Preventing and controlling intra-hospital spread of COVID-19 in Taiwan - Looking back and moving forward.

COVID-19 has exposed major weaknesses in the healthcare settings. The surge in COVID-19 cases increases the demands of health care, endangers vulnerable patients, and threats occupational safety. In contrast to a hospital outbreak of SARS leading to a whole hospital quarantined, at least 54 hospital outbreaks following a COVID-19 surge in the community were controlled by strengthened infection prevention and control measures for preventing transmission from community to hospitals as well as within hospitals. Access control measures include establishing triage, epidemic clinics, and outdoor quarantine stations. Visitor access restriction is applied to inpatients to limit the number of visitors. Health monitoring and surveillance is applied to healthcare personnel, including self-reporting travel declaration, temperature, predefined symptoms, and test results. Isolation of the confirmed cases during the contagious period and quarantine of the close contacts during the incubation period are critical for containment. The target populations and frequency of SARS-CoV-2 PCR and rapid antigen testing depend on the level of transmission. Case investigation and contact tracing should be comprehensive to identify the close contacts to prevent further transmission. These facility-based infection prevention and control strategies help reduce hospital transmission of SARS-CoV-2 to a minimum in Taiwan.

SARS-CoV-2 testing, infection and places of contamination in France, a national cross-sectional study, December 2021.

BACKGROUND: This study aimed to describe the use of diagnostic testing for SARS-CoV-2 in France until December 2021, the characteristics of people infected, and places of contamination. METHODS: Data were collected from the national 2021 Health Barometer cross-sectional study, which was conducted between February and December 2021 and included French-speaking individuals aged 18-85 years old selected through randomly generated landline and mobile phone numbers. Participants were interviewed about COVID-19-like symptoms in the previous 12 months, diagnostic testing for SARS-CoV-2, positive diagnosis for SARS-CoV-2, and the place(s) of contamination. Determinants of diagnostic testing and of infection were studied using univariate and multivariate Poisson regressions. RESULTS: A total of 24,514 persons participated in the study. We estimated that 66.4% [65.0-67.7] of persons had been tested for SARS-CoV-2 the last time they experienced COVID-19-like symptoms, and that 9.8% [9.3-10.3] of the population in France - with or without symptoms - had been tested positive. Diagnostic testing was less frequent in men, unemployed persons, and people living alone; it was also less frequent during the first months of the pandemic. The estimated proportion of the population infected was higher in healthcare professionals (PRa: 1.5 [1.3-1.7]), those living in large cities ( > = 200 000 inhabitants, and Paris area) (1.4 [1.2-1.6]), and in households comprising > 3 persons (1.7 [1.5-2.0]). It was lower in retired persons (0.8 [0.6-0.97]) and those over 65 years old (0.6 [0.4-0.9]). Almost two-thirds (65.7%) of infected persons declared they knew where they were contaminated; 5.8% [4.5-7.4] reported being contaminated outdoors, 47.9% [44.8-51.0] in unventilated indoor environments, and 43.4% [40.3-46.6] in ventilated indoor environments. Specifically, 51.1% [48.0-54.2] declared they were contaminated at home or in a family of friend's house, 29.1% [26.4-31.9] at their workplace, 13.9% [11.9-16.1] in a healthcare structure, and 9.0% [7.4-10.8] in a public eating place (e.g., cafeteria, bar, restaurant). CONCLUSIONS: To limit viral spread, preventive actions should preferentially target persons tested least frequently and those at a higher risk of infection. They should also target contamination in households, healthcare structures, and public eating places. Importantly, contamination is most frequent in places where prevention measures are most difficult to implement.

Comparison of Igm/Igg Antibody Tests in Severe COVID Infections and Standard rtPCR Diagnostic Testing in The Hospital for Active Treatment "Dr. Atanas Dafovski”, Kardzhali

We present the results from ELISA IgG/IgM tests vs rtPCR diagnostic testing of individuals both with and without clinical symptoms, travel arrangements and cross-border movement, in an effort to contain the COVID-19 pandemic during the entire 2021. rtPCR test results were a prerequisite for any planned trip, requirement for diagnosis and protocol treatment. The collected data are cumulative and the statistics might become helpful to each individual in deciding on a particular line of action. Our Molecular Diagnostics Unit is licensed within the territory of Bulgaria. Our methods present strict protocols from the guidelines of the National Center for Infectious and Parasitic Diseases, the kits used were all CE, the overall concept in sync with the global regulations per CDC and the WHO. The cumulated results for each month show high correlation between the levels of IgM and the number of patients testing positive for COVID with the rtPCR. We present retrospective data of utmost importance for the regions near border crossing point in a situation of pandemic with involvement of local and international authorities. Determining the titer of Covid antibodies provides important information with regard to vaccination and compare levels of titers of acute elevated IgM titers in patients with severe COVID-19 with positive PCR results in an attempt to implement more ELISA testing as a significant, informative and important part of establishing a patient's status, given the easier access to rapid tests when triaging patients for admission to hospital and with the need for emergency resuscitation. © 2022, Bulgarian Society for Microbiology (Union of Scientists in Bulgaria). All rights reserved.

COVID-19-Related Facilitators and Barriers to In-Person Learning for Children With Intellectual and Development Disabilities.

BACKGROUND: Schools provide essential functions for children with intellectual and developmental disabilities (IDD), but their vulnerability to infection with SARS-CoV-2 are a barrier to in-person learning. This qualitative study aimed to understand how weekly SARS-CoV-2 screening testing of students and staff could best facilitate in-school learning during the pandemic. METHODS: Thirty-one focus groups were held with school staff and parents of children with IDD to examine the perceptions of COVID-19 during the 2020-2021 school year. Responses were analyzed using a directed thematic content analysis approach. RESULTS: Five principal themes were identified: risks of returning to in-person learning; facilitators and barriers to participation in SARS-CoV-2 screening testing; messaging strategies; and preferred messengers. IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY: Staff and families agreed that saliva-based SARS-CoV-2 screening testing helps increase comfort with in-person learning. Screening testing increased family and school staff comfort with in-person learning particularly because many students with special needs cannot adhere to public health guidelines. CONCLUSION: To keep children with IDD in school during the pandemic, families found SARS-CoV-2 screening testing important, particularly for students that cannot adhere to mitigation guidelines.

SARS-CoV-2 testing and detection during peripartum hospitalizations among a multi-center cohort of pregnant persons, March 2020-February 2021.

BACKGROUND: Identifying SARS-CoV-2 infections during peripartum hospitalizations is important to guide care, implement prevention measures, and understand infection burden. METHODS: This cross-sectional analysis used electronic health record data from hospitalizations during which pregnancies ended (peripartum hospitalizations) among a cohort of pregnant persons at 3 U.S. integrated healthcare networks (Sites 1-3). Maternal demographic, medical encounter, SARS-CoV-2 testing, and pregnancy and neonatal outcome information was extracted for persons with estimated delivery and pregnancy end dates during March 2020-February 2021 and ≥1 prenatal care record. Site-stratified multivariable logistic regression was used to identify factors associated with testing and compare pregnancy and neonatal outcomes among persons tested. RESULTS: Among 17,858 pregnant persons, 10,863 (60.8%) had peripartum SARS-CoV-2 testing; 222/10,683 (2.0%) had positive results. Testing prevalence varied by site and was lower during March-May 2020. Factors associated with higher peripartum SARS-CoV-2 testing odds were Asian race (adjusted odds ratio [aOR]: 1.36; 95% CI: 1.03-1.79; referent: White) (Site 1), Hispanic or Latina ethnicity (aOR: 1.33; 95% CI: 1.08-1.64) (Site 2), peripartum Medicaid coverage (aOR: 1.33; 95% CI: 1.06-1.66) (Site 1), and preterm hospitalization (aOR: 1.69; 95% CI: 1.19-2.39 [Site 1]; aOR: 1.39; 95% CI: 1.03-1.88 [Site 2]). CONCLUSIONS: Findings highlight potential disparities in SARS-CoV-2 peripartum testing by demographic and pregnancy characteristics. Testing practice variations should be considered when interpreting studies relying on convenience samples of pregnant persons testing positive for SARS-CoV-2. Efforts to address testing differences between groups could improve equitable testing practices and care for pregnant persons with SARS-CoV-2 infections.

Values of COVID-19 Self-Testing among Urban and Rural South Africans: A Cross-Sectional Survey.

Self-testing for COVID-19 may be a preferable strategy for identifying SARS-CoV-2 infection among populations in low- and middle-income settings. To determine South Africans' values related to COVID-19 self-testing should it become widely available, a cross-sectional survey was administered in Durban, KwaZulu-Natal Province and the King Sabata Dalindyebo sub-district of the Eastern Cape. A 35-question survey was administered to 531 participants (268 female) in one urban and one rural setting of South Africa. Survey participants were randomly selected by household in the rural setting, while in the urban setting participants were approached in randomly selected public places. The survey assessed participants' likelihood of using and willingness to pay for a COVID-19 self-test and actions they would take following a COVID-19 self-test. The results were analysed using descriptive statistics and bivariate and multivariate regression. Overall, 93.03% of participants supported COVID-19 self-testing, 61.62% of participants were willing to pay for self-testing, and 90.15% indicated they would communicate their results if they tested positive. Rural participants were more positively associated with each of these outcomes compared with urban-based participants. Should they test positive, most participants said they would: go in-person to a health facility for counselling (76.45%), self-isolate (95.85%), notify close contacts (97.74%), and inform their employer (95.14%). COVID-19 self-testing was a preferable option for most participants, although this varied with setting and demographic characteristics. Self-testing may overcome barriers to care for South Africans, but to achieve this, policies for self-testing and delivery methods must not exacerbate individuals' underlying economic vulnerabilities.

Inter-laboratory testing as a strategy for external quality assessment for qualitative detection of SARS-CoV-2 by real-time RT-PCR testing in India.

To implement the strategy of test, track and treat to tackle the ongoing COVID-19 pandemic, the number of real-time RT-PCR-based testing laboratories was increased for diagnosis of SARS-CoV-2 in the country. To ensure reliability of the laboratory results, the Indian Council of Medical Research initiated external quality assessment (EQA) by deploying inter-laboratory quality control (ILQC) activity for these laboratories by nominating 34 quality control (QC) laboratories. This report presents the results of this activity for a period of September 2020 till November 2020. A total of 597 laboratories participated in this activity and 86 per cent of these scored ≥90 per cent concordance with QC laboratories. This ILQC activity showcased India's preparedness in quality diagnosis of SARS-CoV-2.

Group Testing Matrix Design for PCR Screening with Real-Valued Measurements.

Single-step nonadaptive group testing approaches for reducing the number of tests required to detect a small subset of positive samples from a larger set require solving two algorithmic problems. First, how to design the samples-to-tests measurement matrix, and second, how to decode the results of the tests to uncover positive samples. In this study, we focus on the first challenge. We introduce real-valued group testing, which matches the characteristics of existing PCR testing pipelines more closely than combinatorial group testing or compressed sensing settings. We show a set of conditions that allow measurement matrices to guarantee unambiguous decoding of positives in this new setting. For small matrix sizes, we also propose an algorithm for constructing matrices that meet the proposed condition. On simulated data sets, we show that the matrices resulting from the algorithm can successfully recover positive samples at higher positivity rates than matrices designed for combinatorial group testing setting. We use wet laboratory experiments involving SARS-CoV-2 nasopharyngeal swab samples to further validate the approach.

The Agreement Between Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and Rapid Antigen Test (RAT) in Diagnosing COVID-19.

Background False-negative results derived from RT-PCR tests for diagnosing coronavirus disease (COVID-19) have raised questions about whether to consider them the gold standard for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Using an imperfect gold standard to assess other diagnostic tests would never let the other tests show better diagnostic performance. The best strategy in such cases is to do an agreement analysis, and this study aims to estimate the agreement between real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid antigen test (RAT) for COVID-19 detection. Methods A retrospective study was done using paired data of individuals tested for COVID-19, both by RT-PCR and RAT, obtained from the virology laboratory of Government Bundelkhand Medical College, Sagar, Madhya Pradesh, India. A sample size of 93 was calculated, and the data were abstracted in a data abstraction sheet. Variables included were results of RT-PCR and RAT, age, gender, presence of symptoms, test kit used, and the time duration between sampling for RT-PCR and RAT. Apart from descriptive statistics, keeping in mind the binary outcome of RT-PCR and RAT, Cohen's kappa was calculated for agreement analysis. A p-value of <0.05 was considered significant. Results The data on 100 participants suspected to be infected with COVID-19 (58 male and 42 female) with a mean age of 39.8 (±19.0) years were analysed. The number of discordant pairs was eight. Cohen's kappa showed substantial agreement between RT-PCR and RAT, κ=0.646, (95% CI 0.420 to 0.871), p<0.001. Conclusion Considering the ease of conducting RAT with quick results and substantial agreement with RT-PCR, RAT could be a better choice in detecting SARS-CoV-2 and, hence, COVID-19 disease on a large scale.

Rapid antigen test for COVID-19: A useful weapon in the arsenal of public health

Rapid antigen test has a very important value as one of tools to address the Covid pandemic. Though this test is not as accurate as polymerase chain reaction (PCR) testing. As viral antigen appears before antibody formation in infected person. It is a specific marker of virus. Therefore, for detection of this highly infectious disease at an early stage, viral antigen testing can be a useful strategy in scenario of community transmission to prevent further spread. In India an advisory was issued by ICMR (on 14th June 2020) regarding usage of RAT for quick detection of COVID-19 positive patients. During second wave, Rapid antigen testing was advised only in symptomatic individuals and immediate contacts of laboratory confirmed positive cases. Though no test is perfect when it comes to the attributes of accuracy, accessibility, affordability, and timeliness of results. However, Rapid antigen test can be used as a useful test in public health that can benefit the larger population in breaking the chain of transmission if used wisely in different settings and according to the timeline of symptoms. © Medical Journal of Dr. D.Y. Patil Vidyapeeth 2022.

Are Kenyans Likely to Use COVID-19 Self-Testing Kits? Results From a Cross-Sectional Survey.

Objectives: To understand the public's perceptions around rapid SARS-CoV-2 antigen self-testing in Kenya, including the drivers of acceptability, willingness to pay, and adherence to hygiene and prevention recommendations following a positive self-test. Methods: A household-based, cross-sectional survey, using a 35-item questionnaire, was conducted in Mombasa and Taita-Taveta counties, Kenya, during August 2021. Individuals aged ≥18 years were enrolled using a stratified sampling approach. Results: There were 419 participants (mean age 35.7 years). A minority (10.5%) had ever tested for SARS-CoV-2. If SARS-CoV-2 self-testing were available, 39.9% and 41.5% would be likely and very likely, respectively, to use it. If unavailable free-of-charge, 63.01% would pay for it. Multivariate analyses suggested that people in rural areas (Coefficient 0.30, 95%CI: 0.11-0.48, p = 0.002), aged 36-55 (Coefficient 0.21, 95%CI: 0.03-0.40, p = 0.023), and employed full time (Coefficient 0.32, 95%CI: 0.06-0.58, p = 0.016) would have more odds to adhere to recommended hygiene and prevention actions. Conclusion: SARS-CoV-2 self-testing was considered acceptable. Availability of self-testing could expand access to COVID-19 testing in Kenya, particularly among rural communities who have limited access to testing, and among mildly symptomatic individuals.

Self-testing for SARS-CoV-2 in São Paulo, Brazil: results of a population-based values and attitudes survey.

BACKGROUND: Brazil is among the countries in South America where the COVID-19 pandemic has hit the general population hardest. Self-testing for SARS-CoV-2 infection is one of the community-based strategies that could help asymptomatic individuals at-risk of COVID-19, as well as those living in areas that are difficult for health personnel to reach, to know their infectious status and contribute to impeding further transmission of the virus. METHODS: A population-based survey was conducted in November 2021, to assess the acceptability of rapid SARS-CoV-2 antigen self-testing among the population of São Paulo. Survey respondents were approached at more than 400 different street-points that were randomly selected using a five-stage randomization process. A 35-item structured questionnaire was used. Dependent variables for our analyses were the likelihood to use and willingness to pay for self-testing, and the likelihood of taking preventive measures to prevent onward transmission of SARS-CoV-2 following a reactive self-test result. Bivariate and multivariate regression analyses were performed. RESULTS: Overall, 417 respondents (44.12% female) participated; 19.66% had previously had COVID-19 disease. A minority (9.59%) felt at high-risk of COVID-19. The majority of both females and males (73.91% and 60.09%, respectively) were in favor of the idea of SARS-CoV-2 self-testing. Overall, if self-tests were available, almost half of the sample would be very likely (n = 54, 12.95%) or likely (n = 151, 36.21%) to use one if they felt they needed to. Upon receiving a positive self-test result, the majority of respondents would communicate it (88.49%), request facility-based post-test counseling (98.32%), self-isolate (97.60%), and warn their close contacts (96.64%). CONCLUSION: Rapid SARS-CoV-2 antigen self-testing could be an acceptable screening tool in São Paulo. The population would be empowered by having access to a technology that would allow them to test, even if asymptomatic, when traveling, or going to work or school. If there is a surge in the incidence of cases, self-testing could be a good approach for mass case detection by Brazil's already overstretched Unified Health System.

COVID-19 and isolation: Risks and implications in the scenario of new variants.

With the emergence of new variants of SARS-CoV-2, questions about transmissibility, vaccine efficacy, and impact on mortality are important to support decision-making in public health measures. Modifications related to transmissibility combined with the fact that much of the population has already been partially exposed to infection and/or vaccination, have stimulated recommendations to reduce the isolation period for COVID-19. However, these new guidelines have raised questions about their effectiveness in reducing contamination and minimizing impact in work environments. Therefore, a collaborative task force was developed to review the subject in a non-systematic manner, answering questions about SARS-CoV-2 variants, COVID-19 vaccines, isolation/quarantine periods, testing to end the isolation period, and the use of masks as mitigation procedures. Overall, COVID-19 vaccines are effective in preventing severe illness and death but are less effective in preventing infection in the case of the Omicron variant. Any strategy that is adopted to reduce the isolation period should take into consideration the epidemiological situation of the geographical region, individual clinical characteristics, and mask for source control. The use of tests for isolation withdrawal should be evaluated with caution, due to results depending on various conditions and may not be reliable.

Sensitivity and specificity of rapid antibody diagnostic test for diagnosis COVID 19 in pediatric patients

Objective: Aim of this observational is to evaluate the sensitivity and specificity a rapid diagnostic test for COVID-19 for screening COVID-19 pediatric patients. Study Design: 179 Patients under 18 years old with a history of COVID-19 symptoms, and who underwent PCR and/or reference antibody testing for COVID-19. Results: The sampel of this study consisted of 179 patient who 100 sunject with reactive in rapid antibody diagnostic test COVID 19 which consisting of 40 subject positive SARS-CoV2 PCR swab examination and 60 subject negative SARS-CoV2 PCR swab examination. The patient with nonreactive result in rapid antibody diagnostic test COVID 19 which consisting of 19 subject positive SARS-CoV2 PCR swab examination and 60 subject negative SARS-CoV2 PCR swab examination. The sensitivity of the test was 67%. Specificity was 50%. There was substantial agreement between SARS-CoV2 PCR results and a rapid antibody diagnostic test COVID 19. Conclusion: The current evaluation of antibody-based system shows low sensitivity and low specificity result. © 2022 Universidad Tecnica de Manabi. All rights reserved.

Taking the Path Into the Dark Woods - Initial Industry Impact of the COVID-19 Pandemic.

During the initial onset of the COVID-19 pandemic, each industry experienced hardships. One area that has not been explored in great detail was how the diagnostic industry managed while bringing SARS-CoV-2 tests to the market. This perspective piece provides a sample view of what went on behind the walls of a diagnostic manufacturer that released one of the initial SARS-CoV-2 testing options, some of the barriers that were encountered, and how they could be overcome.

Effect of Frequent SARS-CoV-2 Testing on Weekly Case Rates in Long-Term Care Facilities, Florida, USA.

We analyzed 1,292,165 SARS-CoV-2 test results from residents and employees of 361 long-term care facilities in Florida, USA. A 1% increase in testing resulted in a 0.08% reduction in cases 3 weeks after testing began. Increasing SARS-CoV-2 testing frequency is a viable tool for reducing virus transmission in these facilities.

Clinical presentation of COVID-19 at the time of testing and factors associated with pre-symptomatic cases in Cameroon.

Objectives: To describe the clinical features at time of testing and explore factors associated with SARS-CoV-2 infection and pre-symptomatic cases in Cameroon. Methods: Data was collected on people in Cameroon who participated in COVID-19 testing by real-time reverse transcriptase-polymerase chain reaction between 1 March and 5 October 2020. After descriptive analysis, multivariate logistic regression was used to identify factors associated with SARS-CoV-2 infection and pre-symptomatic cases. Results: Of 85 206 test participants, 14 863 (17.4%) were infected with SARS-CoV-2. The median age for cases was 38.4 years (interquartile range 29.6-49.4); 6.1% were aged <19 years, and 6.3% were ≥65 years. Of these cases, 46.5% had at least one symptom/sign with a median time from illness onset to testing of 6 days (interquartile range 3-9). Cough (64.2%), headache (46.5%), fatigue/malaise (46.0%), shortness of breath (30.6%) and myalgia/arthralgia (25.6%) were the most commonly observed symptoms/signs. Pre-symptomatic SARS-CoV-2 infection was associated with age <50 years, being male and absence of comorbidities. Conclusion: This study provides a comprehensive summary of the early clinical profile of SARS-CoV-2 infection during the first wave of COVID-19 in Cameroon, which was dominated by pre-symptomatic illness. These findings would be helpful for SARS-CoV-2 surveillance and control at a regional level.

Real-Valued Group Testing for Quantitative Molecular Assays

Combinatorial group testing and compressed sensing both focus on recovering a sparse vector of dimensionality n from a much smaller number m< n of measurements. In the first approach, the problem is defined over the Boolean field – the goal is to recover a Boolean vector and measurements are Boolean;in the second approach, the unknown vector and the measurements are over the reals. Here, we focus on real-valued group testing setting that more closely fits modern testing protocols relying on quantitative measurements, such as qPCR, where the goal is recovery of a sparse, Boolean vector and the pooling matrix needs to be Boolean and sparse, but the unknown input signal vector and the measurement outcomes are nonnegative reals, and the matrix algebra implied in the test protocol is over the reals. With the recent renewed interest in group testing, focus has been on quantitative measurements resulting from qPCR, but the method proposed for sample pooling were based on matrices designed with Boolean measurements in mind. Here, we investigate constructing pooling matrices dedicated for the real-valued group testing. We provide conditions for pooling matrices to guarantee unambiguous decoding of positives in this setting. We also show a deterministic algorithm for constructing matrices meeting the proposed condition, for small matrix sizes that can be implemented using a laboratory robot. Using simulated data, we show that the proposed approach leads to matrices that can be applied for higher positivity rates than combinatorial group testing matrices considered for viral testing previously. We also validate the approach through wet lab experiments involving SARS-CoV-2 nasopharyngeal swab samples. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

K-8 Classroom Self-Collection Using XpressCollect Nasal Swab: A Usability and Efficacy Study.

This study demonstrates that students in kindergarten through eighth grade can use the XpressCollect nasal swab to self-collect a specimen under the guidance of a teacher. This phased study was conducted with parents, teachers, and students. Phases 1 and 2 were conducted as interviews with teachers and parents to assess the suitability of the XpressCollect for children in kindergarten through eighth grade. Additionally, teacher and parent feedback was obtained to develop and optimize the instructional materials for subsequent phases. In Phases 3 and 4, teachers guided small groups and full classes of students through the sample collection process with XpressCollect. The samples collected by the students were sent to a laboratory to analyze the effectiveness of specimen self-collection based on the presence of ribonuclease P (RNase P) on each nasal swab. The presence of RNase P enables disease determination; thus, student samples were analyzed for adequate or inadequate sampling. All students in kindergarten through eighth grade are capable of self-collecting an anterior nares specimen with XpressCollect, as the laboratory results identified acceptable RNase P Ct values for the samples collected in a classroom setting.