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1.
Viruses ; 16(4)2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38675899

RESUMO

Lumpy skin disease virus (LSDV) is a member of the capripoxvirus (CPPV) genus of the Poxviridae family. LSDV is a rapidly emerging, high-consequence pathogen of cattle, recently spreading from Africa and the Middle East into Europe and Asia. We have sequenced the whole genome of historical LSDV isolates from the Pirbright Institute virus archive, and field isolates from recent disease outbreaks in Sri Lanka, Mongolia, Nigeria and Ethiopia. These genome sequences were compared to published genomes and classified into different subgroups. Two subgroups contained vaccine or vaccine-like samples ("Neethling-like" clade 1.1 and "Kenya-like" subgroup, clade 1.2.2). One subgroup was associated with outbreaks of LSD in the Middle East/Europe (clade 1.2.1) and a previously unreported subgroup originated from cases of LSD in west and central Africa (clade 1.2.3). Isolates were also identified that contained a mix of genes from both wildtype and vaccine samples (vaccine-like recombinants, grouped in clade 2). Whole genome sequencing and analysis of LSDV strains isolated from different regions of Africa, Europe and Asia have provided new knowledge of the drivers of LSDV emergence, and will inform future disease control strategies.


Assuntos
Genoma Viral , Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Filogenia , Sequenciamento Completo do Genoma , Vírus da Doença Nodular Cutânea/genética , Vírus da Doença Nodular Cutânea/classificação , Vírus da Doença Nodular Cutânea/isolamento & purificação , Animais , Doença Nodular Cutânea/virologia , Doença Nodular Cutânea/epidemiologia , Bovinos , África Central/epidemiologia , África Ocidental/epidemiologia , Surtos de Doenças
2.
PLoS One ; 19(4): e0302627, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38662749

RESUMO

BACKGROUND: Intimate partner violence (IPV) has increasingly received attention in the last three decades. However, IPV-related studies in both high- and low- and middle-income countries adopted a victim-oriented perspective in which men are perpetrators and women, the victims. Using socio-cultural and resource theories as guiding frameworks, this paper assessed the associations between men's education and IPV in Central Africa, using nationally representative data of married and cohabiting women of reproductive ages. METHODS: Data included in the analyses come from Demographic and Health Surveys (DHSs) in the Democratic Republic of the Congo (DRC), Cameroon, Gabon, and Chad. Analyzed sub-samples consisted of 3421, 5023, 3930, and 3221 married/cohabiting women of reproductive ages in Chad, DRC, Cameroon, and Gabon, respectively. RESULTS: Findings indicated significant variations of IPV prevalence within and across countries. Previous research demonstrated that men's education is a protective factor in health-related studies. The present study, however, provide no clear evidence on the linkages between men's education and IPV. In contrast, the paper substantiated that highly educated women were at higher risks of IPV when spouses/partners were less educated. CONCLUSION: These findings have policy and programmatic implications because they might impede progress towards SDG goals on the elimination of all forms of violence against girls and women in Central Africa, which recorded the worst development indicators in sub-Saharan Africa. On a methodological note, studies are increasingly using pooled data to increase statistical power. Those studies can be very limited to devise effective IPV-interventions since they mask geographical variations within and across countries. More effective IPV-interventions should be culturally rooted and accounting for geographical variations because some areas are more affected than others.


Assuntos
Escolaridade , Inquéritos Epidemiológicos , Violência por Parceiro Íntimo , Humanos , Feminino , Masculino , Violência por Parceiro Íntimo/estatística & dados numéricos , África Central/epidemiologia , Adulto , Adolescente , Pessoa de Meia-Idade , Adulto Jovem , Prevalência
3.
Emerg Infect Dis ; 30(3): 560-563, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38407162

RESUMO

Analysis of genome sequencing data from >100,000 genomes of Mycobacterium tuberculosis complex using TB-Annotator software revealed a previously unknown lineage, proposed name L10, in central Africa. Phylogenetic reconstruction suggests L10 could represent a missing link in the evolutionary and geographic migration histories of M. africanum.


Assuntos
Evolução Biológica , Mycobacterium , Filogenia , Mycobacterium/genética , Software , África Central/epidemiologia
4.
Science ; 382(6670): 595-600, 2023 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-37917680

RESUMO

Historically, mpox has been characterized as an endemic zoonotic disease that transmits through contact with the reservoir rodent host in West and Central Africa. However, in May 2022, human cases of mpox were detected spreading internationally beyond countries with known endemic reservoirs. When the first cases from 2022 were sequenced, they shared 42 nucleotide differences from the closest mpox virus (MPXV) previously sampled. Nearly all these mutations are characteristic of the action of APOBEC3 deaminases, host enzymes with antiviral function. Assuming APOBEC3 editing is characteristic of human MPXV infection, we developed a dual-process phylogenetic molecular clock that-inferring a rate of ~6 APOBEC3 mutations per year-estimates that MPXV has been circulating in humans since 2016. These observations of sustained MPXV transmission present a fundamental shift to the perceived paradigm of MPXV epidemiology as a zoonosis and highlight the need for revising public health messaging around MPXV as well as outbreak management and control.


Assuntos
Desaminases APOBEC , Monkeypox virus , Mpox , Edição de RNA , Zoonoses Virais , Animais , Humanos , África Central/epidemiologia , África Ocidental/epidemiologia , Desaminases APOBEC/genética , Surtos de Doenças , Mpox/epidemiologia , Mpox/genética , Mpox/transmissão , Monkeypox virus/genética , Monkeypox virus/metabolismo , Mutação , Filogenia , Zoonoses Virais/genética , Zoonoses Virais/transmissão
5.
Lancet Microbe ; 4(12): e983-e993, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37865113

RESUMO

BACKGROUND: Efficacy of sulfadoxine-pyrimethamine, the malaria chemoprophylaxis used in pregnant women, and in children when combined with amodiaquine, is threatened by the accumulation of mutations in the Plasmodium falciparum dihydropteroate synthase (pfdhps) and dihydrofolate reductase (pfdhfr) genes. Data on the prevalence of resistant alleles in central Africa and the new pfdhps I431V mutation, particularly associated with other mutations to form the pfdhps vagKgs allele, are scarce. We explored the frequency and geographical distribution of pfdhps and pfdhfr mutations in central Africa in 2014-18, and assessed the evolutionary origin of the vagKgs allele. METHODS: Samples were collected at 18 health-care centres in seven countries (Angola, Cameroon, Central African Republic, Democratic Republic of the Congo, Gabon, Nigeria, and Republic of the Congo) from patients who showed possible symptoms of malaria between March 1, 2014, and Oct 31, 2018. Samples that were positive for P falciparum were transported to a laboratory in Toulouse, France, and genotyped. The frequency of pfdhfr and pfdhps mutations was studied in 1749 samples. Microsatellites in pfdhps flanking regions and whole-genome analysis compared with parasite genomes from the data-sharing network MalariaGEN were performed on samples carrying the vagKgs allele. FINDINGS: Mapping of the prevalence of single nucleotide polymorphisms and corresponding alleles of pfdhfr and pfdhps showed a substantial spread of alleles associated with sulfadoxine-pyrimethamine resistance in central Africa during the 2014-18 period, especially an increase going west to east in pfdhps alleles carrying the K540E and A581G mutations. A high prevalence of the pfdhps I431V mutation was observed in Cameroon (exceeding 50% in the northern region) and Nigeria. Genomic analysis showed a recent African emergence and a clonal expansion of the most frequent pfdhps vagKgs allele. INTERPRETATION: Reduced sulfadoxine-pyrimethamine efficacy due to increased resistance is a worrying situation, especially because the malaria transmission level is high in central Africa. Although the resistance phenotype remains to be confirmed, the emergence and spread of the vagKgs allele in west and central Africa could challenge the use of sulfadoxine-pyrimethamine. FUNDING: Toulouse Institute for Infectious and Inflammatory Diseases.


Assuntos
Antimaláricos , Malária Falciparum , Criança , Humanos , Feminino , Gravidez , Plasmodium falciparum/genética , Estudos Transversais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Resistência a Medicamentos/genética , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Mutação , África Central/epidemiologia , Di-Hidropteroato Sintase/genética
6.
Front Public Health ; 11: 1239274, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37711239

RESUMO

Objectives: The widespread occurrence of anti-malarial drug resistance threatens the current efforts to control malaria in African regions. Molecular marker surveillance helps to track the emergence and spread of drug-resistant malaria cases. Methods: A total of 237 Plasmodium falciparum infections imported from central Africa to Zhejiang Province, China, between 2016 and 2021, were investigated. Genomic DNA was extracted from blood samples of each patient and nested PCRs was used to detect molecular markers in k13, Pfcrt, and Pfmdr1 genes. The spatial and temporal distributions of the molecular markers were analyzed. Results: A limited polymorphism of k13 was observed, including two nonsynonymous (D464E and K503E) and five synonymous mutations. Wild-type CVMNK of Pfcrt predominated (78.5%), whereas 19.5% of the samples harbored the mutant haplotype, CVIET. The point mutation Y184F and the single mutant haplotype NF of Pfmdr1 were the most frequently observed. The geographical distributions of the Pfcrt and Pfmdr1 haplotypes displayed distinct patterns, with the mutant haplotype of Pfcrt more common in Gabon (53.9%) and Congo (50.0%), and wild haplotypes of Pfmdr1 more frequently found in Cameroon, Angola, and Congo. The prevalence of wild-type CVMNK of Pfcrt increased from 68.5-74.6% in 2016-2017 to 81.8-87.5% in 2018-2021. The proportion of wild-type Pfmdr1 also increased from 27.1% in 2016 to 38.5% in 2019. Conclusion: The geographical and temporal distribution of k13, Pfcrt, and Pfmdr1 polymorphisms in P. falciparum parasites imported from central Africa between 2016 and 2021 are demonstrated. Our data provide updated evidence that can be used to adjust anti-malarial drug policies in central Africa and China.


Assuntos
Antimaláricos , Parasitos , Humanos , Animais , Plasmodium falciparum/genética , Antimaláricos/farmacologia , Biomarcadores , África Central/epidemiologia
7.
J Med Virol ; 95(5): e28775, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37212310

RESUMO

Mpox is a viral zoonotic disease endemic in Central and West Africa that is caused by the Mpox virus, which belongs to the Orthopoxvirus genus and Poxviridae family. The clinical manifestations of mpox infection are milder than those of smallpox, and the incubation time of mpox varies from 5 to 21 days. Since May 2022, the mpox outbreak (formerly known as monkeypox) has suddenly and unexpectedly spread in non-endemic countries, suggesting that there may have been some undetected transmissions. Based on molecular analysis, there are two major genetic clades that represent the mpox virus: Clade I (formerly the Congo Basin clade OR the Central African clade) and Clade II (formerly the West African clade). It is believed that people who are asymptomatic or paucisymptomatic may spread the mpox virus. Infectious viruses cannot be distinguished by PCR testing; therefore, virus culture should be carried out. Recent evidence regarding the detection of the mpox virus (Clade IIb) in air samples collected from the patient's environment during the 2022 mpox outbreak was reviewed. Further studies are needed to evaluate the extent to which the presence of mpox virus DNA in the air could affect immunocompromised patients in healthcare facilities, and further epidemiological studies are crucial, especially in Africa.


Assuntos
Microbiologia do Ar , Monkeypox virus , Mpox , Humanos , África Ocidental/epidemiologia , Mpox/diagnóstico , Mpox/epidemiologia , Monkeypox virus/genética , Monkeypox virus/isolamento & purificação , África Central/epidemiologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-36768062

RESUMO

The Central African Region is an agricultural and fishing-based economy, with 40% of the population living in rural communities. The negative impacts of climate change have caused economic/health-related adverse impacts and food insecurity. This original article aims to research four key themes: (i) acute food insecurity (AFI); (ii) childhood malnutrition and mortality; (iii) infectious disease burden; and (iv) drought and mean temperature projections throughout the twenty-first century. Food insecurity was mapped in Central Africa based on the Integrated Food Security Phase Classification (IPC) for AFI. The global hunger index (GHI) was presented along with the proportion of children with undernourishment, stunting, wasting, and mortality. Data for infectious disease burden was computed by assessing the adjusted rate of change (AROC) of mortality due to diarrhea among children and the burden of death rates due to pneumonia across all age groups. Finally, the mean drought index was computed through the year 2100. This population-based study identifies high levels of hunger across a majority of the countries, with the mean drought index suggesting extreme ends of wet and dry days and an overall rise of 1-3 °C. This study is a source of evidence for stakeholders, policymakers, and the population residing in Central Africa.


Assuntos
Doenças Transmissíveis , Desnutrição , Humanos , Criança , Secas , Temperatura , Abastecimento de Alimentos , Desnutrição/epidemiologia , Insegurança Alimentar , África Central/epidemiologia
9.
J Infect Dis ; 227(6): 752-760, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35867855

RESUMO

BACKGROUND: Central Africa is one of the largest areas of high endemicity for human T-cell leukemia virus-1 (HTLV-1). However, no preventive measures are yet implemented to reduce its transmission, which can be sexual, from mother-to-child, or through contaminated blood products. Rare zoonotic transmissions from nonhuman primates (NHPs) have also been reported in this region. Here we investigated the HTLV-1 prevalence and associated risk factors in a rural population in Cameroon. METHODS: From 2019 to 2021, we performed a cross-sectional survey in the eastern region of Cameroon. HTLV-1 infection was first screened by ELISA, then tested by western blot and envelope gene targeted polymerase chain reaction. Risk factors associated with HTLV-1 infection were identified by logistic regression in univariable and multivariable analyses. RESULTS: Among 3400 participants, HTLV-1 prevalence was 1.1% (95% confidence interval [CI], .7-1.5). Factors independently associated with HTLV-1 infection were Pygmy ethnicity (adjusted odd ratio [aOR], 2.9; 95% CI, 1.3-6.2), history of surgery (aOR, 6.3; 95% CI, 2.2-17.8), and NHP bite (aOR, 6.6; 95% CI, 2.2-19.8). CONCLUSIONS: These results suggest both iatrogenic and zoonotic transmission of HTLV-1 in Cameroon. Further studies are needed to assess the risk of nosocomial transmission of HTLV-1, to guide public health authorities in implementing preventive measures to control HTLV-1 transmission.


Assuntos
Infecção Hospitalar , Infecções por HTLV-I , Vírus Linfotrópico T Tipo 1 Humano , Leucemia de Células T , Animais , Humanos , Feminino , Vírus Linfotrópico T Tipo 1 Humano/genética , População Rural , Estudos Transversais , Transmissão Vertical de Doenças Infecciosas , África Central/epidemiologia , Infecções por HTLV-I/epidemiologia
10.
Pan Afr Med J ; 43: 45, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36523280

RESUMO

Chronic malnutrition is a major public health concern that is the focus of a large body of scientific research. However, there is no synthesis of knowledge about the factors associated with this disease in West and Central Africa, where its prevalence is particularly high. We conducted a systematic search for scientific articles published between January 1st, 2000, and October 15th, 2020, that focus on chronic malnutrition in children in West and Central Africa. We queried CAIRN, PubMed, CINAHL, MEDLINE, Scopus, and Google Scholar databases for this purpose. The search process followed the recommendations of Arksey and O'Malley. Items reported in this review follow the PRISMA-ScR guidelines. Sixty articles involving children from a total of twenty (20) countries, mainly Ghana and Nigeria, were included in the final analysis. The data used were predominantly cross-sectional and were mainly drawn from demographic and health surveys. The analysis revealed that chronic malnutrition in children is associated with sociocultural, economic, and healthcare factors related to the characteristics of children, mothers, households, and communities. The association with children's vulnerability to disease, maternal education, purchasing power, and autonomy need to be further investigated in West and Central Africa. Further analysis using longitudinal data is also needed to better understand the factors associated with chronic malnutrition in West and Central Africa.


Assuntos
Transtornos da Nutrição Infantil , Desnutrição , Feminino , Criança , Humanos , Transtornos da Nutrição Infantil/epidemiologia , Estudos Transversais , Nigéria , Desnutrição/epidemiologia , África Central/epidemiologia
11.
Clin Microbiol Rev ; 35(4): e0009222, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36374082

RESUMO

Human monkeypox is a viral zoonosis endemic to West and Central Africa that has recently generated increased interest and concern on a global scale as an emerging infectious disease threat in the midst of the slowly relenting COVID-2019 disease pandemic. The hallmark of infection is the development of a flu-like prodrome followed by the appearance of a smallpox-like exanthem. Precipitous person-to-person transmission of the virus among residents of 100 countries where it is nonendemic has motivated the immediate and widespread implementation of public health countermeasures. In this review, we discuss the origins and virology of monkeypox virus, its link with smallpox eradication, its record of causing outbreaks of human disease in regions where it is endemic in wildlife, its association with outbreaks in areas where it is nonendemic, the clinical manifestations of disease, laboratory diagnostic methods, case management, public health interventions, and future directions.


Assuntos
COVID-19 , Mpox , Varíola , Humanos , Monkeypox virus , Mpox/diagnóstico , Mpox/epidemiologia , COVID-19/epidemiologia , África Central/epidemiologia
12.
Emerg Infect Dis ; 28(12): 2435-2445, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36328951

RESUMO

We analyzed monkeypox disease surveillance in Central African Republic (CAR) during 2001-2021. Surveillance data show 95 suspected outbreaks, 40 of which were confirmed as monkeypox, comprising 99 confirmed and 61 suspected monkeypox cases. After 2018, CAR's annual rate of confirmed outbreaks increased, and 65% of outbreaks occurred in 2 forested regions bordering the Democratic Republic of the Congo. The median patient age for confirmed cases was 15.5 years. The overall case-fatality ratio was 7.5% (12/160) for confirmed and suspected cases, 9.6% (8/83) for children <16 years of age. Decreasing cross-protective immunity from smallpox vaccination and recent ecologic alterations likely contribute to increased monkeypox outbreaks in Central Africa. High fatality rates associated with monkeypox virus clade I also are a local and international concern. Ongoing investigations of zoonotic sources and environmental changes that increase human exposure could inform practices to prevent monkeypox expansion into local communities and beyond endemic areas.


Assuntos
Mpox , Criança , Humanos , Adolescente , Mpox/epidemiologia , República Centro-Africana/epidemiologia , Monkeypox virus/genética , Surtos de Doenças , África Central/epidemiologia
14.
Microbiol Spectr ; 10(5): e0200522, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36121226

RESUMO

Sulfadoxine-pyrimethamine (SP) resistance impairs the efficacy of antimalarial drugs. Monitoring molecular markers in exported malaria infections provides an efficient way to trace the emergence of drug resistance in countries where malaria is endemic. Molecular markers in Pfdhfr and Pfdhps of 237 Plasmodium falciparum infections imported from central Africa between 2016 and 2021 were detected. The spatial and temporal distributions of Pfdhfr and Pfdhps mutations were analyzed. A high prevalence of Pfdhfr single-nucleotide polymorphisms (SNPs) (~92.34% to 99.10%) and a high frequency of the triple mutation haplotype I51R59N108 were observed. Cameroon, Equatorial Guinea, and Gabon showed a higher frequency (~96.61% to 100.00%) of I51R59N108 than other countries (~71.11% to 88.10%). The prevalence of C59R and I51R59N108 increased while that of other SNPs or haplotypes did not fluctuate greatly from 2016 to 2021. Large proportions of Pfdhps SNPs (A437G and K540E) were demonstrated. The SNP distribution of Pfdhps differed between countries, with S436A dominating in northern countries and A437G dominating in others. The proportions of I431V, A437G, and the triple mutant haplotype declined between 2016 and 2021, whereas the prevalence of the single mutant haplotype rose from 61.60% to 73.68%. Combinations of Pfdhfr-Pfdhps alleles conferring partial resistance, full resistance, and superresistance to SP, as defined in the text, were detected in 63.64%, 8.64%, and 0.91% of the samples, respectively. The octuple Pfdhfr-Pfdhps allele (I51R59N108-V431A436G437K540G581S613) was seen in 5.00% of the samples. We demonstrated the wide geographic spread and increasing trends in highly SP-resistant Pfdhfr genes and varying spatial patterns of Pfdhps mutants across countries in central Africa. The high prevalences of partially resistant, fully resistant, and superresistant Pfdhfr-Pfdhps combinations observed here indicated impaired SP efficacy. Increased molecular surveillance is required to monitor the changing status of the Pfdhfr and Pfdhps genes. IMPORTANCE Monitoring drug resistance is important for malaria control because its early detection enables timely action to prevent its spread and mitigate its impact. The wide geographic spread and the increasing trend of highly resistant Pfdhfr genes between 2016 and 2021 found in our study are worrisome and emphasize the urgency to monitor their updated status in central Africa. This study also illustrated the wide spread of the novel mutant Pfdhps I431V as well as the high prevalence of "partially resistant," "fully resistant," and "superresistant" Pfdhfr-Pfdhps combinations, indicating the urgent concern for SP efficacy in central Africa. These findings are alarming in central African countries where malaria is endemic, where SP was is widely used for the intermittent preventive treatment of malaria in pregnancy (IPTp) and the intermittent preventive treatment of malaria in infants below 5 years of age (IPTi), and urge enhanced molecular surveillance and responses to the threat of drug resistance.


Assuntos
Antimaláricos , Malária Falciparum , Plasmodium falciparum , Humanos , África Central/epidemiologia , Alelos , Antimaláricos/uso terapêutico , Resistência a Medicamentos/genética , Malária Falciparum/epidemiologia , Malária Falciparum/tratamento farmacológico , Mutação , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Proteínas de Protozoários/genética
16.
Science ; 376(6597): 1032-1033, 2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35653477
17.
Transbound Emerg Dis ; 69(3): 1479-1505, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-33876579

RESUMO

Brucellosis is regarded as one of the highest burden zoonotic diseases to persist in many regions globally. While sustained vaccination against B. abortus in an endemic setting can markedly reduce the prevalence of large ruminant and human brucellosis and benefit local livelihoods, the implementation of effective and sustainable control programmes has often failed in the worst affected areas. In a cross-sectional study of 728 peri-urban dairy farmers in nine areas of six West and Central African countries, levels of commercialization and farm characteristics were examined alongside B. abortus seroprevalence estimates to hypothesize the most appropriate model for brucellosis vaccination delivery in each country. Demographic and economic data were collated and used to describe the farming systems currently in place. Furthermore, these data were utilized in a likelihood assessment to generate a quantitative score to hypothesize which of three private-public partnership (PPP) vaccine delivery models, that is 1) transformative, 2) transactional or 3) collaborative, would be most appropriate in each setting. The study sites had substantial differences in their levels of dairy commercialization and the farming practices employed; the heterogeneity across the study sites was evident in the conclusions of which models would be appropriate for vaccination delivery. While Lomé (Togo) had a strong indication for a transformative PPP model, Burkina Faso had strong indication for the collaborative PPP model. Of the remaining study sites, the scores were less dominant for any one model with Cameroon and Ivory Coast sites only just scoring highest on the transformative model and Senegal and Mali sites only just scoring highest on the collaborative model. Interestingly, none of the countries included in the study scored highest on the transactional model which currently is the most commonplace delivery model in the majority of sub-Saharan African countries.


Assuntos
Brucelose , África Central/epidemiologia , Animais , Brucelose/epidemiologia , Brucelose/prevenção & controle , Brucelose/veterinária , Estudos Transversais , Fazendas , Estudos Soroepidemiológicos , Vacinação/veterinária
18.
Acta Trop ; 225: 106199, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34740635

RESUMO

Yellow fever (YF) is a major public-health problem in Africa. Yellow fever virus (YFV), the etiological agent responsible for the disease, exhibits clear delineation of phylogeography between East/Central Africa and West Africa. In order to decipher the genetic nature of the YFV epidemic between these areas, we performed a genome-wide study on its African isolates using the McDonald-Kreitman (MK) test in combination with the type II functional divergence analysis. The results showed that adaptive genetic diversifications have occurred on viral nonstructural protein 1 (NS1) and NS5, which are essential for viral genome replication and immune antagonism, with the East/Central African-West African epidemic split. On both proteins, a number of amino acid replacements have been favored by functional divergence. These findings could help to bridge the gap between the phylogeographic delineation and niche adaptation underlying the YFV-epidemic across Africa and shed light on viral determinants of this process.


Assuntos
Febre Amarela , Vírus da Febre Amarela , África Central/epidemiologia , Estudo de Associação Genômica Ampla , Humanos , Epidemiologia Molecular , Filogeografia , Febre Amarela/epidemiologia , Vírus da Febre Amarela/genética
19.
Nat Commun ; 12(1): 5769, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34599175

RESUMO

Distinct SARS-CoV-2 lineages, discovered through various genomic surveillance initiatives, have emerged during the pandemic following unprecedented reductions in worldwide human mobility. We here describe a SARS-CoV-2 lineage - designated B.1.620 - discovered in Lithuania and carrying many mutations and deletions in the spike protein shared with widespread variants of concern (VOCs), including E484K, S477N and deletions HV69Δ, Y144Δ, and LLA241/243Δ. As well as documenting the suite of mutations this lineage carries, we also describe its potential to be resistant to neutralising antibodies, accompanying travel histories for a subset of European cases, evidence of local B.1.620 transmission in Europe with a focus on Lithuania, and significance of its prevalence in Central Africa owing to recent genome sequencing efforts there. We make a case for its likely Central African origin using advanced phylogeographic inference methodologies incorporating recorded travel histories of infected travellers.


Assuntos
COVID-19/transmissão , COVID-19/virologia , SARS-CoV-2/genética , África Central/epidemiologia , Anticorpos Neutralizantes/imunologia , COVID-19/epidemiologia , Europa (Continente)/epidemiologia , Humanos , Evasão da Resposta Imune/genética , Mutação , Filogenia , Filogeografia , SARS-CoV-2/classificação , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Viagem/estatística & dados numéricos
20.
Sci Rep ; 11(1): 16624, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404835

RESUMO

Tuberculosis (TB) incidence and mortality rates are still high in Sub-Saharan Africa, and the knowledge about the current patterns is valuable for policymaking to decrease the TB burden. Based on the Global Burden of Disease (GBD) study 2019, we used a Joinpoint regression analysis to examine the variations in the trends of TB incidence and mortality, and the age-period-cohort statistical model to evaluate their risks associated with age, period, and cohort in males and females from Cameroon (CAM), Central African Republic (CAR), Chad, and the Democratic Republic of the Congo (DRC). In the four countries, TB incidence and mortality rates displayed decreasing trends in men and women; except for the males from DRC that recorded an almost steady pattern in the trend of TB incidence between 1990 and 2019. TB incidence and mortality rates decreased according to the overall annual percentage changes over the adjusted age category in men and women of the four countries, and CAM registered the highest decrease. Although TB incidence and mortality rates increased with age between 1990 and 2019, the male gender was mainly associated with the upward behaviors of TB incidence rates, and the female gender association was with the upward behaviors of TB mortality rates. Males and females aged between 15-54 and 15-49 years old were evaluated as the population at high risks of TB incidence and mortality respectively in CAM, CAR, Chad, and DRC. The period and cohort relative risks (RRs) both declined in men and women of the four countries although there were some upward behaviors in their trends. Relatively to the period and cohort RRs, females and males from CAM recorded the most significant decrease compared to the rest of the countries. New public health approaches and policies towards young adults and adults, and a particular focus on elderlies' health and life conditions should be adopted in CAM, CAR, DRC, and Chad to rapidly decrease TB incidence and mortality in both genders of the four countries.


Assuntos
Tuberculose/epidemiologia , Adulto , África Central/epidemiologia , Idoso , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Tuberculose/mortalidade , Adulto Jovem
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