Marvin Hsiao
A5046584384- SARS-CoV-2 and COVID-19 Research
- SARS-CoV-2 detection and testing
- COVID-19 Clinical Research Studies
- HIV/AIDS Research and Interventions
- Trauma and Emergency Care Studies
- Viral Infections and Outbreaks Research
- COVID-19 epidemiological studies
- HIV Research and Treatment
- HIV, Drug Use, Sexual Risk
- Global Health and Surgery
- Injury Epidemiology and Prevention
- vaccines and immunoinformatics approaches
- Long-Term Effects of COVID-19
- HIV/AIDS drug development and treatment
- Emergency and Acute Care Studies
- Animal Virus Infections Studies
- Abdominal Trauma and Injuries
- CRISPR and Genetic Engineering
- Bacillus and Francisella bacterial research
- Viral gastroenteritis research and epidemiology
- Global Maternal and Child Health
- COVID-19 and healthcare impacts
- Appendicitis Diagnosis and Management
- Surgical Simulation and Training
- Burn Injury Management and Outcomes
University of Cape Town
2011-2024
National Health Laboratory Service
2011-2024
Groote Schuur Hospital
2020-2024
Wellcome Centre for Infectious Diseases Research in Africa
2021-2023
National Public Health Laboratory
2023
University of Toronto
2006-2022
Hospital for Sick Children
2011-2022
Royal Columbian Hospital
2018-2022
University of Botswana
2022
University of KwaZulu-Natal
2022
Abstract The SARS-CoV-2 epidemic in southern Africa has been characterized by three distinct waves. first was associated with a mix of lineages, while the second and third waves were driven Beta (B.1.351) Delta (B.1.617.2) variants, respectively 1–3 . In November 2021, genomic surveillance teams South Botswana detected new variant rapid resurgence infections Gauteng province, Africa. Within days genome being uploaded, it designated concern (Omicron, B.1.1.529) World Health Organization and,...
Summary Continued uncontrolled transmission of the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) in many parts world is creating conditions for significant virus evolution. Here, we describe a new SARS-CoV-2 lineage (501Y.V2) characterised by eight lineage-defining mutations spike protein, including three at important residues receptor-binding domain (K417N, E484K and N501Y) that may have functional significance. This emerged South Africa after first epidemic wave...
Abstract The emergence of the SARS-CoV-2 variant concern Omicron (Pango lineage B.1.1.529), first identified in Botswana and South Africa, may compromise vaccine effectiveness lead to re-infections 1 . Here we investigated escape from neutralization by antibodies African individuals vaccinated with Pfizer BNT162b2. We used blood samples taken soon after vaccination who were previously infected or no evidence previous infection. isolated sequence-confirmed live virus an person observed that...
T cells are involved in control of coronavirus disease 2019 (COVID-19), but limited knowledge is available on the relationship between antigen-specific cell response and severity. Here, we used flow cytometry to assess magnitude, function, phenotype SARS 2–specific (SARS-CoV-2–specific) CD4+ 95 hospitalized COVID-19 patients, 38 them being HIV-1 and/or tuberculosis (TB) coinfected, non–COVID-19 patients. We showed that SARS-CoV-2–specific attributes, rather than were associated with...
ABSTRACT Background The SARS-CoV-2 Omicron variant of concern (VOC) almost completely replaced other variants in South Africa during November 2021, and was associated with a rapid increase COVID-19 cases. We aimed to assess clinical severity individuals infected Omicron, using S Gene Target Failure (SGTF) on the Thermo Fisher Scientific TaqPath PCR test as proxy. Methods performed data linkages for (i) laboratory tests, (ii) case data, (iii) genome (iv) DATCOV national hospital surveillance...
The objective was to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves Western Cape, assess contribution of undiagnosed infection differences a context high seroprevalence due and determine whether protection against severe disease conferred by and/or vaccination maintained.
Among the 30 nonsynonymous nucleotide substitutions in Omicron S-gene are 13 that have only rarely been seen other SARS-CoV-2 sequences. These mutations cluster within three functionally important regions of at sites will likely impact (1) interactions between subunits Spike trimer and predisposition to shift from down up configurations, (2) with ACE2 receptors, (3) priming for membrane fusion. We show here that, based on both rarity these intrapatient sequencing reads patterns selection...
Abstract Omicron lineages BA.4 and BA.5 drove a fifth wave of COVID-19 cases in South Africa. Here, we use the presence/absence S-gene target as proxy for SARS-CoV-2 variant/lineage infections diagnosed using TaqPath PCR assay between 1 October 2021 26 April 2022. We link national individual-level data including case, laboratory test hospitalisation data. assess severity multivariable logistic regression comparing risk severe disease, once hospitalised, Delta, BA.1, BA.2 BA.4/BA.5...
Objectives To quantify and describe the mechanism of road traffic injury (RTI) deaths in India. Design We conducted a nationally representative mortality survey where at least two physicians coded each non-medical field staff's verbal autopsy reports. RTI data were extracted from narrative section these Setting 1.1 million homes Participants Over 122 000 all ages 2001 to 2003. Primary secondary outcome measures Age-specific sex-specific rates, place timing death, modes transportation...
Abstract The Omicron variant is characterised by more than 50 distinct mutations, the majority of which are located in spike protein. implications these mutations for disease transmission, tissue tropism and diagnostic testing still to be determined. We evaluated relative performance saliva mid-turbinate swabs as RT-PCR samples Delta variants. positive percent agreement (PPA) a composite standard was 71% (95% CI: 53-84%) 100% 89-100%), respectively, variant. However, had 90-100%) 86% 71-94%)...
The SARS-CoV-2 epidemic in southern Africa has been characterized by three distinct waves. first was associated with a mix of lineages, while the second and third waves were driven Beta (B.1.351) Delta (B.1.617.2) variants, respectively1–3. In November 2021, genomic surveillance teams South Botswana detected new variant rapid resurgence infections Gauteng province, Africa. Within days genome being uploaded, it designated concern (Omicron, B.1.1.529) World Health Organization and, within...
We aimed to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves Western Cape, contribution of undiagnosed infection differences a context high seroprevalence due infection, and whether protection against severe disease conferred by and/or vaccination was maintained.
Abstract The Beta variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in South Africa late 2020 and rapidly became dominant variant, causing over 95% infections country during after second epidemic wave. Here we show rapid replacement by Delta a highly transmissible concern (VOC) that India subsequently spread around world. was imported to primarily from India, large monophyletic clusters all provinces, within three months introduction. This associated with...
a b s t r c Objectives: We aimed to compare the clinical severity of Omicron BA.4/BA.5 infection with BA.1 and earlier variant infections among laboratory-confirmed SARS-CoV-2 cases in Western Cape, South Africa, using timing infer lineage/variant causing infection.Methods: included public sector patients aged ≥20 years COVID-19 between May 01-May 21, 2022 (BA.4/BA.5 wave) equivalent previous wave periods.We compared risk waves (i) death (ii) severe hospitalization/death (all within 21 days...
Among the 30 non-synonymous nucleotide substitutions in Omicron S-gene are 13 that have only rarely been seen other SARS-CoV-2 sequences. These mutations cluster within three functionally important regions of at sites will likely impact (i) interactions between subunits Spike trimer and predisposition to shift from down up configurations, (ii) with ACE2 receptors, (iii) priming for membrane fusion. We show here that, based on both rarity these intrapatient sequencing reads patterns selection...
Few studies from Africa have described the clinical impact of co-infections on SARS-CoV-2 infection. Here, we investigate presentation and outcome infection in an African setting high HIV-1 tuberculosis prevalence by observational case cohort patients. A comparator group non participants is included. The study includes 104 adults with whom 29.8% are co-infected. Two or more co-morbidities present 57.7% participants, including (30%) active (14%). Amongst patients dually infected SARS-CoV-2,...
In response to the COVID-19 pandemic, we created Network for Genomic Surveillance in South Africa (NGS-SA) May, 2020 with grants from African Medical Research Council and Department of Science Innovation. Our goal is sequence genome at least 10 000 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) samples inform public health Africa. As July 27, 2020, have sequenced 500 isolates, which has provided insights into how when it was introduced country, information on its early spread...
Global genomic surveillance of SARS-CoV-2 has identified variants associated with increased transmissibility, neutralization resistance and disease severity. Here we report the emergence PANGO lineage C.1.2, detected at low prevalence in South Africa eleven other countries. The a high substitution rate, includes changes within spike protein that have been transmissibility or reduced sensitivity VOC/VOIs. Like Beta Delta, C.1.2 shows significantly to plasma from vaccinees individuals infected...
Abstract Global genomic surveillance of SARS-CoV-2 has identified variants associated with increased transmissibility, neutralization resistance and disease severity. Here we report the emergence PANGO lineage C.1.2, detected at low prevalence in South Africa eleven other countries. The initial C.1.2 detection is a high substitution rate, includes changes within spike protein that have been transmissibility or reduced sensitivity concern interest. Like Beta Delta, shows significantly to...
The SARS-CoV-2 genome occupies a unique place in infection biology - it is the most highly sequenced on earth (making up over 20% of public sequencing datasets) with fine scale information sampling date and geography, has been subject to unprecedented intense analysis. As result, these phylogenetic data are an incredibly valuable resource for science health. However, vast majority was by tiling amplicons across full genome, amplicon schemes that changed pandemic as mutations viral interacted...
Few population-based studies quantify mortality from surgical conditions and relate to access care in low-income middle-income countries.We linked deaths acute abdominal within a nationally representative, survey of 1·1 million households India representative facility data. We calculated total age-standardised death rates for conditions. Using 4064 postal codes, we undertook spatial clustering analysis compare geographical well-resourced government district hospitals (24 h anaesthesia...