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1.
J Immunol Methods ; 528: 113652, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38458312

RESUMO

Streptococcus pyogenes, commonly referred to as Group A Streptococcus (Strep A), causes a spectrum of diseases, with the potential to progress into life-threatening illnesses and autoimmune complications. The escalating threat of antimicrobial resistance, stemming from the prevalent reliance on antibiotic therapies to manage Strep A infections, underscores the critical need for the development of disease control strategies centred around vaccination. Phagocytes play a critical role in controlling Strep A infections, and phagocytosis-replicating assays are essential for vaccine development. Traditionally, such assays have employed whole-blood killing or opsonophagocytic methods using HL-60 cells as neutrophil surrogates. However, assays mimicking Fcγ receptors- phagocytosis in clinical contexts are lacking. Therefore, here we introduce a flow cytometry-based method employing undifferentiated THP-1 cells as monocytic/macrophage model to swiftly evaluate the ability of human sera to induce phagocytosis of Strep A. We extensively characterize the assay's precision, linearity, and quantification limit, ensuring robustness. By testing human pooled serum, the assay proved to be suitable for the comparison of human sera's phagocytic capability against Strep A. This method offers a valuable complementary assay for clinical studies, addressing the gap in assessing FcγR-mediated phagocytosis. By facilitating efficient evaluation of Strep A -phagocyte interactions, it may contribute to elucidating the mechanisms required for the prevention of infections and inform the development of future vaccines and therapeutic advancements against Strep A infections.


Assuntos
Fagocitose , Infecções Estreptocócicas , Humanos , Citometria de Fluxo/métodos , Anticorpos Antibacterianos , Neutrófilos , Streptococcus pyogenes
2.
PLOS Glob Public Health ; 4(3): e0002257, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38527043

RESUMO

Group A Streptococcus (Strep A) bacteria causes a broad spectrum of diseases. The most common manifestations of Strep A infection are sore throat and pus-producing skin infections such as impetigo. Complications of Strep A infection can lead to inflammation in the bones, muscles, joints, and internal organs causing acute rheumatic fever and rheumatic heart disease (RHD). In The Gambia, the RHD burden is thought to be very high. However, epidemiological data is minimal, and Strep A control programmes do not exist. This study aimed to explore common beliefs and practices related to sore throats among primary caregivers of children, and healthcare providers in a community with a high Strep A disease burden. Four informal conversations with providers and fifteen semi-structured interviews with caregivers were conducted in the peri-urban area of Sukuta, The Gambia. Sampling was purposive and gradual, beginning from households identified to have recently experienced sore throat through a parallel cohort study. Themes explored in qualitative analysis included: sore throat causal attributions and diagnoses, care practises, health-seeking behaviour, and perceived barriers to using the biomedical sector. We found that sore throats were typically perceived to affect one child in a family, disproportionately or exclusively. Sore throats were rarely perceived as life-threatening, and awareness of links between sore throat and ARF or RHD was not reported among caregivers or providers in this study population. Most cases of sore throat were initially managed at home using traditional medicine which delayed resort to antibiotics, though in two instances of severe pain with the presence of exudate, fear that the child's life was at risk prompted care-seeking through the formal health system. Our findings can inform the development of tailored strategies to increase community knowledge of the potential long-term consequences of sore throats and appropriate care-seeking, alongside improvements in the health system, to prevent Strep A sequelae effectively.

3.
J Immunol Methods ; 526: 113618, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38237697

RESUMO

The high burden of disease and the long-lasting sequelae following Streptococcus pyogenes (Strep A) infections make the development of an effective vaccine a global health priority. Streptolysin O (SLO), is a key toxin in the complex pathogenesis of Strep A infection. Antibodies are elicited against SLO after natural exposure and represent a key target for vaccine-induced immunity. Here we present the setup and characterization of a hemolysis assay to measure functionality of anti-SLO antibodies in human sera. Assay specificity, precision, linearity, reproducibility, and repeatability were determined. The assay was demonstrated to be highly sensitive, specific, reproducible, linear and performed well in assessing functionality of anti-SLO antibodies induced by exposed individuals. Moreover, different sources of critical reagents, in particular red- blood cells, have been compared and had minimal impact on assay performance. The assay presented here has throughput suitable for evaluating sera in vaccine clinical trials and sero-epidemiological studies to gain further insights into the functionality of infection- and vaccine-induced antibodies.


Assuntos
Infecções Estreptocócicas , Vacinas , Humanos , Streptococcus pyogenes , Hemólise , Reprodutibilidade dos Testes , Estreptolisinas/farmacologia , Proteínas de Bactérias , Anticorpos/farmacologia , Infecções Estreptocócicas/diagnóstico
4.
Int J Pharm ; 647: 123494, 2023 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-37806503

RESUMO

Medicines for children often taste bitter, presenting a significant challenge to treatment compliance. However, most studies on paediatric drug development rely on adult volunteers for sensory research, and the level of expertise required from these assessors is unclear. This study aimed to address this gap by investigating perceived bitterness aversion to taste strips impregnated with different concentrations of quinine hydrochloride in 439 school-aged children. Expert (n = 26) and naïve (n = 65) young adult assessors evaluated quinine solutions as well as taste strips, for methodological bridging purposes. All assessors differentiated the aversiveness of the taste strips in a dose dependent manner. Younger children aged 4-8 years had difficulty discriminating higher bitter concentrations, whereas pre-adolescents 9-11 years and naive adults showed better discrimination at the top of the scale. Naive assessors showed similar bitter perception as children. However, the results were slightly different between strips and solution in adults. These findings highlight the key role that adult panels can play in paediatric formulation development. Taste strips show promise as a safe and pragmatic tool for sensory pharmaceutical evaluations, though further studies are warranted to establish the relationship between age and hedonic taste perception using compounds with diverse physicochemical and sensory qualities.


Assuntos
Percepção Gustatória , Paladar , Adolescente , Humanos , Criança , Adulto Jovem , Quinina , Desenvolvimento de Medicamentos
5.
J Infect Dis ; 228(7): 957-965, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37246259

RESUMO

BACKGROUND: Immunity to Streptococcus pyogenes in high burden settings is poorly understood. We explored S. pyogenes nasopharyngeal colonization after intranasal live attenuated influenza vaccine (LAIV) among Gambian children aged 24-59 months, and resulting serological response to 7 antigens. METHODS: A post hoc analysis was performed in 320 children randomized to receive LAIV at baseline (LAIV group) or not (control). S. pyogenes colonization was determined by quantitative polymerase chain reaction (qPCR) on nasopharyngeal swabs from baseline (day 0), day 7, and day 21. Anti-streptococcal IgG was quantified, including a subset with paired serum before/after S. pyogenes acquisition. RESULTS: The point prevalence of S. pyogenes colonization was 7%-13%. In children negative at day 0, S. pyogenes was detected at day 7 or 21 in 18% of LAIV group and 11% of control group participants (P = .12). The odds ratio (OR) for colonization over time was significantly increased in the LAIV group (day 21 vs day 0 OR, 3.18; P = .003) but not in the control group (OR, 0.86; P = .79). The highest IgG increases following asymptomatic colonization were seen for M1 and SpyCEP proteins. CONCLUSIONS: Asymptomatic S. pyogenes colonization appears modestly increased by LAIV, and may be immunologically significant. LAIV could be used to study influenza-S. pyogenes interactions. Clinical Trials Registration. NCT02972957.


Assuntos
Vacinas contra Influenza , Influenza Humana , Humanos , Criança , Gâmbia/epidemiologia , Streptococcus pyogenes , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Vacinas Atenuadas , Imunoglobulina G
6.
mSphere ; 8(1): e0046922, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36507654

RESUMO

Streptococcus pyogenes is a leading cause of human morbidity and mortality, especially in resource-limited settings. The development of a vaccine against S. pyogenes is a global health priority to reduce the burden of postinfection rheumatic heart disease. To support this, molecular characterization of circulating S. pyogenes isolates is needed. We performed whole-genome analyses of S. pyogenes isolates from skin and soft tissue infections in Sukuta, The Gambia, a low-income country (LIC) in West Africa where there is a high burden of such infections. To act as a comparator to these LIC isolates, skin infection isolates from Sheffield, United Kingdom (a high-income country [HIC]), were also sequenced. The LIC isolates from The Gambia were genetically more diverse (46 emm types in 107 isolates) than the HIC isolates from Sheffield (23 emm types in 142 isolates), with only 7 overlapping emm types. Other molecular markers were shared, including a high prevalence of the skin infection-associated emm pattern D and the variable fibronectin-collagen-T antigen (FCT) types FCT-3 and FCT-4. Fewer of the Gambian LIC isolates carried prophage-associated superantigens (64%) and DNases (26%) than did the Sheffield HIC isolates (99% and 95%, respectively). We also identified streptococcin genes unique to 36% of the Gambian LIC isolates and a higher prevalence (48%) of glucuronic acid utilization pathway genes in the Gambian LIC isolates than in the Sheffield HIC isolates (26%). Comparison to a wider collection of HIC and LIC isolate genomes supported our findings of differing emm diversity and prevalence of bacterial factors. Our study provides insight into the genetics of LIC isolates and how they compare to HIC isolates. IMPORTANCE The global burden of rheumatic heart disease (RHD) has triggered a World Health Organization response to drive forward development of a vaccine against the causative human pathogen Streptococcus pyogenes. This burden stems primarily from low- and middle-income settings where there are high levels of S. pyogenes skin and soft tissue infections, which can lead to RHD. Our study provides much needed whole-genome-based molecular characterization of isolates causing skin infections in Sukuta, The Gambia, a low-income country (LIC) in West Africa where infection and RHD rates are high. Although we identified a greater level of diversity in these LIC isolates than in isolates from Sheffield, United Kingdom (a high-income country), there were some shared features. There were also some features that differed by geographical region, warranting further investigation into their contribution to infection. Our study has also contributed data essential for the development of a vaccine that would target geographically relevant strains.


Assuntos
Cardiopatia Reumática , Infecções dos Tecidos Moles , Infecções Estreptocócicas , Humanos , Streptococcus pyogenes/genética , Infecções dos Tecidos Moles/epidemiologia , Infecções Estreptocócicas/microbiologia , Antígenos de Bactérias , Genômica
7.
Commun Biol ; 5(1): 666, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35790808

RESUMO

B.1.1.7 lineage SARS-CoV-2 is more transmissible, leads to greater clinical severity, and results in modest reductions in antibody neutralization. Subgenomic RNA (sgRNA) is produced by discontinuous transcription of the SARS-CoV-2 genome. Applying our tool (periscope) to ARTIC Network Oxford Nanopore Technologies genomic sequencing data from 4400 SARS-CoV-2 positive clinical samples, we show that normalised sgRNA is significantly increased in B.1.1.7 (alpha) infections (n = 879). This increase is seen over the previous dominant lineage in the UK, B.1.177 (n = 943), which is independent of genomic reads, E cycle threshold and days since symptom onset at sampling. A noncanonical sgRNA which could represent ORF9b is found in 98.4% of B.1.1.7 SARS-CoV-2 infections compared with only 13.8% of other lineages, with a 16-fold increase in median sgRNA abundance. We demonstrate that ORF9b protein levels are increased 6-fold in B.1.1.7 compared to a B lineage virus in vitro. We hypothesise that increased ORF9b in B.1.1.7 is a direct consequence of a triple nucleotide mutation in nucleocapsid (28280:GAT > CAT, D3L) creating a transcription regulatory-like sequence complementary to a region 3' of the genomic leader. These findings provide a unique insight into the biology of B.1.1.7 and support monitoring of sgRNA profiles to evaluate emerging potential variants of concern.


Assuntos
COVID-19 , RNA , COVID-19/diagnóstico , COVID-19/genética , Humanos , SARS-CoV-2/genética
8.
Methods Protoc ; 5(4)2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35893581

RESUMO

The measurement of antibodies to vaccine antigens is crucial for research towards a safe and effective vaccine for Streptococcus pyogenes (Strep A). We describe the establishment and detailed characterisation of a four-plex assay to measure IgG to the Strep A vaccine antigens SpyCEP, Slo, SpyAD and GAC using the Luminex multiplex platform. A standard curve was established and characterized to allow the quantification of antigen-specific IgG. Assay specificity, precision, linearity, reproducibility and repeatability were determined via the measurement of antigen-specific IgG from pooled human serum. The assay is highly specific, reproducible and performs well across a large range of antibody concentrations against all four antigens. It is, therefore, suitable for future clinical trials in humans with a four-component vaccine, as well as for seroepidemiological studies to gain insights into naturally occurring immunity.

9.
Pharmaceutics ; 14(4)2022 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-35456614

RESUMO

Spironolactone (SPL), a potent anti-aldosterone steroidal drug used to treat several diseases in paediatric patients (e.g., hypertension, primary aldosteronism, Bartter's syndrome, and congestive heart failure), is not available in child-friendly dosage forms, and spironolactone liquids have been reported to be unpalatable. Aiming to enhance SPL solubility in aqueous solution and overcome palatability, herein, the effects of (2-hydroxypropyl)-ß-cyclodextrin (HP-ß-CyD) were thoroughly investigated on solubilisation in water and on masking the unpleasant taste of SPL in vivo. Although the complexation of SPL with HP-ß-CyD was demonstrated through phase solubility studies, Job's plot, NMR and computational docking studies, our in vivo tests did not show significant effects on taste aversion. Our findings, on the one hand, suggest that the formation of an inclusion complex of SPL with HP-ß-CyD itself is not necessarily a good indicator for an acceptable degree of palatability, whereas, on the other hand, they constitute the basis for investigating other cyclodextrin-based formulations of the poorly water-soluble steroidal drug, including solid dosage forms, such as spray-dried powders and orodispersible tablets.

10.
Nat Commun ; 13(1): 671, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35115517

RESUMO

Hospital outbreaks of COVID19 result in considerable mortality and disruption to healthcare services and yet little is known about transmission within this setting. We characterise within hospital transmission by combining viral genomic and epidemiological data using Bayesian modelling amongst 2181 patients and healthcare workers from a large UK NHS Trust. Transmission events were compared between Wave 1 (1st March to 25th J'uly 2020) and Wave 2 (30th November 2020 to 24th January 2021). We show that staff-to-staff transmissions reduced from 31.6% to 12.9% of all infections. Patient-to-patient transmissions increased from 27.1% to 52.1%. 40%-50% of hospital-onset patient cases resulted in onward transmission compared to 4% of community-acquired cases. Control measures introduced during the pandemic likely reduced transmissions between healthcare workers but were insufficient to prevent increasing numbers of patient-to-patient transmissions. As hospital-acquired cases drive most onward transmission, earlier identification of nosocomial cases will be required to break hospital transmission chains.


Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , Genoma Viral , Epidemiologia Molecular , Pandemias , SARS-CoV-2/genética , Teorema de Bayes , Estudos de Coortes , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/transmissão , Surtos de Doenças , Genômica , Pessoal de Saúde , Hospitais , Humanos , Reino Unido/epidemiologia
12.
BMC Infect Dis ; 22(1): 103, 2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35093029

RESUMO

BACKGROUND: Group A Streptococcus (GAS) is a major human pathogen and an important cause of maternal and neonatal sepsis. Asymptomatic bacterial colonization is considered a necessary step towards sepsis. Intra-partum azithromycin may reduce GAS carriage. METHODS: A posthoc analysis of a double-blind, placebo-controlled randomized-trial was performed to determine the impact of 2 g oral dose of intra-partum azithromycin on maternal and neonatal GAS carriage and antibiotic resistance. Following screening, 829 mothers were randomized who delivered 843 babies. GAS was determined by obtaining samples from the maternal and newborn nasopharynx, maternal vaginal tract and breastmilk. Whole Genome Sequencing (WGS) of GAS isolates was performed using the Illumina Miseq platform. RESULTS: GAS carriage was lower in the nasopharynx of both mothers and babies and breast milk among participants in the azithromycin arm. No differences in GAS carriage were found between groups in the vaginal tract. The occurrence of azithromycin-resistant GAS was similar in both arms, except for a higher prevalence in the vaginal tract among women in the azithromycin arm. WGS revealed all macrolide-resistant vaginal tract isolates from the azithromycin arm were Streptococcus dysgalactiae subspecies equisimilis expressing Lancefield group A carbohydrate (SDSE(A)) harbouring macrolide resistant genes msr(D) and mef(A). Ten of the 45 GAS isolates (22.2%) were SDSE(A). CONCLUSIONS: Oral intra-partum azithromycin reduced GAS carriage among Gambian mothers and neonates however carriage in the maternal vaginal tract was not affected by the intervention due to azithromycin resistant SDSE(A). SDSE(A) resistance must be closely monitored to fully assess the public health impact of intrapartum azithromycin on GAS. Trial registration ClinicalTrials.gov Identifier NCT01800942.


Assuntos
Azitromicina , Portador Sadio , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Portador Sadio/tratamento farmacológico , Portador Sadio/epidemiologia , Feminino , Gâmbia/epidemiologia , Humanos , Lactente , Recém-Nascido , Streptococcus pyogenes
13.
Pathog Immun ; 6(2): 27-49, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34541432

RESUMO

BACKGROUND: Genetic variations across the SARS-CoV-2 genome may influence transmissibility of the virus and the host's anti-viral immune response, in turn affecting the frequency of variants over time. In this study, we examined the adjacent amino acid polymorphisms in the nucleocapsid (R203K/G204R) of SARS-CoV-2 that arose on the background of the spike D614G change and describe how strains harboring these changes became dominant circulating strains globally. METHODS: Deep-sequencing data of SARS-CoV-2 from public databases and from clinical samples were analyzed to identify and map genetic variants and sub-genomic RNA transcripts across the genome. Results: Sequence analysis suggests that the 3 adjacent nucleotide changes that result in the K203/R204 variant have arisen by homologous recombination from the core sequence of the leader transcription-regulating sequence (TRS) rather than by stepwise mutation. The resulting sequence changes generate a novel sub-genomic RNA transcript for the C-terminal dimerization domain of nucleocapsid. Deep-sequencing data from 981 clinical samples confirmed the presence of the novel TRS-CS-dimerization domain RNA in individuals with the K203/R204 variant. Quantification of sub-genomic RNA indicates that viruses with the K203/R204 variant may also have increased expression of sub-genomic RNA from other open reading frames. CONCLUSIONS: The finding that homologous recombination from the TRS may have occurred since the introduction of SARS-CoV-2 in humans, resulting in both coding changes and novel sub-genomic RNA transcripts, suggests this as a mechanism for diversification and adaptation within its new host.

14.
Elife ; 102021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34184637

RESUMO

Background: Rapid identification and investigation of healthcare-associated infections (HCAIs) is important for suppression of SARS-CoV-2, but the infection source for hospital onset COVID-19 infections (HOCIs) cannot always be readily identified based only on epidemiological data. Viral sequencing data provides additional information regarding potential transmission clusters, but the low mutation rate of SARS-CoV-2 can make interpretation using standard phylogenetic methods difficult. Methods: We developed a novel statistical method and sequence reporting tool (SRT) that combines epidemiological and sequence data in order to provide a rapid assessment of the probability of HCAI among HOCI cases (defined as first positive test >48 hr following admission) and to identify infections that could plausibly constitute outbreak events. The method is designed for prospective use, but was validated using retrospective datasets from hospitals in Glasgow and Sheffield collected February-May 2020. Results: We analysed data from 326 HOCIs. Among HOCIs with time from admission ≥8 days, the SRT algorithm identified close sequence matches from the same ward for 160/244 (65.6%) and in the remainder 68/84 (81.0%) had at least one similar sequence elsewhere in the hospital, resulting in high estimated probabilities of within-ward and within-hospital transmission. For HOCIs with time from admission 3-7 days, the SRT probability of healthcare acquisition was >0.5 in 33/82 (40.2%). Conclusions: The methodology developed can provide rapid feedback on HOCIs that could be useful for infection prevention and control teams, and warrants further prospective evaluation. The integration of epidemiological and sequence data is important given the low mutation rate of SARS-CoV-2 and its variable incubation period. Funding: COG-UK HOCI funded by COG-UK consortium, supported by funding from UK Research and Innovation, National Institute of Health Research and Wellcome Sanger Institute.


Assuntos
COVID-19/diagnóstico , COVID-19/epidemiologia , Infecção Hospitalar/diagnóstico , Infecção Hospitalar/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Vigilância da População/métodos , SARS-CoV-2/genética , Genoma Viral , Hospitais/estatística & dados numéricos , Humanos , Probabilidade , Estudos Retrospectivos , Reino Unido/epidemiologia , Sequenciamento Completo do Genoma
15.
bioRxiv ; 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-33880475

RESUMO

BACKGROUND: Genetic variations across the SARS-CoV-2 genome may influence transmissibility of the virus and the host’s anti-viral immune response, in turn affecting the frequency of variants over-time. In this study, we examined the adjacent amino acid polymorphisms in the nucleocapsid (R203K/G204R) of SARS-CoV-2 that arose on the background of the spike D614G change and describe how strains harboring these changes became dominant circulating strains globally. METHODS: Deep sequencing data of SARS-CoV-2 from public databases and from clinical samples were analyzed to identify and map genetic variants and sub-genomic RNA transcripts across the genome. RESULTS: Sequence analysis suggests that the three adjacent nucleotide changes that result in the K203/R204 variant have arisen by homologous recombination from the core sequence (CS) of the leader transcription-regulating sequence (TRS) rather than by stepwise mutation. The resulting sequence changes generate a novel sub-genomic RNA transcript for the C-terminal dimerization domain of nucleocapsid. Deep sequencing data from 981 clinical samples confirmed the presence of the novel TRS-CS-dimerization domain RNA in individuals with the K203/R204 variant. Quantification of sub-genomic RNA indicates that viruses with the K203/R204 variant may also have increased expression of sub-genomic RNA from other open reading frames. CONCLUSIONS: The finding that homologous recombination from the TRS may have occurred since the introduction of SARS-CoV-2 in humans resulting in both coding changes and novel sub-genomic RNA transcripts suggests this as a mechanism for diversification and adaptation within its new host.

16.
Genome Res ; 31(4): 645-658, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33722935

RESUMO

We have developed periscope, a tool for the detection and quantification of subgenomic RNA (sgRNA) in SARS-CoV-2 genomic sequence data. The translation of the SARS-CoV-2 RNA genome for most open reading frames (ORFs) occurs via RNA intermediates termed "subgenomic RNAs." sgRNAs are produced through discontinuous transcription, which relies on homology between transcription regulatory sequences (TRS-B) upstream of the ORF start codons and that of the TRS-L, which is located in the 5' UTR. TRS-L is immediately preceded by a leader sequence. This leader sequence is therefore found at the 5' end of all sgRNA. We applied periscope to 1155 SARS-CoV-2 genomes from Sheffield, United Kingdom, and validated our findings using orthogonal data sets and in vitro cell systems. By using a simple local alignment to detect reads that contain the leader sequence, we were able to identify and quantify reads arising from canonical and noncanonical sgRNA. We were able to detect all canonical sgRNAs at the expected abundances, with the exception of ORF10. A number of recurrent noncanonical sgRNAs are detected. We show that the results are reproducible using technical replicates and determine the optimum number of reads for sgRNA analysis. In VeroE6 ACE2+/- cell lines, periscope can detect the changes in the kinetics of sgRNA in orthogonal sequencing data sets. Finally, variants found in genomic RNA are transmitted to sgRNAs with high fidelity in most cases. This tool can be applied to all sequenced COVID-19 samples worldwide to provide comprehensive analysis of SARS-CoV-2 sgRNA.


Assuntos
Genoma Viral , RNA Viral/genética , SARS-CoV-2/genética , Análise de Sequência de RNA/métodos , Animais , Sequência de Bases , Chlorocebus aethiops , Humanos , Limite de Detecção , Células Vero
17.
Pan Afr Med J ; 40: 204, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35136467

RESUMO

Sepsis is common and represents a major public health burden with significant associated morbidity and mortality. However, despite substantial advances in sepsis recognition and management in well-resourced health systems, there remains a distinct lack of research into sepsis in Africa. The lack of evidence affects all levels of healthcare delivery from individual patient management to strategic planning at health-system level. This is particular pertinent as African countries experience some of the highest global burden of sepsis. The 2017 World Health Assembly resolution on sepsis and the creation of the Africa Sepsis Alliance provided an opportunity for change. However, progress so far has been frustratingly slow. The recurrent Ebola virus disease outbreaks and the COVID-19 pandemic on the African continent further reinforce the need for urgent healthcare system strengthening. We recommend that African countries develop national action plans for sepsis which should address the needs of all critically ill patients.


Assuntos
COVID-19 , Sepse , África/epidemiologia , Humanos , Pandemias , SARS-CoV-2 , Sepse/diagnóstico , Sepse/epidemiologia , Sepse/terapia
18.
Energy Policy ; 155: 112330, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35722223

RESUMO

As a market for sustainability investing is growing rapidly, understanding the impact of environmental, social, and governance (ESG) activities on firms' financial performance is becoming increasingly important. In this study, we examine the effect of ESG performance on stock returns and volatility during the financial crisis resulting from the coronavirus (COVID-19) pandemic. To quantify the impact, we use company-level daily ESG score data and United Nations Global Compact (GC) score data. In our dataset, ESG scores indicate ESG performance that is deemed important to financial materiality, and the GC score indicates the firm reputation for following UN rules. Our results indicate that during the pandemic, an increase in the ESG score, especially the E score component, is related to higher returns and lower volatility. Conversely, increasing GC scores is correlated with lower stock returns and higher volatility. In addition, we find that firms in lower return groups benefit more than other firms. Focusing on energy sector impacts, we show that although the non-energy sector benefits more than the energy sector from increasing E scores, energy sector firms can still reduce their stock price volatility by increasing these scores. Our study offers significant implications for ESG investment strategies during financial crises.

20.
Trans R Soc Trop Med Hyg ; 115(8): 863-869, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-33197258

RESUMO

BACKGROUND: In less well-resourced settings, where access to radiology services is limited, point-of-care ultrasound (POCUS) can be used to assess patients and guide clinical management. The aim of this study was to describe ultrasound practice in the assessment of medical inpatients at Queen Elizabeth Central Hospital, Blantyre, Malawi, and evaluate uptake and impact of POCUS following the introduction of a training programme at the college of Medicine, Blantyre, Malawi. METHODS: : A weekly prospective record review of sequential adult medical inpatients who had received an ultrasound examination was conducted. RESULTS: Of 835 patients screened, 250 patients were included; 267 ultrasound examinations were performed, of which 133 (50%) were POCUS (defined as performed by a clinician at the bedside). The time from request to performance of examination was shorter for POCUS examinations than radiology department ultrasound (RDUS) (median 0 [IQR 0-2, range 0-11] vs 2 [IQR 1-4, range 0-15] d, p=0.002); 104/133 (78.2%) POCUS and 90/133 (67.7%) RDUS examinations were deemed to have an impact on management. CONCLUSION: Following the introduction of a training programme in POCUS, half of all ultrasound examinations were delivered as POCUS. POCUS was performed rapidly and impacted on patient management. POCUS may relieve the burden on radiology services in less well-resourced settings.


Assuntos
Pacientes Internados , Sistemas Automatizados de Assistência Junto ao Leito , Adulto , Hospitais , Humanos , Malaui , Estudos Prospectivos , Ultrassonografia
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