The United States government and climate researchers have recently released the Fifth National Climate Assessment, providing a comprehensive overview of the impacts of climate change on the country's quality of life. This assessment, unlike annual reports, is published once every four years due to its extensive research and concrete observations.
In the 2018 edition of the report, predictions were made about the potential rise in climate-related diseases such as fungal pathogens, toxic algal blooms, and mosquito- and tick-borne illnesses, resulting from rising temperatures, extreme weather events, drought, and flooding. The newly published report confirms that these predictions are already becoming a reality.
The report emphasizes that the changing climate has led to an increase in infectious diseases due to their geographical spread. Diseases such as West Nile virus, dengue fever, Lyme disease, Rocky Mountain spotted fever, rabies, and Valley fever, which are transmitted by mosquitoes, ticks, mammals, and soil, are identified as "climate-sensitive." It is important to note that climate change is not the sole contributing factor for the spread of these illnesses, as urbanization, deforestation, and other environmental changes also play a role.
Specific attention is given to the expansion of tick-borne diseases in different regions of the country. Previously prevalent in the Northeast and mid-Atlantic regions, Lyme disease has now become endemic to the Midwest due to milder winters. Western black-legged ticks, carriers of Lyme disease, are even spreading into Alaska where they previously could not survive. The costs associated with treating Lyme disease, which affects around half a million Americans annually, are significant. As temperatures continue to rise, other tick-borne diseases like Rocky Mountain spotted fever, babesiosis, and alpha-gal syndrome are also expected to expand in range and severity.
Similar to ticks, mosquitoes are benefiting from milder winters and longer breeding seasons caused by climate change. Flooding, resulting from a warmer and wetter atmosphere, further facilitates the spread of mosquito-borne illnesses across the contiguous U.S. West Nile virus, carried by Culex mosquitoes, is expanding in the Northeast and becoming a greater threat in other parts of the country. The report also highlights the impact of West Nile virus on marginalized communities in Chatham County, Georgia. While most individuals infected with West Nile virus show no symptoms, those who are more vulnerable, such as the immunocompromised, elderly, pregnant, or those with underlying health conditions, may experience severe symptoms and even death. Dengue fever, a dangerous viral infection, poses an increasing threat in various regions of the United States and its affiliated territories. Meanwhile, malaria, a mosquito-borne illness once eradicated in the U.S. during the 1950s, has resurfaced in the Southeast and Pacific Islands.
The spread of Vibrio bacteria is being facilitated by climate change, primarily in warm ocean waters. Vibriosis, an illness caused by this bacteria, exhibits symptoms like vomiting, diarrhea, and a rash that can progress to a serious infection known as necrotizing fasciitis. According to projections, cases of vibriosis are anticipated to surge by 51 percent by 2090, assuming temperatures rise by up to 2.6 degrees Celsius. Rising ocean temperatures in the continental U.S. provide an ideal environment for Vibrio to flourish and expand further north, potentially reaching states like New York and Connecticut.
Leptospirosis, a waterborne illness caused by a pathogenic bacteria, is spreading in Hawai‘i and the U.S.-affiliated Pacific Islands due to rising ocean temperatures and tropical storms. Additionally, the region faces a climate-driven risk from fecal coliform bacteria, which can lead to various diseases.
The report sheds light on unexpected ailments occurring in states ranging from Texas to Alaska. In the Southwest, a fungal disease known as Valley fever is spreading, causing distressing symptoms and the potential to move into states like Oregon and Washington as a result of warming. Alaska is witnessing the emergence of rabies in animals, heightening concerns about the possibility of human cases. Furthermore, reported cases of Naegleria fowleri, a brain-attacking amoeba, in Arkansas and Texas indicate the potential for the disease to spread northward.
The authors underline the necessity for further research to better comprehend and address the emerging health risks associated with climate change.