Ehrlichiosis is a bacterial infection that results from an infected tick bite. It is closely related to another tick-borne disease, anaplasmosis, but the two are derived from different bacteria. The disease was first reported in the United States in 1999 and the highest number of cases are in states of the lower Midwest and the upper Southeast.

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Signs and Symptoms 

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Ehrlichiosis in humans generally presents flu-like symptoms. Aches, fever, chills, nausea, and vomiting are all acute symptoms that can show up between 1 and 2 weeks after being bitten by an infected tick. Sometimes a rash can occur, but it’s more common in children than in adults.

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Some of the late effects of ehrlichiosis can be severe if it’s left untreated. These could include kidney failure, heart failure, respiratory failure, seizures, and coma. It’s also possible in some cases that symptoms of ehrlichiosis don’t occur and the body’s immune system is strong enough to fight off the infection.

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Ehrlichiosis in dogs passes through 3 phases. In the first, acute phase, dogs have a fever, swollen lymph nodes, weight loss, or respiratory problems. The second phase, the sub-clinical phase, is when the infection has passed through the acute phase undetected and persists, without any outward signs. Clinical ehrlichiosis, the third phase, sees a failure of the dog’s immune system, leading to anemia, bleeding, eye problems, or swollen limbs. Check out this link https://vcahospitals.com/know-your- pet/ehrlichiosis-in-dogs for more info about ehrlichiosis in dogs.

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 What is the Bacterium that Causes Ehrlichiosis?  

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Ehrlichiosis is caused by three bacteria in the United States - Ehrlichia chaffeensis, E. ewingii, or E. muris eauclairensis. Most cases result from E. chaffeensis. These bacteria infect and kill the white blood cells or monocytes. For this reason, the disease is also referred to as “human monocytic ehrlichiosis.” The bacterium that infects dogs and causes canine ehrlichiosis is Ehrlichia canis.

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To be infected with these bacteria, you usually must be bitten by an infected tick. The tick gets the bacteria by feeding on a host, such as a white-tail deer, who carries the bacteria. The tick then falls off that host and seeks out another in the next phase of its lifecycle. Its next host, human or animal, becomes infected if the tick has latched on and started feeding for at least 24 hours.

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If you spot a tick on you, then, try to remove it as quickly as you can to reduce your chances of becoming infected. While both humans and dogs must be bitten by an infected tick to contract ehrlichiosis, it’s also rarely a result of blood transfusions or organ transplants.

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Which Type of Tick Carries Ehrlichiosis? 

 

E. chaffeensis and E. ewingii are carried by the lone star tick and E. muris eauclairensis is carried by the black-legged tick. The lone star tick is commonly found in southern and eastern states. It has, however, started making its way northward, and lone star tick populations were spotted in Connecticut in 2018. https://www.nejm.org/doi/full/10.1056/NEJMp1911661?query=featured_home

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The black-legged tick is prevalent throughout the eastern United States, in the Northeast and upper Midwest. It’s a vector for many tick-borne diseases, including Lyme disease and babesiosis. Ehrlichiosis in dogs is usually carried by the brown dog tick.

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Cures and Treatments 

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The decision of how to treat ehrlichiosis will depend on if its acute or late-stage. If it’s caught early, it’s fully treatable with antibiotics. To avoid severe health complications later on, it’s recommended by Mayo Clinic https://www.mayoclinic.org/diseases-conditions/ehrlichiosis/symptoms-causes/syc-20372142 to see a doctor if you start experiencing the symptoms of ehrlichiosis within two weeks of being bitten.

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The treatment for dogs with ehrlichiosis is also a course of antibiotics. If your dog is suffering from anemia, then a blood transfusion might be necessary as well.

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Areas in Danger of Being Bitten

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Cases of ehrlichiosis are more commonly reported in the mid-Atlantic and lower Midwest states than in the Northeast. Since the lone star tick, one of the main carriers for the disease has so recently arrived in Connecticut, there are not many cases reported – only 1 confirmed in 2019. https://portal.ct.gov/DPH/Epidemiology-and-Emerging-Infections/Ehrlichiosis

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But it’s still possible to contract tick-borne diseases from other tick species, like the black-legged tick. The best way to defend against these diseases is prevention. By avoiding potential tick habitats – bushy areas with lots of undergrowth in the case of lone star ticks – you lower your chances of being bitten.

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If you do venture into these areas, the CDC recommends using DEET repellent or treating your clothes with permethrin beforehand. https://www.cdc.gov/ehrlichiosis/prevention/index.html It’s also vital to check yourself and your pets once arriving home, before going back inside the house.

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Final Thoughts  

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Ehrlichiosis can be a severe disease if left untreated. As with all tick-borne illnesses, prevention is the most recommended way to avoid infectious tick bites. Know the risks associated with these parasites and take the proper precautions to protect yourself and your loved ones.

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