Incidence and risk factors of omicron variant SARS-CoV-2 breakthrough infection among vaccinated and boosted individuals.

Background: SARS-CoV-2 vaccines have been shown to be safe and effective against infection and severe COVID-19 disease worldwide. Certain co-morbid conditions cause immune dysfunction and may reduce immune response to vaccination. In contrast, those with co-morbidities may practice infection prevention strategies. Thus, the real-world clinical impact of co-morbidities on SARS-CoV-2 infection in the recent post-vaccination period is not well established. We performed this study to understand the epidemiology of Omicron breakthrough infection and evaluate associations with number of comorbidities in a vaccinated and boosted population. Methods and Findings: We performed a retrospective clinical cohort study utilizing the Northwestern Medicine Enterprise Data Warehouse. Our study population was identified as fully vaccinated adults with at least one booster. The primary risk factor of interest was the number of co-morbidities. Our primary outcome was incidence and time to first positive SARS-CoV-2 molecular test in the Omicron predominant era. We performed multivariable analyses stratified by calendar time using Cox modeling to determine hazard of SARS-CoV-2. In total, 133,191 patients were analyzed. Having 3+ comorbidities was associated with increased hazard for breakthrough (HR=1.2 CI 1.2-1.6). During the second half of the study, having 2 comorbidities (HR= 1.1 95% CI 1.02-1.2) and having 3+ comorbidities (HR 1.7, 95% CI 1.5-1.9) were associated with increased hazard for Omicron breakthrough. Older age was associated with decreased hazard in the first 6 months of follow-up. Interaction terms for calendar time indicated significant changes in hazard for many factors between the first and second halves of the follow-up period. Conclusions: Omicron breakthrough is common with significantly higher risk for our most vulnerable patients with multiple co-morbidities. Age related behavioral factors play an important role in breakthrough infection with the highest incidence among young adults. Our findings reflect real-world differences in immunity and exposure risk behaviors for populations vulnerable to COVID-19.

Using SCENTinel® to predict SARS-CoV-2 infection: insights from a community sample during dominance of Delta and Omicron variants.

Introduction: Based on a large body of previous research suggesting that smell loss was a predictor of COVID-19, we investigated the ability of SCENTinel®, a newly validated rapid olfactory test that assesses odor detection, intensity, and identification, to predict SARS-CoV-2 infection in a community sample. Methods: Between April 5, 2021, and July 5, 2022, 1,979 individuals took one SCENTinel® test, completed at least one physician-ordered SARS-CoV-2 PCR test, and endorsed a list of self-reported symptoms. Results: Among the of SCENTinel® subtests, the self-rated odor intensity score, especially when dichotomized using a previously established threshold, was the strongest predictor of SARS-CoV-2 infection. SCENTinel® had high specificity and negative predictive value, indicating that those who passed SCENTinel® likely did not have a SARS-CoV-2 infection. Predictability of the SCENTinel® performance was stronger when the SARS-CoV-2 Delta variant was dominant rather than when the SARS-CoV-2 Omicron variant was dominant. Additionally, SCENTinel® predicted SARS-CoV-2 positivity better than using a self-reported symptom checklist alone. Discussion: These results indicate that SCENTinel® is a rapid assessment tool that can be used for population-level screening to monitor abrupt changes in olfactory function, and to evaluate spread of viral infections like SARS-CoV-2 that often have smell loss as a symptom.

Integration of individualized and population-level molecular epidemiology data to model COVID-19 outcomes.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with enhanced transmissibility and immune escape have emerged periodically throughout the coronavirus disease 2019 (COVID-19) pandemic, but the impact of these variants on disease severity has remained unclear. In this single-center, retrospective cohort study, we examined the association between SARS-CoV-2 clade and patient outcome over a two-year period in Chicago, Illinois. Between March 2020 and March 2022, 14,252 residual diagnostic specimens were collected from SARS-CoV-2-positive inpatients and outpatients alongside linked clinical and demographic metadata, of which 2,114 were processed for viral whole-genome sequencing. When controlling for patient demographics and vaccination status, several viral clades were associated with risk for hospitalization, but this association was negated by the inclusion of population-level confounders, including case count, sampling bias, and shifting standards of care. These data highlight the importance of integrating non-virological factors into disease severity and outcome models for the accurate assessment of patient risk.

Effect of early medication adherence on behavioral treatment utilization and smoking cessation among individuals with current or past major depressive disorder.

SIGNIFICANCE: Little is known about the mechanisms by which medication adherence promotes smoking cessation among adults with MDD. We tested the hypothesis that early adherence promotes abstinence by increasing behavioral treatment (BT) utilization. METHODS: Data for this post-hoc analysis were from a randomized trial of 149 adults with current or past MDD treated with BT and either varenicline (n = 81) or placebo (n = 68). Arms were matched on medication regimen. Early medication adherence was measured by the number of days in which medication was taken at the prescribed dose during the first six of 12 weeks of pharmacological treatment (weeks 2-7). BT consisted of eight 45-minute sessions (weeks 1-12). Bioverified abstinence was assessed at end-of-treatment (week 14). A regression-based approach was used to test whether the effect of early medication adherence on abstinence was mediated by BT utilization. RESULTS: Among 141 participants who initiated the medication regimen, BT utilization mediated the effect of early medication adherence on abstinencea) an interquartile increase in early medication days from 20 to 42 predicted a 4.2 times increase in abstinence (Total Risk Ratio (RR) = 4.24, 95% CI = 2.32-13.37; p <.001); b) increases in BT sessions predicted by such an increase in early medication days were associated with a 2.7 times increase in abstinence (Indirect RR = 2.73, 95% CI = 1.54-7.58; p <.001); and c) early medication adherence effects on abstinence were attenuated, controlling for BT (Direct RR = 1.55, 95% CI = 0.83-4.23, p =.17). CONCLUSIONS: The effect of early medication adherence on abstinence in individuals with current or past MDD is mediated by intensive BT utilization.

The Association of HIV Control and Immunosuppression With Risk of Non-AIDS-Defining Cancer Risk Among Patients on Antiretroviral Therapy.

BACKGROUND: People living with HIV (PWH) are experiencing an increased prevalence of non-AIDS-defining cancers (NADCs). Our study investigated the association of immunosuppression and HIV control with NADCs among PWH on antiretroviral therapy (ART) in the United States. METHODS: Among patients across 8 clinical cohorts on ART between 1996 and 2016, we assessed immune function and HIV control using 3 parameterizations of CD4 count and HIV-RNA viral load (VL): (1) CD4 or VL at ART initiation; (2) change in CD4 or VL after ART initiation; and (3) proportion of follow-up time at CD4 >500 cells/µL or VL <50 copies/mL. Cox models were used to ascertain the association of these measures with risk of a viral NADC or nonviral NADC. RESULTS: Among 29,568 patients on ART, there were 410 nonviral NADCs and 213 viral NADCs. PWH with a CD4 <200 cells/µL at ART initiation had an 80% elevated risk for developing a viral NADC. Each increase of 100 cells/µL in CD4 after ART initiation decreased risk by 14%. For viral and nonviral NADCs, 10% more follow-up time spent with a CD4 >500 cells/µL was associated with decreased risk [viral, adjusted hazard ratio (aHR): 0.82; 95% confidence intervals (CI): 0.78 to 0.86; nonviral, aHR: 0.88; 95% CI: 0.86 to 91], even after accounting for CD4 at ART initiation. When examining HIV control only, 10% more time with VL <50 copies/mL was significantly associated with decreased viral (aHR: 0.85; 95% CI: 0.82 to 0.89) and nonviral NADC risk (aHR: 0.88; 95% CI: 0.85 to 0.90). CONCLUSIONS: This study demonstrates that even for PWH on ART therapy, maintaining HIV control is associated with lower risk of both viral and nonviral NADCs.

Differential Viral Dynamics by Sex and Body Mass Index During Acute SARS-CoV-2 Infection: Results from a Longitudinal Cohort Study.

BACKGROUND: There is evidence of an association of severe COVID-19 outcomes with increased body mass index (BMI) and male sex. However, few studies have examined the interaction between sex and BMI on SARS-CoV-2 viral dynamics. METHODS: Participants conducted RT-PCR testing every 24-48 hours over a 15-day period. Sex and BMI were self-reported, and Ct values from E-gene were used to quantify viral load. Three distinct outcomes were examined using mixed effects generalized linear models, linear models, and logistic models, respectively: all Ct values (Model 1); nadir Ct value (model 2); and strongly detectable infection (at least one Ct value ≤28 during their infection) (Model 3). An interaction term between BMI and sex was included, and inverse logit transformations were applied to quantify the differences by BMI and sex using marginal predictions. RESULTS: In total, 7,988 participants enrolled in this study, and 439 participants (Model 1) and 309 (Model 2 and 3) were eligible for these analyses. Among males, increasing BMI was associated with lower Ct values in a dose-response fashion. For participants with BMIs greater than 29, males had significantly lower Ct values and nadir Ct values than females. In total, 67.8% of males and 55.3% of females recorded a strongly detectable infection; increasing proportions of men had Ct values <28 with BMIs of 35 and 40. CONCLUSIONS: We observed sex-based dimorphism in relation to BMI and COVID-19 viral load. Further investigation is needed to determine the cause, clinical impact, and transmission implications of this sex-differential effect of BMI on viral load.

Epidemiology and survival outcomes of HIV-associated cervical cancer in Nigeria.

INTRODUCTION: Invasive cervical cancer (ICC) is an HIV-associated cancer that is preventable and precancerous stages including early ICC stages could be detected through screening offering opportunities for treatment and cure. The high incidence in women living with HIV and late presentation often at advanced stages of ICC with limited treatment facilities often result in early mortality. We sought to compare the epidemiologic characteristics and survival differences in HIV status of ICC patients in Nigeria. METHODS: We conducted a cohort study at two federal academic hospital-based research sites in Jos University Teaching Hospital, and Lagos University Teaching Hospital Nigeria, between March 2018 and September 2022. We enrolled women with histologically confirmed ICC with known HIV status, and FIGO staging as part of the United States of America's National Institutes of Health/National Cancer Institute funded project titled 'Epigenomic Biomarkers of HIV-Associated Cancers in Nigeria'. The primary outcome was all-cause mortality with assessment of overall survival (OS) and time to death after ICC diagnosis. OS distribution was estimated using the method of Kaplan-Meier and compared between groups using the log-rank test. RESULTS: A total of 239 women with confirmed ICC were enrolled and included in this analysis, of whom 192 (80.3%) were HIV-negative (HIV-/ICC +), and 47 (19.7%) were HIV-positive (HIV +/ICC +). The HIV +/ICC + patients were younger with median age 46 (IQR: 40-51) years compared to 57 (IQR: 45-66) among HIV-/ICC + (P < 0.001). Squamous cell carcinoma was the commonest histopathologic variant in 80.4% of ICC diagnosis, moderately differentiated tumor grade in 68.1% in both groups. HIV +/ICC + diagnosis was at FIGO advanced stages in 64.9% compared to 47.9% in HIV-/ICC +. The HIV-/ICC + women had better OS compared to HIV +/ICC + participants (p = 0.018), with 12-month OS 84.1% (95%CI 75-90%) and 67.6% (95%CI 42-84%) respectively. CONCLUSION: ICC is diagnosed at a relatively young age in women living with HIV, with a significantly lower overall survival probability compared to women without HIV. The trend of presentation and diagnosis at advanced stages in women living with HIV could partly explain the differences in overall survival.

Incident Kaposi sarcoma during the expansion of antiretroviral therapy eligibility in Nigeria: a retrospective cohort study.

INTRODUCTION: The expansion of antiretroviral therapy (ART) eligibility could lead to earlier initiation of Human Immunodeficiency Virus (HIV) treatment and consequently reduce the risk of HIV-associated Kaposi Sarcoma (KS). We investigated the impact of changes in the Nigerian HIV treatment guidelines on KS incidence among adults enrolled in HIV care in Nigeria. METHODS: We analyzed data of adults who enrolled for HIV care from January 2006 to December 2016 at one of Nigeria's largest HIV treatment centers. Based on changes in HIV treatment guidelines, we classified 2006-2009 as the pre-expansion period and 2010-2016 as the post-expansion period. We used Kaplan Meier curves to compare the incidence of KS in the pre-expansion to the post-expansion period. We used Cox regression models to assess the hazard for incident KS between the two periods after adjusting for potential confounders. RESULTS: Among 14,479 patients with HIV, the overall KS incidence was 2.35; 95% CI 2.01-2.74/1,000 person-years. The incidence of KS decreased from 2.53 to 1.58 per 1,000 person-years from 2006 to 2009 to 2010-2016. In models adjusting for age, sex, CD4-T cell count, and ART use, the risk for KS remained lower in 2010-2016 compared to 2006-2009. In analyses restricted to time on ART, there was no significant difference in KS incidence between HIV patients who enrolled in 2006-2009 and 2010-2016 after adjusting for age, sex, and CD4 T-cell count. CONCLUSION: The expansion of ART eligibility was associated with a reduced incidence of HIV-associated KS among adults initiating HIV care in Jos, Nigeria. The reduction was likely driven by earlier enrollment for HIV care and ART initiation.

Quantity of SARS-CoV-2 RNA copies exhaled per minute during natural breathing over the course of COVID-19 infection.

SARS-CoV-2 is spread through exhaled breath of infected individuals. A fundamental question in understanding transmission of SARS-CoV-2 is how much virus an individual is exhaling into the environment while they breathe, over the course of their infection. Research on viral load dynamics during COVID-19 infection has focused on internal swab specimens, which provide a measure of viral loads inside the respiratory tract, but not on breath. Therefore, the dynamics of viral shedding on exhaled breath over the course of infection are poorly understood. Here, we collected exhaled breath specimens from COVID-19 patients and used RTq-PCR to show that numbers of exhaled SARS-CoV-2 RNA copies during COVID-19 infection do not decrease significantly until day 8 from symptom-onset. COVID-19-positive participants exhaled an average of 80 SARS-CoV-2 viral RNA copies per minute during the first 8 days of infection, with significant variability both between and within individuals, including spikes over 800 copies a minute in some patients. After day 8, there was a steep drop to levels nearing the limit of detection, persisting for up to 20 days. We further found that levels of exhaled viral RNA increased with self-rated symptom-severity, though individual variation was high. Levels of exhaled viral RNA did not differ across age, sex, time of day, vaccination status or viral variant. Our data provide a fine-grained, direct measure of the number of SARS-CoV-2 viral copies exhaled per minute during natural breathing-including 312 breath specimens collected multiple times daily over the course of infection-in order to fill an important gap in our understanding of the time course of exhaled viral loads in COVID-19.

Epidemiology and Survival outcomes of HIV-associated cervical cancer in Nigeria.

Introduction: Invasive cervical cancer (ICC) is an HIV-associated cancer that is preventable and precancerous stages including early ICC stages could be detected through screening offering opportunities for treatment and cure. The high incidence in women living with HIV and late presentation often at advanced stages of ICC with limited treatment facilities often result in early mortality. We sought to compare the epidemiologic characteristics and survival differences in HIV status of ICC patients in Nigeria. Methods: We conducted a cohort study at two federal academic hospital-based research sites in Jos University Teaching Hospital, and Lagos University Teaching Hospital Nigeria, between March 2018 and September 2022. We enrolled women with histologically confirmed ICC with known HIV status, and FIGO staging as part of the United States of America's National Institutes of Health/National Cancer Institute funded project titled 'Epigenomic Biomarkers of HIV-Associated Cancers in Nigeria'. The primary outcome was all-cause mortality with assessment of overall survival (OS) and time to death after ICC diagnosis. OS distribution was estimated using the method of Kaplan-Meier and compared between groups using the log-rank test. Results: A total of 239 women with confirmed ICC were enrolled and included in this analysis, of whom 192 (80.3%) were HIV-negative (HIV-/ICC+), and 47 (19.7%) were HIV-positive (HIV+/ICC+). The HIV+/ICC) patients were younger with median age 46 (IQR: 40-51) years compared to 57 (IQR: 45-66) among HIV-/ICC+) (P<0.001. Squamous cell carcinoma was the commonest histopathologic variant in 80.4% of ICC diagnosis, moderately differentiated tumor grade in 68.1% in both groups. HIV+/ICC+ diagnosis was at FIGO advanced stages in 64.9% compared to 47.9% in HIV-/ICC+. The HIV-/ICC+ women had better OS compared to HIV+/ICC+ participants (p=0.018), with 12-month OS 84.1% (95%CI: 75% - 90%) and 67.6% (95%CI: 42%-84%) respectively. Conclusion: ICC is diagnosed at a relatively young age in women living with HIV, with a significantly lower overall survival probability compared to women without HIV. The trend of presentation and diagnosis at advanced stages in women living with HIV could partly explain the differences in overall survival.

Relationship between patient sex and anatomical sites of extrapulmonary tuberculosis in Mali.

Background: Contribution of host factors in mediating susceptibility to extrapulmonary tuberculosis is not well understood. Objective: To examine the influence of patient sex on anatomical localization of extrapulmonary tuberculosis. Methods: We conducted a retrospective cross-sectional study in Mali, West Africa. Hospital records of 1,304 suspected cases of extrapulmonary tuberculosis, available in TB Registry of a tertiary tuberculosis referral center from 2019 to 2021, were examined. Results: A total of 1,012 (77.6%) were confirmed to have extrapulmonary tuberculosis with a male to female ratio of 1.59:1. Four clinical forms of EPTB predominated, namely pleural (40.4%), osteoarticular (29.8%), lymph node (12.5%), and abdominal TB (10.3%). We found sex-based differences in anatomical localization of extrapulmonary tuberculosis, with males more likely than females to have pleural TB (OR: 1.51; 95% CI [1.16 to 1.98]). Conversely, being male was associated with 43% and 41% lower odds of having lymph node and abdominal TB, respectively (OR: 0.57 and 0.59). Conclusion: Anatomical sites of extrapulmonary tuberculosis differ by sex with pleural TB being associated with male sex while lymph node and abdominal TB are predominately associated with female sex. Future studies are warranted to understand the role of sex in mediating anatomical site preference of tuberculosis.

Performance of Rapid Antigen Tests to Detect Symptomatic and Asymptomatic SARS-CoV-2 Infection : A Prospective Cohort Study.

BACKGROUND: The performance of rapid antigen tests (Ag-RDTs) for screening asymptomatic and symptomatic persons for SARS-CoV-2 is not well established. OBJECTIVE: To evaluate the performance of Ag-RDTs for detection of SARS-CoV-2 among symptomatic and asymptomatic participants. DESIGN: This prospective cohort study enrolled participants between October 2021 and January 2022. Participants completed Ag-RDTs and reverse transcriptase polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 every 48 hours for 15 days. SETTING: Participants were enrolled digitally throughout the mainland United States. They self-collected anterior nasal swabs for Ag-RDTs and RT-PCR testing. Nasal swabs for RT-PCR were shipped to a central laboratory, whereas Ag-RDTs were done at home. PARTICIPANTS: Of 7361 participants in the study, 5353 who were asymptomatic and negative for SARS-CoV-2 on study day 1 were eligible. In total, 154 participants had at least 1 positive RT-PCR result. MEASUREMENTS: The sensitivity of Ag-RDTs was measured on the basis of testing once (same-day), twice (after 48 hours), and thrice (after a total of 96 hours). The analysis was repeated for different days past index PCR positivity (DPIPPs) to approximate real-world scenarios where testing initiation may not always coincide with DPIPP 0. Results were stratified by symptom status. RESULTS: Among 154 participants who tested positive for SARS-CoV-2, 97 were asymptomatic and 57 had symptoms at infection onset. Serial testing with Ag-RDTs twice 48 hours apart resulted in an aggregated sensitivity of 93.4% (95% CI, 90.4% to 95.9%) among symptomatic participants on DPIPPs 0 to 6. When singleton positive results were excluded, the aggregated sensitivity on DPIPPs 0 to 6 for 2-time serial testing among asymptomatic participants was lower at 62.7% (CI, 57.0% to 70.5%), but it improved to 79.0% (CI, 70.1% to 87.4%) with testing 3 times at 48-hour intervals. LIMITATION: Participants tested every 48 hours; therefore, these data cannot support conclusions about serial testing intervals shorter than 48 hours. CONCLUSION: The performance of Ag-RDTs was optimized when asymptomatic participants tested 3 times at 48-hour intervals and when symptomatic participants tested 2 times separated by 48 hours. PRIMARY FUNDING SOURCE: National Institutes of Health RADx Tech program.

Vaginal microbiome community state types and high-risk human papillomaviruses in cervical precancer and cancer in North-central Nigeria.

BACKGROUND: High risk human papillomaviruses (HR-HPV) have a causal role in cervical oncogenesis, and HIV-mediated immune suppression allows HR-HPV to persist. We studied whether vaginal microbiome community state types (CSTs) are associated with high-grade precancer and/or invasive cervical cancer (HSIL/ICC). METHODS: This was a cross-sectional study of adult women with cervical cancer screening (CCS) at the Jos University Teaching Hospital (JUTH) in Jos, Nigeria, between January 2020 and February 2022. Cervical swabs underwent HPV genotyping (Anyplex™ II HPV28). Cervico-vaginal lavage (CVL) sample was collected for 16 S rRNA gene amplicon sequencing. We used multivariable logistic regression modelling to assess associations between CSTs and other factors associated with HSIL/ICC. RESULTS: We enrolled 155 eligible participants, 151 with microbiome data for this analysis. Women were median age 52 (IQR:43-58), 47.7% HIV positive, and 58.1% with HSIL/ICC. Of the 138 with HPV data, 40.6% were negative for HPV, 10.1% had low-risk HPV, 26.8% had single HR-HPV, and 22.5% had multiple HR-HPV types. The overall prevalence of any HR-HPV type (single and multiple) was 49.3%, with a higher proportion in women with HSIL/ICC (NILM 31.6%, LSIL 46.5%, HSIL 40.8%, and 81.5% ICC; p = 0.007). Women with HIV were more likely to have HSIL/ICC (70.3% vs. 29.7% among women without HIV). In crude and multivariable analysis CST was not associated with cervical pathology (CST-III aOR = 1.13, CST-IV aOR = 1.31). However, in the presence of HR-HPV CST-III (aOR = 6.7) and CST-IV (aOR = 3.6) showed positive association with HSIL/ICC. CONCLUSION: Vaginal microbiome CSTs were not significantly associated with HSIL/ICC. Our findings suggest however, that CST could be helpful in identifying women with HSIL/ICC and particularly those with HR-HPV. Characterization of CSTs using point-of-care molecular testing in women with HR-HPV should be studied as an approach to improve early detection and cervical cancer prevention. Future longitudinal research will improve our understanding of the temporal effect of non-optimal CST, HR-HPV, and other factors in cervical cancer development, prevention, and control.

A Multicenter Retrospective Cohort Study to Characterize Patients Hospitalized With Multisystem Inflammatory Syndrome in Adults and Coronavirus Disease 2019 in the United States, 2020-2021.

BACKGROUND: The diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated multisystem inflammatory syndrome in adults (MIS-A) requires distinguishing it from acute coronavirus disease 2019 (COVID-19) and may affect clinical management. METHODS: In this retrospective cohort study, we applied the US Centers for Disease Control and Prevention case definition to identify adults hospitalized with MIS-A at 6 academic medical centers from 1 March 2020 to 31 December 2021. Patients MIS-A were matched by age group, sex, site, and admission date at a 1:2 ratio to patients hospitalized with acute symptomatic COVID-19. Conditional logistic regression was used to compare demographic characteristics, presenting symptoms, laboratory and imaging results, treatments administered, and outcomes between cohorts. RESULTS: Through medical record review of 10 223 patients hospitalized with SARS-CoV-2-associated illness, we identified 53 MIS-A cases. Compared with 106 matched patients with COVID-19, those with MIS-A were more likely to be non-Hispanic black and less likely to be non-Hispanic white. They more likely had laboratory-confirmed COVID-19 ≥14 days before hospitalization, more likely had positive in-hospital SARS-CoV-2 serologic testing, and more often presented with gastrointestinal symptoms and chest pain. They were less likely to have underlying medical conditions and to present with cough and dyspnea. On admission, patients with MIS-A had higher neutrophil-to-lymphocyte ratio and higher levels of C-reactive protein, ferritin, procalcitonin, and D-dimer than patients with COVID-19. They also had longer hospitalization and more likely required intensive care admission, invasive mechanical ventilation, and vasopressors. The mortality rate was 6% in both cohorts. CONCLUSIONS: Compared with patients with acute symptomatic COVID-19, adults with MIS-A more often manifest certain symptoms and laboratory findings early during hospitalization. These features may facilitate diagnosis and management.

Design and implementation of a digital site-less clinical study of serial rapid antigen testing to identify asymptomatic SARS-CoV-2 infection.

Background: Rapid antigen detection tests (Ag-RDT) for SARS-CoV-2 with emergency use authorization generally include a condition of authorization to evaluate the test's performance in asymptomatic individuals when used serially. We aim to describe a novel study design that was used to generate regulatory-quality data to evaluate the serial use of Ag-RDT in detecting SARS-CoV-2 virus among asymptomatic individuals. Methods: This prospective cohort study used a siteless, digital approach to assess longitudinal performance of Ag-RDT. Individuals over 2 years old from across the USA with no reported COVID-19 symptoms in the 14 days prior to study enrollment were eligible to enroll in this study. Participants throughout the mainland USA were enrolled through a digital platform between October 18, 2021 and February 15, 2022. Participants were asked to test using Ag-RDT and molecular comparators every 48 hours for 15 days. Enrollment demographics, geographic distribution, and SARS-CoV-2 infection rates are reported. Key Results: A total of 7361 participants enrolled in the study, and 492 participants tested positive for SARS-CoV-2, including 154 who were asymptomatic and tested negative to start the study. This exceeded the initial enrollment goals of 60 positive participants. We enrolled participants from 44 US states, and geographic distribution of participants shifted in accordance with the changing COVID-19 prevalence nationwide. Conclusions: The digital site-less approach employed in the "Test Us At Home" study enabled rapid, efficient, and rigorous evaluation of rapid diagnostics for COVID-19 and can be adapted across research disciplines to optimize study enrollment and accessibility.

Serodominant SARS-CoV-2 Nucleocapsid Peptides Map to Unstructured Protein Regions.

The SARS-CoV-2 nucleocapsid (N) protein is highly immunogenic, and anti-N antibodies are commonly used as markers for prior infection. While several studies have examined or predicted the antigenic regions of N, these have lacked consensus and structural context. Using COVID-19 patient sera to probe an overlapping peptide array, we identified six public and four private epitope regions across N, some of which are unique to this study. We further report the first deposited X-ray structure of the stable dimerization domain at 2.05 Å as similar to all other reported structures. Structural mapping revealed that most epitopes are derived from surface-exposed loops on the stable domains or from the unstructured linker regions. An antibody response to an epitope in the stable RNA binding domain was found more frequently in sera from patients requiring intensive care. Since emerging amino acid variations in N map to immunogenic peptides, N protein variation could impact detection of seroconversion for variants of concern. IMPORTANCE As SARS-CoV-2 continues to evolve, a structural and genetic understanding of key viral epitopes will be essential to the development of next-generation diagnostics and vaccines. This study uses structural biology and epitope mapping to define the antigenic regions of the viral nucleocapsid protein in sera from a cohort of COVID-19 patients with diverse clinical outcomes. These results are interpreted in the context of prior structural and epitope mapping studies as well as in the context of emergent viral variants. This report serves as a resource for synthesizing the current state of the field toward improving strategies for future diagnostic and therapeutic design.

Performance of Rapid Antigen Tests Based on Symptom Onset and Close Contact Exposure: A secondary analysis from the Test Us At Home prospective cohort study.

Background: The performance of rapid antigen tests for SARS-CoV-2 (Ag-RDT) in temporal relation to symptom onset or exposure is unknown, as is the impact of vaccination on this relationship. Objective: To evaluate the performance of Ag-RDT compared with RT-PCR based on day after symptom onset or exposure in order to decide on 'when to test'. Design Setting and Participants: The Test Us at Home study was a longitudinal cohort study that enrolled participants over 2 years old across the United States between October 18, 2021 and February 4, 2022. All participants were asked to conduct Ag-RDT and RT-PCR testing every 48 hours over a 15-day period. Participants with one or more symptoms during the study period were included in the Day Post Symptom Onset (DPSO) analyses, while those who reported a COVID-19 exposure were included in the Day Post Exposure (DPE) analysis. Exposure: Participants were asked to self-report any symptoms or known exposures to SARS-CoV-2 every 48-hours, immediately prior to conducting Ag-RDT and RT-PCR testing. The first day a participant reported one or more symptoms was termed DPSO 0, and the day of exposure was DPE 0. Vaccination status was self-reported. Main Outcome and Measures: Results of Ag-RDT were self-reported (positive, negative, or invalid) and RT-PCR results were analyzed by a central laboratory. Percent positivity of SARS-CoV-2 and sensitivity of Ag-RDT and RT-PCR by DPSO and DPE were stratified by vaccination status and calculated with 95% confidence intervals. Results: A total of 7,361 participants enrolled in the study. Among them, 2,086 (28.3%) and 546 (7.4%) participants were eligible for the DPSO and DPE analyses, respectively. Unvaccinated participants were nearly twice as likely to test positive for SARS-CoV-2 than vaccinated participants in event of symptoms (PCR+: 27.6% vs 10.1%) or exposure (PCR+: 43.8% vs. 22.2%). The highest proportion of vaccinated and unvaccinated individuals tested positive on DPSO 2 and DPE 5-8. Performance of RT-PCR and Ag-RDT did not differ by vaccination status. Ag-RDT detected 78.0% (95% Confidence Interval: 72.56-82.61) of PCR-confirmed infections by DPSO 4. For exposed participants, Ag-RDT detected 84.9% (95% CI: 75.0-91.4) of PCR-confirmed infections by day five post-exposure (DPE 5). Conclusions and Relevance: Performance of Ag-RDT and RT-PCR was highest on DPSO 0-2 and DPE 5 and did not differ by vaccination status. These data suggests that serial testing remains integral to enhancing the performance of Ag-RDT.

Association of statin use with outcomes of patients admitted with COVID-19: an analysis of electronic health records using superlearner.

IMPORTANCE: Statin use prior to hospitalization for Coronavirus Disease 2019 (COVID-19) is hypothesized to improve inpatient outcomes including mortality, but prior findings from large observational studies have been inconsistent, due in part to confounding. Recent advances in statistics, including incorporation of machine learning techniques into augmented inverse probability weighting with targeted maximum likelihood estimation, address baseline covariate imbalance while maximizing statistical efficiency. OBJECTIVE: To estimate the association of antecedent statin use with progression to severe inpatient outcomes among patients admitted for COVD-19. DESIGN, SETTING AND PARTICIPANTS: We retrospectively analyzed electronic health records (EHR) from individuals ≥ 40-years-old who were admitted between March 2020 and September 2022 for ≥ 24 h and tested positive for SARS-CoV-2 infection in the 30 days before to 7 days after admission. EXPOSURE: Antecedent statin use-statin prescription ≥ 30 days prior to COVID-19 admission. MAIN OUTCOME: Composite end point of in-hospital death, intubation, and intensive care unit (ICU) admission. RESULTS: Of 15,524 eligible COVID-19 patients, 4412 (20%) were antecedent statin users. Compared with non-users, statin users were older (72.9 (SD: 12.6) versus 65.6 (SD: 14.5) years) and more likely to be male (54% vs. 51%), White (76% vs. 71%), and have ≥ 1 medical comorbidity (99% vs. 86%). Unadjusted analysis demonstrated that a lower proportion of antecedent users experienced the composite outcome (14.8% vs 19.3%), ICU admission (13.9% vs 18.3%), intubation (5.1% vs 8.3%) and inpatient deaths (4.4% vs 5.2%) compared with non-users. Risk differences adjusted for labs and demographics were estimated using augmented inverse probability weighting with targeted maximum likelihood estimation using Super Learner. Statin users still had lower rates of the composite outcome (adjusted risk difference: - 3.4%; 95% CI: - 4.6% to - 2.1%), ICU admissions (- 3.3%; - 4.5% to - 2.1%), and intubation (- 1.9%; - 2.8% to - 1.0%) but comparable inpatient deaths (0.6%; - 1.3% to 0.1%). CONCLUSIONS AND RELEVANCE: After controlling for confounding using doubly robust methods, antecedent statin use was associated with minimally lower risk of severe COVID-19-related outcomes, ICU admission and intubation, however, we were not able to corroborate a statin-associated mortality benefit.

Finding a Needle in a Haystack: Design and Implementation of a Digital Site-less Clinical Study of Serial Rapid Antigen Testing to Identify Asymptomatic SARS-CoV-2 Infection.

Background: Rapid antigen tests (Ag-RDT) for SARS-CoV-2 with Emergency Use Authorization generally include a condition of authorization to evaluate the test's performance in asymptomatic individuals when used serially. Objective: To describe a novel study design to generate regulatory-quality data to evaluate serial use of Ag-RDT in detecting SARS-CoV-2 virus among asymptomatic individuals. Design: Prospective cohort study using a decentralized approach. Participants were asked to test using Ag-RDT and molecular comparators every 48 hours for 15 days. Setting: Participants throughout the mainland United States were enrolled through a digital platform between October 18, 2021 and February 15, 2022. Ag-RDTs were completed at home, and molecular comparators were shipped to a central laboratory. Participants: Individuals over 2 years old from across the U.S. with no reported COVID-19 symptoms in the 14 days prior to study enrollment were eligible to enroll in this study. Measurements: Enrollment demographics, geographic distribution, and SARS-CoV-2 infection rates are reported. Key Results: A total of 7,361 participants enrolled in the study, and 492 participants tested positive for SARS-CoV-2, including 154 who were asymptomatic and tested negative to start the study. This exceeded the initial enrollment goals of 60 positive participants. We enrolled participants from 44 U.S. states, and geographic distribution of participants shifted in accordance with the changing COVID-19 prevalence nationwide. Limitations: New, complex workflows required significant operational and data team support. Conclusions: The digital site-less approach employed in the 'Test Us At Home' study enabled rapid, efficient, and rigorous evaluation of rapid diagnostics for COVID-19, and can be adapted across research disciplines to optimize study enrollment and accessibility.

Performance of Rapid Antigen Tests to Detect Symptomatic and Asymptomatic SARS-CoV-2 Infection.

Background: Performance of rapid antigen tests for SARS-CoV-2 (Ag-RDT) varies over the course of an infection, and their performance in screening for SARS-CoV-2 is not well established. We aimed to evaluate performance of Ag-RDT for detection of SARS-CoV-2 for symptomatic and asymptomatic participants. Methods: Participants >2 years old across the United States enrolled in the study between October 2021 and February 2022. Participants completed Ag-RDT and molecular testing (RT-PCR) for SARS-CoV-2 every 48 hours for 15 days. This analysis was limited to participants who were asymptomatic and tested negative on their first day of study participation. Onset of infection was defined as the day of first positive RT-PCR result. Sensitivity of Ag-RDT was measured based on testing once, twice (after 48-hours), and thrice (after 96 hours). Analysis was repeated for different Days Post Index PCR Positivity (DPIPP) and stratified based on symptom-status. Results: In total, 5,609 of 7,361 participants were eligible for this analysis. Among 154 participants who tested positive for SARS-CoV-2, 97 were asymptomatic and 57 had symptoms at infection onset. Serial testing with Ag-RDT twice 48-hours apart resulted in an aggregated sensitivity of 93.4% (95% CI: 89.1-96.1%) among symptomatic participants on DPIPP 0-6. Excluding singleton positives, aggregated sensitivity on DPIPP 0-6 for two-time serial-testing among asymptomatic participants was lower at 62.7% (54.7-70.0%) but improved to 79.0% (71.0-85.3%) with testing three times at 48-hour intervals. Discussion: Performance of Ag-RDT was optimized when asymptomatic participants tested three-times at 48-hour intervals and when symptomatic participants tested two-times separated by 48-hours.