Ticks and Lyme Disease: Why are rates so high?

Posted August 08, 2018 by Thomas File, M.D. Infectious Diseases, Summa Health

Warmer weather is in full force now, and for many of us this season means outdoor activities including camping and exploring, plus the insects that call these spots home.

According to the Centers for Disease Control, there are more than 36,000 cases of Lyme disease reported each year and hundreds to thousands of cases go unreported. Since the CDC began tracking this disease, the number of annual cases has increased dramatically. Between 2004 and 2016, researchers found cases almost doubled from 19,804 to 36,429.

Before we get into possible causes of this increase, let’s explore what Lyme disease is and how to tell if you may have been infected.

What is Lyme disease?

Caused by the bacteria Borrelia burgdorferi, Lyme disease is transmitted to humans by the bite of an infected blacklegged (or deer) tick. It’s the most common vector-borne disease in the U.S., surpassing West Nile and the Zika virus combined. Vector-borne diseases are illnesses that are transmitted by mosquitoes, ticks and fleas.

The only way to get Lyme disease is from the bite of an infected tick. Generally speaking, this tick needs to be attached for 36 to 48 hours before the bacteria can be transmitted. There are exceptions to this time rule, but the sooner you remove the tick, the lower your chances of contracting the disease are.

Individuals who have been bitten by an infected tick usually report symptoms of fever, headache and fatigue. However, the clearest symptom of Lyme disease is the skin rash that can appear around the infected bite, usually resembling a red ring, which appears on average of 7 days after the bite (but can vary from 3-30 days).

If the disease is caught in the early stage of the rash, within a few days or weeks, an antibiotic can be quite successful at treating the illness. However, if left untreated, the infection can spread to the heart, joints and even the nervous system as part of later stage infection, which can occur up to several months after the bite. The infection can become a serious condition that causes symptoms such as arthritis, heart palpitations, nerve pain and brain swelling. Antibioitcs may also help in treating these later stages of infection.

The only way to prevent Lyme disease is to not get bitten by an infected tick. When exploring outdoors, it’s highly recommended that you use insect repellent. Consider wearing long sleeves, pants and closed-toe shoes in wooded or high-grass areas. After coming indoors from being in a wooded or grassy area, check your clothes and skin for ticks. If you find a tick on your skin, remove as soon as possible. A plain set of fine-tipped tweezers works well. Grasp the tick as close to the skin as possible and pull upward with a steady, even pressure.

Why have rates almost doubled in the last 10 years?

In 2015, 95 percent of confirmed cases were reported from 14 states: Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia and Wisconsin. Infected ticks can also be found in neighboring states and a few areas in Northern California, Oregon and Washington. Since that time, the geographic distribution of ticks has widened to other states. Infection of Lyme within Ohio used to be uncommon. In fact during the 1990s, the Ohio Department of Health (ODH) reported one to two dozen cases. Since then the number of reported cases has increased substantially. In 2017, the ODH reported 270 cases, and these numbers continue to increase throughout 2018.

One reason for such a heavy increase in cases is a much larger and longer “tick season.”

As parts of the country experience earlier springs and longer falls, the optimal deer tick activity season (May-October) is ending later, and in some cases starting earlier. Ticks can be found year-round if the “freeze” season is short. Warmer temperatures also shorten the duration of development from larvae to adult tick.

On the positive side, researchers suggest the increase could be attributed to people knowing more about Lyme disease. Now, people know what to look for and they are seeking treatment at the onset of symptoms.

If you or someone you know may be experiencing signs or symptoms of Lyme disease, see your primary care physician as soon as possible. Diagnosis can be based on the presence of the rash in the early stage or by a blood test in the later stages. To make an appointment with a Summa Health physician, call 800.237.8662.