Data diving: Vermont has the highest Lyme disease rate in the country. Where is your county?

The Lyme disease rate in Vermont was the highest in the country in 2017, with 174 new cases diagnosed per 100,000 population.

This is reflected in the figures from the Centers for Disease Control, which monitors newly diagnosed cases of Lyme disease at the state and county levels.

Although other states recorded more cases than the 1,089 residents of Vermont, the total is the highest in Vermont after adjusting for population. Maine is ranked second with 139 cases per 100,000 population.

Nationally, 2017 was the worst year of Lyme disease in the last 10 years, with 42,321 cases diagnosed, nearly 5,000 more than the previous peak of 2015.

This includes the "confirmed" and "probable" diagnoses that each state reports to the Centers for Disease Control each year. Confirmed cases include cases in which a patient has been in an area where ticks usually live (mainly wooded, brushed or grbady areas) and have a revealing rash or positive test for Lyme disease. Probable cases are those where there is laboratory evidence of Lyme disease, but patients are unaware that they have been exposed to ticks.

Although national data is not yet available for 2018, the Vermont Health Department has finalized its 2018 numbers to send to the CDC last month. The department counted 576 cases in that state, just over half of the number recorded in 2017.

This does not mean that you should stop checking ticks. Patti Casey, director of the Environmental Monitoring Program at the Vermont Agency of Agriculture, said that although tick populations have declined last year, they have increased dramatically this spring. Its program monitors tick fields for the Ministry of Health. Samples taken this spring revealed a 55% increase in the number of blacklegged and dog ticks compared to the previous year. (Blacklegged ticks, also known as deer ticks, have Lyme disease, and dog ticks do not.)

Ticks relying on hosts such as rodents and deer, cycles in their populations can have an impact on the number of ticks. And weather can also have negative consequences: low temperatures without snow for insulation can kill ticks, as well as long periods of hot, dry weather in summer.

In addition, climate change is leading to milder temperatures earlier in the spring and later in the fall, extending the tick season to find hosts, feed and shelter before winter.

"It's a longer season for invasive pests," Casey said.

Tick ​​migration, animal population cycles and weather fluctuations complicate the prediction of the worst years for the incidence of Lyme disease.

"It's almost impossible to predict what will happen," Casey said. "All this is really new in our region."

Indeed, Vermont has not always dominated the pack in terms of Lyme disease rates. In 2008, the CDC changed its definition of Lyme disease surveillance to include probable cases rather than simply confirmed cases. That year, Green Mountain State ranked fourth in the United States, behind New Hampshire, Delaware and Maine. In 2017, Vermont and Maine led the pack, followed by Rhode Island, New Hampshire and Pennsylvania.

Lyme rate in the five US states with the highest incidence

Rate of new cases per year per 100,000 inhabitants

Map: Andrea Suozzo • Source: US Centers for Disease Control, US Census Bureau

The CDC noted that not all cases are diagnosed or reported. Natalie Kwit, a veterinarian in charge of public health in Vermont, said this was one of the reasons why it is important for people in Vermont to be aware of tick bites and symptoms of Lyme disease. "We and other health departments can only investigate things we hear about," she said.

From one state to another, health services may exercise different disease surveillance. The increase in Lyme disease rates may indicate changes in levels of awareness of the disease.

To further complicate matters, Mbadachusetts uses a different case definition from the CDC in its notification, which results in much lower figures than neighboring New England states.

Nevertheless, the numbers show that the disease migrated from southern Connecticut where it was first discovered.

Lyme disease rates fluctuate from year to year. Since states began reporting cases to the Centers for Disease Control in 1991, however, tick populations and the diseases they transmit are spreading gradually from southern New England.

A 2015 badysis in the newspaper Emerging infectious diseases have found that "geographic expansion of high-risk areas is underway" and that the disease is not only moving south or north, but migrating in all directions.

In Vermont, Lyme disease has slowly migrated northward over the past decade, with rates in northern counties rising.

Bennington County, however, dominated each year with a rate of 473 per 100,000 in 2011. (To be clear, this represents only 174 real cases Bennington County has less than 40,000 residents, the rate has been adjusted 100,000 inhabitants, since this is the standard for disease surveillance).

What are the Lyme disease rates in your county?

Rate of new cases per year per 100,000 inhabitants. Click or tap a county for more information.

Map: Andrea Suozzo • Source: US Centers for Disease Control, US Census Bureau

Lyme disease is not the only disease to look for. Anaplasmosis has also increased in recent years. In 2018, the Vermont Department of Health received 244 cases of anaplasmosis in Vermont, up from 3 in 2010 alone.

Although it is not as widespread as Lyme disease, anaplasmosis is of particular concern to Vermont seniors. It often manifests as flu-like symptoms – fever, chills and headaches.

You never want to go out?

Kwit said that as long as you take precautions, there is no reason not to participate in this hike.

"Tick-borne diseases are treatable and preventable," she said.

Kwit advises people to wear an EPA-approved insect repellent, to know common tick habitats, to take a shower, and to do a thorough check on ticks shortly after their stay outside. Learn about tick removal properly and watch for common symptoms of tick-borne diseases.

If you find a tick attached to your body, you can help the state monitor tick populations and send the bug itself or a close-up snapshot to the agency's tick surveillance program. Agriculture. In this way, you can know if it is a deer tick.

And most importantly, if you have symptoms of Lyme disease or anaplasmosis, consult a doctor.