RESUMO
Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , Nigéria/epidemiologia , SARS-CoV-2/genéticaRESUMO
Lassa fever is a severe multisystem disease that often has haemorrhagic manifestations. The epitopes of the Lassa virus (LASV) surface glycoproteins recognized by naturally infected human hosts have not been identified or characterized. Here we have cloned 113 human monoclonal antibodies (mAbs) specific for LASV glycoproteins from memory B cells of Lassa fever survivors from West Africa. One-half bind the GP2 fusion subunit, one-fourth recognize the GP1 receptor-binding subunit and the remaining fourth are specific for the assembled glycoprotein complex, requiring both GP1 and GP2 subunits for recognition. Notably, of the 16 mAbs that neutralize LASV, 13 require the assembled glycoprotein complex for binding, while the remaining 3 require GP1 only. Compared with non-neutralizing mAbs, neutralizing mAbs have higher binding affinities and greater divergence from germline progenitors. Some mAbs potently neutralize all four LASV lineages. These insights from LASV human mAb characterization will guide strategies for immunotherapeutic development and vaccine design.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vírus Lassa/imunologia , Especificidade de Anticorpos , Antígenos Virais/química , Antígenos Virais/genética , Antígenos Virais/imunologia , Arenavirus/imunologia , Reações Cruzadas , Mapeamento de Epitopos , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Humanos , Febre Lassa/imunologia , Febre Lassa/prevenção & controle , Vírus Lassa/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Deleção de Sequência , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologiaRESUMO
To determine the prevalence of malaria and anemia among pregnant women attending a traditional birth center as well as the effect of herbal remedies, gravidity, age, educational background and malaria prevention methods on their prevalence. Blood specimens were collected from 119 pregnant women attending a Traditional Birth Home in Benin City, Nigeria. Malaria parasitemia was diagnosed by microscopy while anemia was defined as hemoglobin concentration <11 g/dL. The prevalence of malaria infection was [OR=4.35 95% CI=1.213, 15.600; p=0.016] higher among primigravidae [92.1%]. Pregnant women [38.5%] with tertiary level of education had significantly lower prevalence of malaria infection [p=0.002]. Malaria significantly affected the prevalence of anemia [p<0.05]. Anemia was associated with consumption of herbal remedies [OR=2.973; 95% CI=1.206, 7.330; p=0.017]. The prevalence of malaria parasitemia and anemia were not affected by malaria prevention methods used by the participants. The overall prevalence of malaria infection and anemia observed in this study were 78.9% and 46.2%, respectively. Higher prevalence of malaria infection was associated with primigravidae and lower prevalence with tertiary education of subjects. Anemia was associated with consumption of herbal remedies. There is urgent need to control the prevalence of malaria and anemia among pregnant women attending traditional birth homes
Assuntos
Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Complicações Parasitárias na Gravidez/epidemiologia , Anemia/epidemiologia , Prevalência , Malária/prevenção & controle , Número de GestaçõesRESUMO
Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massive increase in the number of sequences, exceeding 100,000 genomes generated to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence within their own borders, coupled with a decrease in sequencing turnaround time. Findings from this genomic surveillance underscores the heterogeneous nature of the pandemic but we observe repeated dissemination of SARS-CoV-2 variants within the continent. Sustained investment for genomic surveillance in Africa is needed as the virus continues to evolve, particularly in the low vaccination landscape. These investments are very crucial for preparedness and response for future pathogen outbreaks. One-Sentence SummaryExpanding Africa SARS-CoV-2 sequencing capacity in a fast evolving pandemic.