Analysis of Spatial and Spatiotemporal Anomalies Using Persistent Homology: Case Studies with COVID-19 Data

We develop a method for analyzing spatial and spatiotemporal anomalies in geospatial data using topological data analysis (TDA). To do this, we use persistent homology (PH), which allows one to algorithmically detect geometric voids in a data set and quantify the persistence of such voids. We construct an efficient filtered simplicial complex (FSC) such that the voids in our FSC are in one-to-one correspondence with the anomalies. Our approach goes beyond simply identifying anomalies;it also encodes information about the relationships between anomalies. We use vineyards, which one can interpret as time-varying persistence diagrams (which are an approach for visualizing PH), to track how the locations of the anomalies change with time. We conduct two case studies using spatially heterogeneous COVID-19 data. First, we examine vaccination rates in New York City by zip code at a single point in time. Second, we study a year-long data set of COVID-19 case rates in neighborhoods of the city of Los Angeles.

OLDER ADULT ONLINE EXERCISE CLASSES DURING THE COVID-19 PANDEMIC: A SURVEY OF SERVICE PROVIDER PERSPECTIVESS

COVID-19 rendered the availability of exercise facilities sporadic and online exercise programs subsequently became more common. This research explored online exercise classes delivered to older adults during the pandemic from the perspective of service providers. Sixty-seven service providers completed the survey (88% female). The majority (54%) of respondents had worked in the fitness industry for greater than 10 years, and 66% were fitness class instructors, while fewer were managers (9%) and personal trainers (8%). Three participants had experience providing online exercise classes prior to the pandemic, while 43 more had experience providing online exercise classes since the pandemic began. Of these 46 service providers, 87% offered classes live through Zoom. The majority (64%) offered classes through an organization, and 61% charged a fee for participants to take part. The most common type of class was a general fitness class (63%), followed by yoga and flexibility classes (39%), and strength training (17%). Regarding equipment used, weights were most frequently required (69%), followed by resistance bands (49%) and mats (44%). Most classes lasted 40–60 minutes (59%) and were low intensity (74%). Of the 21 respondents who did not provide online exercise classes, 43% indicated this was because of a lack of interest, and 19% cited not knowing how to use technology to deliver classes online, though most (71%) indicated they would consider offering online classes in the future. This research reveals the adaptability of service providers and may serve to inform the continued development of online exercise programs for older adults.

OLDER ADULT PERSPECTIVES ABOUT ONLINE EXERCISE CLASSES DURING THE COVID-19 PANDEMIC AT MULTIPLE TIME POINTS

Engaging in physical activity can bring health benefits for older adults. However, during the pandemic the availability of in-person exercise classes has been sporadic. As such, online exercise programs have become more common. This research had the goal of exploring the uptake of online exercise programs by older adults in Manitoba, Canada in the first few months in the pandemic and then more than 1.5 years into the pandemic. Older adults (65 years and older) were recruited via emails from a variety of community organizations. Participants completed anonymous online surveys in summer 2020 (n=678) and fall 2021 (n=570). Less than 50% of respondents reported participating in online exercise classes during the pandemic in both surveys. For both surveys, pre-recorded classes were the most common, however, this decreased from 80% in the first survey, to 57% in the second survey. Conversely, live classes where the instructor could see the participants increased from 17% in the 2020 survey, to 47% in the 2021 survey. Additionally, platform use shifted from YouTube as the most popular in the first survey, to Zoom in the second survey. Most of the online classes originated from their local communities. Of those who participated in online exercise early and later in the pandemic, about two thirds reported that they would continue online exercise classes outside of the pandemic. A major reason for not participating was because they enjoy the social aspect of in-person classes. The perspectives of the study participants will be valuable for policymakers, programmers, and instructors.

Building-Level Wastewater Surveillance for SARS-CoV-2 in Occupied University Dormitories as an Outbreak Forecasting Tool: One Year Case Study

Congregate living poses one of the highest risk situations for the transmission of respiratory viruses including SARS-CoV-2. University dormitories exemplify such high-risk settings. We demonstrate the value of using building-level SARS-CoV-2 wastewater surveillance as an early warning system to inform when prevalence testing of all building occupants is warranted. Coordinated daily testing of composite wastewater samples and clinical testing in dormitories was used to prompt the screening of otherwise unrecognized infected occupants. We overlay the detection patterns in the context of regular scheduled occupant testing to validate a wastewater detection model. The trend of wastewater positivity largely aligned well with the clinical positivity and epidemiology of dormitory occupants. However, the predictive ability of wastewater-surveillance to detect new positive cases is hampered by convalescent shedding in recovered/noncontagious individuals as they return to the building. Building-level pooled wastewater-surveillance and forecasting is most productive for predicting new cases in low-prevalence instances at the community level. For higher-education facilities and other congregate living settings to remain in operation during a pandemic, a thorough surveillance-based decision-making system is vital. Building-level wastewater monitoring on a daily basis paired with regular testing of individual dormitory occupants is an effective and efficient approach for mitigating outbreaks on university campuses. © 2012 American Chemical Society. All rights reserved.

A multi-disciplinary e-learning starter course - would you like some salt with that?

Introduction: Peripartum hyponatraemia is a potentially serious condition with implications for both mother and baby [1,2]. Pregnant women are more at risk of developing hyponatraemia due to a lower baseline sodium, impaired ability to excrete water, the antidiuretic effect of oxytocin and excessive fluid intake during labour. We found that peripartum hyponatraemia was often poorly managed and there was no trust guidance for diagnosis and management. Hence, we designed a new departmental protocol based on the GAIN guidelines [2]. Due to the impact of COVID 19 on traditional teaching methods,we upskilled staff by designing a tailored e-learning package using articulate software and re-assessed the team’s knowledge of the condition. Methods: After trust approval and advice from the hospital’s audit department, a local survey was sent out to members of the obstetric multi-disciplinary team before and after the introduction of a departmental peripartum hyponatraemia guideline together with its associated e-learning package. Results: We received a total of 74 responses. Initially, we identified a large proportion of the team were not confident in managing hyponatraemia. After implementation of our e-learning package, we demonstrated an increase in staff confidence (Figure). The initial survey showed much uncertainty surrounding the indications for fluid balance monitoring, prescription of intravenous fluids and management of hyponatraemia. However, results from the post e-learning survey showed improved knowledge in all these areas. Discussion: Our survey suggests that many members of the obstetric multi-disciplinary team were unfamiliar and not confident in managing peripartum hyponatraemia. However, a tailored e-learning programme is an extremely useful adjunct in highlighting new guidance, upskilling members of the team and changing the attitudes of the multidisciplinary team to unfamiliar medical conditions. (Figure Presented)

An Application of the Partially Observed Markov Process in the Analysis of Transmission Dynamics of COVID-19 via Wastewater

As the ongoing outbreak of Coronavirus Disease 2019 (COVID-19) is severely affecting all over the world, analysis of the transmission of COVID-19 is of more and more interest. We focus on the application of compartmental models in the analysis of transmission of COVID-19 based on the detected viral load in wastewater and the reported number of cases. The measurement of COVID-19 RNA concentrations in primary sludge gives us information about the virus prevalence on a population level. Since the transmission of COVID-19 is a partially observed Markov process including different states, we consider a likelihood-based approach to our statistical inference to understand the inner relationship between different states and how COVID-19 actually transmits. Understanding the transmission dynamics of COVID-19 could give suggestions on public policies.

SCREENING COLONOSCOPY REFERRALS DURING THE SARS-COV-2 PANDEMIC: IMPACT OF GASTROENTEROLOGIST RECOMMENDATION FOR FECAL IMMUNOHISTOCHEMICAL TESTING AS A PREFERRED COLORECTAL CANCER SCREENING METHOD AT A VA HEALTHCARE SYSTEM

Background: During the early stages of the SARS-CoV-2 pandemic, many endoscopic colorectal cancer (CRC) screening programs were temporarily halted, including at the Veteran's Administration (VA). The VA instituted triage and prioritization of endoscopic procedures, and fecal immunohistochemical testing (FIT) was recommended as the preferred CRC screening option over colonoscopy. We sought to determine impact of gastroenterologist (GI) recommendation to primary care providers (PCPs) to offer FIT testing to veterans who were referred for screening colonoscopy. Methods: Veterans referred for average risk screening colonoscopy, verified by GI chart review, between 3/11/2020 and 12/29/2020 at the VA Pittsburgh Health Care System (VAPHS) were included. Referring PCPs were sent standardized communication regarding assignment of a low priority to the screening colonoscopy request, and recommendation of FIT testing as the preferred CRC screening strategy. Recommendation was active, by requiring PCP acknowledgement of the FIT recommendation, or passive, by adding a comment to the procedure referral. We reviewed the charts of veterans to collect demographic information, then determine if FIT ordered, subsequently completed, or if colonoscopy was completed. Results: Eighty one screening colonoscopy requests were identified. Minimum follow-up from initial procedure consult order to chart review was 10 months with a median of 16 months. A total of 40 FIT were ordered (49.4%). Among those with FITs ordered, 24 (60.0%) were completed, 5 underwent screening colonoscopy (12.5%), and screening outcome was not available for 11 (27.5%). For veterans whom FIT was not ordered (n = 41), 15 (36.6%) underwent screening colonoscopy, and screening outcome was not available for 26 (63.4%). PCP ordering of FIT was not related to mean patient age (58.7 vs 57.2, p = 0.91), clinic location (academic urban vs urban vs satellite, c2 = 0.47), intervention type (active vs passive, c2 = 0.47), or phase of the pandemic (early vs late, c2 = 0.90). Overall veteran CRC screening completion was significantly greater for those whom FIT was ordered by their PCP vs those who did not have FIT ordered (72.5% vs 36.6%, c2 = 0.01). Conclusions: During the 2020 SARS-CoV-2 pandemic, when there were limitations on access to colonoscopy, gastroenterologist recommendation to PCPs to order FIT as an alternative to screening colonoscopy was successful half the time. FIT ordering was independent of veteran age, clinic location, intervention type, or pandemic phase. When ordered, veteran completion of FIT was 60%. There was wide variation in veteran CRC completion rate by PCP FIT ordering, suggesting either that FIT enhanced access to CRC screening, or, veteran factors influenced FIT ordering. This will inform future interventions aimed at increasing FIT utilization as an alternative to colonoscopy.(Figure Presented)

Situational awareness among prehospital providers during an online high-fidelity simulation – A Novel Study

BackgroundIt has been suggested that prehospital providers need to be situationally aware in order to reduce human error. By reducing human error, patient outcomes may be improved. Research during the COVID19 pandemic has been difficult and while many projects were put on hold, the authors created a novel manner in which to complete this study and measure SA – through online simulation.MethodThis was a mixed-methods explanatory sequential study where prehospital providers participated in an online simulation. The situational awareness global assessment technique (SAGAT) was utilized during periodic freezes in the simulation where the participants would answer questions related to the environments of the patient and the scene. Questions were focused on perception, interpretation, and prediction. Following the simulation, participants provided feedback during interviews.ResultsThe providers did not possess high levels of SA. Overall SA was 45% (p-value, .162), where participants performed best at perception with a steady decline to interpretation and then prediction. Those with higher levels of education did perform better, although this was not statistically significant, (p-value, .09). Those with more experience initially had higher SA but then tended to decrease with more experience (p-value, .24). Participants did feel satisfied with the online simulation and also felt that the simulation and SAGAT were beneficial to their continuing education and improving their care in the field.ConclusionPrehospital providers are not situationally aware during online simulation. They focused on the surroundings at first, but did not focus as much on the patient. The SAGAT can be utilized in an online format and may possibly enhance overall performance. Further research is needed to determine if higher levels of education and experience play a role in prehospital SA.Conflict of interestNone.FundingNone.

Topological Data Analysis of Spatial Systems

In this chapter, we discuss applications of topological data analysis (TDA) to spatial systems. We briefly review a recently proposed level-set construction of filtered simplicial complexes, and we then examine persistent homology in two cases studies: street networks in Shanghai and anomalies in the spread of COVID-19 infections. We then summarize our results and provide an outlook on TDA in spatial systems. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Wastewater-Based Epidemiological Modeling for Continuous Surveillance of COVID-19 Outbreak

Using wastewater surveillance as a continuous pooled sampling technique has been in place in many countries since the early stages of the outbreak of COVID-19. Since the beginning of the outbreak, many research works have emerged, studying different aspects of viral SARS-CoV-2 DNA concentrations (viral load) in wastewater and its potential as an early warning method. However, one of the questions that has remained unanswered is the quantitative relation between viral load and clinical indicators such as daily cases, deaths, and hospitalizations. Few studies have tried to couple viral load data with an epidemiological model to relate the number of infections in the community to the viral burden. This paper proposes a stochastic wastewater-based SEIR model to showcase the importance of viral load in the early detection and prediction of an outbreak in a community. We built three models based on whether or not they use the case count and viral load data and compared their simulations and forecasting quality. Our results demonstrate that a simple SEIR model based on viral load data can reliably predict the number of infections in the future. Therefore, wastewater-based surveillance is a promising way of monitoring the spread of COVID19 and can provide city officials with timely information about the circulation of COVID-19 in the community. © 2021 IEEE.