Lyme disease thrives on climate change


gThe forensic pathologist, Alfred Buchwald, was absolutely unaware that the chronic inflammation of the skin that he described in 1883 was the first recorded case of a serious illness that carried ticks, a disease that will manifest itself. in a small Connecticut town nearly a century later and will hit people all over the world. United States.

Today, we know much more than Buchwald about Lyme disease – that it is caused by a bacterium, Borrelia burgdorferi, and it is transmitted to humans by blacklegged ticks, which can cause immense suffering to infected people. American scientists first recognized the disease in the 1970s in Old Lyme, Connecticut – hence his name. The illness begins with fever, headache, fatigue and a characteristic rash. Untreated, it can spread to the joints, heart and nervous system, producing long-lasting debilitating symptoms. The early use of antibiotics is crucial.

According to the Center for Disease Control and Prevention, approximately 300,000 Americans are diagnosed each year with Lyme disease, with cases concentrated in the Northeast and Upper Midwest. The incidence of the disease has doubled in the United States since 1991, according to the EPA. And the climate will get worse.

"Warmer temperatures make cold places tick-prone, so new places have cases of Lyme disease and endemic areas have more than average," said Edson Severnini, assistant professor of 39, Economics and Public Policy at Heinz College, Carnegie Mellon University. and co-author of a new study that predicts that the incidence of Lyme disease will increase by about 21% by mid-century.

Climate change has already amplified the range of invasive insects that devour crops, destroy homes and spread disease. "Tick-borne diseases are an important public health problem and the incidence of these infections is increasing in the United States and around the world," said Igor Dumic, lead author of the study and researcher at the Mayo Clinic College of Medicine and Science. many patients with Lyme disease. "Lyme disease is a classic example of the link between environmental factors and the occurrence and spread of the disease."

Ticks spend most of their lives in environments where temperature and humidity directly affect their survival. For this reason, the EPA uses Lyme disease as an indicator of climate change. Higher temperatures encourage ticks to venture further in search of hosts, such as deer, which are more numerous after warmer winters. "The tick vector of Lyme disease needs deer to carry out its life cycle, which means that more ticks will have completed their life cycle and, as a result, their population will increase, "said Severnini. "In addition, as the temperature increases, people can participate in more outdoor activities, thereby increasing tick exposure."

The search, which appears in the Canadian Journal of Infectious Diseases and Medical Microbiology, examined the relationship between meteorological conditions and Lyme disease in 15 US states. These states, located primarily in the Northeast and Upper Midwest, account for 95% of all reported cases in the United States. Scientists used epidemiological data from the CDC and meteorological data from the National Oceanic and Atmospheric Administration.

Assuming that the temperature will increase by 2 degrees Celsius by the middle of the century (US National Climate Assessment forecast), the US will see 8.6 additional cases of Lyme disease per 100,000 population per year. This is bad news, but governments can take steps to control the disease, Severnini said.

"We need to educate people on how to look for ticks after going to woodlands where ticks are abundant," he said. "Second, people and clinicians need to be aware that ticks are not present in certain areas, so people do not go to areas where they are present. For example, a resident of Arizona, where Lyme disease is rare, can acquire it while camping in Wisconsin and have symptoms when he returns to Canada. [his or her] State of origin of Arizona. "

It's not just education, Severnini said. "We can also invest in the development of a vaccine against Lyme disease, using an insecticide and an acaricide to reduce the tick population," he added. "Finally, we can prevent serious global warming."

Marlene Cimons writes for Nexus Media, an outsourced newswire covering the climate, energy, politics, arts and culture.