美国国家公共电台 NPR Lyme Disease Is On The Rise Again. Here's How To Prevent It（在线收听）

RACHEL MARTIN, HOST:

It is tick season, and with it comes the risk of Lyme disease. Once found mainly in New England, Lyme disease is now being reported in a much wider range of the U.S. NPR's Allison Aubrey reports that cases have more than doubled over the last decade. Now there's an estimated 300,000 sicknesses a year.

ALLISON AUBREY, BYLINE: Lyme disease was once unheard of in Western Pennsylvania, where Barbara Thorne spent time as a kid, so she was completely surprised by what happened to her after a July Fourth visit there a few years back.

BARBARA THORNE: About eight to nine days after that Fourth of July weekend, I noticed a roundish, red rash on my back just above my waistline. And it expanded each day, so it made me suspicious. And I was also feeling sick with exhaustion and achiness.

AUBREY: Her primary care doctor diagnosed her with Lyme disease, prescribed her antibiotics, and she did get better. Now, Thorne is an entomologist by training, so she knows she must have been bitten by a blacklegged tick. When these ticks are infected with the bacteria called Borrelia burgdorferi, they can transmit Lyme to people. And what she realizes now is that she'd been in a new Lyme hot spot.

THORNE: Lyme disease is on the move. Its range continues to expand fairly quickly, so we all need to be aware.

AUBREY: The CDC estimates the number of infections each year is 10 times higher than the reported cases. One reason is that some people who get infected don't know it. The nymphs, or the young ticks that transmit most of the infections, are teeny-tiny - no bigger than a pinhead or poppy seed - and nearly weightless, so it's super easy to miss a tick bite. And symptoms of Lyme overlap with other common illnesses. Paul Fiedler is a physician and chair of the department of pathology at Western Connecticut Health Network. He says even when people do suspect Lyme, there are shortcomings in the way it's diagnosed.

PAUL FIEDLER: Many of the tests for Lyme disease are negative at the time the patients first visit their doctor.

AUBREY: He says blood tests to detect Lyme disease rely on a person's immune response. The tests detect Lyme-specific antibodies. When someone gets infected with bacteria, it takes time - sometimes 10 to 30 days - to mount a measurable response. So if they get tested too soon...

FIEDLER: The tests will be negative, and the diagnosis could be missed.

AUBREY: ...Which could lead to serious problems. When Lyme is left untreated, the infection can spread to joints, the heart and the nervous system. Entomologist Barbara Thorne says it is possible to prevent Lyme disease if you're meticulous. Ticks tend to hang out in the grass or brush in or near wooded areas. So when you're outside, wear long sleeves and light-colored clothing. Insect repellent can help, too, but Thorne says the best thing to do is a thorough tick check.

THORNE: The ticks do tend to climb upward. They climb up your legs. They often attach where there was a constriction of clothing, like around the waistline.

AUBREY: Other favorite hiding spots include armpits or behind the ears. Now, if you do find one, use a pair of tweezers to pull it out. And don't freak out if it's been there for a few hours. The CDC says, in general, ticks need to be attached for 36 to 48 hours before they can transmit the bacteria that causes Lyme disease. Allison Aubrey, NPR News.