Tick, Tick, Tick: It’s Lyme Time

May 18, 2015

Warmer weather has arrived, and with it the season of tick-borne illnesses. Here’s the latest about Lyme disease and some surprising new scourges of spring.

Warmer weather has arrived, and with it the season of tick-borne illnesses. Here’s the latest about Lyme disease and some surprising new scourges of spring.

Lyme Statistics Do Lie

About 300,000 Americans receive a diagnosis of Lyme disease each year.

More than 30,000 cases of Lyme disease are reported to the CDC annually, making it the most commonly reported tick-borne illness in the United States.

The actual number of persons who receive a diagnosis of Lyme disease may be roughly 10 times higher than the reported number.

Survey Says: More Work Needs to Be Done

Although most Americans appear to have a basic knowledge of Lyme disease, more than half do nothing to reduce the risk of tick bites during warm weather.

Just more than one-fifth of survey respondents said a tick was found on the body of a household member in the previous year; only 11% consulted a doctor.

Other reported activities: about one-third perform regular tick checks, 21% use insect repellents, 15.7% shower to prevent tick bites, 51.2% do nothing.

Close to two-thirds of respondents said Lyme disease occurs in their area. But many lived in regions where the disease does not occur.

Finer Points of Lyme Diagnosis

Lyme disease diagnosis may be challenging because many of the symptoms are similar to those of other illnesses, such as the flu.

The bull’s eye rash is unique to Lyme disease, but it does not develop in everyone infected with Lyme bacteria.

A tick must be attached to the body for at least 36 hours to transmit Lyme disease.

Transmission cannot occur without the tick bite, but many persons may not remember being bitten.

Putting Lyme to the Test

If a person has Lyme disease symptoms but does not have the rash, clinicians may rely on the medical history:

-whether symptoms first appeared during the summer months.

-whether the person had been outdoors in an area where Lyme disease is common.

-whether the person was bitten by a tick.

Laboratory tests may be conducted to check for the presence of antibodies to Borrelia burgdorferi, which are produced after a few weeks.

The CDC does not recommend a Western blot test without conducting a first-level blood screening. Using the Western blot alone increases the potential for false-positive results.

Lyme Treatment Breeds Rapid Recovery

Patients treated in the early stages of Lyme disease with appropriate antibiotics usually recover rapidly and completely.

Doxycycline, amoxicillin, and cefuroxime axetil are frequently used antibiotics for oral treatment.

Intravenous treatment with ceftriaxone, penicillin, or other drugs may be required for patients with some neurological or cardiac forms of illness.

For detailed recommendations on treatment, see the Infectious Diseases Society of America’s 2006 clinical practice guidelines for treatment.

Powassan Virus Has Powerful Bite

In addition to Lyme disease, ticks can carry the rare but deadly Powassan virus (POW). Ticks with the virus have been found in New Jersey and Connecticut.

Symptoms may be Lyme-like, such as fever, rash, and headache, but also include vomiting, confusion, seizures, and memory loss. POW can cause deaths.

An estimated 60 cases of POW have been reported in the United States over the past 10 years.

Currently there is no vaccine to treat patients with POW.

Don’t Let New Tick-borne Disease Get Your Goat!

A newly discovered bacterial species, Anaplasma capra, is transmitted by the taiga tick, which is closely related to the deer tick.

The illness could be a “substantial health threat” to humans and animals in areas where the tick is common-Eastern Europe and across Russia and Asia, including China and Japan.

In China, the species appears to be common in goats, although it also may infect other animals.

Diagnosis of infection is difficult because there is no simple blood test. Symptoms include fever, headache, tiredness, dizziness, and muscle aches.

Researchers successfully treated the infection with antibiotics.

Other Things You Should Know About Tick-borne Diseases

Tick-borne infections may be confused with other childhood illnesses-the initial clinical findings are nonspecific and patients may not be aware of their preceding tick exposures.

Adverse outcomes from the infections, especially Rocky Mountain spotted fever (RMSF), are more likely with delays in starting antibiotic therapy.

Therapy should be started presumptively for patients in whom RMSF is a reasonable diagnostic consideration.

Doxycycline is the drug of choice for RMSF and other American rickettsial infections. Concerns over possible toxicity of doxycycline in young children are unfounded.

Insect repellents that contain DEET are safe and effective for preventing tick exposures when used appropriately.