Babesia microti-induced fulminant sepsis in an immunocompromised host: A case report and the case-specific literature review

A Presentation of Babesiosis in the Setting of Low-Grade Follicular B-cell Lymphoma

Babesiosis is a tick-borne parasitic infection seen in the Northeast and upper Midwest regions of the United States. Clinically, this intra-erythrocytic parasitic infection can present in a variety of ways, including fever, fatigue, malaise, or myalgia. Of note, these presenting symptoms are very similar to symptoms that can also be seen in patients with low-grade lymphoma. Thus, differentiating between babesiosis infection and active, symptomatic low-grade lymphoma can be difficult. We present a patient with concurrent severe babesiosis infection and follicular lymphoma. This case report provides a unique overlap of Hematology/Oncology and Infectious Disease and the ensuing diagnostic challenges when both tick-borne illnesses and low-grade lymphoma present together. We suggest including babesiosis screening in the pretreatment evaluation for the use of rituximab in patients with the above symptomatology and geography. This will help rule out alternate confounding diagnoses of babesiosis infection before initiating immunosuppressive treatment for active, symptomatic low-grade lymphoma. Using immunosuppressive agents such as rituximab to treat suspected low-grade lymphoma, before ruling out tick-borne illnesses, can be harmful. Our goal is to reduce such instances.

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

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.

Reduced Cholesterol Levels during Acute Human Babesiosis

BACKGROUND

Babesiosis, an intra-erythrocytic protozoan disease, is an emerging zoonotic parasitic disease worldwide. Cholesterol levels are correlated with severe infections, such as sepsis and COVID-19, and anecdotal reports suggest that high-density lipoprotein (HDL) cholesterol declines during acute babesiosis. Our aim was to describe the cholesterol levels in patients with acute babesiosis diagnosed in an endemic area in New York, hypothesizing that HDL levels correlate with the severity of infection.

METHODS

We reviewed the medical records of adult patients with babesiosis diagnosed by identification of Babesia parasites on a thin blood smear and confirmed by polymerase chain reaction from 2013 to 2018, who also had available a lipid profile drawn at the time of clinical presentation. Additional lipid profile levels were considered as "baseline" if they were drawn within 2 months before or after the infection as part of routine care.

RESULTS

A total of 39 patients with babesiosis had a lipid profile drawn on presentation. The patients were divided into two groups for comparison based on the treating physician's clinical decision: 33 patients who were admitted to the hospital and 8 patients who were evaluated as outpatients. A history of hypertension was more common in admitted patients (37% vs. 17%, p = 0.02). The median levels of low-density lipoprotein (LDL) and HDL were significantly reduced in admitted patients compared to non-admitted patients (46 vs. 76 mg/dL, p = 0.04; and 9 vs. 28.5 mg/dL, p = 0.03, respectively). In addition, LDL and HDL levels returned to baseline values following resolution of acute babesiosis.

CONCLUSION

LDL and HDL levels are significantly reduced during acute babesiosis, suggesting that cholesterol depletion may predict disease severity. Pathogen and host factors may contribute to a reduction in serum cholesterol levels during acute babesiosis.