A series of cases in the Northeast of the US during 2013–2015 described a new Borrelia species, Borrelia miyamotoi, which is transmitted by the same tick species that transmits Lyme disease and causes a relapsing fever-like illness. The geographic expansion of B. miyamotoi in the US also extends to other Lyme endemic areas such as the Midwestern US. Co-infections with other tick borne diseases (TBD) may contribute to the severity of the disease. On Long Island, NY, 3–5% of ticks are infected by B. miyamotoi, but little is known about the frequency of B. miyamotoi infections in humans in this particular region. The aim of this study was to perform a chart review in all patients diagnosed with B. miyamotoi infection in Stony Brook Medicine (SBM) system to describe the clinical and epidemiological features of B. miyamotoi infection in Suffolk County, NY. In a 5 year time period (2013–2017), a total of 28 cases were positive for either IgG EIA (n = 19) or PCR (n = 9). All 9 PCR-positive cases (median age: 67; range: 22–90 years) had clinical findings suggestive of acute or relapsing infection. All these patients were thought to have a TBD, prompting the healthcare provider to order the TBD panel which includes a B. miyamotoi PCR test. In conclusion, B. miyamotoi infection should be considered in the differential diagnosis for flu-like syndromes during the summer after a deer tick bite and to prevent labeling a case with Lyme disease.

Background Current literature presents conflicting results regarding the clinical manifestations of coinfection with Babesia microti (Babesiosis) and Borrelia burgdorferi (Lyme disease). The aim of this study is to investigate the effect that coinfection with Babesiosis and Lyme Disease has on standard and novel biomarkers markers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and procalcitonin (Pc), which may assist in elucidating how these pathogens interact within human hosts. Methods Babesia cases were collected from Stony Brook University Hospital from 2012 to 2019. Cases of Babesia were included if parasites were detected by peripheral blood smear and confirmed by PCR. Lyme disease diagnosis criteria involved 2-tier testing per CDC guidelines. Cases were divided into three cohorts based on if they had CRP, ESR or Pc tested. Cohorts were divided into two groups: Babesiosis alone vs coinfection with Lyme Disease. Median values were analyzed for the following biomarkers across both groups: parasitemia, hemoglobin (Hgb), white blood cells (WBC), platelets, indirect bilirubin (IB), lactate dehydrogenase, ESR, CRP and Pc. Fisher Exact and Wilcoxon Rank sum tests were used and P values < 0.05 were considered statistically significant. Results ESR values trended higher in monoinfection compared to coinfection (50 vs 36 mm/hr, p=0.63). Within this cohort, the coinfection group had significantly lower platelet values compared to monoinfection (52 vs. 75.5 K/uL, p=0.04, Table 1). Within the CRP and Pc cohorts, monoinfection had higher trends of parasitemia compared to coinfection (CRP group: 1.6 vs 0.7%, p=0.14, Pc group: 1.4 vs 0.7% p=1.0, Table 2&3). Pc levels were similar in both groups (1.1 vs 1.2 ng/mL, p=1.0, Table 3). Table 1: Demographics and Biomarkers for Patients with Babesiosis Monoinfection vs. Coinfection with Babesiosis and Lyme Disease that had ESR Measured. Table 2: Demographics and Biomarkers for Patients with Babesiosis Monoinfection vs. Coinfection with Babesiosis and Lyme Disease that had CRP Measured. Table 3: Demographics and Biomarkers for Patients with Babesiosis Alone vs Coinfection with Babesiosis and Lyme Disease that had Procalcitonin Measured. Conclusion Coinfection had significantly lower platelets within the ESR cohort but not in other cohorts. While not statistically significant, monoinfection showed greater trends of ESR and parasitemia, which is consistent with previous studies that suggest that B. burgdorferi may mitigate the effects of B. microti infection. CRP and Pc levels were similar across both groups suggesting that the utility of using novel biomarkers to elucidate the interaction between B. burgdorferi and B. microti during simultaneous infection requires further study. Disclosures All Authors: No reported disclosures

Background Research is currently lacking on the interplay between Babesiosis and Lyme disease (LD) and how this coinfection may translate into morbidity and mortality. The aim of this study is to compare the clinical features of patients with single-infection with Babesia microti to those co-infected with Borrelia burgdorferi and Babesia microti. Methods A retrospective review of all adult patients diagnosed with babesiosis and tested for LD at Stony Brook University Hospital between 2014 and 2019 was performed (n=40). Patients with single babesia infection (Group 1, n=22) were compared to those with Babesia and LD (Group 2, n=18). Babesiosis diagnosis was determined by microscopic visualization of Babesia spp under peripheral blood smear, and confirmed by PCR for B. microti. LD inclusion criteria included a positive screened ELISA test for lyme followed by positive IgM antibody by western blot per CDC criteria (2-3 positive bands). Statistical analysis of the data involved Fisher exact test, Chi-square test, independent t-test, and Wilcoxon rank sum tests. Statistical significance was considered as a p-value less than 0.05. Results There was no significant difference in gender, race, and age (p >.75) between both groups as well as comorbidities including hypertension, diabetes, heart conditions, and immunocompromised state (p=1.0). Maximum parasitemia (Group 1: 1.1%, Group 2: 1.7%, p= 0.26) and percentage admitted to the ICU (Group 1: 18.18%, Group 2: 22.22%, p=1.0) were similar among both groups. While lab values on admission including WBC, hemoglobin, platelets, LDH, ALT, and AST did not significantly differ (p >.09), the length of hospital stay in group 2 was significantly longer than group 1 (Group 1: 3.0 days, Group 2: 5.5 days; p=0.03). There was a 0% mortality rate among both groups. Table 2: Biomarkers of Patients Monoinfected with Babesiosis Versus Patients Coinfected with Babesiosis and Lyme Disease. Table 1: Demographics of Patients Monoinfected with Babesiosis Versus Patients Coinfected with Babesiosis and Lyme Disease. Conclusion It is remarkable that despite no differences in lab values on admission, comorbidities, and demographics, patients with a coinfection had a longer hospital stay than those with only babesiosis. This suggests that having a coinfection with babesiosis and LD may lead to a more severe illness than a single infection with babesiosis. Disclosures All Authors: No reported disclosures