421. Babesiosis: Retrospective Review of 38 Cases from Upper Midwest
Session: Poster Abstract Session: Global Health and Travel Medicine
Thursday, October 4, 2018
Room: S Poster Hall
Background: Babesiosis is a tick-borne illness caused by protozoal infection of the genus Babesia. Clinical presentation varies widely from asymptomatic to rapidly fatal infection and diagnosis requires a high index of clinical suspicion. It is an emerging health risk and clinicians need to be aware of its different clinical manifestations.

Methods: We retrospectively collected and analyzed data from 38 patients with babesiosis from 1990-2015.

Results: Mean age of patients was 63 years. 68% of patients required hospitalization with 21% requiring intensive care unit (ICU) stay. Mean length of illness before diagnosis was 15.6 days and symptoms comprised of malaise (82%), subjective fever (71%), chills (55%), anorexia (29%), arthralgia (29%), and nausea (16%). Only 47% of the patients recalled tick bites. Mean hemoglobin in the outpatients was 12.4 g/dL compared to 9.8 g/dL in the hospitalized patients (p <0.01). Among hospitalized patients, mean hemoglobin for ICU admissions was 7.5 g/dL vs 10.9 g/dL (p<0.01) for those without ICU stay. Mean parasitemia was 10.1% in those requiring ICU compared to 1.4% in those admitted to the medical floor (p<0.01). 28.9% had Lyme disease, and 10.5% had anaplasma coinfection. Co-morbidities included diabetes mellitus (n=3), asplenia (n=5), and immunosuppression (n=3). Diagnosis was made with PCR and peripheral smear in 50% of patient whereas 50% were diagnosed with PCR alone. In 27% of patients with positive PCR, peripheral smear was negative. All patients with asplenia required hospitalization with 3/5 requiring ICU with initial parasitemia ranging from 2.5-28% and duration of parasitemia ranging from 10-142 days. Initial treatment comprised of clindamycin plus quinine in 31% of patients whereas combination of atovaquone and azithromycin was used in 69% of patients. Median duration of treatment was 10 days. Overall three patients underwent exchange transfusion with parasitemias ranging from 12.3-28.5%. None of the patients died during hospitalization.

Conclusion: Less than half of the patients with babesiosis recall tick bites. There is usually a delay in diagnosis of up to 2 weeks due to nonspecific nature of symptoms. In more than ¼ of patients with babesiosis peripheral smear may be falsely negative. Hemoglobin and percentage parasitemia seemed to correlate with severity of illness.

Madiha Fida, MD1, Ahmed Hamdi, MD1, Omar Abu Saleh, MD2 and John O'Horo, MD, MPH3, (1)Infectious Disease, Mayo Clinic, Rochester, MN, (2)Division of Infectious Diseases, Mayo Clinic, Rochester, MN, (3)Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN

Disclosures:

M. Fida, None

A. Hamdi, None

O. Abu Saleh, None

J. O'Horo, None

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