Babesiosis is a disease caused by an infection from the parasite Babesia. It can be transmitted by ticks but also by blood transfusion and congenitally – from infected mother to child. It was first discovered in cattle in 1888 in Romania, by Victor Babes. The first human cases were in 1957 in Croatia and in 1969 on Nantucket Island in the United States.

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Signs and Symptoms 

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Those infected with babesiosis may not present any symptoms. For those that do, the signs are similar to those of malaria. Fever and hemolytic anemia (destruction of the red blood cells) are the most common symptoms. Others can include fever, chills, headaches, fatigue, or nausea.

 

Babesiosis puts particular groups of people at risk: people who’ve had their spleen removed; those with immunodeficiencies such as HIV/AIDS or cancer patients; and the elderly. Signs of babesiosis can start developing between 1 and 4 weeks after a tick bite or between 1 and 9 weeks after an infected blood transfusion.

 

Diagnosis of babesiosis in humans is difficult since many laboratories don’t have the proper tests. It’s even thought that cases might be underreported. Patients are diagnosed, then, based on their symptoms and history of potential exposure to endemic tick areas or blood transfusion within the last 9 weeks.

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 What is the Bacterium that Causes Babesiosis?  

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Babesiosis is not caused by a bacterium but by a eukaryotic parasite, Babesia. Once they enter your body, these parasites reproduce inside your red blood cells, leading to their potential destruction. This is why those with weaker immune systems are more at risk if infected with babesiosis.  

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Like most tick-borne diseases, Babesiosis is transmitted from a host mammal, like a white-footed mouse, to a tick when the tick feeds on it. The tick then carries the Babesia parasites and transmits them when biting and feeding on humans or cattle. There are technically 4 main species of parasites that can cause babesiosis, with the most common one in New England being B. microti.

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Which Type of Tick Carries Babesiosis? 

 

The black-legged tick is the most common tick vector for babesiosis. This tick is prevalent throughout the Northeast United States, including Connecticut. The black-legged tick is also a known vector for Lyme disease, so sometimes this occurs in conjunction with babesiosis.

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Black-legged ticks are vectors for babesiosis in humans, but other tick species can spread the disease to animals. The brown dog tick, for example, can spread canine babesiosis through the parasite Babesia canis. The disease can also spread to cattle, who also develop hemolytic anemia if bitten by an infected tick. In areas where the parasite is endemic, farmers often cope with economic losses resulting in infected cattle.

 

Since the black-legged tick prefers wooded, shady areas, as well as forest-to-meadow transition zones, it’s best to avoid these areas to prevent infection. Black-legged ticks are also most likely to bite humans when they’re in the nymph stage of life – their pre-adult phase in which they’re much smaller and therefore harder to detect.

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Cures and Treatments 

 

Babesiosis is usually treated with a combination of atovaquone and azithromycin. This typically lasts 7- 10 days. Life-threatening cases will usually require a blood transfusion, in which the infected red blood cells are replaced with new ones. 

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Since some cases of the disease show no symptoms, they might go untreated. If the parasites are still present in your body after 3 months though, it’s usually recommended to seek treatment. In canine babesiosis, imizol is often used for treatment. See here https://vcahospitals.com/know-your-pet/babesiosis-in-dogs for more about canine babesiosis.  

 

Babesiosis is treatable, but it may be hard to detect. The CDC recommends that you visit a healthcare provider if you suspect you might have the disease. Your blood will be tested for the Babesia parasites by a specialized laboratory to confirm if you have it or not. To see more of the CDC’s info on babesiosis, head here. https://www.cdc.gov/parasites/babesiosis/

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Areas in Danger of Being Bitten 

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Babesiosis is prevalent in the northern Midwest and the Northeast of the United States, as well as Europe. Many cases have been reported near Long Island, Fire Island, Nantucket Island, and Martha’s Vineyard. In Connecticut, 309 cases of Babesiosis were reported in 2017. https://www.cdc.gov/parasites/babesiosis/data-statistics/index.html As mentioned, however, Babesiosis can be difficult to diagnose, so cases might exist and go unreported.

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Final Thoughts 

 

Since the black-legged tick and brown dog tick are commonly found throughout Connecticut, one of the best ways to protect yourself and your pets against Babesiosis is prevention. There is no vaccine available for Babesiosis, so taking precautions when venturing through tick habitats is a must. The CDC recommends using repellent and staying on cleared paths and trails, to avoid the leafy and shrubby areas where ticks might be. It’s also recommended to check for ticks daily after outdoor activities and before going back inside.

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Babesiosis is prevalent throughout the Northeast. While it is treatable, the best defense is always prevention.

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