Relapsing Babesiosis With Molecular Evidence of Resistance to Certain Antimicrobials Commonly Used to Treat Babesia microti Infections

Luis A Marcos; Gary P Wormser

doi:10.1093/ofid/ofad391

Relapsing Babesiosis With Molecular Evidence of Resistance to Certain Antimicrobials Commonly Used to Treat Babesia microti Infections

Open Forum Infect Dis. 2023 Jul 20;10(8):ofad391. doi: 10.1093/ofid/ofad391. eCollection 2023 Aug.

Authors

Luis A Marcos^{1

2}, Gary P Wormser³

Affiliations

¹ Division of Infectious Diseases, Department of Medicine, Stony Brook University, Stony Brook, New York, USA.
² Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA.
³ Division of Infectious Diseases, New York Medical College, Valhalla, New York, USA.

Abstract

Human babesiosis cases are emerging with an increased incidence and a wider geographic range worldwide. Relapsing babesiosis cases are becoming more frequently encountered in clinical practice associated with the use of immunosuppressive medications. The 2020 Infectious Diseases Society of America babesiosis guideline recommends at least 6 weeks of antimicrobial treatment for highly immunocompromised patients with Babesia microti infection. Nevertheless, cases have relapsed even after 6 weeks of treatment. Genetic mutations regarded as the potential cause of antimicrobial resistance in B microti have been identified in certain relapsing cases. A few alternative antimicrobial regimens have been used successfully to achieve cure for some of these cases, but other cases have had fatal outcomes. In this review, we discuss the molecular evidence of genetic resistance to certain antimicrobials commonly used to treat B microti infections based on an evaluation of 9 patients with relapsing infection.

Keywords: Babesia microti; babesiosis; persistent babesiosis; relapsing babesiosis; resistance.

Publication types

Review