Lyme disease: Is climate change spreading this disease?

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  Quantumrun Foresight
• February 27, 2022

Insight summary

Lyme disease, a prevalent vector-borne illness in the US, is transmitted through tick bites and can lead to severe health complications if untreated. Urbanization and climate change have contributed to the spread of ticks, increasing human exposure and the risk of Lyme disease. Despite efforts to combat the disease, its rapid spread has significant implications, from changing outdoor recreational habits to influencing urban planning and conservation efforts.

Lyme disease context 

Lyme disease, caused by borrelia burgdorferi and occasionally borrelia mayonii, is the most common vector-borne disease in the US. The illness is transmitted via the bite of infected black-legged ticks. Typical symptoms include fever, fatigue, headache, and a distinctive skin rash known as erythema migrans. An untreated infection can spread to the heart, joints, and nervous system. A Lyme disease diagnosis is based on the probability of tick exposure as well as the presentation of physical symptoms. 

Ticks are typically associated with the New England woodlands and other forested areas in the US; however, new research indicates that ticks carrying Lyme disease have been discovered near beaches in Northern California for the first time. Human settlement expansion into wildland areas, including forests in the eastern United States, has resulted in fragmented forest habitat that has been linked to an increased entomological risk for Lyme disease. New housing developments, for example, bring people into contact with tick populations that previously lived in wooded or undeveloped areas. 

Urbanization may have also caused a rise in the number of mice and deer, which ticks need for blood meals, thereby increasing the tick population. According to the US Environmental Protection Agency, temperature and humidity have a significant impact on the prevalence and life cycle of deer ticks. For example, deer ticks flourish in locations with at least 85 percent humidity and are most active when the temperature rises over 45 degrees Fahrenheit. As a result, rising temperatures linked with climate change are anticipated to expand the area of suitable tick habitat and are one of several factors driving the observed spread of Lyme disease.

Disruptive impact

Although it is unknown how many Americans get infected with Lyme disease, the latest evidence published by the US Centers for Disease Control and Prevention (CDC) indicates that up to 476,000 Americans are identified and treated for the disease each year. There have been reports of cases in all 50 states. A major clinical need includes the necessity for better diagnostics; this includes the capacity to identify early Lyme disease before antibody testing can reliably detect it as well as the development of Lyme disease vaccines. 

Assuming a two-degree Celsius increase in yearly average temperature—per mid-century estimates from the most recent US National Climate Assessment (NCA4)—the number of Lyme Disease cases in the country is predicted to rise by more than 20 percent in the coming decades. These findings may help public health experts, clinicians, and policymakers in strengthening preparedness and response, as well as boosting public awareness of the necessity of exercising caution when participating in outdoor activities. Understanding how present and future land-use changes are likely to influence human disease risk has become a priority for disease ecologists, epidemiologists, and public health practitioners.

Despite substantial federal government investments, the rapid rise of Lyme and other tick-borne illnesses has emerged. According to the CDC, personal protection is the best barrier against Lyme disease along with landscape changes and acaricide treatments to individual homes. However, there is limited evidence that any of these measures work. Backyard pesticide usage reduces tick numbers but does not directly influence human illness or tick-human interaction.

Implications of the spread of Lyme disease

Wider implications of the spread of Lyme disease may include:

• A surge in research funding for Lyme disease, resulting in a better understanding of the illness and improved treatment options.


• The creation of community awareness programs, leading to a more informed public about the risks and preventive measures.


• An increase in collaboration between urban planners and environmentalists, leading to city designs that respect natural habitats and reduce human-wildlife conflicts


• The emergence of a new market for Lyme disease prevention products, leading to consumers spending more on protective gear and repellents.


• A shift in outdoor recreational habits, with people becoming more cautious and possibly avoiding certain activities, leading to potential losses for businesses like camping sites or hiking tour operators.


• A potential decline in property values in areas identified as high-risk for Lyme disease, affecting homeowners and the real estate industry.


• The government introducing stricter regulations on land development, leading to increased costs for construction companies and potential delays in urban expansion.


• An uptick in labor absenteeism as affected individuals take time off work for treatment, impacting productivity in various sectors.


• A heightened focus on environmental conservation, leading to stricter land use policies and potentially limiting industrial expansion in certain areas.

Questions to consider

• Do you know of anyone who has contracted Lyme disease? What has their experience been like managing this disease?


• What precautions do you take to keep ticks at bay when you are outdoors?