If you are worried about a tick bite you may have received or are starting to get ill after being outdoors in woodland areas or areas with long grass, you may be wondering whether you may have contracted a tick-borne illness. In this article, we will discuss what ehrlichiosis is, how it can be caused, potential risk factors, and how to treat or prevent it.

Ehrlichiosis is a type of tick-borne illness which is caused by Ehrlichia bacteria. It is a condition that is rare in the United Kingdom, but it is usually found within the United States (USA) in woodland areas or areas with long grass. It often causes flu-like symptoms and can be easily treated if immediate medical attention is sought. However, if treatment is not sought immediately, serious complications can occur.

In this article, we will delve deeper into the causes, signs, risk factors, symptoms, and treatments. If you are looking for more information on the topic of ehrlichiosis, keep reading.

Overview

Human ehrlichiosis is an acute tick-borne illness that is usually caused by different members of the genus Ehrlichia.¹ The severity of the clinical manifestations can range from minor to potentially life-threatening.¹ Usually, ehrlichiosis patients recover within a few days if they seek medical treatment quickly. Unfortunately, there is currently no commercially available vaccine for human ehrlichiosis.² Therefore, it is essential that those who do notice a tick bite and are displaying flu-like symptoms immediately seek medical advice.

Causes of ehrlichiosis

The primary cause of ehrlichiosis is Ehrlichia bacteria which are carried by the Lone Star tick. This type of tick is usually found within south-central, southeastern and eastern-coastal states of the USA. A less common carrier of these bacteria is the black-legged tick (or deer tick). This type of tick is usually found in the upper Midwest.

Additionally, it is also possible for transmission to occur through being bitten by animals such as dogs, deer or coyotes that are infected with Ehrlichia bacteria.

Signs and symptoms of ehrlichiosis

Signs and symptoms of ehrlichiosis are usually mild at first. However, symptoms may become more severe, and even life-threatening if not treated quickly. Symptoms may begin as any of the following:

• Nausea
• Vomiting
• Diarrhea
• A loss of appetite
• Fatigue
• Cough
• Feelings of confusion
• Rashes (this occurs in about 30% of patients)
• Headaches which can be severe
• Muscle pain
• Stomach pains
• A high temperature
• Chills

Management and treatment for ehrlichiosis

Ehrlichiosis is usually treated using a course of doxycycline antibiotics. This should not be stopped until 3 days after a high temperature has subsided and symptoms of the disease have improved. Typically, a course of doxycycline for ehrlichiosis will last 5–7 days. However, more serious cases of this type of infection may not clear up so quickly and may require 2–3 weeks of doxycycline treatment.

Alternatively, those who are pregnant or are allergic to doxycycline antibiotics may be treated with rifampin antibiotics instead.

Diagnosis

Since ehrlichiosis is a tick-borne infection, a doctor or medical professional may initially perform a physical examination on the patient and try to identify any history of potential exposure to ticks or tick bites.

To perform a diagnosis for ehrlichiosis, a medical professional may also conduct various blood tests that indicate the presence of this infection. The blood tests that a medical professional may perform may look at:

• Low blood platelet cell count. Platelets are cell fragments which have the function of forming blood clots and preventing excessive bleeding
• Low white blood cell count. White blood cells are cells of the immune system which attack foreign cells that enter the body and thus protect the body from infection
• An elevation in liver enzyme levels indicates an abnormality in the function of the liver
• Specific antibodies which are created by your immune system in response to the infection
• Certain genes that are uniquely found within the Ehrlichiosa bacteria

Risk factors

Risk factors for tick bites which may transmit tick-borne infections such as ehrlichiosis include:

• Exposing skin that is not covered by clothing to woodland or bushy areas that may be infested with ticks
• Being outdoors in general in warm weather
• Participating in activities held in woodland areas

You may be at higher risk for complications resulting from an ehrlichiosis infection if:

• You are immunocompromised (for example, you may be living with HIV or cancer or be taking certain medicines which compromise the immune system)
• You have a chronic illness (for example diabetes)

How does ehrlichiosis affect the body?

Once the Ehrlichia bacteria enter the bloodstream following the bite of an infected tick, they act to destroy the white blood cells. White blood cells are a very important component of the immune system which act to defend against pathogens (foreign cells which are harmful to the body and can cause disease). With a lack of white blood cells, your body will struggle to fight any potential infection which you are exposed to. 

Complications

It is best to get ehrlichiosis treated as soon as possible since those who receive quick treatment usually recover within a few days. However, if ehrlichiosis is not treated quickly, the outcome can be severe. Almost 60% of patients are hospitalised, with 1% of cases being fatal.

Those who do not seek treatment may be at risk of developing serious complications³ such as:

• Septic shock syndrome
• Respiratory failure
• Heart failure
• Kidney failure
• Seizures
• Coma
• Haemorrhage
• Damage to the brain
• Central nervous system damage
• Severe secondary infections

FAQs

How can I prevent ehrlichiosis?

There are many ways you can prevent the contraction of ehrlichiosis via tick bites, such as:

• Keeping grass in the garden short
• Avoid walking through areas where the grass is very long
• If entering a woodland area, try to stay on a designated path and cover up with clothing
• Using bug sprays with at least 20-30% DEET
• Checking your skin for any tick bites if you have been outdoors or in high-risk areas. Ask someone to assist with areas you cannot assess yourself, such as your back
• Seeking advice for the safe removal of a tick immediately if you find one in your skin. The NHS website contains some helpful advice on how to safely remove a tick
• Seeking medical assistance quickly if you are concerned about ehrlichiosis

How common is ehrlichiosis?

Ehrlichiosis is rare in the United Kingdom. However, in the United States, 2,093 cases occurred in the year of 2019 according to the CDC.

When should I see a doctor?

Look for any signs or symptoms of ehrlichiosis if you have been bitten by a tick or have been in a high-risk area. If you display any symptoms of ehrlichiosis, contact a doctor or seek medical assistance immediately. Alternatively, you can call 111 to speak to the NHS 111 advice line.

You can make a list of questions you would like to ask your doctor or you can take notes into your consultation that will help you to explain all of your symptoms and what happened or where you have travelled to. This might help the doctor to investigate whether you have contracted ehrlichiosis.

When should I attend A&E?

You should visit the nearest A&E if you display the following symptoms:

• You are confused
• You have other abnormal mental changes
• Severe stomach pains
• Seizures
• You are coughing up blood

How soon after treatment will I start to feel better?

Your antibiotics will start to work within 24 to 48 hours. However, you must not stop taking your antibiotics, even if you feel better. If you find that you are not getting any better, you should contact your doctor or a medical professional for advice.

How else can I look after myself if I have ehrlichiosis?

To ensure that the infection does not return, you must ensure that you take all of the antibiotics, and try not to miss any doses.

You can also ask your doctor or medical professional what you can do to manage any symptoms that you are finding particularly uncomfortable. They may offer a specific painkiller to manage some of your symptoms.

Summary

Ehrlichiosis is a type of tick-borne infection caused by Ehrlichia bacteria. Those who spend a lot of time outdoors in woodland areas or in areas where there is long grass are most at risk. Even though recovery can take only a few days if you seek medical treatment quickly, you can develop severe complications if you do not seek treatment. Therefore, it is important to keep yourself protected with 20-30% DEET bug spray, avoid high-risk areas for ticks, and check your skin for any potential tick bites. If you are concerned that you may have been exposed to a tick bite, you can ask someone if they can check areas of your body where you are not able to do so, such as your back. In the event you do notice that you are developing symptoms for ehrlichiosis, and have spent time outdoors in high-risk areas or have noticed a tick bite, it is vital that you seek medical advice immediately.