Babesiosis

From Anvita Health Wiki

Contents 1 Etiology 2 Epidemiology 3 Pathology 4 Clinical-manifestations 5 Laboratory 6 Complications 7 Management 8 More General Terms 9 Additional Terms 10 References

Etiology

• protozoan infection with Babesia species

Epidemiology

• Babesia microti in northeastern & midwestern states

• transmitted by:

• Ixodes dammini, the same tick that transmits Lyme disease & possibly ehrlichiosis
• Ixodes scapularis

• Babesia species (WA-1) in western states

• transmitted by western black-legged tick Ixodes pacificus

• Babesia divergens in Euorope

• canine parasite
• transmitted by Ixodes ricinus

• transfusion-related cases in USA [4]

Pathology

• parasitic infection of erythrocytes
• parasitemia varies from 1-80% of erythrocytes
• parasites multiply within erythrocytes by schizogony
• co-infection with Borrelia burgdorferi &/or Ehrlichia

Clinical-manifestations

• generally asymptomatic
• severe infections in asplenic & immunocompromised patients including:

• elderly
• patients with malignancy
• patients receiving immunosupressive agent(s)

• malarial-like symptoms

• fever
• chills
• sweats
• headache
• malaise
• hemolytic anemia
• no recognizable periodicity

Laboratory

• completed blood count ( CBC) anemia
• Wright-stained peripheral blood smear obtained during a chill

• trophozoites appear as multiple ring forms within RBC that may form a tetrad ( maltese cross)
• no large growing trophozoites or gametocytes
• no hemozoin pigment present in Plasmodium- infected cells
• schistocytes

• serology:

• serology for malaria is negative in babesiosis
• patients with malaria may cross-react with babesia serology
• fluorescent antibody (IFA)

• polymerase chain reaction ( PCR)
• urinaylsis: hemoglobinuria

Complications

• renal failure
• death

Management

• infections are generally self-limited in patients with intact spleens without treatment
• pharmaceutical agents

• clindamycin 600 mg PO TID or 1.2 g IV BID
• quinine sulfate 650 mg PO TID
• either agent in patients with normal immunity, both in immunocompromised patients
• atovaquone 750 mg BID plus azithromycin 500-1000 mg QD when quinine & clindamycin fail
• duration of therapy 7-10 days, may not completely eliminate parasites

• exchange transfusions in seriously ill patients

More General Terms

• protozoan infection

Additional Terms

• Babesia microti
• gametocyte
• malaria
• schizogony
• trophozoite

References

1. Medical Knowledge Self Assessment Program (MKSAP) 11, 15, American College of Physicians, Philadelphia 1998, 2009
2. Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 1264-65
3. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, 1188
4. Herwaldt BL et al. Transfusion-associated babesiosis in the United States: A description of cases. Ann Intern Med 2011 Sep 5 PMID: [1]
   - Leiby DA. Transfusion-associated babesiosis: Shouldn't we be ticked off? Ann Intern Med 2011 Sep 5 PMID: [2]
5. National Guideline Clearinghouse Infectious Diseases Society of America practice guidelines for clinical assessment, treatment and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis. ngc-guideline: [3]

babesiosis