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1.
medRxiv ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38947021

RESUMO

Nigeria and Cameroon reported their first mpox cases in over three decades in 2017 and 2018 respectively. The outbreak in Nigeria is recognised as an ongoing human epidemic. However, owing to sparse surveillance and genomic data, it is not known whether the increase in cases in Cameroon is driven by zoonotic or sustained human transmission. Notably, the frequency of zoonotic transmission remains unknown in both Cameroon and Nigeria. To address these uncertainties, we investigated the zoonotic transmission dynamics of the mpox virus (MPXV) in Cameroon and Nigeria, with a particular focus on the border regions. We show that in these regions mpox cases are still driven by zoonotic transmission of a newly identified Clade IIb.1. We identify two distinct zoonotic lineages that circulate across the Nigeria-Cameroon border, with evidence of recent and historic cross border dissemination. Our findings support that the complex cross-border forest ecosystems likely hosts shared animal populations that drive cross-border viral spread, which is likely where extant Clade IIb originated. We identify that the closest zoonotic outgroup to the human epidemic circulated in southern Nigeria in October 2013. We also show that the zoonotic precursor lineage circulated in an animal population in southern Nigeria for more than 45 years. This supports findings that southern Nigeria was the origin of the human epidemic. Our study highlights the ongoing MPXV zoonotic transmission in Cameroon and Nigeria, underscoring the continuous risk of MPXV (re)emergence.

2.
medRxiv ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38947052

RESUMO

Five years before the 2022-2023 global mpox outbreak Nigeria reported its first cases in nearly 40 years, with the ongoing epidemic since driven by sustained human-to-human transmission. However, limited genomic data has left questions about the timing and origin of the mpox virus' (MPXV) emergence. Here we generated 112 MPXV genomes from Nigeria from 2021-2023. We identify the closest zoonotic outgroup to the human epidemic in southern Nigeria, and estimate that the lineage transmitting from human-to-human emerged around July 2014, circulating cryptically until detected in September 2017. The epidemic originated in Southern Nigeria, particularly Rivers State, which also acted as a persistent and dominant source of viral dissemination to other states. We show that APOBEC3 activity increased MPXV's evolutionary rate twenty-fold during human-to-human transmission. We also show how Delphy, a tool for near-real-time Bayesian phylogenetics, can aid rapid outbreak analytics. Our study sheds light on MPXV's establishment in West Africa before the 2022-2023 global outbreak and highlights the need for improved pathogen surveillance and response.

3.
Nat Med ; 29(9): 2317-2324, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37710003

RESUMO

The 2022 global mpox outbreak raises questions about how this zoonotic disease established effective human-to-human transmission and its potential for further adaptation. The 2022 outbreak virus is related to an ongoing outbreak in Nigeria originally reported in 2017, but the evolutionary path linking the two remains unclear due to a lack of genomic data between 2018, when virus exportations from Nigeria were first recorded, and 2022, when the global mpox outbreak began. Here, 18 viral genomes obtained from patients across southern Nigeria in 2019-2020 reveal multiple lineages of monkeypox virus (MPXV) co-circulated in humans for several years before 2022, with progressive accumulation of mutations consistent with APOBEC3 activity over time. We identify Nigerian A.2 lineage isolates, confirming the lineage that has been multiply exported to North America independently of the 2022 outbreak originated in Nigeria, and that it has persisted by human-to-human transmission in Nigeria for more than 2 years before its latest exportation. Finally, we identify a lineage-defining APOBEC3-style mutation in all A.2 isolates that disrupts gene A46R, encoding a viral innate immune modulator. Collectively, our data demonstrate MPXV capacity for sustained diversification within humans, including mutations that may be consistent with established mechanisms of poxvirus adaptation.


Assuntos
Monkeypox virus , Mpox , Humanos , Animais , Monkeypox virus/genética , Mpox/epidemiologia , Mpox/genética , Zoonoses , Surtos de Doenças , Evolução Biológica
4.
Int J Med Mushrooms ; 25(5): 1-15, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37183915

RESUMO

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 is characterized by acute respiratory distress syndrome (ARDS) facilitated by cytokine storm and other risk factors that increase susceptibility and complications leading to death. Emerging as a major global public health challenge, the disease has claimed more than 6 million lives and caused catastrophic global economic disruptions. However, there are concerns about the safety as well as the efficacy of drugs and vaccines presently used to control the pandemic, therefore necessitating intense global search for safe natural products that can effectively and safely combat it. This work reviews studies on lingzhi or reishi medicinal mushroom, Ganoderma lucidum and its properties that may potentially combat SARS-CoV-2 infection and the co-morbidities. Available evidence suggests that medicinal properties of the Ganoderma mushroom can combat the complications of SARS-CoV-2 infection and the co-morbidities that can aggravate the severity of the disease. Preclinical and clinical evaluation to establish dose, efficacy, and potential toxicity and possible use in the management of COVID-19 is recommended.


Assuntos
Agaricales , COVID-19 , Reishi , Humanos , Síndrome da Liberação de Citocina/tratamento farmacológico , SARS-CoV-2
5.
PLoS One ; 18(1): e0280756, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36696405

RESUMO

The COVID-19 global pandemic is being driven by evolving SARS-CoV-2 variants with consequential implications on virus transmissibility, host immunity, and disease severity. Continuous molecular and genomic surveillance of the SARS-CoV-2 variants is therefore necessary for public health interventions toward the management of the pandemic. This study is a retrospective analysis of COVID-19 cases reported in a Nigerian tertiary institution from July to December 2021. In total, 705 suspected COVID-19 cases that comprised 547 students and 158 non-students were investigated by real time PCR (RT-PCR); of which 372 (~52.8%) tested positive for COVID-19. Using a set of selection criteria, 74 (~19.9%) COVID-19 positive samples were selected for next generation sequencing. Data showed that there were two outbreaks of COVID-19 within the university community over the study period, during which more females (56.8%) tested positive than males (47.8%) (p<0.05). Clinical data together with phylogenetic analysis suggested community transmission of SARS-CoV-2 through mostly asymptomatic and/or pre-symptomatic individuals. Confirmed COVID-19 cases were mostly mild, however, SARS-CoV-2 delta (77%) and omicron (4.1%) variants were implicated as major drivers of respective waves of infections during the study period. This study highlights the importance of integrated surveillance of communicable disease during outbreaks.


Assuntos
COVID-19 , SARS-CoV-2 , Feminino , Masculino , Humanos , SARS-CoV-2/genética , COVID-19/epidemiologia , Nigéria/epidemiologia , Filogenia , Estudos Retrospectivos , Surtos de Doenças , Pandemias
6.
Clin Exp Vaccine Res ; 11(3): 249-263, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36451670

RESUMO

Purpose: Lassa fever is a zoonotic acute viral hemorrhagic disease caused by Lassa virus (LASV). There is currently no licensed vaccine for the prevention of the disease. This study is aimed at discovering immunodominant epitopes from the envelope glycoprotein of the Lassa mammarenavirus and designing of a multi-epitope vaccine candidate (VC). Materials and Methods: The amino acid sequences of the envelope glycoprotein of 26 strains of LASV from five countries were selected. After evaluation for antigenicity, immunogenicity, allergenicity, and toxicity, immunodominant CD8, CD4, and linear B lymphocytes were also selected. The selected epitopes were modelled and a molecular docking with the appropriate major histocompatibility complex (MHC) proteins was performed. Using an adjuvant and linkers, a multi-epitope VC was designed. The VC was evaluated for its physicochemical and immunological properties and structurally refined, validated, and mutated (disulphide engineering). The complex formed by the VC and the toll-like receptor-4 receptor was subjected to molecular dynamic simulation (MDS) followed by in silico cloning in a plasmid vector. Results: A VC with 203 sequences, 22.13 kDa weight, isoelectric point of 9.85 (basic), instability index value of 27.62, aliphatic index of 68.87, and GRAVY value of -0.455 (hydrophilic) emerged. The VC is predicted to be non-allergenic with antigenicity, MHC I immunogenicity, and solubility upon overexpression values of 0.81, 2.04, and 0.86 respectively. The VC also has an estimated half-life greater than 10 hours in Escherichia coli and showed stability in all the parameters of MDS. Conclusion: The VC shows good promise in the prevention of Lassa fever but further tests are required to validate its safety and efficacy.

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