Abstract Background Cryptosporidium is a parasitic protozoan that causes severe and potentially life-threatening diarrheal disease in immunocompromised patients. Infections can be asymptomatic, cause self-limited disease, or chronic diarrhea and in some cases result in biliary and pulmonary disease Methods We performed a detailed retrospective analysis of patients that presented with diarrheal illness, and Cryptosporidium infection diagnosed by GI multiplex (Biofire) at UT MD Anderson Cancer Center between January 2017 and March 2023. Results We identified 51 patients aged 24 to 89 years with cryptosporidiosis. Hematological malignancies (HM) were present in 44% of patients, while non-hematological malignancies (NHM) in 55%. Thirty-seven percent of patients had received hematopoietic stem cell transplantation (HSCT), 8% chimeric antigen receptor T-cell (CAR-T) therapy, 18% immunosuppressive therapy, and 65% received chemotherapy in the last 90 days. Two patients had human immunodeficiency virus (HIV). All patients presented with diarrhea, 39% with nausea, 43% with abdominal pain, and 51% had fever. The median duration of symptoms was 3 days. About 41% were severely neutropenic, and 61% had severe lymphopenia. Computed tomography (CT) abdomen was normal in 43% of patients, 16% had colitis, 12% had enteritis, and 4% had enterocolitis. All patients were treated with Nitazoxanide, with a median duration of therapy (DOT) of 14 days. The DOT was longer in HM than in NHM (14 ± 7.9 vs. 9.9 ± 5.6, p= 0.016) and in HSCT/CAR-T patients than without HSCT/CAR-T (13.8 ± 6.1 vs. 10.3 ± 7.3, p = 0.009). About 18% of patients had co-infections with other enteropathogens. Death from other causes occurred in 13 of 51 (23%) of patients. All cause mortality between HM and NHM (p=0.207), HSCT/CAR-T and non-HSCT/CAR-T (p=0.52), or chemotherapy vs. without chemotherapy (p=0.34) was similar. Most infections were encountered in the month of October. Conclusion We observed a limited response to nitazoxanide at our center, contributing factors and confounders included co-infections with other pathogens, active chemotherapy, or HSCT/CAR-T induced intestinal epithelium injury. Controlled, double blinded studies with new agents are needed to determine the optimal management of cryptosporidiosis in this population. Disclosures Pablo C. Okhuysen, M.D., FACP, FIDSA, Astra Zeneca: Stocks/Bonds|Beam Therapeutics: Stocks/Bonds|Biontech: Stocks/Bonds|Deinove Pharmaceutucals: Grant/Research Support|Ferring: Advisor/Consultant|GSK PLC: Stocks/Bonds|Haleon: Stocks/Bonds|Johnson and Johnson: Stocks/Bonds|Melinta Pharmaceuticals: Grant/Research Support|Merk Sharp and Dohme: Grant/Research Support|Moderna: Stocks/Bonds|Napo Pharmaceuticals: Advisor/Consultant|Napo Pharmaceuticals: Grant/Research Support|Novavax: Stocks/Bonds|Pfizer: Stocks/Bonds|SNIPR Biome: Advisor/Consultant|Summit Pharmaceuticals: Grant/Research Support

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.

Mann, Inderjit MD; Froehlich, Morgan PharmD; Bailey, Lisa RN, BSN, MS, CIC; Psevdos, George MD; Lobo, Zeena MD Author Information

Abstract Background Anti-SARS-CoV-2 monoclonal antibodies (mABs) target the viral spike protein and have been shown to have clinical benefit in treating COVID-19. The FDA had given emergency use authorization to mAB products: bamlanivimab+etesevinab (BAM), casirivimab+imdevimab (CAS), sotrovimab (SOT). However, due to reduced activity against the omicron variant the FDA recommended against use of BAM and CAS. SOT has retained efficacy against omicron. We reviewed the utilization of mABS in our institution during the pandemic as delta variant was replaced by omicron. Methods Retrospective chart review of US Veterans (USV) with confirmed SARS-CoV-2 infection who received mABs from 9/1/2021 to 2/28/22 at Northport Veterans Affairs Medical Center. Demographic data, comorbidities, choice of mAB, history of COVID-19 vaccination, SARS-CoV-2 sequencing, and IgG levels to the receptor-biding domain (RBD) of the spike protein in vaccinated USV were reviewed. Results 66 USV received mAB therapy, tolerated well. 30 got CAS, 29 BAM, 7 SOT. 52 doses were given from Dec 2021 to Jan 2022, none were given in Feb. The median age of the cohort was 72.5 (range 32 to 97 years). 97% were men. 85% White, 12% Black, 3% Hispanic. 22 USV were not vaccinated. The vaccine recipients were: 3 Janssen, Moderna-2 shots (MOD-2): 6; MOD-3: 3; Pfizer 2 (PFZ-2) shots: 22; PFZ-3:10 The median days of COVID diagnosis from last dose of vaccine: Janssen 211 days (104 to 257); MOD-2 291 (205-322); MOD-3 56 (16-61), PFZ-2 222 (96-302) PFZ-3 78 (8-112). 62% had cough, dyspnea 24%, malaise 50%, diarrhea 11%, anosmia 11%, sore throat 17%, nasal congestion 41%, fever 32% Median BMI 30.8 (16.6 - 47.3). 36% had Diabetes, HTN 67%. COPD 23%, Asthma 11%, CAD 32%, HLD 67%; one woman was 28 weeks pregnant. Two coinfections with rhinovirus, 1 with RSV. 20 vaccine recipients had anti-SARS-CoV-2 RBD titers at presentation, median 2.60 (0.06-48.08). 11 USV were hospitalized but only 4 got steroids/remdesivir. 3 USV died but not directly due to COVID. 15 USV with omicron who received CAS (8) and BAM (7) survived. See tables for further data. Demographic Data of US Veterans after receiving monoclonal antibody therapy Data on hospitalized US Veterans after receiving monoclonal antibody therapy Conclusion As the pandemic transitioned from Delta to Omicron variants, mAB treatments in USV remained successful even in those USV who received therapies not active for omicron. Delta and omicron infections were seen in vaccinated and boosted USV. Disclosures All Authors: No reported disclosures.

Abstract Background The novel coronavirus SARS-CoV2 is the causative agent for COVID-19 responsible for the ongoing global pandemic. The spike protein on its surface binds to the angiotensin-converting enzyme 2 receptor helps to enter human cells. Neutralizing antibodies to this protein can be protective and helpful in alleviating symptoms. Monoclonal antibodies (mAb) have been utilized in the U.S. under an emergency use authorization by the FDA, including bamlanivimab (BAM) and casirivimab-imdevimab (CAR/IMD). We report our experience of using COVID mAb. Methods We conducted a retrospective chart review of patients that received CAR/IMD or BAM between December 1st, 2020, and May 15th, 2021. Medical records were reviewed to determine demographic and clinical information as well as tolerability and effectiveness of mAb. Results 463 patients with mild to moderate symptoms of SARS-CoV2 received mAb: 355(176 Men) BAM, 108(53 Men) CAR/IMD. The median BMI was 31 (17.4 to 62.5), 85% Caucasian, 4% Asian, 3% African American, 4% Hispanic, 4% others. The average duration of symptoms was 3.4 days and included cough (74%), malaise (71%), Headache (28%), dyspnea (28%), rhinorrhea (25%), fever (20%), diarrhea (18%), and anosmia (14%). Risk factors included hypertension (65%), diabetes mellitus (32%), coronary artery disease (22%), asthma (16%), COPD (9%), CHF (9%), CKD (8%), active malignancy (6%), and immunocompromised state (7%). Those who received BAM were older (p=0.000) and have underlying dementia and congestive heart failure (p=0.025 and 0.034, respectively). 27 patients (2 CAR/IMG, 25 BAM) got admitted to the hospital due to worsening of their respiratory status and were treated for COVID-19. 4 patients in the BAM group and 0 in the CAR/IMD group died. 2 patients developed a mild allergic reaction to CAR/IMD, no other side effects were reported in both groups. 37 patients (19 CAR/IMD, 18 BAM) received mRNA COVID vaccine prior. Overall mortality rate was 0.8%. There was no significant difference between BAM and CAR/IMR in terms of hospitalization (p= 0.104) or mortality (p=0.268). Conclusion Treatment with BAM versus CAR/IMR was well tolerated and resulted in similar outcomes in terms of hospitalization or mortality. Disclosures All Authors: No reported disclosures

From the ∗Department of Infectious Diseases, Stony Brook Medical Center, Stony Brook †Department of Infectious Diseases, Northport Veterans Affairs Medical Center, Northport, NY. Correspondence to: George Psevdos, MD, Department of Infectious Diseases, Northport Veterans Affairs Medical Center, 79 Middleville Road, Northport, NY 11678. E-mail: [email protected]. The authors have no funding or conflicts of interest to disclose.

To the Editor: Human rhinovirus (HRV) is the most common cause of upper respiratory tract infection worldwide, nearly year-round.1 Clinical manifestations of HRV infection can be similar to those caused by the severe respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic. Thus, most of the patients presenting with upper respiratory tract infection symptoms during the pandemic were tested with reverse transcriptase-polymerase chain reaction viral respiratory panels that included SARS-CoV-2 and other known pathogenic respiratory viruses including HRV. We report the incidence of HRV infections in our institution. We retrospectively reviewed the charts of the veterans who had positive reverse transcriptase-polymerase chain reaction for HRV from July 1, 2020, to February 28, 2021. During this period, 32 cases of HRV infection and 363 cases of SARS-CoV-2, but no influenza cases, were identified! Figure 1 shows the incidence of both infections monthly. All 32 cases were tested in the emergency department. The median age of the HRV cohort was 54 (23–83) years; 84% were men; and 81% were White, 13% were African American, 3% were Asian, and 3% were Hispanic. Median body mass index was 29.9 (22–51) kg/m2. Main presenting symptoms were cough (75%), rhinorrhea (56%), and sore throat (22%); 2 of the patients were asymptomatic. Most frequent comorbidities documented were hypertension (31%), current smoking (25%), chronic obstructive pulmonary disease (22%), and diabetes (19%); 4 of the patients had active malignancy (1 leukemia, 2 lymphomas, 1 melanoma), and 2 had chronic human immunodeficiency virus infection. Eleven patients (34%) received antibiotics (5 azithromycin, 3 amoxicillin, 1 cephalosporin/azithromycin, 1 fluoroquinolone (for otitis), and 1 cephalosporin [for pyuria in a pregnant woman]). Four required hospitalization: 1 with chronic obstructive pulmonary disease exacerbation, 1 for blood transfusion, 1 for depression, and 1 for cholecystitis. No deaths were recorded. There were no coinfections with HRV and SARS-CoV-2. However, 6 patients from the HRV cohort were also diagnosed with COVID-19—at a different time—this last year!FIGURE 1: Human rhinovirus and SARS-CoV-2: July 2020 to February 2021.In a year marked by a novel coronavirus pandemic, affecting all aspects of life, from creating an unimaginable burden to health care, financial hardships to many, to a new norm of masking, social distancing, and meticulous hand washing, it is worth mentioning that, in the United States, national influenza activity has been decreased.2 Human rhinovirus is likely able to be transmitted despite COVID control measures owing to its nonenveloped nature, which makes it resistant to lipophilic disinfectants.3 Also, face masks are less efficacious in blocking HRV release in exhaled breath.4 Interestingly, an increased number of HRV infections were noted in school children in Hong Kong who followed masking rules in the autumn of 2020.5 Our findings highlight the possibility of HRV and other common cold viruses being captured during increased testing for SARS-CoV-2. Inderjit Mann, MDAikaterini Papamanoli, MD Department of Infectious Diseases Stony Brook Medical Center Stony Brook, NYMary Creed, IT Department of Microbiology Northport Veterans Affairs Center Northport, NYMonique Thorne, EdD, MS, NPD-BC Department of Nursing Infection Control Northport Veterans Affairs Center Northport, NYZeena Lobo, MDGeorge Psevdos, MD Department of Infectious Diseases Northport Veterans Affairs Medical Center Northport, NY [email protected]

Abstract Background Babesiosis has gained attention as an emerging protozoal zoonotic disease with an expanding known incidence and geographical range in the US. The infection is caused by Babesia microti in the US and is transmitted by the bite of Ixodes ticks, and occasionally by blood transfusion. The diagnosis is usually established by microscopic examination of a stained blood smear to see intraerythrocytic organisms. The level of parasitemia is only loosely correlated with clinical severity. Anecdotal reports suggest that HDL cholesterol levels decline during acute babesiosis. In this study, we report cholesterol levels in a series of patients with acute babesiosis with the hypothesis that HDL levels may be a potential biomarker for more severe infections. Methods A retrospective chart review was performed at Stony Brook University Hospital and Stony Brook Southampton Hospital between 2013 and 2018. Inclusion criteria was defined as a case of acute Babesia infection proven by peripheral blood smear microscopy and who had a lipid profile drawn during presentation to the emergency department. Cholesterol levels that were measured either before or after the infection (at least 1 month apart) were also recorded to compare to the levels reported during acute infection. Results A total of 40 patients (27.5% female) met criteria for acute Babesia infection. Fifteen (37.5%) had a history of splenectomy. The patients were divided into two groups for comparisons based on the treating physician’s clinical decision: 32 patients who were admitted to the hospital and 8 patients who were not-admitted. History of hypertension was more common in admitted than non-admitted patients (37% vs. 17%, Chi-square test p=0.02); the median levels of LDL and HDL were more reduced in admitted than non-admitted patients (46 vs 76 mg/dL, p=0.04 and 9 vs 28.5 mg/dL, p=0.03, based on t-test respectively) Conclusion LDL and HDL levels are significantly reduced in acute babesiosis, and LDL levels are inversely proportional to the parasitemia, suggesting that low levels of LDL may predict worsening disease in babesiosis. The mechanism of this phenomenon is unknown. Further prospective studies are needed. Disclosures All Authors: No reported disclosures

In 2013, the US Preventive Services Task Force made a grade B recommendation to offer HCV screening for at-risk individuals and baby boomers (born between 1945 and 1965). However, only 50% of HCV-positive individuals are aware they are infected, and far fewer attend an outpatient appointment and are initiated on treatment (Linkage to Care: LTC). The aim of this study is to assess the factors affecting LTC among HCV positives in a suburban tertiary medical center on Long Island, NY. A retrospective chart review was performed on all patients with ICD-9 or 10 diagnostic codes for HCV positive antibody from January 2016 to March 2017 at Stony Brook University Hospital. Data were collected for HCV RNA, LTC, demographics, insurance and employment status, psychiatric diagnosis, comorbid medical conditions, substance use disorder, injection drug use, liver and kidney function, level of fibrosis. A total of 155 cases (61.9% male; mean age 53.9 years) had a positive HCV antibody, 110 (71%) had a follow-up HCV RNA test and 35.1% were LTC. The comorbidities present in this cohort were psychiatric disease (54.9%), cirrhosis (22.6%), HBV infection (14.1%) and HIV (8.5%). In the univariate analysis, new inpatient HCV diagnosis (OR = 0.09, 95% CI: 0.02–0.36, P = 0.001), employment (OR = 3, 95% CI: 1.01–8.95, P = 0.049) and history of substance use disorder (OR = 0.38, 95% CI: 0.15–0.96, P = 0.043) were associated with LTC. In the logistic regression analysis, inpatient HCV diagnosis was negatively correlated with LTC (OR: 0.03, 95% CI: 0.002–0.41, P = 0.009). Two hot spots of HCV infection were identified in south central Suffolk County. In this population, new inpatient HCV diagnosis and history of substance use disorder were less likely to have LTC, whereas those employed were more likely to have LTC. Innovative interventions in the inpatient setting may be beneficial for newly diagnosed HCV cases to improve LTC after discharge. All authors: No reported disclosures.

Hypervirulent Klebsiella pneumoniae (hvKp) strains are predicted to become a major threat in Asia if antibiotic resistance continues to spread. Anticapsular antibodies (Abs) were developed because disseminated infections caused by hvKp are associated with significant morbidity and mortality, even with antibiotic-sensitive strains. K1-serotype polysaccharide capsules (K1-CPS) are expressed by the majority of hvKp strains. In this study, K1-CPS-specific IgG Abs were generated by conjugation of K1-CPS to immunogenic anthrax protective antigen (PA) protein. Opsonophagocytic efficacy was measured in vitro and in vivo by intravital microscopy in murine livers. In vivo protection was tested in murine models, including a novel model for dissemination in hvKp-colonized mice. Protective efficacy of monoclonal antibodies (MAbs) 4C5 (IgG1) and 19A10 (IgG3) was demonstrated both in murine sepsis and pulmonary infection. In hvKp-colonized mice, MAb treatment significantly decreased dissemination of hvKp from the gut to mesenteric lymph nodes and organs. Intravital microscopy confirmed efficient opsonophagocytosis and clearance of bacteria from the liver. In vitro studies demonstrate that MAbs work predominantly by promoting FcR-mediated phagocytosis but also indicate that MAbs enhance the release of neutrophil extracellular traps (NETs). In anticipation of increasing antibiotic resistance, we propose further development of these and other Klebsiella-specific MAbs for therapeutic use.