Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Verywell / Emily Roberts
Babesiosis may not cause symptoms. The majority of people who are infected withBabesiaeither don’t feel sick (asymptomatic) or have only mild symptoms.
Common SymptomsIf a person does feel unwell, at first they may have nonspecific “flu-like” symptoms such as:A general sick feeling (malaise)Feeling tired or rundown (fatigue)Loss of appetite and nauseaFever, chills, and “cold sweats” (diaphoresis)Joint paint
Common Symptoms
If a person does feel unwell, at first they may have nonspecific “flu-like” symptoms such as:A general sick feeling (malaise)Feeling tired or rundown (fatigue)Loss of appetite and nauseaFever, chills, and “cold sweats” (diaphoresis)Joint paint
If a person does feel unwell, at first they may have nonspecific “flu-like” symptoms such as:
When symptoms do occur, they usually show up one to four weeks after exposure. Sometimes, it may be longer—up to six months.
Since ticks carrying diseases like babesiosis or Lyme disease infect when they are still very small and hard to see, it’s not unusual for a person to find out they have a tick-borne illness and not remember ever having a tick bite.
Babesiosis is also more common and can be more serious, in people who already have another tick-borne disease, such as Lyme.
Severe Symptoms
More severe cases of Babesiosis can include:
In these severe cases, babesiosis can last for months, if not years, and potentially be fatal if not treated.
Most otherwise-healthy people who become infected withBabesiamay not even know since they don’t feel sick. If they do get sick from babesiosis, symptoms are generally mild.
How to Recognize the Symptoms of Lyme Disease
Of the 100-some species ofBabesiaparasite, six seem to infect humans:
In the U.S., these ticks are mostly found (endemic) to New England and some states in the mid-to-northwest, including Washington, Minnesota, and California.Babesiosis casesoccur more frequently on several islands off the East Coast U.S. including Martha’s Vineyard, Long Island, Fire Island, and Nantucket Island.
Despite their name, deer ticks are not only found on deer. They may attach themselves to many wild and domestic animals, humans included. For example, a person may get a tick on them because it hitched a ride on their dog or from participating in outdoor activities like hiking or gardening in tall grass.
After a tick attaches itself to the skin and bites, it begins feeding on the blood supply of the host. If the tick is infected with theBabesiaparasite, the microorganism enters the bloodstream of the host as the tick feeds. A tick infected withB. microtineeds to stay attached for36–48 hoursto transmitBabesiato a host.
In very rare instances,Babesiahas been transmitted human-to-human viablood transfusion.
Anyone who lives in or visits an area where deer ticks are common and where cases ofBabesiainfection have been reported, especially if they work or play outside, are at risk for tick-borne illness.Babesiosis occurs in both men and women, of all ages and races. While it’s considered to be a rare infection, with only 16,456 reported cases between 2011 and 2019, since many people are asymptomatic, the true number of cases could be much higher.
Diagnostic TestsBlood tests to check for low blood cell counts (anemia, thrombocytopenia, leukopenia)Antibody tests to look forBabesiaantibodies in the bloodMicroscopic analysis of the red blood cells to look forBabesiaparasitesTests to rule out other infections that cause similar symptoms orconfirm co-occurring Lyme infectionOther blood tests to check the function of major organs (liver)Urine test (urinalysis) to assess kidney function
Diagnostic Tests
Blood tests to check for low blood cell counts (anemia, thrombocytopenia, leukopenia)Antibody tests to look forBabesiaantibodies in the bloodMicroscopic analysis of the red blood cells to look forBabesiaparasitesTests to rule out other infections that cause similar symptoms orconfirm co-occurring Lyme infectionOther blood tests to check the function of major organs (liver)Urine test (urinalysis) to assess kidney function
Other tests may be needed if the patient is very ill or has other health conditions.
A person with Babesiosis who doesn’t have symptoms or feel sick probably won’t go to the doctor. Usually,this is not a problem: in mild cases, the infection will resolve on its own (spontaneously) and not cause any long-term complications or health issues.
For people who do get sick, have conditions that compromise their immune system (HIV), or don’t have a spleen (asplenic), treatment for babesiosis usually begins as soon as they are diagnosed. The first-line treatment is antibiotic therapy.
Depending on the patient, several different antibiotics can be used. People are commonly treated withoneof the following two medication combinations:
To treat the initial illness and prevent complications, treatment may need to be more aggressive or go on longer in patients who don’t have a spleen, are elderly, and are immunocompromised.
In rare cases, if a person still has the parasite in their blood even after taking antibiotics as prescribed, they may need ablood transfusion—but this usually only happens when patients don’t have a spleen.
Babesiosis is treatable, even curable, but the best strategy is prevention. People who live in or are planning to visit areas where deer ticks are common can take several steps to help avoid tick bites that could potentially transmitBabesia.
Preventing BabesiosisDress in long-sleeved clothing, pants, and socks (tuck pants into socks or boots).Wear clothing that is light-colored, which makes ticks easier to see.When hiking, stay on cleared paths and avoid areas of tall grass.Check your pets for ticks and make sure they get flea and tick prevention medication regularly.Check yourself and family for ticks after working and playing outside; promptlyremove ticksif you find any.Use different types of tick-repellent, which can be applied to clothes and bare skin.
Preventing Babesiosis
Dress in long-sleeved clothing, pants, and socks (tuck pants into socks or boots).Wear clothing that is light-colored, which makes ticks easier to see.When hiking, stay on cleared paths and avoid areas of tall grass.Check your pets for ticks and make sure they get flea and tick prevention medication regularly.Check yourself and family for ticks after working and playing outside; promptlyremove ticksif you find any.Use different types of tick-repellent, which can be applied to clothes and bare skin.
If you start to feel sick within a few weeks or months after a tick bite, seek medical attention.
A Word From Verywell
Babesiosis is treatable, even curable, once diagnosed. The best strategy is prevention. If you’re living in or visiting an area where deer ticks are common or Babesiosis cases have been reported (throughout the Northeastern U.S. and some mid-and-northwestern states), be sure to wear light-colored, long-sleeved clothes when working or playing outside, use tick-repellents on skin and clothes, and check yourself, your family, and pets for ticks.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Kumar A, O’Bryan J, Krause PJ.The global emergence of human babesiosis.Pathogens. 2021;10(11). doi:10.3390/pathogens10111447Venigalla T, Adekayode C, Doreswamy S, Al-Sudani H, Sekhar S.Atypical presentation of babesiosis with neurological manifestations as well as hematological manifestations.Cureus. 2022;14(7):e26811. doi:10.7759/cureus.26811Sanchez E, Vannier E, Wormser GP, Hu LT.Diagnosis, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: a review.JAMA. 2016;315(16):1767-1777. doi:10.1001/jama.2016.2884Swanson M, Pickrel A, Williamson J, Montgomery S.Trends in reported babesiosis cases - United States, 2011-2019.MMWR Morb Mortal Wkly Rep. 2023;72(11):273-277. doi:10.15585/mmwr.mm7211a1Centers for Disease Control and Prevention.Clinical care of babesiosis.Additional ReadingCenters for Disease Control and Prevention.Babesiosis.NORD (National Organization for Rare Disorders).Babesiosis.Vannier E, Gewurz BE, Krause PJ.Human Babesiosis.Infectious Disease Clinics of North America. 2008;22(3):469-488. doi:10.1016/j.idc.2008.03.010.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Kumar A, O’Bryan J, Krause PJ.The global emergence of human babesiosis.Pathogens. 2021;10(11). doi:10.3390/pathogens10111447Venigalla T, Adekayode C, Doreswamy S, Al-Sudani H, Sekhar S.Atypical presentation of babesiosis with neurological manifestations as well as hematological manifestations.Cureus. 2022;14(7):e26811. doi:10.7759/cureus.26811Sanchez E, Vannier E, Wormser GP, Hu LT.Diagnosis, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: a review.JAMA. 2016;315(16):1767-1777. doi:10.1001/jama.2016.2884Swanson M, Pickrel A, Williamson J, Montgomery S.Trends in reported babesiosis cases - United States, 2011-2019.MMWR Morb Mortal Wkly Rep. 2023;72(11):273-277. doi:10.15585/mmwr.mm7211a1Centers for Disease Control and Prevention.Clinical care of babesiosis.Additional ReadingCenters for Disease Control and Prevention.Babesiosis.NORD (National Organization for Rare Disorders).Babesiosis.Vannier E, Gewurz BE, Krause PJ.Human Babesiosis.Infectious Disease Clinics of North America. 2008;22(3):469-488. doi:10.1016/j.idc.2008.03.010.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Kumar A, O’Bryan J, Krause PJ.The global emergence of human babesiosis.Pathogens. 2021;10(11). doi:10.3390/pathogens10111447Venigalla T, Adekayode C, Doreswamy S, Al-Sudani H, Sekhar S.Atypical presentation of babesiosis with neurological manifestations as well as hematological manifestations.Cureus. 2022;14(7):e26811. doi:10.7759/cureus.26811Sanchez E, Vannier E, Wormser GP, Hu LT.Diagnosis, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: a review.JAMA. 2016;315(16):1767-1777. doi:10.1001/jama.2016.2884Swanson M, Pickrel A, Williamson J, Montgomery S.Trends in reported babesiosis cases - United States, 2011-2019.MMWR Morb Mortal Wkly Rep. 2023;72(11):273-277. doi:10.15585/mmwr.mm7211a1Centers for Disease Control and Prevention.Clinical care of babesiosis.
Kumar A, O’Bryan J, Krause PJ.The global emergence of human babesiosis.Pathogens. 2021;10(11). doi:10.3390/pathogens10111447
Venigalla T, Adekayode C, Doreswamy S, Al-Sudani H, Sekhar S.Atypical presentation of babesiosis with neurological manifestations as well as hematological manifestations.Cureus. 2022;14(7):e26811. doi:10.7759/cureus.26811
Sanchez E, Vannier E, Wormser GP, Hu LT.Diagnosis, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: a review.JAMA. 2016;315(16):1767-1777. doi:10.1001/jama.2016.2884
Swanson M, Pickrel A, Williamson J, Montgomery S.Trends in reported babesiosis cases - United States, 2011-2019.MMWR Morb Mortal Wkly Rep. 2023;72(11):273-277. doi:10.15585/mmwr.mm7211a1
Centers for Disease Control and Prevention.Clinical care of babesiosis.
Centers for Disease Control and Prevention.Babesiosis.NORD (National Organization for Rare Disorders).Babesiosis.Vannier E, Gewurz BE, Krause PJ.Human Babesiosis.Infectious Disease Clinics of North America. 2008;22(3):469-488. doi:10.1016/j.idc.2008.03.010.
Centers for Disease Control and Prevention.Babesiosis.
NORD (National Organization for Rare Disorders).Babesiosis.
Vannier E, Gewurz BE, Krause PJ.Human Babesiosis.Infectious Disease Clinics of North America. 2008;22(3):469-488. doi:10.1016/j.idc.2008.03.010.
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