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It is possible that the main title of the report Babesiosis is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • Piriplasmosis
  • Redwater Fever

Disorder Subdivisions

  • None

General Discussion

Babesiosis is a rare infectious disease caused by single-celled microorganisms (protozoa) belonging to the Babesia family. It is believed that the Babesia protozoa are usually carried and transmitted by ticks (vectors). Babesiosis occurs primarily in animals; however, in rare cases, babesiosis infection may occur in humans. Certain Babesia species are known to cause babesiosis infection in humans (e.g., Babesia microti), and the deer tick is a known vector. Human babesiosis infection may cause fever, chills, headache, nausea, vomiting, and/or muscle aches (myalgia). Symptoms may be mild in otherwise healthy people; in addition, some infected individuals may exhibit no symptoms (asymptomatic). However, a severe form of babesiosis, which may be life-threatening if untreated, may occur in individuals who have had their spleens removed (splenectomized) or who have an impaired immune system. A different form of babesiosis has been reported in Europe that is associated with a more severe expression of symptoms.


Lyme Disease Foundation
P.O. Box 332
Tolland, CT 06084-0332

Centers for Disease Control and Prevention
1600 Clifton Road NE
Atlanta, GA 30333
Tel: (404)639-3534
Tel: (800)232-4636
TDD: (888)232-6348

NIH/National Institute of Allergy and Infectious Diseases
Office of Communications and Government Relations
6610 Rockledge Drive, MSC 6612
Bethesda, MD 20892-6612
Tel: (301)496-5717
Fax: (301)402-3573
Tel: (866)284-4107
TDD: (800)877-8339

World Health Organization (WHO)
Avenue Appia 20
Geneva 27, 1211
Tel: 41227912111
Fax: 41227913111

Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311
TDD: (888)205-3223

For a Complete Report:

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site or email

Last Updated: 4/8/2009
Copyright 1986, 1989, 1990, 1994, 2001, 2003, 2009 National Organization for Rare Disorders, Inc.

WebMD Medical Reference from the National Organization for Rare Disorders

Last Updated: May 28, 2015
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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