lifespan of pathogens or their vectors. Lack of water and other problems associated with caring for livestock and other domesticated animals can lead to increased contact with wild animals. Changes in the amount and timing of rainfall contribute to the survival and spread of pathogens.
The “deadly dozen” include diseases such as cholera, which is more tenacious in the warmth, Lyme disease and babesiosis carried by ticks, and avian influenza, which can be spread by disruptions in migratory birds' migration caused by climate change.
Malaria, another disease whose range is expected to expand due to climate change, was excluded from the list, as pathogens that infect humans are safe for animals, although they are carried by mosquitoes. Christina Smith of WCS also called for an expanded observer network. She noted: “We are beginning to identify trends in climate impacts on disease. The alarm has lit up. Wildlife can become our early warning system."
Coming contagion
Bird flu. More frequent storms can interfere with bird migration and drive infected wild birds to new areas where they will come into contact with poultry more often.
Babesiosis. This disease is spread by ticks. Its danger to people is growing. It is hypothesized that climate change in East Africa has contributed to a "demographic boom" in tick populations that parasitize lions and buffaloes.
Cholera. In warm water, its pathogen feels great. Global warming will cause widespread epidemics.
Ebola fever. Its connection with variations in precipitation was revealed. Deadly for gorillas, chimpanzees and humans.
Skin and intestinal parasites. A warmer climate and heavy rainfall help the parasites survive. They create more and more problems for people and animals.
Lyme disease. Changes in populations of white-tailed deer and white-footed hamsters have resulted in the spread of the tick-borne disease northward in the United States and its emergence in Canada.
Plague. Deadly to humans and animals. It is carried by rodents and fleas - species whose ranges change under warming conditions.
"Red tides". This is the name of some algae bloom. It is deadly to humans as it releases brevetoxins, tannic acid, and saxitoxins. The most ambitious consequence is the death of natural resources.
Rift Valley Fever. A viral disease with significant negative impacts on people's health, food security and the economy, especially in Africa and the Middle East.
Sleeping sickness. The distribution area of its carrier, the tsetse fly, is now changing.
Tuberculosis. A person can become infected with tuberculosis by eating milk from an infected cow. Warming is causing rivers to become shallow, and livestock will have to go to the watering hole with infectious wild animals.
Yellow fever. Mosquitoes carry it. Changes in rainfall and temperature conditions are expected to spread mosquitoes to new areas.