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1.
Eur J Obstet Gynecol Reprod Biol X ; 15: 100153, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1851100

ABSTRACT

Objectives: This study aims to provide a semi-qualitative histopathological report of the dual SARS-CoV-2 and HIV infected placentae in the third trimester of Advanced Abdominal Pregnancy (AAP). Study design: Four AAP placentae in the third trimester of pregnancy (two positive for HIV-1 and two positives for SARS-CoV-2) were histologically examined. Results: The SARS-CoV-2+ HIV+ placentae were dysmorphic in shape compared to the flattened disc-like shape noted in the SARS-CoV-2+HIV-, SARS-CoV-2-HIV+and SARS-CoV-2-HIV- placentae. Diffused syncytial knots and syncytial degeneration were observed in all placentae. Intermittent cytotrophoblast increase, perivillous and intravillous fibrin deposition, mononuclear inflammatory cells with widespread degeneration/necrosis of the syncytiotrophoblast and microcalcification were pronounced in the SARS-CoV-2+HIV+ compared to the SARS-CoV-2+HIV- placentae. Vascular pathological changes included thrombi, ectasis, mural hypertrophy and atherotic vessels. Conclusion: Elevated syncytial trophoblast injury, villitis, microcalcifications and mineralisation of the syncytial basement membrane in the AAP placentae may be due to SARS-CoV-2 viral transgression instead of HIV infection alone. Vascular malperfusion is suggestive of a hypoxic insult arising from a compensatory response to meet the fetal oxygen and nutrient demands of an AAP. Placentae from HIV infected women on antiretroviral treatment were characterised by vascular malperfusion.

2.
Embase; 2021.
Preprint in English | EMBASE | ID: ppcovidwho-336070

ABSTRACT

Introduction: Globally, there have been more than 404 million cases of SARS-CoV-2, with 5.8 million confirmed deaths, as of February 2022. South Africa has experienced four waves of SARS-CoV-2 transmission, with the second, third, and fourth waves being driven by the Beta, Delta, and Omicron variants, respectively. A key question with the emergence of new variants is the extent to which they are able to reinfect those who have had a prior natural infection. We developed two approaches to monitor routine epidemiological surveillance data to examine whether SARS-CoV-2 reinfection risk has changed through time in South Africa, in the context of the emergence of the Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529) variants. We analyze line list data on positive tests for SARS-CoV-2 with specimen receipt dates between 04 March 2020 and 31 January 2022, collected through South Africa's National Notifiable Medical Conditions Surveillance System. Individuals having sequential positive tests at least 90 days apart were considered to have suspected reinfections. Our routine monitoring of reinfection risk included comparison of reinfection rates to the expectation under a null model (approach 1) and estimation of the time-varying hazards of infection and reinfection throughout the epidemic (approach 2) based on model-based reconstruction of the susceptible populations eligible for primary and second infections. Results: 105,323 suspected reinfections were identified among 2,942,248 individuals with laboratory-confirmed SARS-CoV-2 who had a positive test result at least 90 days prior to 31 January 2022. The number of reinfections observed through the end of the third wave in September 2021 was consistent with the null model of no change in reinfection risk (approach 1). Although increases in the hazard of primary infection were observed following the introduction of both the Beta and Delta variants, no corresponding increase was observed in the reinfection hazard (approach 2). Contrary to expectation, the estimated hazard ratio for reinfection versus primary infection was lower during waves driven by the Beta and Delta variants than for the first wave (relative hazard ratio for wave 2 versus wave 1: 0.71 (CI95: 0.60-0.85);for wave 3 versus wave 1: 0.54 (CI95: 0.45-0.64)). In contrast, the recent spread of the Omicron variant has been associated with an increase in reinfection hazard coefficient. The estimated hazard ratio for reinfection versus primary infection versus wave 1 was 1.75 (CI95: 1.48-2.10) for the period of Omicron emergence (01 November 2021 to 30 November 2021) and 1.70 (CI95: 1.44-2.04) for wave 4 versus wave 1. Individuals with identified reinfections since 01 November 2021 had experienced primary infections in all three prior waves, and an increase in third infections has been detected since mid-November 2021. Many individuals experiencing third infections had second infections during the third (Delta) wave that ended in September 2021, strongly suggesting that these infections resulted from immune evasion rather than waning immunity. Conclusion: Population-level evidence suggests that the Omicron variant is associated with substantial ability to evade immunity from prior infection. In contrast, there is no population-wide epidemiological evidence of immune escape associated with the Beta or Delta variants. This finding has important implications for public health planning, particularly in countries like South Africa with high rates of immunity from prior infection. Further development of methods to track reinfection risk during pathogen emergence, including refinements to assess the impact of waning immunity, account for vaccine-derived protection, and monitor the risk of multiple reinfections will be an important tool for future pandemic preparedness.

3.
African Journal of Health Professions Education ; 14(1):13-16, 2022.
Article in English | Academic Search Complete | ID: covidwho-1771704

ABSTRACT

Background. The advent of COVID-19 and the subsequent national lockdown has catapulted higher education institutions into emergency remote teaching (ERT). A principal challenge in this shift is the ability to stimulate student interest towards engagement with, and retention of, course content. The creation of teaching and learning (T&L) resources and activities using a combination of the visual, aural, read/write and kinaesthetic (VARK) modes is fundamental in ensuring student engagement. Objectives. To determine the learning style profiles of undergraduate students and to explore how student learning profiles may be incorporated in T&L approaches during ERT. Methods. This descriptive study profiles the learning preferences of undergraduate students in a health science faculty using the VARK questionnaire. The study further outlines modifications in T&L implemented to support the varied learning preferences during the COVID-19 ERT response. Results. Our findings demonstrate that the majority of our students have a multimodal learning preference, with the kinaesthetic modality being the most preferred. Voice-over PowerPoint presentations with transitioning images, and audio files, supported the visual and aural learners through asynchronous engagement. Additionally, online discussion forums and applied projects (such as theme park designs) enhanced asynchronous learning by stimulating the visual, read/write and kinaesthetic preferences, respectively. Microsoft Team sessions with PowerPoint presentations supported visual and aural learning preferences through synchronous engagement. Conclusions. Rethinking traditional T&L approaches towards supporting the diverse student learning preferences is critical in student-centred T&L amidst the many challenges that ERT has precipitated. Academics need to be dynamic in their T&L approaches and intuitive in their awareness of how subject content may be modified/enhanced in the ERT environment. [ FROM AUTHOR] Copyright of African Journal of Health Professions Education is the property of South African Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

4.
Pertanika Journal of Tropical Agricultural Science ; 45(1):235-244, 2022.
Article in English | CAB Abstracts | ID: covidwho-1727536

ABSTRACT

Cat's whiskers or the 'misai kucing' is an herbal plant native to the Southeast Asian region. The polyphenol enriched leaf extract contains numerous medicinal properties of major pharmaceutical interest. In this study, selected cat's whiskers polyphenols were screened computationally to predict the minimum binding affinities with severe acute respiratory syndrome coronavirus (SARS-CoV) molecular targets. Molecular docking analysis showed that the caffeic acid derivatives and polymethoxylated flavonoids from cat's whiskers bound stably to the binding pocket regions of SARS-CoV molecular targets at - 4.2 to - 7.1 kcal/mol. Furthermore, these cat's whiskers polyphenol-bound SARS-CoV complexes were held fairly strongly by hydrophobic interactions, hydrogen bonds, and electrostatic interactions at various extents.

5.
Embase;
Preprint in English | EMBASE | ID: ppcovidwho-326899

ABSTRACT

A new SARS-CoV-2 variant of concern, Omicron (B.1.1.529), has been identified based on genomic sequencing and epidemiological data in South Africa. Presumptive Omicron cases in South Africa have grown extremely rapidly, despite high prior exposure and moderate vaccination coverage. The available evidence suggests that Omicron spread is at least in part due to evasion of this immune protection, though Omicron may also exhibit higher intrinsic transmissibility. Using detailed laboratory and epidemiological data from South Africa, we estimate the constraints on these two characteristics of the new variant and their relationship. Our estimates and associated uncertainties provide essential information to inform projection and scenario modeling analyses, which are crucial planning tools for governments around the world.

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