Using a household-structured branching process to analyse contact tracing in the SARS-CoV-2 pandemic

We explore strategies of contact tracing, case isolation and quarantine of exposed contacts to control the SARS-CoV-2 epidemic using a branching process model with household structure. This structure reflects higher transmission risks among household members than among non-household members. We explore strategic implementation choices that make use of household structure, and investigate strategies including two-step tracing, backwards tracing, smartphone tracing and tracing upon symptom report rather than test results. The primary model outcome is the effect of contact tracing, in combination with different levels of physical distancing, on the growth rate of the epidemic. Furthermore, we investigate epidemic extinction times to indicate the time period over which interventions must be sustained. We consider effects of non-uptake of isolation/quarantine, non-adherence, and declining recall of contacts over time. Our results find that, compared to self-isolation of cases without contact tracing, a contact tracing strategy designed to take advantage of household structure allows for some relaxation of physical distancing measures but cannot completely control the epidemic absent of other measures. Even assuming no imported cases and sustainment of moderate physical distancing, testing and tracing efforts, the time to bring the epidemic to extinction could be in the order of months to years. This article is part of the theme issue ‘Modelling that shaped the early COVID-19 pandemic response in the UK’.

A - 29 Language Differences in Neurocognitive Scores and Symptom Report in Professional Football Players

Objective The purpose of this study was to investigate the role of language on neurocognitive test outcomes and concussion symptom ratings in professional football players. Methods Design/Setting - A retrospective cross-section analysis of 1546 male Canadian Football League (CFL) athletes was conducted using baseline data collected from the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) across the 2016–18 competitive seasons. Independent Variables - Participants (1546) were divided into three language categories, native English-speaking, bilingual – whose first language was English, and English as a second language (ESL). Years of education, age, and concussion history were entered as co-variates. Outcome Measure -The 5 Composite scores from ImPACT and the 22 symptoms from the post-concussion symptom scale (PCSS). Results Results of the MANCOVA showed no significant differences between language groups on any of the five ImPACT composite scores F(10, 3072) = 1.09, p = 0.36. The Kruskall-Wallis test revealed significant differences were found in three symptoms including dizziness [X2(2, 1486) = 32.85, p < 0.001)], sadness [X2(2, 1486) = 6.505, p = 0.04], and concentration [X2(2, 1486) = 11.01, p = 0.004)] with the bilingual and non-native English speakers having higher scores. Conclusions This study suggests that cultural and linguistic differences should be considered when administering CNTs. While differences in cognitive outcomes have not been consistently found across studies, differences in baseline symptom reports have been consistently demonstrated. Information pertaining to a patient’s level of acculturation and language proficiency is important for examiners when working with diverse populations. Continuing to develop language-specific normative databases is encouraged.

Non-credible symptom report in the clinical evaluation of adult ADHD: development and initial validation of a new validity index embedded in the Conners’ adult ADHD rating scales

As attention-deficit/hyperactivity disorder (ADHD) is a feasible target for individuals aiming to procure stimulant medication or accommodations, there is a high clinical need for accurate assessment of adult ADHD. Proven falsifiability of commonly used diagnostic instruments is therefore of concern. The present study aimed to develop a new, ADHD-specific infrequency index to aid the detection of non-credible self-report. Disorder-specific adaptations of four detection strategies were embedded into the Conners’ Adult ADHD Rating Scales (CAARS) and tested for infrequency among credible neurotypical controls (n = 1001) and credible adults with ADHD (n = 100). The new index’ ability to detect instructed simulators (n = 242) and non-credible adults with ADHD (n = 22) was subsequently examined using ROC analyses. Applying a conservative cut-off score, the new index identified 30% of participants instructed to simulate ADHD while retaining a specificity of 98%. Items assessing supposed symptoms of ADHD proved most useful in distinguishing genuine patients with ADHD from simulators, whereas inquiries into unusual symptom combinations produced a small effect. The CAARS Infrequency Index (CII) outperformed the new infrequency index in terms of sensitivity (46%), but not overall classification accuracy as determined in ROC analyses. Neither the new infrequency index nor the CII detected non-credible adults diagnosed with ADHD with adequate accuracy. In contrast, both infrequency indices showed high classification accuracy when used to detect symptom over-report. Findings support the new indices’ utility as an adjunct measure in uncovering feigned ADHD, while underscoring the need to differentiate general over-reporting from specific forms of feigning.

Using a household structured branching process to analyse contact tracing in the SARS-CoV-2 pandemic

We explore strategies of contact tracing, case isolation and quarantine of exposed contacts to control the SARS-CoV-2 epidemic using a branching process model with household structure. This structure reflects higher transmission risks among household members than among non-household members, and is also the level at which physical distancing policies have been applied. We explore implementation choices that make use of household structure, and investigate strategies including two-step tracing, backwards tracing, smartphone tracing and tracing upon symptom report rather than test results. The primary model outcome is the effect on the growth rate of the epidemic under contact tracing in combination with different levels of physical distancing, and we investigate epidemic extinction times to indicate the time period over which interventions must be sustained. We consider effects of non-uptake of isolation/quarantine, non-adherence, and declining recall of contacts over time. We find that compared to self-isolation of cases but no contact tracing, a household-based contact tracing strategy allows for some relaxation of physical distancing measures; however, it is unable to completely control the epidemic in the absence of other measures. Even assuming no imported cases and sustainment of moderate distancing, testing and tracing efforts, the time to bring the epidemic to extinction could be in the order of months to years.

Endogenous Endophthalmitis: Recommendation for Empiric Dual Antibacterial and Antifungal Therapy

Purpose: This work compares clinical presentation and course of bacterial and fungal causes of endogenous endophthalmitis (EE). Methods: A single-institutional study of consecutive patients diagnosed with EE was conducted at the University of Pittsburgh Medical Center between September 2015 and September 2018. Exclusion criteria included history of ocular trauma, intraocular surgery or injection 6 months before presentation, or primary external ocular infection. Data included demographics, medical and ocular history, clinical examination, culture data, therapeutic interventions, final corrected visual acuity (VA), and mortality. Results: Thirty-six eyes of 26 patients were diagnosed with EE during a 3-year period. Median age at diagnosis was 55.5 years (range, 19-86 years). Based on ocular and systemic cultures, 19 patients had bacterial EE and 6 patients had fungal EE; findings from all cultures remained negative in 1 patient. All patients had risk factors for EE. Presenting VA, subjective symptom report, and objective measures of intraocular inflammation were similar between bacterial and fungal causes. Overall, EE presented indolently and was initially misdiagnosed in 19% of cases. Complications including final VA less than 20/200, retinal detachment, enucleation, or death within 6 months of diagnosis were equivalent between bacterial and fungal cases. Conclusions: The presentation of EE is remarkably different from that of exogenous endophthalmitis. Without a high index of suspicion, the indolent presentation of EE may lead to misdiagnosis. No clinical features reliably differentiated bacterial and fungal sources. This highlights the importance of considering empiric therapy for antibacterial and antifungal coverage on initial presentation.

Cross-Sectional Prevalence of SARS-CoV-2 Among Skilled Nursing Facility Employees and Residents Across Facilities in Seattle

Background Skilled nursing facilities (SNFs) are high-risk settings for SARS-CoV-2 transmission. Infection rates among employees are infrequently described. Objective To describe SARS-CoV-2 rates among SNF employees and residents during a non-outbreak time period, we measured cross-sectional SARS-CoV-2 prevalence across multiple sites in the Seattle area. Design SARS-CoV-2 testing was performed for SNF employees and residents using quantitative real-time reverse transcription polymerase chain reaction. A subset of employees completed a sociodemographic and symptom questionnaire. Participants Between March 29 and May 13, 2020, we tested 1583 employees and 1208 residents at 16 SNFs for SARS-CoV-2. Main Measure SARS-CoV-2 testing results and symptom report among employees and residents. Key Results Eleven of the 16 SNFs had one or more resident or employee test positive. Overall, 46 (2.9%) employees had positive or inconclusive testing for SARS-CoV-2, and among those who completed surveys, most were asymptomatic and involved in direct patient care. The majority of employees tested were female (934, 73%), and most employees were Asian (392, 30%), Black (360, 28%), or white (360, 28%). Among the 1208 residents tested, 110 (9.1%) had positive or inconclusive results. There was no association between the presence of positive residents and positive employees within a SNF (p = 0.62, McNemar’s test). Conclusions In the largest study of SNFs to date, SARS-CoV-2 infections were detected among both employees and residents. Employees testing positive were often asymptomatic and involved in direct patient care. Surveillance testing is needed for SNF employees and residents during the pandemic response.

Use of the Sport Concussion Assessment Tool 5 (SCAT5) in professional hockey, part 2: which components differentiate concussed and non-concussed players?

ObjectivesTo examine the utility of Sport Concussion Assessment Tool (SCAT5) subcomponents in differentiating physician diagnosed concussed players from controls.MethodsWe evaluated 1924 professional hockey players at training camp using the National Hockey League (NHL) Modified SCAT5 prior to the 2018–2019 season. Over the course of the season, 314 English-speaking players received SCAT5 evaluations within 1 day of a suspected concussive event. Of these players, 140 (45%) were subsequently diagnosed with concussion by their team physicians.ResultsConcussed players reported more symptoms (Concussed M=8.52, SD=4.78; Control M=3.32, SD=3.97), and recalled fewer words than Controls on both the Immediate Memory (Concussed M=19.34, SD=4.06; Control M=21.53, SD=2.94) and Delayed Recall (Concussed z=−0.91; Control z=−0.09) tasks during the acute evaluation. Concussed players also made more errors than Controls on the mBESS and were more likely to report double vision and exhibit clinician-observed balance problems than controls. There were no between-group differences on the Concentration component of the SCAT5. Stepwise regression revealed that symptom report and list learning tasks both accounted for independent variance in identifying players diagnosed with concussion.ConclusionsThese findings provide support for use of the SCAT5 to assist in identifying concussed professional hockey players. When examining SCAT5 subtests, both symptom report and the 10-item word list accounted for independent variance in identifying concussion status in this sample of professional hockey players. The mBESS also differentiated Concussed players and Controls. The Concentration component of the SCAT5 did not significantly differentiate Concussed players and Controls.