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1.
Infect Genet Evol ; 102: 105300, 2022 08.
Article in English | MEDLINE | ID: covidwho-1946053

ABSTRACT

Since the beginning of the Coronavirus disease-2019 pandemic, there has been a growing interest in exploring SARS-CoV-2 genetic variation to understand the origin and spread of the pandemic, improve diagnostic methods and develop the appropriate vaccines. The objective of this study was to identify the SARS-CoV-2s lineages circulating in Tunisia and to explore their amino acid signature in order to follow their genome dynamics. Whole genome sequencing and genetic analyses of fifty-eight SARS-CoV-2 samples collected during one-year between March 2020 and March 2021 from the National Influenza Center were performed using three sampling strategies.. Multiple lineage introductions were noted during the initial phase of the pandemic, including B.4, B.1.1, B.1.428.2, B.1.540 and B.1.1.189. Subsequently, lineages B1.160 (24.2%) and B1.177 (22.4%) were dominant throughout the year. The Alpha variant (B.1.1.7 lineage) was identified in February 2021 and firstly observed in the center of our country. In addition, A clear diversity of lineages was observed in the North of the country. A total of 335 mutations including 10 deletions were found. The SARS-CoV-2 proteins ORF1ab, Spike, ORF3a, and Nucleocapsid were observed as mutation hotspots with a mutation frequency exceeding 20%. The 2 most frequent mutations, D614G in S protein and P314L in Nsp12 appeared simultaneously and are often associated with increased viral infectivity. Interestingly, deletions in coding regions causing consequent deletions of amino acids and frame shifts were identified in NSP3, NSP6, S, E, ORF7a, ORF8 and N proteins. These findings contribute to define the COVID-19 outbreak in Tunisia. Despite the country's limited resources, surveillance of SARS-CoV-2 genomic variation should be continued to control the occurrence of new variants.


Subject(s)
COVID-19 , SARS-CoV-2 , Amino Acids/genetics , COVID-19/epidemiology , Genome, Viral , Humans , Mutation , Phylogeny , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Tunisia/epidemiology
3.
Thromb Haemost ; 121(8): 992-1007, 2021 08.
Article in English | MEDLINE | ID: covidwho-1320246

ABSTRACT

BACKGROUND: One year after the declaration of the coronavirus disease 2019 (COVID-19) pandemic by the World Health Organization (WHO) and despite the implementation of mandatory physical barriers and social distancing, humanity remains challenged by a long-lasting and devastating public health crisis. MANAGEMENT: Non-pharmacological interventions (NPIs) are efficient mitigation strategies. The success of these NPIs is dependent on the approval and commitment of the population. The launch of a mass vaccination program in many countries in late December 2020 with mRNA vaccines, adenovirus-based vaccines, and inactivated virus vaccines has generated hope for the end of the pandemic. CURRENT ISSUES: The continuous appearance of new pathogenic viral strains and the ability of vaccines to prevent infection and transmission raise important concerns as we try to achieve community immunity against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) and its variants. The need of a second and even third generation of vaccines has already been acknowledged by the WHO and governments. PERSPECTIVES: There is a critical and urgent need for a balanced and integrated strategy for the management of the COVID-19 outbreaks organized on three axes: (1) Prevention of the SARS-CoV-2 infection, (2) Detection and early diagnosis of patients at risk of disease worsening, and (3) Anticipation of medical care (PDA). CONCLUSION: The "PDA strategy" integrated into state policy for the support and expansion of health systems and introduction of digital organizations (i.e., telemedicine, e-Health, artificial intelligence, and machine-learning technology) is of major importance for the preservation of citizens' health and life world-wide.


Subject(s)
COVID-19/epidemiology , COVID-19/prevention & control , Public Health , COVID-19/diagnosis , COVID-19 Testing/methods , COVID-19 Vaccines/therapeutic use , Disease Management , Humans , Immunization Programs/methods , Pandemics/prevention & control , Public Health/methods , Risk Assessment , SARS-CoV-2/isolation & purification
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