Ehrlichiosis is a bacterial illness transmitted by ticks that causes flu-like symptoms. Ehrlichiosis is most common in spring and summer, when ticks are active and you're more likely to be outdoors.
The signs and symptoms of ehrlichiosis range from mild body aches to severe fever and usually appear within a week or two of a tick bite. If treated quickly with antibiotics, ehrlichiosis generally improves within a few days.
Another tick-borne infection — anaplasmosis — is closely related to ehrlichiosis. But the two have distinct differences and are caused by different microorganisms.
The best way to prevent these infections is to avoid tick bites. Tick repellents, thorough body checks after being outside and proper removal of ticks give you the best chance of avoiding ehrlichiosis.
If a tick carrying the bacterium that causes ehrlichiosis has been feeding on you for at least 24 hours, the following flu-like signs and symptoms may appear within five to 14 days of the bite:
Some people infected with ehrlichiosis may have symptoms so mild that they never seek medical attention, and the body fights off the illness on its own. But untreated ehrlichiosis with persistent symptoms can result in an illness serious enough to require hospitalization.
When to see a doctor
Ehrlichiosis is caused by Ehrlichia chaffeensis bacteria and is transmitted primarily by the Lone Star tick.
Ticks feed on blood, latching onto a host and feeding until they're swollen to many times their normal size. During feeding, ticks that carry disease-producing bacteria can transmit the bacteria to a healthy host. Or they may pick up bacteria themselves if the host, such as a white-tailed deer or a coyote, is infected.
Usually, to get ehrlichiosis, you must be bitten by an infected tick. The bacteria enter your skin through the bite and eventually make their way into your bloodstream. Before bacteria can be transmitted, a tick must be attached and feeding for at least 24 hours. An attached tick with a swollen appearance may indicate that the tick has been feeding long enough to have transmitted bacteria. Removing ticks as soon as possible may prevent infection.
It's also possible that ehrlichiosis may be transmitted through blood transfusions, from mother to fetus and through direct contact with an infected, slaughtered animal.
Ehrlichiosis spreads when an infected tick, primarily the Lone Star tick, bites you and feeds on you for 24 hours or longer. The following factors may increase your risk of getting tick-borne infections:
Ehrlichiosis can have serious effects on an otherwise healthy adult or child if you don't seek prompt treatment.
People with weakened immune systems are at an even higher risk of more-serious and potentially life-threatening consequences. Serious complications of untreated infection include:
Preparing for your appointment
You're likely to first see your primary care physician or possibly an emergency room doctor, depending on the severity of your signs and symptoms. However, you may then be referred to a doctor who specializes in infectious diseases.
If you have time before your appointment to prepare, it's helpful to have certain information available. Here's what you can do to help get ready for your appointment, and what to expect from your doctor.
What you can do
Your time with your doctor may be limited, so preparing a list of questions can help you make the most of your time together. For erhlichiosis, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
Tests and diagnosis
Tick-borne infections are difficult to diagnose based solely on signs and symptoms because the signs and symptoms, such as fever and muscle aches, are similar to many other common conditions.
Abnormal findings on a number of blood tests may lead your doctor to suspect a tick-borne illness. If you have ehrlichiosis, your blood tests will likely show:
In addition, there are other possible blood tests that may be done if you live in an area where they are available. These tests include:
If you live in an area where ticks are common, your doctor may start you on antibiotics before the results of the blood tests return because earlier treatment results in a better outcome for some tick-borne diseases.
Treatments and drugs
If your doctor suspects that you have ehrlichiosis or another tick-borne illness, you'll likely receive a prescription for an antibiotic, such as doxycycline or tetracycline. You'll generally take the antibiotics for seven to 10 days and should see signs and symptoms begin to subside within two days. Your doctor may have you take antibiotics for a longer period if he or she believes you might be infected with Lyme disease as well.
If you're pregnant, your doctor may prescribe the antibiotic rifampin instead, because tetracycline and doxycycline aren't recommended during pregnancy.
Lifestyle and home remedies
If you find a tick on your body, don't be alarmed. If you remove the tick within 24 hours of its attachment, chances of transmission of ehrlichiosis or other tick-borne illnesses are slim. Follow these steps for safe removal of ticks:
The best way to steer clear of ehrlichiosis is to avoid tick bites.
Most ticks attach themselves to your lower legs and feet as you walk or work in grassy, wooded areas or overgrown fields. After a tick attaches to your body, it usually crawls upward to find a location to burrow into your skin. You may find a tick on the back of your knees, groin, underarms, ears, back of your neck and elsewhere.
If you remove a tick in the first 24 hours after attachment, you reduce your risk of infection. While you may not be able to avoid going into areas where ticks are present, the following tips can make it easier to discover and remove ticks before they attach to your skin:
Last Updated: 2010-04-17
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