379. Abstract For Comparison of Mandatory vs Non-Mandatory Compliance Rates For SARS-CoV-2 Testing in Grades K-12

Background Rapid testing to identify asymptomatically infected students with SARS-CoV-2 in elementary schools has been suggested as a possible method to reduce risk for in person instruction. As of August 3, 2020 (updated on January 25, 2021), California schools who obtained a waiver to conduct in-person instruction are not required to have mandatory testing for asymptomatic students, except for high contact sports which are required to undergo weekly testing. We explored the uptake of voluntary vs mandatory testing in a private waivered school. Methods Between the dates January 25, 2021 to April 16, 2021, the K-12 school superintendent sent an email to all parents outlining the voluntary testing program with a link to the on-line sign up and consent form. All students were offered weekly self-collected anterior nares BinaxNOW Rapid Antigen Test. Signed parental consent was required and tests were performed at the school. Students participating in contact sports were required to undergo testing the week a varsity game was played as a condition of participation. Data was gathered from the school administration and de-identified. Results K-5 Lower school had a school population of 448 students. Testing was offered on 8 weeks during the period of 2/15-2/19 to 4/5-4/9. 2 students (0.45%) receive screening on the week of 3/22-3/26. The other seven weeks when screening was offered 0 students received screening. 6-12 Upper school had a school population of 360 enrolled students. Testing was offered 3/8-3/12 and 3/15-3/19. The upper school had 22 students (6.11%) receive testing on the week of 3/8-3/12 and 21 students (5.83%) on the week of 3/15-3/19. Contact sports teams had 67 students on their roster. Weekly testing was offered from 3/22-3/26 to 4/12-4/16. Contact sports teams had 10 students (14.93%) receive testing on the week of 3/22-3/26, 33 students (52.24%) on the week of 4/5-4/9, and 32 students (49.25%) on the week of 4/12-4/16. Figure 1. Percent of students from each campus and sports team screened per week offered. Conclusion Voluntary SARS-CoV-2 screening was not a feasible approach for detection of asymptomatically infected individuals due to low uptake, however in the same school, mandatory testing had high uptake and would be a feasible strategy. Disclosures All Authors: No reported disclosures

THE COURT’S POWER TO COMPEL DNA TESTING IN PATERNITY DISPUTES – LB v YD 2009 5 SA 463 (T)

A fundamental scientific breakthrough was made in 1900 by Landsteiner, who demonstrated that the red blood cells of some individuals contained different chemical substances from the blood cells of others; and that all blood could be classified into a small number of groups. In accordance with recognized principles of genetics these characteristics are transmitted from one generation to another, and thus “[A] comparison of the characteristics of a child’s blood with that of his mother and a particular man may show that the man cannot be the father … [and] if it is known that at the material times the mother had had intercourse only with H (her husband) and X and the blood test excludes H but not X, then X must be the father”. Whilst English courts began to accept such evidence in paternity cases, Heaton points out that until a few decades ago the unreliability of blood tests meant that they were seldom employed in such cases in South Africa. A further complication in the use of these tests as a means of determining parentage, however, related to the fact that in order for an acceptable result to ensue it was necessary to have samples not only from a child but also from the adults involved. What if an adult refused to be tested, or a parent refused to allow the child to undergo a test? The South African courts initially held that they could not compel any person to undergo blood tests, although they were prepared to accept evidence obtained through voluntary testing. The potential consequences of the courts refusing to compel testing are that a non-biological “father” will be compelled to maintain the child. More recently the South African courts have seen fit to order blood tests in paternity disputes, although whether such orders should be made remains controversial. The latest case dealing with this issue is that of LB v YD (2009 5 SA 463 (T)). (Leave to appeal the decision in this matter was dismissed in YD v LB (A) 2009 5 SA 479 (GNP)).

Testing behaviour and positivity for SARS-CoV-2 infection: Insights from web-based participatory surveillance

BackgroundVoluntary testing for SARS-CoV-2 infection is an integral component of an effective response to the COVID-19 pandemic. It is essential to identify populations at a high risk for infection but who are less likely to present for testing. Here, we use internet-based participatory surveillance data from the Netherlands to identify sociodemographic and household factors that are associated with a lower propensity to be tested and, if tested, with a higher risk of a positive test result.MethodsMultivariable analyses using generalised estimating equations for binomial outcomes were conducted to estimate the adjusted odds ratios of testing and of positivity associated with participant and household characteristics.ResultsBased on five months (17 November 2020 to 18 April 2021) of weekly surveys obtained from 12,026 participants, males (adjusted odds ratio for testing (ORt): 0.92; adjusted odds ratio for positivity (ORp): 1.30, age-groups <20 (ORt: 0.89; ORp: 1.27) 50-64 years (ORt: 0.94; ORp: 1.06) and 65+ years (ORt: 0.78; ORp: 1.24), diabetics (ORt: 0.97; ORp: 1.06), and sales/administrative employees (ORt: 0.93; ORp: 1.90) were distinguished as lower propensity/higher positivity factors.ConclusionsThe factors identified using this approach can help identify potential target groups for improving communication and encouraging testing among those with symptoms and thus increase the effectiveness of testing, which is essential for the response to the COVID-19 pandemic and for public health strategies in the longer term.

Linking Staff Cases in a Hospital COVID-19 Outbreak Using Electronic Tracking Data

Background: Significant outbreaks of SARS-CoV-2 infections have occurred in healthcare personnel (HCP). We used an electronic tracking system (ETS) as a tool to link staff cases of COVID-19 in place and time during a COVID-19 outbreak in a community hospital. Methods: We identified SARS-CoV-2 infection cases through surveillance, case investigation and contact tracing, and voluntary testing. For those wearing ETS badges (Centrak), data were reviewed for places occupied by the personnel during their incubation and infectious windows. Contacts beyond 15 minutes in the same location were considered close contacts. Results: Over 6 weeks (August 10–September 14, 2020), 35 HCPs tested positive for SARS-CoV-2 by NAAT testing. In total, 18 nurses and aides were clustered on 1 hospital unit, 7 cases occurred among respiratory therapists that visited that unit, and 10 occurred in other departments. Overall, 17 individuals wore ETS badges as part of hand hygiene monitoring. ETS data established potential transmission opportunities in 17 instances, all but 2 before symptom onset or positive test result. Contacts were most often (10 of 17) in common work areas (nursing stations), with a median time of 45 minutes (IQR, 21–137). Contacts occurred within and between departments. A few COVID-19 patients were cared for in this location at the time of the outbreak. However, we did not detect HCP-to-patient nor patient-to-HCP transmission. Conclusions: Significant HCP-to-HCP transmission occurred during this outbreak based on ETS location. These events often occurred in shared work areas such as the nursing station in addition to break areas noted in other reports. ETS systems, installed for other purposes, can serve to reinforce standard epidemiology.Funding: NoDisclosures: None

Information Validates the Prior: A Theorem on Bayesian Updating and Applications

We develop a result on expected posteriors for Bayesians with heterogenous priors, dubbed information validates the prior (IVP). Under familiar ordering requirements, Anne expects a (Blackwell) more informative experiment to bring Bob’s posterior mean closer to Anne’s prior mean. We apply the result in two contexts of games of asymmetric information: voluntary testing or certification, and costly signaling or falsification. IVP can be used to determine how an agent’s behavior responds to additional exogenous or endogenous information. We discuss economic implications. (JEL C11, D82, D84)

Voluntary Testing Practice Among People with Clinical Symptoms of COVID-19 in Somalia: Using Andersen’s Behavioral model

Background: COVID-19, is a respiratory disease caused by a novel coronavirus. The virus is a global pandemic which threatens children and their rights in countries around the world. Epidemiologists have advocated for a robust testing and contact tracing as a potential solution to balance public health and economic priorities. Using Anderson Behavioral Model, our study aimed to analyze predisposing, Enabling and Need factors associated with VT4C-19 practice in Somalia. Methods: A cross sectional community-based survey were conducted at household level among adults above the age 18 years living in Mogadishu and Garowe cities. The study used multi-stage stratified-cluster sampling method. Out of the Four main towns in Somalia with a designated free National laboratory for COVID-19 testing by the government, the study randomly selected two cities (Mogadishu & Garowe) using Simple Random Sampling (SRS) Method. The study used univariate analysis and Multivariable Binary Logistic Regression model to control other possible confounders and to give the Andersen Behavioral Modal that were independently associated with voluntary testing for COVID-19 in Somalia. The statistical significance tests were accepted at p < 0.05.Results: Only 113 (6.6%) out of (1,708) study participants who experienced clinical symptoms of COVID-19 (between 16 March – 31 December 2020) voluntarily tested their COVID-19 status. The study found Predisposing factors including gender (P<0.001), marital status (p<0.05), mass media availability (p<0.05), telephone ownership (p<0.05), peer influence (P<0.001) and stigma of COVID-19 positive individuals in the community (P<0.001), and Enabling factors including: place of residence (p<0.001), expense decision maker at household level (p<0.05), insurance status (p<0.001) and access to outreach and health education program (p<0.05), as well as the Need factors including: perceived importance of COVID-19 voluntary test (p<0.001) and chronic diseases status among the study participants (p<0.05) were among the factors associated with the practice of voluntary tests of COVID-19 among the clinically symptomatic individuals in Somalia.Conclusion: The uptake of Voluntary testing for COVID-19 is very low in Somalia. To promote this, health officials and policy makers need to focus on a consistent and culturally sensitive community sensitization programs and bringing the COVID-19 test closer to the communities including rural communities.

Epidemiological factors associated with recent HIV infection among newly-diagnosed cases in Singapore, 2013–2017

BackgroundEarly diagnosis is crucial in securing optimal outcomes in the HIV care cascade. Recent HIV infection (RHI) serves as an indicator of early detection in the course of HIV infection. Surveillance of RHI is important in uncovering at-risk groups in which HIV transmission is ongoing. The study objectives are to estimate the proportion of RHI among persons newly-diagnosed in 2013–2017, and to elucidate epidemiological factors associated with RHI in Singapore.MethodsAs part of the National HIV Molecular Surveillance Programme, residual plasma samples of treatment-naïve HIV-1 positive individuals were tested using the biotinylated peptide-capture enzyme immunoassay with a cutoff of normalized optical density ≤ 0.8 for evidence of RHI. A recent infection testing algorithm was applied for the classification of RHI. We identified risk factors associated with RHI using logistic regression analyses.ResultsA total of 701 newly-diagnosed HIV-infected persons were included in the study. The median age at HIV diagnosis was 38 years (interquartile range, 28–51). The majority were men (94.2%), and sexual route was the predominant mode of HIV transmission (98.3%). Overall, 133/701 (19.0, 95% confidence interval [CI] 16.2–22.0%) were classified as RHI. The proportions of RHI in 2015 (31.1%) and 2017 (31.0%) were significantly higher than in 2014 (11.2%). A significantly higher proportion of men having sex with men (23.4, 95% CI 19.6–27.6%) had RHI compared with heterosexual men (11.1, 95% CI 7.6–15.9%). Independent factors associated with RHI were: age 15–24 years (adjusted odds ratio [aOR] 4.18, 95% CI 1.69–10.31) compared with ≥55 years; HIV diagnosis in 2015 (aOR 2.36, 95% CI 1.25–4.46) and 2017 (aOR 2.52, 95% CI 1.32–4.80) compared with 2013–2014; detection via voluntary testing (aOR 1.91, 95% CI 1.07–3.43) compared with medical care; and self-reported history of HIV test(s) prior to diagnosis (aOR 1.72, 95% CI 1.06–2.81).ConclusionAlthough there appears to be an increasing trend towards early diagnosis, persons with RHI remain a minority in Singapore. The strong associations observed between modifiable behaviors (voluntary testing and HIV testing history) and RHI highlight the importance of increasing the accessibility to HIV testing for at-risk groups.

No cases of asymptomatic SARS-CoV-2 infection among healthcare staff in a city under lockdown restrictions: lessons to inform ‘Operation Moonshot’

ABSTRACT Background Leicester was the first city in the UK to have ‘local lockdown’ measures imposed in response to high community rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. As part of this response, a directive was issued by NHS England to offer testing of asymptomatic healthcare workers (HCWs) at University Hospitals of Leicester NHS Trust (UHL) for SARS-CoV-2 infection. Methods Between 20 July and 14 August 2020, we invited all HCWs at UHL to attend for SARS-CoV-2 testing by nucleic acid amplification (NAAT). We combined the result of this assay with demographic information from the electronic staff record. Results A total of 1150 staff (~8% of the workforce) volunteered. The median age was 46 years (IQR 34–55), 972 (84.5%) were female; 234 (20.4%) were of South Asian and 58 (5.0%) of Black ethnicity; 564 (49.0%) were nurses/healthcare assistants. We found no cases of asymptomatic infection. In comparison, average community test positivity rate in Leicester city was 2.6%. Conclusions Within the context of local lockdowns due to high community transmission rates, voluntary testing of asymptomatic staff has low uptake and low yield and thus its premise and cost-effectiveness should be re-considered.