Every year, U.S. state health departments report about 30,000 cases of Lyme disease to the Centers for Disease Control and Prevention (CDC). But theCDC says the true number of cases in the United States could be ten times as high.
Lyme disease is transmitted to humans from tick bites. The ticks that transmit the disease are most active from April to September, which means spring and summer are the prime times for infection. With the right steps, and regular tick checks, however, you can prevent Lyme disease.
Here are 10 things you should know about this tickborne disease:
1. You can only get Lyme disease from a tick bite.
There is no evidence that Lyme disease can be transmitted from person-to-person, according to the CDC. You also can’t get Lyme disease from your dog, but your furry friend can bring ticks into your home or yard, so check your pet for ticks before letting him in the house.
2. Not all ticks carry Lyme disease.
Blacklegged ticks are the ones you need to avoid. Also known as deer ticks, these parasites spread the disease in northeastern, mid-Atlantic, and north-central states, while western blacklegged ticks transmit infection on the Pacific Coast. According to CDC data, in 2013, 95 percent of Lyme disease cases occurred in 14 states, most of which were on the East Coast.
3. You can probably remove the tick by yourself if you notice it in time. 
To remove a tick before it’s too late, you can purchase a tick removal device, but a pair of fine-tipped tweezers will do the trick. The CDC recommends that you avoid “folklore remedies,” such as painting the tick with nail polish or using heat to detach it. The goal is to remove the tick as quickly as possible after you notice it.
4. In most cases, it takes 36 to 48 hours for an infected tick to transmit Lyme disease after it attaches itself to you.
Nymphs, which are immature ticks that measure less than 2 mm in size, are theprimary transmitters of Lyme disease. Because they’re so small, nymphs can go unnoticed in difficult-to-see areas such as the scalp, armpits, and groin. Adult ticks can also transmit the disease, but because they’re bigger, many are noticed and removed before they can transmit the infection.
5. There used to be a Lyme disease vaccine, but it was discontinued in 2002.
The vaccine manufacturer said demand was insufficient, so production stopped. Because the protection given by the vaccine lessens over time, even people who received the vaccine in 2002 are no longer immune to Lyme disease.
6. The most common symptom of Lyme disease is a bullseye rash.
In 70 percent to 80 percent of infected people, the bullseye rash, also known by its technical name, erythema migrans, will appear 3 to 30 days after becoming infected. The CDC says the average time for the rash to show up is a week. As the rash spreads, parts of it might clear up, which is how the bullseye becomes evident.
But, says Phillip J. Baker, executive director of the American Lyme Disease Foundation, not all patients notice the rash, and a significant percentage will not develop a “textbook case” of the rash at all. He says other symptoms can be described as “flu-like,” and include fatigue, headache, joint swelling, and dizziness, to name a few.
7. Lyme disease is officially diagnosed with a blood test.
If done in the early stages of infection, however, most tests will come out negative. Baker says it usually takes four to five weeks for antibodies that fight Lyme disease to appear in the bloodstream, which means that anyone tested sooner may not get will not receive an accurate diagnosis.
8. Most cases of Lyme disease can be treated with antibiotics.
Marina Makous, MD, a postdoctoral research fellow at Columbia University’s Lyme and Tick-Borne Diseases Research Center, said antibiotics are effective for most cases of early Lyme disease if started in time, and the earlier the better. “It’s best if they’re started within the first two weeks,” Dr. Makous says. “But that can be difficult because tests won’t pick up on Lyme disease that early.”
9. There is controversy surrounding Lyme disease.
The CDC’s criteria for Lyme disease was established to make it easy for state departments to report cases back to the agency, Makous said. But she says it is too narrow, and doesn’t include an accurate representation of “post-treatment Lyme disease syndrome,” which the CDC says affects 10 to 20 percent of Lyme disease patients. Symptoms of post-treatment Lyme disease include extended fatigue, pain, and joint and muscle aches, according to the National Institute of Allergy and Infectious Diseases (NIAID). “It can be hard to make a correct diagnosis because the symptoms are too similar to other diseases,” Baker says. However, “if people continue to have symptoms, they should persist and not give up,” says Makous, who is opening her own clinic in Exton, Pennsylvania, specifically to treat post-treatment Lyme disease syndrome.
10. You can take precautions to prevent Lyme disease.
If you’re going outdoors in a shady grassland or densely wooded area, the National Institute of Allergy and Infectious Disease recommends wearing light-colored long-sleeved pants and shirts to make ticks easier to spot. Spray clothing with permethrin repellent, and spray DEET directly on your skin. Once inside, you should check for ticks in hairy areas of your body, and be sure to wash all clothing.