Lyme Disease Is Just One Of The Threats Posed By Deer Ticks

By Kaaren Valenta

The ticks that carry Lyme disease also can carry a second potentially serious but less well known disease: Ehrlichiosis.

“In Connecticut, about 60 percent of [deer] ticks are positive for Lyme. About 40 percent are co-infected with ehrlichia,” said Jo-Anne Passalacqua, MD, of St Vincent’s Medical Center at a recent program sponsored by the Paris Nurse Ministry at St Rose Church.

Symptoms for persons infected with ehrlichia range from  mild to severe, with some persons winding up hospitalized in critical condition, Dr Passalacqua said. Nationwide reports showed that at least 60 people were stricken last year and four persons died.

“We believe a lot is unrecognized, probably because unlike Lyme, a rash is rare with ehrlichia,” Dr Passalacqua said.

Both Lyme and ehrlichia are most prevalent in the spring and summer, in rural areas where more ticks are found, and more often in men, especially those who work outdoors.

“We are in peak Lyme season,” Dr Passalacqua warned.

Ehrlichia can produce more severe flu-like symptoms than Lyme disease and diagnosing it can be more difficult. Lyme disease often is signaled by a telltale circular rash, or bullseye, around the site of a tick bite. Ehrlichia usually hits unannounced, multiplying inside white blood cells and then typically causing a sudden fever, chills, headaches, and muscle aches.

“It can look like a bad case of the flu,” Dr Passalacqua said. “Less often there is nausea and vomiting, abdominal pain, cough, confusion. Only 30 percent show a rash, and that is a very faint spotting, usually on the trunk, not at the site of the bite. The rash is more common in children than adults.”

“When we see headache and high fever this time of year, we always think of ehrlichia,” she said. “But it can mimic other diseases like mononeuclosis and encephalitis. It is more severe in older people and those with debilitated immune systems.”

Diagnosis requires two blood tests a week or two apart, Dr Passalacqua said. Antibiotic treatment generally is effective and leads to improvement in the patient within 24 to 48 hours.

Symptoms Of Lyme

By contrast, about 80 percent of the people infected with Lyme disease will develop a rash within five to seven days of being bitten by an infected tick.

“The bullseye-like rash develops as the bacterial organisms move out in waves in the body,” Dr Passalacqua said. “Nothing else looks like this. If you see it, it is Lyme disease.”

Infected persons also may have fever, muscle aches and join aches. The rash itself is red, flat, but not itchy; nor does it hurt.

It is important to treat Lyme disease at this stage, before it enters the bloodstream and enters its second stage, she said.

 Dr Passalacqua said half of the Lyme patients who reach the secondary stage of the disease will develop a rash on other parts of the body and will feel sick. They even may experience Bell’s Palsy, paralysis on one side of the face. The third stage develops into an autoimmune disorder that can involve a severe arthritis that becomes permanent, neurological symptoms, memory loss, and many other problems.

“If left untreated, they can become very sick, with permanent damage,” she said. “At that stage, antibiotics don’t appear to help very much so it is important to be treated quickly.”

Blood tests can show the presence of Lyme disease but they take 10 to 14 days to obtain a positive result. A rash, on the other hand, can appear in five to seven days.

“If you wait for a test to become positive, the disease can go into the blood stream,” Dr Passalacqua said.

Lyme should be treated with antibiotics for at least 14 days, and in some cases 21 days. “You have to take the whole series, not part of it,” Dr Passalacqua emphasized.

But not all cases progress to stage two or three. “It depends upon how our body’s immune system is responding,” she said. “If you are exposed repeatedly, it is believed that the body gets better at fighting the disease off.”

 Dr Passalacqua said the source of most Lyme and ehrlichia infections are not adult ticks from deer, but rather the larva and nymph stages of the ticks, which feed on white-footed mice and other small rodents. The adult tick lives on deer in the winter months when, except for an occasional hunter, few persons are infected.

“A tick has to be attached to a human for 18 to 24 hours or longer to transmit the disease to them,” Dr Passalacqua said.

Avoiding Tick-Borne Diseases

To avoid Lyme disease and ehrlichliosis, it is important to wear an effective repellent while outdoors. DEET is most effective when applied to skin; perethrin is to be applied only to clothing and is useful for gardeners and others who work outside all day.

“Perethrin kills ticks that walk across the fabric,” Dr Passalacqua said. “It lasts several days. DEET is incorporated into repellents at various strengths which determine how often they should be reapplied. The ideal percentage of DEET is 20 to 25 percent, which allows you to reapply it every three to four hours. If that bothers you, use 10 to 15 percent DEET but reapply it every 1 to 2 hours.”

Dr Passalacqua said that to avoid tick bites, brush and woodpiles should be clear away from houses, children should be encouraged to play in open areas, and hikers should stay on paths. “Wear long pants, long sleeves, hats – a lot of bites happen on scalps – and socks, with the pants tucked into the socks.”

A new Lyme vaccine, licensed a year and a half ago, is intended for healthy adults aged 15 to 70 and requires at least three doses. It reduces the risk of Lyme by about 70 percent.

“But 30 percent of those who receive the vaccine can still get Lyme, and it doesn’t work on ehrlichliosis at all,” Dr Passalacqua said.

 Before the vaccine was approved, it was studied in 15,000 volunteers, none of whom had serious side effects. But persons who have had acute Lyme disease should not be vaccinated. “Your immune system remembers the disease, and [the vaccine can cause] auto-immune effects weeks or months after treatment.”

With a three-injection series, the vaccine takes a year to reach maximum 70 percent effectiveness. An accelerated series of three shots in three months, with a booster a year later, provides faster immunity. But it is unknown how long the immunity lasts for either series, Dr Passalacqua said.

“Ticks can carry three different diseases,” she said. “There is a misconception that if you get the Lyme vaccine, you will be okay and don’t have to worry. I’m afraid we will start to see a lot of these others diseases.”