12 deadly pathogens could spread into new regions aided by climate change

A report by Wildlife Conservation Society released on October 7 lists 12 deadly pathogens that could spread globally as a result of climate change. “All have potential impacts to both human and wildlife health as well as global economies.” Report said.

Titled ‘The Deadly Dozen: Wildlife Diseases in the Age of Climate Change,’ the report illustrates examples of diseases that could spread due to temperatures changes and variations in regional precipitation levels.

Gram-positive Mycobacterium Tuberculosis Bacteria

Under a high magnification of 15549x, this colorized scanning electron micrograph (SEM) depicted some of the ultrastructural details seen in the cell wall configuration of a number of Gram-positive Mycobacterium tuberculosis bacteria. As an obligate aerobic organism M. tuberculosis can only survive in an environment containing oxygen.

TB bacteria become active, and begin to multiply, if the immune system can’t stop them from growing. The bacteria attack the body and destroy tissue. If in the lungs, the bacteria can actually create a hole in the lung tissue. Some people develop active TB disease soon after becoming infected, before their immune system can fight off the bacteria. Other people may get sick later, when their immune system becomes weak for another reason.

Babies and young children often have weak immune systems. People infected with HIV, the virus that causes AIDS, have very weak immune systems. Other people can have weak immune systems, too, especially people with any of these conditions: substance abuse; diabetes mellitus; silicosis; cancer of the head or neck; leukemia or Hodgkin’s disease; severe kidney disease; low body weight; certain medical treatments (such as corticosteroid treatment or organ transplants); specialized treatment for rheumatoid arthritis, or Crohn’s disease. [Source: CDC – Caption: CDC/ Dr. Ray Butler; Janice Carr. Photo Credit: Janice Carr]

“The term ‘climate change’ conjures images of melting ice caps and rising sea levels that threaten coastal cities and nations, but just as important is how increasing temperatures and fluctuating precipitation levels will change the distribution of dangerous pathogens,” said Dr. Steven E. Sanderson, WCS President and CEO. “The health of wild animals is tightly linked to the ecosystems in which they live and influenced by the environment surrounding them, and even minor disturbances can have far-reaching consequences on what diseases they might encounter and transmit as climate changes. Monitoring wildlife health will help us predict where those trouble spots will occur and plan how to prepare.”

The “Deadly Dozen” list [ABC order]:

Avian influenza Babesia Cholera Ebola Intestinal and external parasites Lyme disease Plague Red tides Rift Valley fever Sleeping sickness (trypanosomiasis) Tuberculosis Yellow fever

This micrograph of human liver tissue infected with the Ebola virus, the cause of Ebola hemorrhagic fever (Ebola HF), depicts the hepatic histopathologic changes that occur due to this illness.



The Ebola pathogen is a member of the Filoviridae family of RNA viruses. The exact origin, locations, and natural habitat (known as the “natural reservoir”) of Ebola virus remain unknown. However, on the basis of available evidence and the nature of similar viruses, researchers believe that the virus is zoonotic i.e., animal-borne, and is normally maintained in an animal host that is native to the African continent. A similar host is probably associated with Ebola-Reston which was isolated from infected cynomolgous monkeys that were imported to the United States and Italy from the Philippines. The virus is not known to be native to other continents, such as North America.

Source: CDC. Caption and photo credit: CDC/ Dr. Lyle Conrad]

The report “builds upon the recommendations included in a recently published paper titled ‘Wildlife Health as an Indicator of Climate Change,'” which is featured in a new book, Global Climate Change and Extreme Weather Events: Understanding the Contributions to Infectious Disease Emergence, which was published by the National Academy of Sciences/Institute of Medicine. The study examines the the impacts of climate change on wild animals and its implications for human health.

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