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The geographic range of blastomycosis is thought to include New England, but documentation is sparse. We report 5 cases of infection with Blastomyces dermatitidis that were likely acquired in New England between 2011 and 2021. Our experience suggests that chart coding for the diagnosis of blastomycosis is imprecise and that mandatory reporting might help resolve uncertainties about the prevalence and extent of blastomycosis.

In the EPIC-HR (Evaluation of Protease Inhibition for Covid-19 in High-Risk Patients) trial, nirmatrelvir plus ritonavir led to an 89% reduction in hospitalization or death among unvaccinated outpatients with early COVID-19. The clinical impact of nirmatrelvir plus ritonavir among vaccinated populations is uncertain.To assess whether nirmatrelvir plus ritonavir reduces risk for hospitalization or death among outpatients with early COVID-19 in the setting of prevalent SARS-CoV-2 immunity and immune-evasive SARS-CoV-2 lineages.Population-based cohort study analyzed to emulate a clinical trial using inverse probability-weighted models to account for anticipated bias in treatment.A large health care system providing care for 1.5 million patients in Massachusetts and New Hampshire during the Omicron wave (1 January to 17 July 2022).44 551 nonhospitalized adults (90.3% with ≥3 vaccine doses) aged 50 years or older with COVID-19 and no contraindications for nirmatrelvir plus ritonavir.The primary outcome was a composite of hospitalization within 14 days or death within 28 days of a COVID-19 diagnosis.During the study period, 12 541 (28.1%) patients were prescribed nirmatrelvir plus ritonavir, and 32 010 (71.9%) were not. Patients prescribed nirmatrelvir plus ritonavir were more likely to be older, have more comorbidities, and be vaccinated. The composite outcome of hospitalization or death occurred in 69 (0.55%) patients who were prescribed nirmatrelvir plus ritonavir and 310 (0.97%) who were not (adjusted risk ratio, 0.56 [95% CI, 0.42 to 0.75]). Recipients of nirmatrelvir plus ritonavir had lower risk for hospitalization (adjusted risk ratio, 0.60 [CI, 0.44 to 0.81]) and death (adjusted risk ratio, 0.29 [CI, 0.12 to 0.71]).Potential residual confounding due to differential access to COVID-19 vaccines, diagnostic tests, and treatment.The overall risk for hospitalization or death was already low (1%) after an outpatient diagnosis of COVID-19, but nirmatrelvir plus ritonavir reduced this risk further.National Institutes of Health.

Background Epstein-Barr virus (EBV) donor seropositive/recipient seronegative (D+/R-) status is a risk factor for post-transplant lymphoproliferative disorder (PTLD) which is associated with increased mortality post-lung transplant. The optimal surveillance strategy for PTLD post-lung transplant stratified by EBV serostatus for early diagnosis is unknown. We assessed serial EBV viral loads (VL) for early diagnosis of PTLD and compared outcomes in EBV D+/R- and R+ lung transplant recipients at our center. Methods A single-center retrospective study of lung transplants between January 2017 and September 2021 was performed, with a 6-month minimum follow-up. Recipient characteristics, outcomes, and serial EBV VL (biweekly months 1-3, monthly 4-12; using the cobas quantitative PCR assay on serum) were assessed. Results Of the 242 lung transplant recipients, 14 (6%) were EBV D+/R- and 228 (94%) were EBV R+ [Figure 1]. Median age and lung allocation score were similar between the two cohorts [Table 1]. 7 (50%) EBV D+/R- recipients had 2 consecutive, detectable EBV VL in the first-year post-transplant compared to 30 (13%) R+ recipients (p=0.002). 5 (71%) EBV D+/R- recipients with 2 consecutive, detectable EBV VL developed PTLD compared with 2 (7%) R+ recipients (p=0.001). Median weeks post-transplant for two consecutive, detectable EBV VL were 14 (IQR 7, 15) and 10 (IQR 6, 24); and median weeks post-transplant for diagnosis of PTLD were 22 (IQR 17, 31) and 17 (IQR 16, 17) for EBV D+/R- and R+, respectively. Only recipients with at least 2 consecutive, detectable VL in the first-year post-transplant developed PTLD. EBV VL level was not associated with development of PTLD. 6-month outcomes were similar between EBV D+/R- and R+. Though there were no differences in mortality at 1 and 2-years stratified by EBV serostatus, all 5 EBV D+/R- recipients with PTLD were alive 2 years post-transplant, whereas both EBV R+ PTLD recipients died < 2 years post-transplant (p=0.048). Figure 1:Study cohort characteristics and PTLD outcomes based on serial EBV viral loads within the first-year post-lung transplant*7 recipients were excluded per study criteria due to having died less than 1-month post-transplant and therefore not having sufficient EBV VL testing post-transplant for this analysis.Table 1:Baseline characteristics, index hospitalization, and clinical outcomes of lung transplant recipients stratified by EBV serostatus*P-values are based on Fisher’s two-sided exact test (for categorial variables) or the Wilcoxon rank-sum test (for continuous variables).**Time to ≥2 consecutive, detectable EBV VL was calculated based on the date of the second consecutive, detectable result. Conclusion Two consecutive, detectable EBV VL within the first-year post-lung transplant should prompt additional work-up for the early diagnosis of PTLD in all recipients regardless of the EBV VL level or serostatus. Though the attack rate of PTLD was greater in EBV D+/R- recipients, survival outcomes were similar irrespective of serostatus. Disclosures Nicolas C. Issa, MD, AiCuris: Grant/Research Support|Merck: Grant/Research Support.

Background Staphylococcus aureus (S. aureus) infections post-lung transplant lead to increased mortality. The impact of S. aureus peri-transplant respiratory cultures on post-transplant outcomes is unknown as is the optimal duration of peri-transplant antibiotics. We compared lung transplant recipients with and without S. aureus growth on peri-transplant cultures and the impact on 6-month outcomes including rejection, survival, and occurrence of S. aureus infections. Methods A single-center, retrospective study of lung transplant recipients between January 2017 and April 2021 was performed. Donor/recipient characteristics, microbiologic data, antibiotics, and 6-month outcomes were analyzed. Results In this 4.5-year study period, 229 patients underwent lung transplant. 121 (53%) had S. aureus growth on peri-transplant cultures, of which 84 (69%) were methicillin-susceptible (MSSA), 30 (25%) methicillin-resistant (MRSA), and 7 (6%) had MSSA and MRSA. Median duration of antibiotics post-transplant was 28-days in the S. aureus group. 67% of non-S. aureus recipients received S. aureus targeting antibiotics (p = < 0.001) for other indications for a median of 13-days. In the S. aureus cohort, donors were younger (median age 33 vs 38 years, p = 0.027) and more donors died from drug intoxication (50% vs 31%, p = 0.005) [Table 1]. Recipient baseline characteristics and median length of hospitalization were similar in both cohorts. There were no statistically significant differences in 6-month outcomes, including rates of rejection or survival [Figure 1]. Having grown S. aureus in peri-transplant cultures was not associated with a higher incidence of post-transplant S. aureus infections (10% vs 13%, p = 0.534). Patients who had a S. aureus infection post-transplant had lower 6-month survival that was not statistically significant (85% vs 93%, p = 0.131). Conclusion The growth of S. aureus on peri-transplant respiratory cultures with a median 4-week antibiotic course does not increase the risk of having a S. aureus infection post-transplant and is not associated with increased mortality or rejection at 6-months. The impact of a shorter duration of peri-transplant antibiotics on recurrence of infection and outcomes needs to be further studied. Disclosures Nicolas C. Issa, MD, AiCuris: Grant/Research Support|Merck: Grant/Research Support.

Coronavirus disease 2019 (COVID‐19) manifests with high clinical variability and warrants sensitive and specific assays to analyze immune responses in infected and vaccinated individuals. Using Single Molecule Arrays (Simoa), we developed an assay to assess antibody neutralization with high sensitivity and multiplexing capabilities based on antibody‐mediated blockage of the ACE2‐spike interaction. The assay does not require live viruses or cells and can be performed in a biosafety level 2 laboratory within two hours. We used this assay to assess neutralization and antibody levels in patients who died of COVID‐19 and patients hospitalized for a short period of time and show that neutralization and antibody levels increase over time. We also adapted the assay for SARS‐CoV‐2 variants and measured neutralization capacity in pre‐pandemic healthy, COVID‐19 infected, and vaccinated individuals. This assay is highly adaptable for clinical applications, such as vaccine development and epidemiological studies., Using Single Molecule Arrays (Simoa), we developed a simple neutralization assay based on antibody‐mediated blockage of the ACE2‐spike interaction. This assay can assess antibody neutralization with high sensitivity and multiplexing capabilities. We used this assay to profile neutralization capacity in patients infected with SARS‐CoV‐2 and vaccinated individuals and show that this assay is useful for various clinical applications.

Patients with coronavirus disease 2019 (COVID-19) can present with severe respiratory distress requiring intensive care unit (ICU)-level care. Such care often requires placement of an arterial line for monitoring of pulmonary disease progression, hemodynamics, and laboratory tests. During the first wave of the COVID-19 pandemic in March 2020, experienced physicians anecdotally reported multiple attempts, decreased insertion durations, and greater need for replacement of arterial lines in patients with COVID-19 due to persistent thrombosis. Because invasive procedures in patients with COVID-19 may increase the risk for caregiver infection, better defining difficulties in maintaining arterial lines in COVID-19 patients is important. We sought to explore the association between COVID-19 infection and arterial line thrombosis in critically ill patients.In this primary exploratory analysis, a multivariable Fine-Gray subdistribution hazard model was used to retrospectively estimate the association between critically ill COVID-19 (versus sepsis/acute respiratory distress syndrome [ARDS]) patients and the risk of arterial line removal for thrombosis (with arterial line removal for any other reason treated as a competing risk). As a sensitivity analysis, we compared the number of arterial line clots per 1000 arterial line days between critically ill COVID-19 and sepsis/ARDS patients using multivariable negative binomial regression.We retrospectively identified 119 patients and 200 arterial line insertions in patients with COVID-19 and 54 patients and 68 arterial line insertions with non-COVID ARDS. Using a Fine-Gray subdistribution hazard model, we found the adjusted subdistribution hazard ratio (95% confidence interval [CI]) for arterial line clot to be 2.18 (1.06-4.46) for arterial lines placed in COVID-19 patients versus non-COVID-19 sepsis/ARDS patients (P = .034). Patients with COVID-19 had 36.3 arterial line clots per 1000 arterial line days compared to 19.1 arterial line clots per 1000 arterial line days in patients without COVID-19 (adjusted incidence rate ratio [IRR] [95% CI], 1.78 [0.94-3.39]; P = .078).Our study suggests that arterial line complications due to thrombosis are more likely in COVID-19 patients and supports the need for further research on the association between COVID-19 and arterial line dysfunction requiring replacement.

Background Unbiased assessment of the risks associated with acquisition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to informing mitigation efforts during pandemics. The objective of our study was to understand the risk factors for acquiring coronavirus disease 2019 (COVID-19) in a large prospective cohort of adult residents in a large US metropolitan area. Methods We designed a fully remote longitudinal cohort study involving monthly at-home SARS-CoV-2 polymerase chain reaction (PCR) and serology self-testing and monthly surveys. Results Between October 2020 and January 2021, we enrolled 10 289 adults reflective of the Boston metropolitan area census data. At study entry, 567 (5.5%) participants had evidence of current or prior SARS-CoV-2 infection. This increased to 13.4% by June 15, 2021. Compared with Whites, Black non-Hispanic participants had a 2.2-fold greater risk of acquiring COVID-19 (hazard ratio [HR], 2.19; 95% CI, 1.91–2.50; P < .001), and Hispanics had a 1.5-fold greater risk (HR, 1.52; 95% CI, 1.32–1.71; P < .016). Individuals aged 18–29, those who worked outside the home, and those living with other adults and children were at an increased risk. Individuals in the second and third lowest disadvantaged neighborhood communities were associated with an increased risk of acquiring COVID-19. Individuals with medical risk factors for severe disease were at a decreased risk of SARS-CoV-2 acquisition. Conclusions These results demonstrate that race/ethnicity and socioeconomic status are the biggest determinants of acquisition of infection. This disparity is significantly underestimated if based on PCR data alone, as noted by the discrepancy in serology vs PCR detection for non-White participants, and points to persistent disparity in access to testing. Medical conditions and advanced age, which increase the risk for severity of SARS-CoV-2 disease, were associated with a lower risk of COVID-19 acquisition, suggesting the importance of behavior modifications. These findings highlight the need for mitigation programs that overcome challenges of structural racism in current and future pandemics.

The impact of coronavirus disease 2019 vaccination on viral characteristics of breakthrough infections is unknown. In this prospective cohort study, incidence of severe acute respiratory syndrome coronavirus 2 infection decreased following vaccination. Although asymptomatic positive tests were observed following vaccination, the higher cycle thresholds, repeat negative tests, and inability to culture virus raise questions about their clinical significance.

Background Serological testing provides a record of prior infection with SARS-CoV-2, but assay performance requires independent assessment. Methods We evaluated 3 commercial (Roche Diagnostics pan-IG, and Epitope Diagnostics IgM and IgG) and 2 non-commercial (Simoa and Ragon/MGH IgG) immunoassays against 1083 unique samples that included 251 PCR-positive and 832 prepandemic samples. Results The Roche assay registered the highest specificity 99.6% (3/832 false positives), the Ragon/MGH assay 99.5% (4/832), the primary Simoa assay model 99.0% (8/832), and the Epitope IgG and IgM 99.0% (8/830) and 99.5% (4/830), respectively. Overall sensitivities for the Simoa, Roche pan-IG, Epitope IgG, Ragon/MGH IgG, and Epitope IgM were 92.0%, 82.9%, 82.5%, 64.5% and 47.0%, respectively. The Simoa immunoassay demonstrated the highest sensitivity among samples stratified by days postsymptom onset (PSO), 21 days PSO (95.18%). Conclusions All assays demonstrated high to very high specificities while sensitivities were variable across assays.

There are limited data for the clinical efficacy of bebtelovimab in preventing severe coronavirus disease 2019. Among outpatients unable to take nirmatrelvir-ritonavir at a large health system, 10 of 377 (2.7%) patients who received bebtelovimab and 17 of 377 (4.5%) matched untreated patients were hospitalized or died. The 43% observed risk reduction with bebtelovimab was not statistically significant (P = 0.14).

BackgroundIn the EPIC-HR trial, nirmatrelvir plus ritonavir led to an 88% reduction in hospitalization or death among unvaccinated outpatients with early COVID-19. Clinical impact of nirmatrelvir plus ritonavir among vaccinated populations is uncertain.ObjectiveTo assess whether nirmatrelvir plus ritonavir reduces risk of hospitalization among outpatients with early COVID-19 in the setting of prevalent SARS-CoV-2 immunity and immune evasive SARS-CoV-2 lineages.DesignPopulation-based cohort study analyzed to emulate a clinical trial utilizing two-stage, inverse-probability weighted models to account for anticipated bias in testing and treatment.SettingA large healthcare system providing care for 1.5 million patients in Massachusetts and New Hampshire during Omicron wave (January 1 to May 15, 2022) with staged access and capacity to prescribe nirmatrelvir plus ritonavir.Patients30,322 non-hospitalized adults (87.2% vaccinated) aged 50 and older with COVID-19 and without contraindications to nirmatrelvir plus ritonavir.MeasurementPrimary outcome was hospitalization within 14 days of COVID-19 diagnosis.ResultsDuring the study period, 6036 (19.9%) patients were prescribed nirmatrelvir plus ritonavir and 24,286 (80.1%) patients were not. Patients prescribed nirmatrelvir were more likely to be older, have more comorbidities, and be unvaccinated. Hospitalization occurred in 40 (0.66%) and 232 (0.96%) patients prescribed and not prescribed nirmatrelvir plus ritonavir, respectively. The adjusted risk ratio was 0.55 (95% confidence interval 0.38 to 0.80, p = 0.002). Observed risk reduction was greater among unvaccinated patients and obese patients.LimitationsPotential for residual confounding due to differential access and uptake of COVID-19 vaccines, diagnostics, and treatment.ConclusionsThe overall risk of hospitalization was already low (FundingNational Institutes of Health (P30 AI060354 and R01 CA236546).

Serological assays are important diagnostic tools for surveying exposure to the pathogen, monitoring immune response post vaccination, and managing spread of the infectious agent among the population. Current serological laboratory assays are often limited because they require the use of specialized laboratory technology and/or work with a limited number of sample types. Here, we evaluate an alternative by developing time-resolved Förster resonance energy transfer (TR-FRET) homogeneous assays that exhibited exceptional versatility, scalability, and sensitivity and outperformed or matched currently used strategies in terms of sensitivity, specificity, and precision. We validated the performance of the assays measuring total immunoglobulin G (IgG) levels; antibodies against severe acute respiratory syndrome coronavirus (SARS-CoV) or Middle Eastern respiratory syndrome (MERS)-CoV spike (S) protein; and SARS-CoV-2 S and nucleocapsid (N) proteins and applied it to several large sample sets and real-world applications. We further established a TR-FRET-based ACE2-S competition assay to assess the neutralization propensity of the antibodies. Overall, these TR-FRET-based serological assays can be rapidly extended to other antigens and are compatible with commonly used plate readers.

BACKGROUND: The efficacy of interleukin-6 receptor blockade in hospitalized patients with coronavirus disease 2019 (Covid-19) who are not receiving mechanical ventilation is unclear. METHODS: We performed a randomized, double-blind, placebo-controlled trial involving patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hyperinflammatory states, and at least two of the following signs: fever (body temperature >38°C), pulmonary infiltrates, or the need for supplemental oxygen in order to maintain an oxygen saturation greater than 92%. Patients were randomly assigned in a 2:1 ratio to receive standard care plus a single dose of either tocilizumab (8 mg per kilogram of body weight) or placebo. The primary outcome was intubation or death, assessed in a time-to-event analysis. The secondary efficacy outcomes were clinical worsening and discontinuation of supplemental oxygen among patients who had been receiving it at baseline, both assessed in time-to-event analyses. RESULTS: We enrolled 243 patients; 141 (58%) were men, and 102 (42%) were women. The median age was 59.8 years (range, 21.7 to 85.4), and 45% of the patients were Hispanic or Latino. The hazard ratio for intubation or death in the tocilizumab group as compared with the placebo group was 0.83 (95% confidence interval [CI], 0.38 to 1.81; P = 0.64), and the hazard ratio for disease worsening was 1.11 (95% CI, 0.59 to 2.10; P = 0.73). At 14 days, 18.0% of the patients in the tocilizumab group and 14.9% of the patients in the placebo group had had worsening of disease. The median time to discontinuation of supplemental oxygen was 5.0 days (95% CI, 3.8 to 7.6) in the tocilizumab group and 4.9 days (95% CI, 3.8 to 7.8) in the placebo group (P = 0.69). At 14 days, 24.6% of the patients in the tocilizumab group and 21.2% of the patients in the placebo group were still receiving supplemental oxygen. Patients who received tocilizumab had fewer serious infections than patients who received placebo. CONCLUSIONS: Tocilizumab was not effective for preventing intubation or death in moderately ill hospitalized patients with Covid-19. Some benefit or harm cannot be ruled out, however, because the confidence intervals for efficacy comparisons were wide. (Funded by Genentech; ClinicalTrials.gov number, NCT04356937.).

Background: There is a low utilization rate of donated donor lungs. Historically, transplantation of lungs from hepatitis C-viremic donors to hepatitis C (HCV) negative recipients was avoided due to concern for worse graft survival. In the past few years with the advent of direct acting antiviral (DAA) therapy, there are emerging data suggesting the safety and efficacy of transplanting thoracic organs from HCV-viremic donors. This study assessed the differences in donor characteristics and allograft-specific clinical features at the time of organ offer and investigated whether these variables differed in HCV-viremic versus HCV-negative donors and impacted recipient outcomes. Methods: We conducted a single-center, retrospective cohort study of adult patients who underwent a lung transplant at Brigham and Women’s Hospital between March 2017 and October 2018. Patients were stratified based on their donor HCV status (HCV-viremic versus HCV-negative). Donor and allograft-specific characteristics and clinical features including chest imaging and bronchoscopy reports, respiratory cultures, and the donor’s oxygenation as measured by the arterial partial pressure of oxygen (PaO 2 ) were collected as well as recipient baseline characteristics and transplant outcomes. Results: During the study period, 42 and 57 lung transplants were performed from HCV-viremic and HCV-negative donors, respectively. Donor age was similar in both cohorts. More HCV-viremic donors died from drug intoxication (71% versus 19%, P=0.0001) and had a history of cigarette use (83% versus 5%, P=0.0001) and drug use (76% versus 49%, P=0.007). There were differences in the baseline recipient characteristics including a lower median lung allocation score in the HCV-viremic cohort. The organ-specific clinical characteristics including the terminal PaO 2 , chest imaging and bronchoscopy findings, and evidence of pulmonary infection were similar between the two cohorts. The recipient outcomes overall were excellent and did not differ significantly in both cohorts in terms of graft and patient survival at 6 and 12 months. Conclusions: Despite a greater proportion of HCV-viremic donors being increased risk with a history of drug and cigarette use and having died as a result of drug intoxication, the quality of the HCV-viremic donor organs did not differ from the HCV-negative donor organs or impact graft and recipient survival. Due to an increasing number of transplants from increased risk donors and in order to develop safe and effective protocols to perform lung transplants from HCV-infected donors, further characterization of the donor and allograft-specific clinical features and longer-term recipient outcomes is greatly needed.

ImportanceUnbiased assessment of risks associated with acquisition of SARS-CoV-2 is critical to informing mitigation efforts during pandemics.ObjectiveUnderstand risk factors for acquiring COVID-19 in a large, prospective cohort of adult residents recruited to be representative of a large US metropolitan area.DesignFully remote longitudinal cohort study launched in October 2020 and ongoing; Study data reported through June 15, 2021.SettingBrigham and Women’s Hospital, Boston MA.ParticipantsAdults within 45 miles of Boston, MA.InterventionMonthly at-home SARS-CoV-2 viral and antibody testing.Main OutcomesBetween October 2020 and January 2021, we enrolled 10,289 adults reflective of Massachusetts census data. At study entry, 567 (5.5%) participants had evidence of current or prior SARS-CoV-2 infection. This increased to 13.4% by June 15, 2021. Compared to whites, Black non-Hispanic participants had a 2.2 fold greater risk of acquiring COVID-19 (HR 2.19, 95% CI 1.91-2.50; p=ConclusionsThese results demonstrate that race/ethnicity and socioeconomic status are not only risk factors for severity of disease but are also the biggest determinants of acquisition of infection. Importantly, this disparity is significantly underestimated if based on PCR data alone as noted by the discrepancy in serology vs. PCR detection for non-white participants, and points to persistent disparity in access to testing. Meanwhile, medical conditions and advanced age that increase the risk for severity of SARS-CoV-2 disease were associated with a lower risk of acquisition of COVID-19 suggesting the importance of behavior modifications. These findings highlight the need for mitigation programs that overcome challenges of structural racism in current and future pandemics.Trial RegistrationN/AKEY POINTSQuestionWhat population and occupational groups in the United States are at increased risk for acquiring COVID-19?FindingsIn this remote, longitudinal cohort study involving monthly PCR and serology self-testing of 10,289 adult residents of the Boston metropolitan area, 9257 (90.0%) of TestBoston participants acquired evidence of immunity to SARS-CoV-2 through vaccination, infection, or both as of June 15, 2021. Residents identifying as Black, Hispanic/Latinx had an increased risk of acquisition of COVID-19. Healthcare workers were not at increased risk of SARS-CoV-2 acquisition. Individuals with medical risk factors for severe COVID-19 disease were at a decreased risk of SARS-CoV-2 acquisition.MeaningThese results demonstrate that race/ethnicity and socioeconomic status are not only risk factors for severity of disease but also are the biggest determinants of acquisition of infection. These findings highlight the need to address the consequences of structural racism during the development of mitigation programs for current and future pandemics.

Background Burkholderia cepacia complex is a group of potential nosocomial pathogens often linked to contaminated water. We report on a cluster of 8 B. cepacia complex infections in cardiothoracic intensive care unit patients, which were attributed to contaminated extracorporeal membrane oxygenation (ECMO) water heaters. Methods In December 2020, we identified an increase in B. cepacia complex infections in the cardiothoracic intensive care unit at Brigham and Women’s Hospital. We sought commonalities, sequenced isolates, obtained environmental specimens, and enacted mitigation measures. Results Whole-genome sequencing of 13 B. cepacia complex clinical specimens between November 2020 and February 2021 identified 6 clonally related isolates, speciated as Burkholderia contaminans. All 6 occurred in patients on ECMO. Microbiology review identified 2 additional B. contaminans cases from June 2020 that may have also been cluster related, including 1 in a patient receiving ECMO. All 8 definite or probable cluster cases required treatment; 3 patients died, and 3 experienced recurrent infections. After ECMO was identified as the major commonality, all 9 of the hospital’s ECMO water heaters were cultured, and B. contaminans grew in all cultures. Cultures from air sampled adjacent to the water heaters were negative. Water heater touch screens were culture positive for B. contaminans, and the sink drain in the ECMO heater reprocessing room also grew clonal B. contaminans. Observations of reprocessing revealed opportunities for cross-contamination between devices through splashing from the contaminated sink. The cluster was aborted by removing all water heaters from clinical service. Conclusions We identified a cluster of 8 B. cepacia complex infections associated with contaminated ECMO water heaters. This cluster underscores the potential risks associated with water-based ECMO heaters and, more broadly, water-based care for vulnerable patients.

Longitudinal clinical studies traditionally require in-person study visits which are well documented to pose barriers to participation and contribute challenges to enrolling representative samples. Remote trial models may reduce barriers to research engagement, improve retention, and reach a more representative cohort. As remote trials become more common following the COVID-19 pandemic, a critical evaluation of this approach is imperative to optimize this paradigm shift in research. The TestBoston study was launched to understand prevalence and risk factors for COVID-19 infection in the greater Boston area through a fully remote home-testing model. Participants (adults, within 45 miles of Boston, MA) were recruited remotely from patient registries at Brigham and Women’s Hospital and the general public. Participants were provided with monthly and “on-demand” at-home SARS-CoV-2 RT-PCR and antibody testing using nasal swab and dried blood spot self-collection kits and electronic surveys to assess symptoms and risk factors for COVID-19 via an online dashboard. Between October 2020 and January 2021, we enrolled 10,289 participants reflective of Massachusetts census data. Mean age was 47 years (range 18–93), 5855 (56.9%) were assigned female sex at birth, 7181(69.8%) reported being White non-Hispanic, 952 (9.3%) Hispanic/Latinx, 925 (9.0%) Black, 889 (8.6%) Asian, and 342 (3.3%) other and/or more than one race. Lower initial enrollment among Black and Hispanic/Latinx individuals required an adaptive approach to recruitment, leveraging connections to the medical system, coupled with community partnerships to ensure a representative cohort. Longitudinal retention was higher among participants who were White non-Hispanic, older, working remotely, and with lower socioeconomic vulnerability. Implementation highlighted key differences in remote trial models as participants independently navigate study milestones, requiring a dedicated participant support team and robust technology platforms, to reduce barriers to enrollment, promote retention, and ensure scientific rigor and data quality. Remote clinical trial models offer tremendous potential to engage representative cohorts, scale biomedical research, and promote accessibility by reducing barriers common in traditional trial design. Barriers and burdens within remote trials may be experienced disproportionately across demographic groups. To maximize engagement and retention, researchers should prioritize intensive participant support, investment in technologic infrastructure and an adaptive approach to maximize engagement and retention.

ImportanceRemote clinical trials may reduce barriers to research engagement resulting in more representative samples. A critical evaluation of this approach is imperative to optimize this paradigm shift in research.ObjectiveTo assess design and implementation factors required to maximize enrollment and retention in a fully remote, longitudinal COVID-19 testing study.DesignFully remote longitudinal study launched in October 2020 and ongoing; Study data reported through July 2021.SettingBrigham and Women’s Hospital, Boston MAParticipantsAdults, 18 years or older, within 45 miles of Boston, MA.InterventionMonthly and “on-demand” at-home SARS-CoV-2 RT-PCR and antibody testing using nasal swab and dried blood spot self-collection kits and electronic surveys to assess symptoms and risk factors for COVID-19.Main OutcomesEnrollment, retention, and lessons learned.ResultsBetween October 2020 and January 2021, we enrolled 10,289 participants reflective of Massachusetts census data. Mean age was 47 years (range 18-93), 5855 (56.9%) were assigned female sex at birth, 7181(69.8%) reported being White non-Hispanic, 952 (9.3%) Hispanic/Latinx, 925 (9.0%) Black, 889 (8.6%) Asian, and 342 (3.3%) other and/or more than one race. Lower initial enrollment among Black and Hispanic/Latinx individuals required an adaptive approach, leveraging connections to the medical system, coupled with community partnerships to ensure a representative cohort. Longitudinal retention was higher among participants who were White non-Hispanic, older, working remotely, and with lower socioeconomic vulnerability. Considerable infrastructure, including a dedicated participant support team and robust technology platforms was required to reduce barriers to enrollment, promote retention, ensure scientific rigor, improve data quality, and enable an adaptive study design to increase real-world accessibility.ConclusionsThe decentralization of clinical trials through remote models offers tremendous potential to engage representative cohorts, scale biomedical research, and promote accessibility by reducing barriers common in traditional trial design. Our model highlights the critical role that hospital-community partnerships play in remote recruitment, and the work still needed to ensure representative enrollment. Barriers and burdens within remote trials may be experienced disproportionately across demographic groups. To maximize engagement and retention, researchers should prioritize intensive participant support, investment in technologic infrastructure and an adaptive approach to maximize engagement and retention.Trial RegistrationN/AKey PointsQuestionLongitudinal clinical studies typically rely on in-person interactions to support recruitment, retention, and implementation. We define factors that promote demographically representative recruitment and retention through implementation of a fully remote COVID-19 study.FindingsRemote trial models can reduce barriers to research participation and engage representative cohorts. Recruitment was strengthened by leveraging the medical system. Implementation highlighted participant burdens unique to this model, underscoring the need for a significant participant support team, robust technological infrastructure, and an adaptive, iterative approach.MeaningAs remote trials become more common following the COVID-19 pandemic, methodologies to ensure accessibility, representation, and efficiency are crucial.

The field of infectious diseases currently takes a reactive approach and treats infections as they present in patients. Although certain populations are known to be at greater risk of developing infection (eg, immunocompromised), we lack a systems approach to define the true risk of future infection for a patient. Guided by impressive gains in “omics” technologies, future strategies to infectious diseases should take a precision approach to infection through identification of patients at intermediate and high-risk of infection and deploy targeted preventative measures (ie, prophylaxis). The advances of high-throughput immune profiling by multiomics approaches (ie, transcriptomics, epigenomics, metabolomics, proteomics) hold the promise to identify patients at increased risk of infection and enable risk-stratifying approaches to be applied in the clinic. Integration of patient-specific data using machine learning improves the effectiveness of prediction, providing the necessary technologies needed to propel the field of infectious diseases medicine into the era of personalized medicine., Translational systems immunology approaches to infectious diseases will enable the switch from reactive to precision treatment of patients, which will improve clinical outcomes while reducing the use of prophylactic antibiotics and incidence of infection in high-risk individuals.

Transmission of coronavirus disease 2019 (COVID-19) from people without symptoms confounds societal mitigation strategies. From April to June 2020, we tested nasopharyngeal swabs by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) from 15 514 staff and 16 966 residents of nursing homes and assisted living facilities in Massachusetts. Cycle threshold (Ct) distributions were very similar between populations with (n = 739) and without (n = 2179) symptoms at the time of sampling (mean Ct, 25.7 vs 26.4; ranges 12–38). However, as local cases waned, those without symptoms shifted towards higher Ct. With such similar viral load distributions, existing testing modalities should perform comparably regardless of symptoms, contingent upon time since infection.

Monoclonal antibodies (mAbs) are a focus in vaccine and therapeutic design to counteract SARS-CoV-2 and its variants. Here, we combined B cell sorting with single-cell VDJ and RNA-seq and mAb structures to characterize B cell responses against SARS-CoV-2. We show that the SARS-CoV-2-specific B cell repertoire consists of transcriptionally distinct B cell populations with cells producing potently neutralizing antibodies (nAbs) localized in two clusters that resemble memory and activated B cells. Cryo-electron microscopy structures of selected nAbs from these two clusters complexed with SARS-CoV-2 spike trimers show recognition of various receptor-binding domain (RBD) epitopes. One of these mAbs, BG10-19, locks the spike trimer in a closed conformation to potently neutralize SARS-CoV-2, the recently arising mutants B.1.1.7 and B.1.351, and SARS-CoV and cross-reacts with heterologous RBDs. Together, our results characterize transcriptional differences among SARS-CoV-2-specific B cells and uncover cross-neutralizing Ab targets that will inform immunogen and therapeutic design against coronaviruses., B cell genomics reveals transcriptionally distinct populations that modulate antibody responses to SARS-CoV-2, with the identification of a monoclonal antibody that locks the virus spike trimer to neutralize recent variants, SARS and heterologous RBDs.

OBJECTIVES: The purpose of this study was to describe our experience with fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography computed tomography (PET/CT) in diagnosing left ventricular assist device (LVAD) infections and perform a meta-analysis of published studies to determine overall diagnostic accuracy. BACKGROUND: Device-related infections are a common complication of LVADs and are linked to worse outcomes. Diagnosis of LVAD infections remains challenging. FDG PET/CT has demonstrated good diagnostic accuracy in several other infectious conditions. METHODS: This was a single-center, retrospective case series of FDG PET/CT scans in suspected LVAD infection between September 2015 and February 2018. A systematic review of PubMed from database inception through March 2018 was also conducted to identify additional studies. RESULTS: Nineteen FDG PET/CT scans were identified for the retrospective case series. The systematic review identified an additional 3 publications, for a total of 4 studies involving 119 scans assessing diagnostic performance. Axial (n = 36) and centrifugal (n = 83) flow LVADs were represented. Pooled sensitivity was 92% (95% confidence interval [CI]: 82% to 97%) and specificity was 83% (95% CI: 24% to 99%) for FDG PET/CT in diagnosing LVAD infections. Summary receiver-operating characteristic curve analysis demonstrated an AUC of 0.94 (95% CI: 0.91 to 0.95). CONCLUSIONS: FDG PET/CT for suspected LVAD infections demonstrates good diagnostic accuracy, with overall high sensitivity but variable specificity.

Background Hearts and lungs from donors with hepatitis C viremia are typically not transplanted. The advent of direct-acting antiviral agents to treat hepatitis C virus (HCV) infection has raised the possibility of substantially increasing the donor organ pool by enabling the transplantation of hearts and lungs from HCV-infected donors into recipients who do not have HCV infection. Methods We conducted a trial involving transplantation of hearts and lungs from donors who had hepatitis C viremia, irrespective of HCV genotype, to adults without HCV infection. Sofosbuvir-velpatasvir, a pangenotypic direct-acting antiviral regimen, was preemptively administered to the organ recipients for 4 weeks, beginning within a few hours after transplantation, to block viral replication. The primary outcome was a composite of a sustained virologic response at 12 weeks after completion of antiviral therapy for HCV infection and graft survival at 6 months after transplantation. Results A total of 44 patients were enrolled: 36 received lung transplants and 8 received heart transplants. The median viral load in the HCV-infected donors was 890,000 IU per milliliter (interquartile range, 276,000 to 4.63 million). The HCV genotypes were genotype 1 (in 61% of the donors), genotype 2 (in 17%), genotype 3 (in 17%), and indeterminate (in 5%). A total of 42 of 44 recipients (95%) had a detectable hepatitis C viral load immediately after transplantation, with a median of 1800 IU per milliliter (interquartile range, 800 to 6180). Of the first 35 patients enrolled who had completed 6 months of follow-up, all 35 patients (100%; exact 95% confidence interval, 90 to 100) were alive and had excellent graft function and an undetectable hepatitis C viral load at 6 months after transplantation; the viral load became undetectable by approximately 2 weeks after transplantation, and it subsequently remained undetectable in all patients. No treatment-related serious adverse events were identified. More cases of acute cellular rejection for which treatment was indicated occurred in the HCV-infected lung-transplant recipients than in a cohort of patients who received lung transplants from donors who did not have HCV infection. This difference was not significant after adjustment for possible confounders. Conclusions In patients without HCV infection who received a heart or lung transplant from donors with hepatitis C viremia, treatment with an antiviral regimen for 4 weeks, initiated within a few hours after transplantation, prevented the establishment of HCV infection. (Funded by the Mendez National Institute of Transplantation Foundation and others; DONATE HCV ClinicalTrials.gov number, NCT03086044.).

Background mRNA vaccines for coronavirus disease 2019 (COVID-19) illicit strong humoral and cellular responses and have high efficacy for preventing and reducing the risk of severe illness from COVID-19. Since solid organ transplant (SOT) recipients were excluded from the phase 3 trials, the efficacy of the COVID-19 vaccine remains unknown. Understanding the serological responses to COVID vaccines among SOT recipients is essential to better understand vaccine protection for this vulnerable population. Methods In this prospective cohort study, a subset of SOT recipients who were part of our center’s larger antibody study were enrolled prior to receipt of two doses of the BNT162b2 (Pfizer, Inc) vaccine for high resolution immunophenotyping. To date, plasma has been collected for 10 participants on the day of their first dose (baseline), day of their second dose, and 28 days post second dose. 23 healthy participants planning to receive either BNT162b2 or mRNA-1273 (ModernaTX, Inc) were also enrolled, providing plasma at the same timepoints. Ultrasensitive single-molecule array (Simoa) assays were used to detect SARS-CoV-2 Spike (S), S1, receptor-binding domain (RBD) and Nucleocapsid (N) IgG antibodies. Results Participant demographics and SOT recipient characteristics are summarized in Table 1. Low titers of anti-N IgG at all timepoints indicate no natural infection with COVID-19 during the study (Fig 1A). There were significantly lower magnitudes for anti-S (p< 0.0001), anti-S1 (p< 0.0001), and anti-RBD (p< 0.0001) IgG titers on the day of dose 2 and day 28 post second dose for SOT recipients compared to healthy controls (Fig 1B,C,D). Using the internally validated threshold of anti-S IgG >1.07 based on pre-pandemic controls, only 50% of the SOT sub-cohort responded to vaccine after series completion (Fig 2). There was a positive trend between months from transplant and anti-S IgG titer (Fig 3). Table 1: Demographics Figure 1: Anti-N, Anti-S, Anti-S1, Anti-RBD and Anti-N Ig G for healthy v. SOT cohort Black error bars denote median and 95% CI. The dotted line on panel B denotes an internally validated cutoff of 1.07; anti-S IgG titers greater than 1.07 denote a positive response. Figure 3: Time from Transplant v. anti-S IgG Titer SOT recipients further out from transplant tend to have a higher anti-S IgG response. The dotted line denotes an internally validated cutoff, with anti-S IgG titers greater than 1.07 indicating a positive response. Conclusion SOT recipients had a significantly decreased humoral response to mRNA COVID-19 vaccines compared to the healthy cohort, with those further out from transplant more likely to respond. Further research is needed to evaluate T-cell responses and clinical efficacy to maximize the SARS-CoV-2 vaccine response among SOT recipients. Disclosures Ann E. Woolley, MD, MPH, COVAX (Consultant) David Walt, PhD, Quanterix Corporation (Board Member, Shareholder)

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types., Graphical abstract, D’Antonio et al. characterize associations between GWAS signals for COVID-19 disease and eQTLs in 69 human tissues to identify causal variants and their underlying molecular mechanisms. They show that diverse symptoms and disease severity of COVID-19 are associated with variants affecting gene expression in a wide variety of tissues.

Background: Despite over one million cases of novel coronavirus disease 2019 (COVID-19) in the United States, limited data, including socioeconomic information and treatment strategies, exist regarding patients hospitalized with the viral infection. Methods: In this case series, we identified patients with COVID-19 admitted to 3 Partners Healthcare hospitals in Boston, Massachusetts between March 7th, 2020, and March 30th, 2020. Patient characteristics; treatment strategies; clinical outcomes including mortality, intensive care utilization, and cardiovascular events were determined. Findings: A total of 247 patients hospitalized with COVID-19 over the study period were identified; the median age was 61 (interquartile range [IQR]: 50-76 years), 58% were men, 30% of Hispanic ethnicity, 21% enrolled in Medicaid, and 12% dual-enrolled Medicare/Medicaid. The median estimated household income was $66,701 [IQR: $50,336- $86,601]. Among patients with employment data (204): 89 (36%) were retired, 23 (9.3%) worked in hospitality, 10 (4%) were healthcare workers, 5 (2%) worked in public transportation, and 21 (8.5%) were unemployed. The majority of patients were treated with hydroxychloroquine (72%), and statins (76%; newly initiated in 34%). Among those treated with hydroxychloroquine with available electrocardiogram data (172), 38% developed QTc prolongation. Discontinuation of statin therapy due to elevated creatinine kinase or elevated liver biochemical tests was also common (29%). New atrial fibrillation/flutter occurred in 8.9% of patients and ventricular tachycardia (non-sustained/sustained) in 7.3% of patients. Other cardiovascular events including myocardial infarction (4.9%) and venous thromboembolism (2.8%) were less common. Within the follow-up period, 103 (42%) required intensive care. At the end of the data collection period (April 19, 2020), 170 patients (68.8%) were discharged alive, 51 patients (20.7%) remain admitted, and 26 patients (10.5%) have died. Interpretation: Patients hospitalized with COVID-19 are frequently of vulnerable socioeconomic status and often require intensive care. Early in the pandemic, off-label drug prescriptions were common. Funding Statement: American Heart Association Declaration of Interests: Dr. Wasfy reports a grant from the American Heart Association (18 CDA 34110215). Dr. Natarajan is supported by a Hassenfeld Scholar Award from the Massachusetts General Hospital, a grant from Fondation Leducq (TNE-18CVD04), and National Heart, Lung, and Blood Institute grants (R01HL148565, R01HL148050, R01HL142711); has received grant support from Amgen, Apple, and Boston Scientific; and has served as a scientific advisor to Apple and Blackstone Life Sciences. Dr. Januzzi is supported by the Hutter Family Professorship, is a Trustee of the American College of Cardiology, has received grant support from Novartis Pharmaceuticals and Abbott Diagnostics, consulting income from Abbott, Janssen, Jana Care, Novartis, Prevencio, and Roche Diagnostics, and participates in clinical endpoint committees/data safety monitoring boards for Abbott, AbbVie, Amgen, Bayer, CVRx, Janssen, and Takeda. Dr. Hibbert receives grant support from the National Heart, Lung and Blood Institute (RO1-AI138999-01, UO1-HL123022-06). The remaining authors have no relevant conflicts of interest to disclose. Ethics Approval Statement: The study was approved by the Partners Healthcare Institutional Review Board and informed consent was waived based on secondary use of data from medical record review.

BackgroundTransmission of COVID-19 from people without symptoms poses considerable challenges to public health containment measures. The distribution of viral loads in individuals with and without symptoms remains uncertain. Comprehensive cross-sectional screening of all individuals in a given setting provides an unbiased way to assess viral loads independent of symptoms, which informs transmission risks. COVID-19 cases initially peaked in Massachusetts in mid-April 2020 before declining through June, and congregate living facilities were particularly affected during this early surge. We performed a retrospective analysis of data from a large public health-directed outbreak response initiative that involved comprehensive screening within nursing homes and assisted living facilities in Massachusetts to compare nasopharyngeal (NP) viral loads (as measured by RT-PCR cycle threshold (Ct) levels) in residents and staff to inform our ability to detect SARS-CoV-2 in individuals with or without symptoms in the population.MethodsBetween April 9 and June 9, 2020, we tested NP swabs from 32,480 unique individuals comprising staff and residents of the majority of nursing homes and assisted living facilities in Massachusetts. Under the direction of the MA Department of Public Health (MDPH), symptomatology at the time of sampling and demographic information was provided by each facility for each individual to facilitate reporting to health officials. NP swabs were collected, RNA extracted, and SARS-CoV-2 testing performed using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR).ResultsThe nursing home and assisted living facilities resident cohort (N =16,966) was 65% female with a mean age of 82 years (SD 13 yrs). The staff cohort (N = 15,514) was 76% female with a median age of 45 (SD 15 yrs). A total 2654 residents (15.5%) and 624 staff (4.1%) tested positive for SARS-CoV-2. 12.7% of residents and 3.7% of staff without symptoms tested positive for SARS-CoV-2, compared to 53.1% of residents and 18.2% of staff with symptoms. Of the individuals who tested positive, 70.8% of residents and 92.4% of staff lacked symptoms at the time of testing. In aggregate, the distributions of Cts for viral probes used in the qRT-PCR assay were very similar, with a statistically but not meaningfully different mean (ΔCt 0.71 cycles, p = 0.006) and a similar range (12-38 cycles), between populations with and without symptoms over the entire time period, across all sub-categories examined (age, race, ethnicity, sex, resident/staff). Importantly, the Ct mean values and range were indistinguishable between the populations by symptom class during the peak of the outbreak in Massachusetts, with a Ct gap appearing only later in the survey period, reaching >3 cycles (p ≤ 0.001) for facilities sampled during the last two weeks of the study.ConclusionsIn a large cohort of individuals screened for SARS-CoV-2 by qRT-PCR, we found strikingly similar distributions of viral load in patients with or without symptoms at the time of testing during the local peak of the epidemic; as the epidemic waned, individuals without symptoms at the time of testing had lower viral loads. The size of the study population, including both staff and residents spanning a wide range of ages, provides a comprehensive cross-sectional point prevalence measurement of viral burden in a study spanning 2 months. Because the distributions of viral loads in infected individuals irrespective of symptomatology are very similar, existing testing modalities that have been validated for detection of SARS-CoV-2 RNA in symptomatic patients should perform similarly in individuals without symptoms at the time of testing.

The advent of therapies for successful treatment of hepatitis C virus has allowed the heart and lung transplant community to re-explore the use of hepatitis C virus-positive donors for organ transplantation, with a benefit for many terminally ill patients. The consensus statements provided herein represent the current state of knowledge and expertise in this area, which we expect will continue to rapidly evolve over the next few years.

T cell exhaustion and dysfunction are hallmarks of severe COVID-19. To gain insights into the pathways underlying these alterations, we performed a comprehensive transcriptome analysis of peripheral-blood-mononuclear-cells (PBMCs), spleen, lung, kidney, liver, and heart obtained at autopsy from COVID-19 patients and matched controls, using the nCounter CAR-T-Characterization panel. We found substantial gene alterations in COVID-19-impacted organs, especially the lung where altered TCR repertoires are noted. Reduced TCR repertoires are also observed in PBMCs of severe COVID-19 patients. ENTPD1/CD39, an ectoenzyme defining exhausted T-cells, is upregulated in the lung, liver, spleen, and PBMCs of severe COVID-19 patients where expression positively correlates with markers of vasculopathy. Heightened ENTPD1/CD39 is paralleled by elevations in STAT-3 and HIF-1α transcription factors; and by markedly reduced CD39-antisense-RNA, a long-noncoding-RNA negatively regulating ENTPD1/CD39 at the post-transcriptional level. Limited TCR repertoire and aberrant regulation of ENTPD1/CD39 could have permissive roles in COVID-19 progression and indicate potential therapeutic targets to reverse disease., Graphical abstract, Immunology; Virology

Background Babesiosis, a tickborne zoonotic disease caused by intraerythrocytic protozoa of the genus babesia, is characterized by nonimmune hemolytic anemia that resolves with antimicrobial treatment and clearance of parasitemia. The development of warm-antibody autoimmune hemolytic anemia (also known as warm autoimmune hemolytic anemia [WAHA]) in patients with babesiosis has not previously been well described. Methods After the observation of sporadic cases of WAHA that occurred after treatment of patients for babesiosis, we conducted a retrospective cohort study of all the patients with babesiosis who were cared for at our center from January 2009 through June 2016. Data on covariates of interest were extracted from the medical records, including any hematologic complications that occurred within 3 months after the diagnosis and treatment of babesiosis. Results A total of 86 patients received a diagnosis of babesiosis during the 7.5-year study period; 18 of these patients were asplenic. WAHA developed in 6 patients 2 to 4 weeks after the diagnosis of babesiosis, by which time all the patients had had clinical and laboratory responses to antimicrobial treatment of babesiosis, including clearance of Babesia microti parasitemia. All 6 patients were asplenic (P

Background Transmission of COVID-19 from people without symptoms confounds public health containment strategies. Comprehensive cross-sectional screening enables assessment of viral load independent of symptoms, informing transmission risks. We quantified SARS-CoV-2 burden by RT-qPCR from comprehensive screening of nursing homes and assisted living facilities in Massachusetts to inform our ability to detect SARS-CoV-2 in individuals with or without symptoms. Methods From 4/9/20 to 6/9/20, we tested nasopharyngeal (NP) swabs from 32,480 unique individuals comprising staff and residents of the majority of nursing homes and assisted living facilities in Massachusetts. Symptomatology at the time of sampling and demographic information were provided by each facility. NP swabs were collected, RNA extracted, and SARS-CoV-2 testing performed by RT-qPCR. We compared cycle thresholds (Ct) with a standard curve to quantify viral loads. Results The nursing home and assisted living facilities resident cohort (N = 16,966) was 65% female with mean age 82. The staff cohort (N = 15,514) was 76% female with mean age 45. In all, 2654 residents (15.5%) and 624 staff (4.1%) tested positive for SARS-CoV-2, including 12.7% of residents and 3.7% of staff without symptoms, compared to 53.1% of residents and 18.2% of staff with symptoms. The Ct distributions for viral probes were very similar between populations with and without symptoms (Fig 1), with a statistically but not meaningfully different mean (ΔCt 0.71 cycles, p = 0.006) and a similar range (12–38 cycles). This similarity persisted across all sub-categories examined (age, race, ethnicity, sex, resident/staff). Figure 1 Conclusion In a large cohort of individuals screened for SARS-CoV-2 by RT-qPCR, we found strikingly similar viral load distributions in patients with or without symptoms at the time of testing. The size of the study population, including both staff and residents spanning a wide range of ages, provides a comprehensive cross-sectional point prevalence measurement of viral burden. Because the distributions of viral loads are very similar regardless of symptoms, existing testing modalities validated for detection of SARS-CoV-2 RNA in symptomatic patients should perform similarly well in individuals without symptoms at the time of testing. Disclosures All Authors: No reported disclosures