Ehrlichiosis

Ehrlichiosis

Definition:

Ehrlichiosis is a bacterial illness transmitted by ticks that causes flu-like symptoms. 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 appropriate 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.


Symptoms:

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:

• Mild fever
• Headache
• Chills
• Muscle aches
• Nausea
• Vomiting
• Diarrhea
• Joint pain
• Confusion
• Rash
• Cough

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
It may take 14 days after a tick bite for you to begin showing signs and symptoms of ehrlichiosis. If you get symptoms within two weeks of a tick bite, see your doctor. If you experience any of the above symptoms soon after you've been in an area known to have ticks, see your doctor. Be sure to tell your doctor that you recently received a tick bite or visited an area with a high population of ticks.


Causes:

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.


Complications:

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:

• Kidney failure
• Respiratory failure
• Heart failure
• Seizures
• Coma

Treatments and drugs:

If your doctor suspects that you have ehrlichiosis or another tick-borne illness, you'll likely receive a prescription for the antibiotic doxycycline (Doryx, Periostat, others). You'll generally take the antibiotic 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 you're severely ill.

If you're pregnant, your doctor may prescribe the antibiotic rifampin (Rifadin, Rimactane) instead, because doxycycline isn't recommended during pregnancy.