Abstract Background In 2021, the state of Arizona experienced the largest focal outbreak of West Nile virus (WNV) in US history. Timely and accurate diagnostic testing remains a challenge for WNV due to transient viremia and limited immunoassay specificity. Recent studies have identified whole blood (WB) and urine as more sensitive specimen types for the detection of WNV RNA. Methods We evaluated ordering practices, test performance, and patient characteristics of probable and confirmed cases. In total, we identified 190 probable and proven cases, including 127 patients (66.8%) with neuroinvasive disease. Results Among all cases, only 29.5% had WNV polymerase chain reaction (PCR) testing ordered on WB, of which 80.3% resulted as positive, including 7 cases in which WNV serologic testing was negative and 5 cases for which serologic testing was not ordered. In comparison, only 23.7% of cases that had cerebrospinal fluid (CSF) PCR ordered had a positive result, including 3 cases that were negative by PCR on WB. In contrast, WNV PCR on WB detected 12 neuroinvasive cases that were CSF PCR negative. WNV PCR testing in urine was only ordered on 2 patients, both of whom were positive. Crossing cycle threshold (Ct) values were not significantly different between WB and CSF specimen types, nor was there a correlation between Ct value and days from symptom onset at the time of sample collection; all specimen types and time points had Ct values, with 98% above 30. WB was positive by WNV PCR in several patients for >7 days (range, 7–25 days) after symptom onset, as was the CSF PCR. Conclusions Taken together, these findings indicate that WNV PCR testing on WB may be the best initial test for timely diagnosis of WNV infection, irrespective of clinical manifestation; however, if negative in patients with suspected neuroinvasive disease, WNV PCR testing on CSF should be ordered.
Neuroinvasive West Nile Virus Infection in Immunosuppressed and Immunocompetent Adults
Importance West Nile virus (WNV) is the leading cause of human arboviral disease in the US, peaking during summer. The incidence of WNV, including its neuroinvasive form (NWNV), is increasing, largely due to the expanding distribution of its vector, the Culex mosquito, and climatic changes causing heavy monsoon rains. However, the distinct characteristics and outcomes of NWNV in individuals who are immunosuppressed (IS) and individuals who are not IS remain underexplored. Objective To describe and compare clinical and radiographic features, treatment responses, and outcomes of NWNV infection in individuals who are IS and those who are not IS. Design, Setting, and Participants This retrospective cohort study used data from the Mayo Clinic Hospital system collected from July 2006 to December 2021. Participants were adult patients (age ≥18 years) with established diagnosis of NWNV infection. Data were analyzed from May 12, 2020, to July 20, 2023. Exposure Immunosuppresion. Main Outcomes and Measures Outcomes of interest were clinical and radiographic features and 90-day mortality among patients with and without IS. Results Of 115 participants with NWNV infection (mean [SD] age, 64 [16] years; 75 [66%] male) enrolled, 72 (63%) were not IS and 43 (37%) were IS. Neurologic manifestations were meningoencephalitis (98 patients [85%]), encephalitis (10 patients [9%]), and myeloradiculitis (7 patients [6%]). Patients without IS, compared with those with IS, more frequently reported headache (45 patients [63%] vs 18 patients [42%]) and myalgias (32 patients [44%] vs 9 patients [21%]). In contrast, patients with IS, compared with those without, had higher rates of altered mental status (33 patients [77%] vs 41 patients [57%]) and myoclonus (8 patients [19%] vs 8 patients [4%]). Magnetic resonance imaging revealed more frequent thalamic T2 fluid-attenuated inversion recovery hyperintensities in individuals with IS than those without (4 patients [11%] vs 0 patients). Individuals with IS had more severe disease requiring higher rates of intensive care unit admission (26 patients [61%] vs 24 patients [33%]) and mechanical ventilation (24 patients [56%] vs 22 patients [31%]). The 90-day all-cause mortality rate was higher in the patients with IS compared with patients without IS (12 patients [28%] vs 5 patients [7%]), and this difference in mortality persisted after adjusting for Glasgow Coma Scale score (adjusted hazard ratio, 2.22; 95% CI, 1.07-4.27; P = .03). Individuals with IS were more likely to receive intravenous immunoglobulin than individuals without IS (12 individuals [17%] vs 24 individuals [56%]), but its use was not associated with survival (hazard ratio, 1.24; 95% CI, 0.50-3.09; P = .64). Conclusions and Relevance In this cohort study of individuals with NWNV infection, individuals with IS had a higher risk of disease complications and poor outcomes than individuals without IS, highlighting the need for innovative and effective therapies to improve outcomes in this high-risk population.
Clinical Characteristics and Outcomes of Neuroinvasive West Nile virus infection in Immunosuppressed and Immunocompetent individuals treated at the Mayo Clinic Hospitals (P11-9.004)
Abstract Background Literature on the natural course of neuroinvasive West Nile virus (WNV) infection in solid organ transplant (SOT) recipients is sparse. In the setting of a 2021 WNV outbreak in Arizona, we reviewed our institution's experience with neuroinvasive WNV infection in patients with SOT. Methods We retrospectively identified SOT recipients treated for neuroinvasive WNV at Mayo Clinic in Arizona from 2007 through 2021. Clinical manifestations, disease course, and outcomes were analyzed. Results Among 24 SOT recipients with WNV infection identified during the study period, 13 infections occurred in 2021. Most patients had gastrointestinal tract symptoms and fever at disease presentation. Five patients had cognitive impairment, and 14 initially or eventually had acute flaccid paralysis. Clinically significant deterioration occurred at a median of 4 (range, 1–11) days after hospital admission. Seventeen patients (71%) were transferred to the intensive care unit, with 15 requiring mechanical ventilation. Initial cerebrospinal fluid analysis mainly demonstrated a neutrophil‐predominant pleocytosis. Almost all patients ( n = 23) were treated with intravenous immunoglobulin alone or in combination with interferon alfa‐2b. Sixteen patients had clinical improvement, 4 of whom recovered completely. Six patients died during hospitalization due to complications of neuroinvasive WNV infection. Two patients were discharged to hospice without clinical recovery. The overall 30‐day mortality rate was 36%. Conclusion Despite advances in supportive care, neuroinvasive WNV infection is associated with substantial morbidity and mortality in SOT recipients. Flaccid paralysis is an indicator of poor prognosis. image
1935. Cardiac Tamponade Following COVID-19 Vaccination
Abstract Background While numerous, most described cases of myocarditis and pericarditis following COVID-19 vaccination are mild and self-limited. We present two cases of life-threatening cardiac tamponade following COVID-19 vaccination. Methods Two cases of cardiac tamponade in temporal association with COVID-19 vaccination were reviewed Results Case 1 : 75-year-old male with rheumatoid arthritis admitted with chest pressure and hypotension 2 days after his 1st dose of Pfizer-BioNTech COVID-19 vaccine. Pericardiocentesis removed 275 ml of exudative effusion with 14,140 nucleated cells/ml. Fluid bacterial and fungal cultures were negative; cytology was inconsistent with malignancy. He had no Epstein-Barr virus (EBV) or cytomegalovirus (CMV) viremia. Symptoms resolved on prednisone and colchicine. A week later, he had an uneventful second COVID-19 vaccine. He went on to have 3 recurrences of pericarditis starting two months after his first. One was within 48 hours of his COVID-19 booster. He is on long term prednisone. Case 2: 66-year-old male with non-Hodgkin’s lymphoma in remission. He developed chest pain a day after his 2nd dose of Pfizer-BioNTech COVID-19 vaccine. Admitted 4 days later with pericardial effusion and managed medically. Readmitted a week later with fever and chest pain. Echocardiogram now showed cardiac tamponade. Pericardiocentesis removed 400 ml of exudative fluid with 1,191 nucleated cells/mL. Cultures for bacteria, fungi, and mycobacteria were negative. Cytology didn't show malignancy. Serologies for CMV, EBV and parvovirus represented past infection. He was discharged with a pericardial drain, colchicine, and NSAIDs. He was later readmitted with fevers. Echocardiogram only showed small pericardial effusion, which did not require drainage. Figure 1Circumferential pericardial effusion seen on trans-thoracic echocardiography from patient in case 1. Conclusion Given the proximity to COVID-19 vaccination and lack of alternative explanations, we believe that tamponade was a direct result of post-vaccine inflammatory pericarditis. Neither patient had a prior history of pericardial effusion. Both tested negative for SARS-CoV-2 by nasopharyngeal swab excluding active infection. Healthcare providers should consider the possibility of pericardial effusion and tamponade in patients with chest pain, shortness of breath, or hypotension following COVID-19 vaccination. Disclosures All Authors: No reported disclosures.
1804. Quality Improvement Project to improve empiric antibiotic therapy for skin and soft tissue infections using the nasal MRSA PCR
Abstract Background Large cohort studies from the Veteran’s Administration support the negative predictive value of the methicillin resistant Staphylococcus aureus (MRSA) nasal polymerase chain reaction (PCR) swabs for skin and soft tissue infection (SSTI). We investigated the use of the nasal MRSA PCR swab to reduce the inappropriate empiric use of vancomycin and piperacillin-tazobactam for SSTI at our institution. Methods Between July and August 2021, we educated Hospital Internal Medicine (HIM) and Internal Medicine Residents (IMR) on the basics of SSTI management and the utility of a negative nasal MRSA PCR swab. Data on empiric use of vancomycin and piperacillin-tazobactam for SSTIs were collected 3/1/2021 to 7/1/2021 (pre-intervention) and 8/30/2021 to 12/29/2021 (post-intervention). We excluded patients who didn’t have an SSTI, weren’t managed by IMR or HIM, and whose empiric antibiotics were for another indication. To account for antibiotics started in the emergency department (ED), a patient was regarded as having received appropriate empiric antibiotics if they were de-escalated in the first 24 hours of being admitted to IMR or HIM. Example of education material. These fliers were distributed to resident rooms following a series of noon conferences Results Pre-intervention there were 106 patient encounters. In 56 of these (52.8%), patients were placed on inappropriate empiric antibiotics. Post-intervention, there were 72 patient encounters. In 23of these (31.9%), patients were placed on inappropriate empiric antibiotic for an absolute risk reduction (ARR) of 20.9% with a statistically significant 95% CI (6.522 - 35.249) and a number needed to treat (NNT) of 4.78. Nasal MRSA PCR testing increased from 40.6% to 56.9%. The ARR among the HIM teams was 21.3% and was statistically significant with a 95% CI (4.24 - 38.394). Their proportion of MRSA testing increased from 41.5% to 50%. The IMR teams had an ARR of 14.8%, which was not statistically significant (95% CI, -11.339 to 40.884). Their MRSA nasal PCR testing increased from 37.5% to 72%. Conclusion Education on SSTI treatment coupled with use of the MRSA nares PCR appeared to improve empiric antibiotic choices. Residents stated that the nasal MRSA PCR facilitated empiric antibiotic choice. Positive ARR was seen in whole and sub-group analyses of physician teams. We theorize that the lack of statistical significance in the IMR group was related to a small sample size. Disclosures All Authors: No reported disclosures.
1029. Clinical Characteristics and Outcomes of Neuroinvasive West Nile Virus Infection in Immunocompromised and Immunocompetent Individuals
Abstract Background Despite the increasing incidence of neuroinvasive West Nile virus (NiWNV) infection in the US, the spectrum of disease characteristics and neuroimaging findings in immunosuppressed (IS) individuals are not adequately described. We aimed to compare the clinical characteristics and outcomes of NiWNV infection in IS and immunocompetent (IC) patients. Methods We extracted relevant data from all NiWNV patients hospitalized 7/2003-10/2021 at Mayo Clinic hospitals. Cohort was inclusive of patients from the recent historic WNV outbreak in Arizona in 2021. Chi-Square or Kruskal-Wallis and logistic regression were used to compare relevant variables and determine predictors of mortality respectively. Results We included 115 patients (72 IC and 43 IS), mean age 63.5 years; neurologic syndromes included meningoencephalitis (85.2%), encephalomyelitis (8.7%) and myeloradiculitis (6.1%). Presenting symptoms were malaise (72%), fever (66%), altered mentation (64%), gastrointestinal (47%) and myalgia (35.7%). MRI brain was abnormal in 62.8% (49/78), demonstrating T2/FLAIR hyperintensities in 47.4% (brainstem, thalamus, temporal lobes), leptomeningeal enhancement (16.7%) and diffusion restriction (20.5%). Altered mental status (76.7% vs 56.9%), myalgia (44.4% vs. 20.9%), myoclonus (18.6% vs. 4.2%) and thalamic MRI T2 FLAIR abnormalities (11.4% vs 0%) were more common in IS patients. Higher CSF WBC counts were observed in IC vs IS patients (P< 0.05). Immunosuppressed patients were more likely to be treated with intravenous immunoglobulin (44.2% vs 8.3% p=< 0.001) and/or interferon therapy (32.6% vs 6.9%, p=0.0003) and had increased odds of 90-day mortality on multivariable analysis (Adjusted Odds Ratio, AOR 2.22; 95% CI 1.065-4.627, p=0.0334). In the IS subgroup, ICU admission, mechanical ventilation, and Glasgow coma scale of < 8 were associated with reduced overall survival/increased 90-day mortality (p< 0.005). Conclusion Individuals presenting in summer/fall months with the aforementioned symptoms and/or MRI abnormalities should be evaluated for NiWNV infection. Compared to the immunocompetent, immunosuppressed patients with NiWNV are at a significantly greater mortality risk. Novel and effective antiviral therapies aimed at improving outcomes are warranted. Disclosures All Authors: No reported disclosures.
A Case of Burkholderia pseudomallei Mycotic Aneurysm Linked to Exposure in the Caribbean via Whole-Genome Sequencing
Abstract Melioidosis, an infection caused by Burkholderia pseudomallei, has a very high risk of mortality when treated, with an even higher risk of fatality if undiagnosed or not treated appropriately. It is endemic to Asia, Australia, South America, and the Caribbean; however, the number of melioidosis cases reported in the United States has been increasing. Therefore, physicians should be aware of this clinical entity and its possible presentations. Mycotic aneurysms due to B. pseudomallei are extremely rare, accounting for ~1%–2% of cases. Here we describe a rare case of melioidosis presenting as a mycotic aneurysm in the United States, highlight the potential for diagnostic challenges and epidemiologic concerns, and provide a review of mycotic aneurysm cases due to B. pseudomallei published to date.
692. Coccidioides sp. Infective Endocarditis: A Review of the Literature
Abstract Background Despite the endemic nature of Coccidioides sp. to the American Southwest, the incidence Coccidioides sp. infective endocarditis (CIE) is rare. Following successful treatment of a patient with CIE at our institution, we reviewed the literature to identify trends in disease presentation, patient characteristics, and outcomes. Methods We reviewed all cases of CIE reported since 1938. Details including patient demographics, underlying immunodeficiency, time to diagnosis, treatment, and outcome were collected for analysis of diagnostic challenges and survival. Results Including ours, we identified 11 published cases of CIE. The majority (7) occurred in men. 5 patients were of either African American or Hispanic descent. Of the 10 patients with reported ages, the median age was 35.5 years (range 3 weeks – 61 years). 5 patients had a previous diagnosis of coccidioidomycosis and only 3 had an immunocompromising condition. These comprised pregnancy, heart transplant, and juvenile inflammatory arthritis. Three cases had multi-valvular involvement, but the majority affected the mitral (5) and the aortic (4) valves. Only 2 of the 11 cases involved a prosthetic valve. Of the 8 cases with reported blood cultures, only 2 were positive. Ten of the 11 cases had extra-cardiac disease. Complement fixation (CF) titers were heterogenous with a median of 1:32 and a range of 1:1 to 1:2048. There was no obvious correlation between a patient’s CF titer and their survival. Average time to diagnosis was 3.5 months (range 2.5 – 36 months). Diagnosis was made post-mortem in 4 of the 11 cases. 6 patients (54%) did not survive. Notably, 2 of the fatal cases preceded the discovery of amphotericin B (1969) and 4 occurred prior to the discovery of fluconazole (1990). Of the five patients that survived, four required surgical intervention in addition to azole therapy. Conclusion CIE is a diagnostic and therapeutic challenge. The diagnosis itself is rare, culture incubation times are long, and the symptoms are often non-specific thus delaying definitive therapy. The introduction of azole therapy appears to have had significant impact on rates of survival. Despite this, successful management of CIE still requires concurrent surgical intervention with aggressive, indefinite anti-fungal therapy. Disclosures All Authors: No reported disclosures
Abstract Background More accounts of opportunistic infection in COVID-19 patients are emerging. At our institution, we identified 2 COVID-19 patients with Pneumocystis jiroveci pneumonia (PJP) opportunistic infection. This prompted a review of the literature to identify trends in patient characteristics, risk factors, and outcomes in this population. Methods A literature review was conducted using PubMed that identified 13 other patients with both COVID-19 and PJP infection. Age, gender, human immunodeficiency virus (HIV) status, other immunocompromised states, time between COVID-19 and PJP diagnosis, and clinical outcomes were captured for analysis. Results Eleven patients were male. The average age was 56 years. All but 2 patients were immunocompromised. At time of PJP diagnosis, seven patients had newly diagnosed HIV and one had known, well-controlled HIV. One patient had rheumatoid arthritis receiving leflunomide, 1 had ulcerative colitis receiving budesonide and sulfasalazine, 2 patients had multiple myeloma whereby both were on lenalidomide, 1 patient was a renal transplant recipient immunosuppressed on tacrolimus, mycophenolate, and methylprednisolone, and 1 patient had chronic lymphocytic leukemia getting fludarabine, cyclophosphamide, and rituximab. Nine patients had positive COVID-19 and PJP tests performed within 7 days of one another. One patient tested positive for PJP 54 days into admission for COVID-19. This patient received high dose steroids and tocilizumab for initial COVID-19 infection. Three patients were re-hospitalized with PJP after a recent admission for COVID-19 pneumonia, with a mean time to readmission of 25 days. One of these 3 patients had no treatment for COVID-19, while 2 received steroids. Five of the total 15 patients (33%) died. Conclusion COVID-19 treatments with high dose steroids and tocilizumab can make patients vulnerable for opportunistic infection with PJP. Furthermore, COVID-19 is known to cause lymphopenia which may further increase this risk. A diagnosis of concomitant PJP can be especially challenging due to nearly identical radiographical findings. Serum beta-D glucan and HIV testing can be especially helpful in this situation, and there should be a low threshold for performing bronchoalveolar lavage. Disclosures All Authors: No reported disclosures