The tiny deer ticks marching northward through Maine may be hard to spot, but the diseases they carry are hard to miss.
Maine is recording increasing numbers of illnesses transmitted by the bite of the eight-legged deer tick, including two lesser-known germs following in Lyme disease’s footsteps. Cases of anaplasmosis, which affects white blood cells, have spiked from nine in 2007 to 26 in 2011, according to state epidemiologist Dr. Stephen Sears. Already in 2012, 15 cases have been reported.
“Although those numbers are very small compared to Lyme, the fact that it’s increasing, and it seems to be increasing pretty significantly each year, suggests to me that we really all need to become aware of all these diseases,” Sears said.
Also on health officials’ radar is babesiosis, a less common but potentially serious tick-borne disease in which microscopic parasites infect red blood cells. It can especially sicken those with weak immune systems and people who have had their spleen removed.
Both anaplasmosis and babesiosis cause fever, headache, and muscle aches, though some people infected with babesiosis experience no symptoms.
“If [people] get fevers and chills in the summer and they don’t have a rash, that could be Lyme disease without a rash, it could be anaplasma, it could be something else,” Sears said. “If they had tick exposure, that’s especially important.”
The deer tick can transmit Lyme, anaplasmosis and babesiosis. With one bite, a tick could infect its host with all three diseases.
The dog tick, meanwhile, which is larger with characteristic white markings, can carry Lyme but doesn’t transmit it.
Numbers wise, anaplasmosis and babesiosis still pale in comparison to Lyme disease. The most conspicuous of the tick-borne diseases, Lyme sickened about 1,000 Mainers in 2011 and more than 180 so far this year.
But the two emerging diseases are shadowing Lyme’s progression from southern to northern New England.
“Anaplasmosis and babesiosis are emerging in southern Maine the way we saw Lyme disease emerge several decades ago,” said Susan Elias, a clinical research associate at Maine Medical Center’s Vector-borne Disease Laboratory in South Portland. “We’re now seeing those two diseases moving inland and up the coast in the same pattern as Lyme.”
The spread of Lyme
Lyme disease has been recognized since 1975, when the first cases were identified in the town of Lyme, Conn. The illness was later traced to the bite of an infected deer tick. In 1982, the bacterium Borrelia burgdorferi was identified as the culprit behind the wide range of symptoms associated with the disease, from a telltale bull’s eye rash to, in more serious cases, nerve damage and heart problems.
Once limited to Maine’s southern counties, Lyme disease in humans has now spread to every county in the state. The number of cases reported each year has multiplied roughly 10 times since 1990 thanks to hungry deer ticks that feed mostly during the summer months.
Ticks are less of a problem in northern counties and at higher elevations, but that could change with a gradually warming climate.
“There’s sort of an imaginary line that you can draw through Bangor, and we can say we have higher density south of Bangor, lower tick density north,” with the exception of coastal Washington County, Elias said.
Maine’s climate prevents ticks from completing their two-year life cycle in the colder northern parts of the state, she said. But by 2050, warmer temperatures will mean ticks can progress from eggs to adults in all regions of Maine, according to research by the Vector-borne Disease Laboratory that’s based on models created by the University of Maine Climate Change Institute.
“It’s not this huge dramatic shift by 2050, it’s not like we’re going to be Virginia,” Elias said. “We’re going to be Massachusetts, which doesn’t seem like a huge change, but it is.”
The lab, which works to control tick-borne diseases, also identifies ticks sent in by the public. (It does not test ticks for disease.)
More ticks were submitted to the lab in March 2012 than in March of any prior year, Elias said.
“We got off to an early start because of the very mild winter where we had so little snow,” she said. “We started having tick submissions to our lab in mid-March, so that’s early.”
Conservatively, an average of 50 percent of Maine deer ticks carry disease, Elias said. In some areas, the infection rate is as high as 80 percent; in other regions it’s as low as 10 percent.
If you’ve been bitten by a deer tick, it’s safer to assume the bug was infected, she said.
With all the warnings about the nasty diseases deer ticks spread, some Mainers might be tempted to hole up inside for the summer.
But even Elias, who studies ticks for a living, encourages her 14-year-old boys to enjoy the outdoors.
“I have a town park behind my house and there are ticks, dog ticks and deer ticks,” she said. “I’d rather send [my sons] out and have them build treehouses and all that stuff. They come back in and we do a thorough tick check.”
Even if you find a tick crawling on your leg, that doesn’t mean you’ve been infected with disease, especially if it’s not engorged with blood.
“The ticks typically wander around for up to 24 hours before they even attach, so there’s a lot of opportunity to get rid of them,” Sears said. “Even if they’ve attached, you’ve got 24 hours at least before they begin to transmit the disease.”
Early signs of disease typically occur within a month of a tick bite. The most common symptom, a ring-like rash, occurs in about 80 percent of cases, Sears said. But patients can miss the rash if the bite occurs where they can’t see it, such as under the hair on the back.
Antibiotics are most effective in the early stages of disease, Sears said.
“It’s important for anybody who has been exposed to get diagnosed and get treated, the sooner the better,” he said.
- Choose light-colored clothing so it’s easier to spot ticks; wear long sleeves and and tuck your pants into your socks.
- Use insect repellent with DEET on your skin and apply permethrin, a common insecticide, to your clothes.
- Check your skin and clothing for ticks and remove them promptly. Don’t miss warm, moist areas such as the ears, armpits and neck.
- Wash possible tick bites with soap and water and apply an antiseptic.
- Keep your lawn mowed and tidy to remove tick habitat.
- If you spot an embedded tick, use tweezers to grasp its mouth and pull it out with steady pressure. Don’t use petroleum jelly, hot matches or nail polish remover, which can increase the risk of infection.
- If a tick isn’t engorged with blood, it’s very unlikely it has transmitted disease.
Symptoms of disease
- In about 80 percent of Lyme cases, patients exhibit a ring-like rash that expands into a bull’s eye pattern. Flu-like symptoms are also common. Left untreated, Lyme can result in joint pain, nerve problems and heart problems.
- Anaplasmosis and babesiosis are also characterized by flu-like symptoms, including fever, chills, headaches, and body aches. Babesiosis can result in anemia and dark urine and can be serious for people with weak immune systems and people who have had a spleen removed.
- Oral antibiotics are used to treat Lyme and anaplasmosis. Babesiosis is treated with a two-drug regimen. Contact your doctor immediately if you’ve been bitten and are experiencing symptoms, as treatment is most effective when started early. The longer the tick is attached to your skin, the greater the risk of illness.
- It takes about three weeks for the body to consistently produce antibodies against Lyme, so early blood tests for the antibodies may not be accurate.
- Your doctor may treat you for Lyme without a blood test if you have the telltale rash or if you don’t exhibit symptoms but live in a high-risk area and an engorged tick was embedded on you for longer than 24 hours.
- A vaccine for Lyme disease was discontinued in 2002; no vaccine is available today.
Source: Maine CDC