What are the symptoms of Babesia (Babesiosis) infection?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 16, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Babesia infection typically presents with flu-like symptoms, including fever, chills, sweats, myalgia, arthralgia, anorexia, nausea, vomiting, or fatigue, as reported in the clinical practice guidelines by the Infectious Diseases Society of America 1. The symptoms of babesiosis can range in severity from asymptomatic to rapidly fatal, with most patients experiencing a viral infection–like illness. Common symptoms include:

  • Fever
  • Chills
  • Sweats
  • Myalgia
  • Arthralgia
  • Anorexia
  • Nausea
  • Vomiting
  • Fatigue On physical examination, patients may exhibit:
  • Fever
  • Splenomegaly
  • Hepatomegaly
  • Jaundice Laboratory findings may include:
  • Hemolytic anemia with an elevated reticulocyte count
  • Thrombocytopenia
  • Proteinuria
  • Elevated levels of liver enzymes, blood urea nitrogen, and creatinine, as noted in the study published in Clinical Infectious Diseases 1. It is essential to note that the infection can range from asymptomatic to life-threatening, with some patients experiencing cyclical symptoms that wax and wane every few days. Prompt treatment is crucial, as babesiosis can become severe or even fatal if left untreated, especially in high-risk individuals.

From the Research

Symptoms of Babesia

The provided studies do not directly mention the symptoms of Babesia. However, they discuss the treatment and management of the disease, which can be related to its symptoms.

  • Severe disease may occur in immunocompromised individuals, resulting in prolonged relapsing disease or death 2.
  • The disease can cause significant health burden, especially on those who are immunocompromised and those who acquire the infection through blood transfusion, with death occurring in up to 20 percent of these groups 3.
  • An infant with Babesia microti infection presented with severe anemia, thrombocytopenia, and an increase in hepatic enzymes, in addition to being ill-appearing, febrile, and cyanotic 4.

Treatment and Management

Treatment for Babesia typically consists of:

  • Atovaquone and azithromycin or clindamycin and quinine 2, 5, 3.
  • Exchange transfusion in severe cases 3.
  • Prolonged treatment may be required for severe disease 2.

Resistance and Limitations

  • Resistance to atovaquone and azithromycin has been reported, associated with mutations in the binding regions of the target proteins of both drugs 6.
  • The current treatment options are limited and can be associated with mild or severe adverse events and a rapid emergence of drug resistance 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Management strategies for human babesiosis.

Expert review of anti-infective therapy, 2020

Research

Human babesiosis.

International journal for parasitology, 2019

Research

Atovaquone and azithromycin treatment for babesiosis in an infant.

The Pediatric infectious disease journal, 2007

Research

Treatment of Human Babesiosis: Then and Now.

Pathogens (Basel, Switzerland), 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.