23 research outputs found
Characterization of the flavonoids of the Argan tree leaves (Argania spinosa (L.) Skeels, Sapotaceae) and study of their antimicrobial activity
Quatre flavonoïdes, la quercétine, la myricétine, la quercétrine et la myricétrine ont été isolés à partir des feuilles d’Argania spinosa (L.) Skeels, Sapotaceae. Ces composés ont été séparés à l’aide de méthodes chromatogaphiques usuelles et identifiés sur la base de leurs caractéristiques spectroscopiques (UV, SM, RMN 1H et13C). La myricétine et la myricétrine ont montré une activité anti-microbienne plus importante contre les bactéries que contre les levures
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Clinical and immunological status of a newly diagnosed HIV positive population, in Marrakech, Morocco
Objective: To evaluate the clinical and the immune status of newly HIV
diagnosed patients, in Marrakech city and its neighboring area, in
Morocco. Methods: We performed a retrospective study on 235 patients
who have been previously confirmed for HIV infection, and underwent a
CD4 T cells using flow cytometry (FacsCount, Becton Dickinson®).
Results: The mean age of patients was 34,3 ± 8,4 years (range:
14-55), with a male predominance (sex-ratio M/F=1.4). On basis of
clinical data of the patients, 62% (n=146) of them were categorized as
"category C", 18.4% (n=43) as "category B", and 19.6% (n=46) as
"category A" according to CDC (Center for Disease Control) HIV
classification. Among all of them, 60.4% (n=142) had less than 200 CD4T
cells, 26% (n=61) had between 200 and 499 CD4T cells, and only 13.6%
(n=32) showed a number of CD4T cells less or equal to 500/mm3.
Conclusion: The results of this study reflect a significant delay in
the diagnosis of HIV infected patients. Therefore, this delay may
compromise timely management of HIV infected individuals and enhances
propagation of the epidemic in our country. These data confirm the need
for intensifying prevention efforts among high-risk population.
Moreover, continuing education in HIV/AIDS among healthcare providers
should be reinforced
Water-Soluble Rhamnose-Coated Fe3O4 Nanoparticles
Water-soluble biocompatible rhamnose-coated Fe3O4 nanoparticles of 4.0 nm are obtained by covalent anchorage of rhamnose on the nanoparticles surface via a phosphate linker. These nanoparticles present superparamagnetic behavior and nuclear relaxivities in the same order of magnitude as Endorem that make them potential magnetic resonance imaging (MRI) contrast agents of a second generation, where the saccharides represent also specific ligands able to target lectins on skin cells
External quality assessment to support the WHO ProSPeRo study for the evaluation of two dual HIV/syphilis point-of-care tests in seven countries
Abstract Background Sexually transmitted infections (STIs) such as syphilis and HIV remain to be a significant public health issue worldwide. Dual rapid point-of-care tests (POCTs) have shown promise for detecting antibodies to HIV and syphilis but have not been fully evaluated in the field. Our study supported the WHO ProSPeRo study on Sexually Transmitted Infection Point-of-Care Testing (STI POCT) by providing external quality assessment (EQA) for HIV and syphilis testing in reference laboratories and their associated clinical sites in seven countries. Methods HIV/syphilis serum liquid and dried tube specimen (DTS) panels were prepared by CDC. Liquid panels were distributed to the reference laboratories for three rounds of testing using commercially and locally available laboratory-based serological tests. DTS panels were sent to the clinical testing sites for 8 rounds of POC testing using the Abbott SD BIOLINE HIV/Syphilis Duo test (hereafter referred to as SD BIOLINE) and the Chembio Dual Path Platform (DPP) HIV-Syphilis assay. EQA panels were tested at CDC using the Rapid Plasma Reagin (RPR) test and the Treponema pallidum Particle Agglutination assay (TP-PA) for syphilis antibodies. Genetic Systems HIV-1/HIV-2 Plus O EIA, Geenius HIV Supplemental Assay and the Oraquick Advance HIV test were used to detect HIV antibodies in the EQA panels. Results from the reference laboratories and POCT sites were compared to those obtained at the CDC and a percentage agreement was calculated. Results Qualitative RPR and TP-PA performed at the reference laboratories demonstrated 95.4–100% agreement with CDC results while quantitative RPR and TP-PA tests demonstrated 87.7% and 89.2% agreement, respectively. A 93.8% concordance rate was observed for qualitative HIV testing in laboratories. EQA testing at clinical sites using dual tests showed 98.7% and 99.1% agreement for detection of HIV antibodies and eight out of 10 sites had > 95.8% agreement for syphilis testing. However, two clinical sites showed only 65.0–66.7% agreement for SD BIOLINE and 84.0–86.7% for DPP, respectively, for syphilis testing. Conclusions Overall, laboratories demonstrated high EQA performance in this study. Both HIV/syphilis POCTs gave expected results in the clinic-based evaluations using DTS. However, testing errors were identified in a few testing sites suggesting the necessity for continuous training and monitoring the quality of POC testing
Influenza vaccination situation in Middle-East and North Africa countries: Report of the 7th MENA Influenza Stakeholders Network (MENA-ISN)
Background: The Middle East and North Africa (MENA) region faces a dual challenge with regard to influenza infection due to severe zoonotic influenza outbreaks episodes and the circulation of Northern Hemisphere human influenza viruses among pilgrims. Methods: The MENA Influenza Stakeholder Network (MENA-ISN) was set-up with the aim of increasing seasonal influenza vaccination coverage by (i) enhancing evidence-based exchanges, and (ii) increasing awareness on the safety and benefits of seasonal vaccination. During the 7th MENA-ISN meeting, representatives from 8 countries presented their influenza surveillance, vaccination coverage and actions achieved and provided a list of country objectives for the upcoming 3 years. Results: MENA-ISN countries share the goal to reduce influenza related morbidity and mortality. Participants admitted that lack of knowledge about influenza, its consequences in terms of morbidity, mortality and economy are the major barrier to attaining higher influenza vaccination coverage in their countries. The cost of the vaccine is another key barrier that could contribute to low vaccination coverage. Participants drew a list of strategic interventions to bridge gaps in the knowledge of influenza burden in this region. Conclusions: Participating countries concluded that despite an increase in vaccine uptake observed during the last few years, influenza vaccination coverage remains relatively low. Priority areas should be identified and action plans tailored to each country situation set-up to investigate the best way to move forward. Keywords: Influenza, Vaccination coverage, Surveillance, Middle East and North Afric