Other Tick-Borne Diseases

Black-legged ticks can transmit pathogens that cause other diseases in addition to, or instead of, Lyme disease. These diseases are called “other tick-borne diseases” or, when you get them along with Lyme disease, co-infections. Though not as common as Lyme disease, other tick-borne diseases are on the rise and can be serious, so it is important to be aware of them.

If you are bitten by a tick, make sure you ask your doctor about the possibility of other tick-borne diseases, not just Lyme disease. Tell your doctor about all your symptoms — they can provide clues about which tests you need, because Lyme disease tests only look for Lyme disease.

Getty Images

Other diseases spread by black-legged ticks may have some symptoms in common with Lyme disease and with one another. Treatment may also overlap: for example, several tick-borne diseases are treated with the same antibiotics as Lyme disease.

Other tick-borne diseases do not respond to the same medications and will not improve without appropriate treatment. Another difference is transmission time, which refers to how long a tick needs to be attached to you in order to transmit the disease-causing pathogen. Transmission time for tick-borne pathogens can range from minutes to days.

Getty Images

There are also many other types of ticks in the U.S. that spread other diseases. We’ll focus first on the diseases carried by black-legged ticks. Later in the section we’ll discuss other ticks found in the U.S., and diseases they can cause. It’s good to be aware of other ticks that you might encounter where you live or when you travel.

Black-legged ticks can spread the following diseases.

What causes it?

The bacteria Anaplasma phagocytophilum

Where is it most common?

In the Northeast and mid-Atlantic U.S., from northeastern Virginia to Maine; in North Central states like Wisconsin and Minnesota; and on the West Coast, particularly in northern California.

How quickly can it be transmitted to humans from a black-legged tick?

In most cases, the tick must be attached to a person for at least 12 to 24 hours to transmit the bacteria that causes anaplasmosis.

What are common symptoms?

• fever

• chills

• shaking

• severe headache

• malaise (a general feeling of discomfort or feeling unwell)

• muscle pain

• nausea, vomiting, diarrhea, or loss of appetite

• cough.

• If not diagnosed and treated early, anaplasmosis can lead to serious illness and even death.

How long does it typically take for symptoms to appear?

Five to 14 days after a tick bite.

Is treatment the same as for Lyme disease?

Yes. Both are usually treated with an antibiotic called doxycycline.

What causes it?

Babesia (various types, most typically Babesia microti), a parasite that infects the red blood cells.

Where is it most common?

Mostly in the Northeast and upper Midwest, especially in New England, New York, New Jersey, Wisconsin, and Minnesota.

How quickly can it be transmitted to humans from a black-legged tick?

In most cases, the tick must be attached to a person for at least 36 hours to transmit the parasite that causes babesiosis.

What are common symptoms?

Some people with babesiosis have no symptoms. Others may experience:

• fever

• chills

• sweats, particularly night sweats

• malaise (a general feeling of discomfort or feeling unwell)

• fatigue

• muscle and joint pains

• headache

• loss of appetite, nausea (less common: abdominal pain, vomiting)

• hemolytic anemia (a type of anemia where red blood cells are destroyed faster than the body can replace them; symptoms include tiredness, dizziness, weakness, dark urine, a yellowing of the skin and whites of the eyes, and a spleen or liver that is larger than normal).

Babesiosis can be serious and even fatal for people who do not have a spleen; older adults; those with weakened immune systems due to conditions like cancer or HIV; and those with other serious health conditions like liver or kidney disease.

How long does it typically take for symptoms to appear?

One to nine weeks or longer.

Is treatment the same as for Lyme disease?

No. Babesiosis is usually treated either with different antibiotics, or with a combination of an antibiotic and an anti-malarial medication.

What causes it?

The bacteria Borrelia miyamotoi. This is a different species of the bacteria that causes Lyme disease.

Where is it most common?

The Upper Midwest, the Northeast, and the mid-Atlantic states.

How quickly can it be transmitted to humans from a black-legged tick?

A tick can transmit the bacteria that causes Borrelia miyamotoi disease within 24 hours of attaching to a person.

Borrelia miyamotoi disease can be transmitted by larval black-legged ticks, which are smaller and in an earlier life stage than the nymphal and adult black-legged ticks that typically spread the Lyme disease bacteria. As with other tick-borne diseases, you may develop symptoms of Borrelia miyamotoi disease without ever noticing a tick or tick bite.

What are common symptoms?

• fever

• chills

• headache

• body and joint pain

• fatigue

How long does it typically take for symptoms to appear?

Days to weeks after a tick bite.

Is treatment the same as for Lyme disease?

Borrelia miyamotoi disease can be treated with the same antibiotic, doxycycline, used to treat Lyme disease, though you may need to take it for a longer amount of time. It is also sometimes treated with other antibiotics.

What causes it?

The bacteria Ehrlichia muris eauclairensis. (Ehrlichiosis transmitted by the lone star tick is discussed in Other types of ticks and the diseases they spread, below).

Where is it most common?

The Upper Midwest.

How quickly can it be transmitted to humans from a black-legged tick?

In most cases, a tick must be attached to a person for about 24 hours to transmit the bacteria that cause ehrlichiosis.

What are common symptoms?

• fever

• chills

• headache

• malaise (a general feeling of discomfort or feeling unwell)

• muscle pain

• nausea, vomiting, diarrhea, or loss of appetite

• confusion

• rash (more common in children)

How long does it typically take for symptoms to appear?

One to two weeks after a tick bite.

Is treatment the same as for Lyme disease?

Yes. Both are usually treated with an antibiotic called doxycycline. The length of treatment may be different for ehrlichiosis and Lyme disease.

What causes it?

The Powassan virus.

Where is it most common?

In the Northeast and Great Lakes regions, particularly Massachusetts, New York, Minnesota, and Wisconsin. (See Other types of ticks and the diseases they spread for information about Powassan virus spread by other ticks in the U.S.).

How quickly can it be transmitted to humans from a black-legged tick?

A tick can transmit the virus that causes Powassan virus disease within 15 minutes of attaching to a person.

What are common symptoms?

Many people with Powassan virus don’t experience symptoms, but early symptoms can include

• fever

• headache

• vomiting

• weakness

Powassan virus can become severe, causing encephalitis (infection of the brain) or meningitis (swelling of the membranes that surround the brain and spinal cord). In some cases, Powassan virus disease can be fatal.

How long does it typically take for symptoms to appear?

One to two weeks after a tick bite.

Is treatment the same as for Lyme disease?

There is currently no treatment for Powassan virus. People with severe Powassan virus are often hospitalized for symptom management.

Different types of ticks are found in various parts of the U.S. All of these ticks look a little different and can spread pathogens that cause different diseases.

Tell your doctor if you are bitten by any type of tick. If you can, take a photo of the tick, to help you and your doctor determine what kind of tick it is.

The following table can help you identify different types of ticks and the diseases they can spread. If you are bitten by a tick, ask your doctor if you should be tested for diseases the tick could have been carrying, and what symptoms you should watch for.