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1.
Circ Res ; 134(11): 1546-1565, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38781300

RESUMO

Cardiac abnormalities were identified early in the epidemic of AIDS, predating the isolation and characterization of the etiologic agent, HIV. Several decades later, the causation and pathogenesis of cardiovascular disease (CVD) linked to HIV infection continue to be the focus of intense speculation. Before the widespread use of antiretroviral therapy, HIV-associated CVD was primarily characterized by HIV-associated cardiomyopathy linked to profound immunodeficiency. With increasing antiretroviral therapy use, viral load suppression, and establishment of immune competency, the effects of HIV on the cardiovascular system are more subtle. Yet, people living with HIV still face an increased incidence of cardiovascular pathology. Advances in cardiac imaging modalities and immunology have deepened our understanding of the pathogenesis of HIV-associated CVD. This review provides an overview of the pathogenesis of HIV-associated CVD integrating data from imaging and immunologic studies with particular relevance to the HIV population originating from high-endemic regions, such as sub-Saharan Africa. The review highlights key evidence gaps in the field and suggests future directions for research to better understand the complex HIV-CVD interactions.


Assuntos
Doenças Cardiovasculares , Infecções por HIV , Humanos , Infecções por HIV/imunologia , Infecções por HIV/epidemiologia , Infecções por HIV/complicações , Doenças Cardiovasculares/imunologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/diagnóstico por imagem , Animais
2.
Emerg Infect Dis ; 30(3): 581-585, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38407189

RESUMO

Middle East respiratory syndrome coronavirus (MERS-CoV) is endemic in dromedaries in Africa, but camel-to-human transmission is limited. Sustained 12-month sampling of dromedaries in a Kenya abattoir hub showed biphasic MERS-CoV incidence; peak detections occurred in October 2022 and February 2023. Dromedary-exposed abattoir workers (7/48) had serologic signs of previous MERS-CoV exposure.


Assuntos
Camelus , Coronavírus da Síndrome Respiratória do Oriente Médio , Humanos , Animais , Quênia/epidemiologia , Incidência , Matadouros
4.
BMC Cancer ; 21(1): 1248, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34798868

RESUMO

BACKGROUND: Glioblastoma is a fatal brain tumour with a poor patient survival outcome. Hypoxia has been shown to reprogram cells towards a stem cell phenotype associated with self-renewal and drug resistance properties. Activation of hypoxia-inducible factors (HIFs) helps in cellular adaptation mechanisms under hypoxia. Similarly, miRNAs are known to be dysregulated in GBM have been shown to act as critical mediators of the hypoxic response and to regulate key processes involved in tumorigenesis. METHODS: Glioblastoma (GBM) cells were exposed to oxygen deprivation to mimic a tumour microenvironment and different cell aspects were analysed such as morphological changes and gene expression of miRNAs and survival genes known to be associated with tumorigenesis. RESULTS: It was observed that miR-128a-3p, miR-34-5p, miR-181a/b/c, were down-regulated in 6 GBM cell lines while miR-17-5p and miR-221-3p were upregulated when compared to a non-GBM control. When the same GBM cell lines were cultured under hypoxic microenvironment, a further 4-10-fold downregulation was observed for miR-34-5p, miR-128a-3p and 181a/b/c while a 3-6-fold upregulation was observed for miR-221-3p and 17-5p for most of the cells. Furthermore, there was an increased expression of SOX2 and Oct4, GLUT-1, VEGF, Bcl-2 and survivin, which are associated with a stem-like state, increased metabolism, altered angiogenesis and apoptotic escape, respectively. CONCLUSION: This study shows that by mimicking a tumour microenvironment, miRNAs are dysregulated, stemness factors are induced and alteration of the survival genes necessary for the cells to adapt to the micro-environmental factors occurs. Collectively, these results might contribute to GBM aggressiveness.


Assuntos
Neoplasias Encefálicas/genética , Glioblastoma/genética , MicroRNAs/metabolismo , Hipóxia Tumoral/genética , Microambiente Tumoral/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Regulação para Baixo , Genótipo , Glioblastoma/metabolismo , Glioblastoma/patologia , Transportador de Glucose Tipo 1/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Fenótipo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Survivina/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
Clin Infect Dis ; 68(10): 1675-1683, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-30407498

RESUMO

BACKGROUND: Genital immunology is a key determinant of human immunodeficiency virus (HIV) susceptibility. Both factors are modulated by bacterial vaginosis (BV) and, to some extent, by Lactobacillus iners, the genital Lactobacillus spp. that predominates in African, Caribbean, and other Black (ACB) women. We conducted a clinical trial to assess the impact of oral metronidazole treatment on the genital immune parameters of HIV acquisition risks in Kenyan women with BV. METHODS: The primary endpoint was ex vivo cervical CD4+ T-cell HIV susceptibility after 1 month; secondary endpoints included genital cytokine/chemokine levels, cervical immune cell populations, and the composition of the cervico-vaginal microbiota by 16S ribosomal RNA gene amplicon sequencing. RESULTS: BV resolved (Nugent score ≤ 3) at 1 month in 20/45 participants, and cervical CD4+ T-cell HIV entry was moderately reduced in all participants, regardless of treatment outcome. Resolution of BV and reduced abundances of BV-associated gram-negative taxa correlated with reduced genital interleukin (IL)-1α/ß. However, BV resolution and the concomitant colonization by Lactobacillus iners substantially increased several genital chemokines associated with HIV acquisition, including interferon-γ inducible protein (IP)-10, macrophage inflammatory protein (MIP)-3α, and monokine induced by gamma interferon (MIG). In an independent cohort of ACB women, most of whom were BV-free, vaginal chemokines were again closely linked with L. iners abundance, though not other Lactobacillus spp. CONCLUSIONS: BV treatment reduced genital CD4+ T-cell HIV susceptibility and IL-1 levels, but dramatically increased the genital chemokines that may enhance HIV susceptibility; the latter effect was related to the restoration of an Lactobacillus iners-dominated microbiota. Further studies are needed before treatment of asymptomatic BV can be recommended for HIV prevention in ACB communities.


Assuntos
Colo do Útero/imunologia , Suscetibilidade a Doenças/virologia , Metronidazol/uso terapêutico , Microbiota/efeitos dos fármacos , Vagina/imunologia , Vagina/microbiologia , Vaginose Bacteriana/tratamento farmacológico , Administração Oral , Adulto , Linfócitos T CD4-Positivos/virologia , Células Cultivadas , Citocinas/imunologia , Feminino , HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Estudos Prospectivos , RNA Ribossômico 16S/genética , Fatores de Risco , Vaginose Bacteriana/imunologia , Adulto Jovem
6.
Arch Virol ; 164(8): 2171-2173, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31093759

RESUMO

We report here the annotation of the complete genomes of four novel lytic Staphylococcus phages; Stab20, Stab21, Stab22 and Stab23. These phages have double-stranded DNA genomes ranging between 153,338 and 155,962 bp in size with terminal repeats of 10,814-12,304 bp. The genome analysis suggests that they represent new phage species within the genus Kayvirus in the subfamily Twortvirinae of the family Herelleviridae.


Assuntos
Myoviridae/genética , Staphylococcus/genética , DNA Viral/genética , Genoma Viral/genética , Genômica/métodos , Filogenia , Análise de Sequência de DNA/métodos , Fagos de Staphylococcus/genética
7.
J Virol ; 88(8): 4291-303, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24478420

RESUMO

UNLABELLED: The antiviral role of TRIM E3 ligases in vivo is not fully understood. To test the hypothesis that TRIM5α and TRIM22 have differential transcriptional regulation and distinct anti-HIV roles according to infection phase and compartment, we measured TRIM5α, TRIM22, and type I interferon (IFN-I)-inducible myxovirus resistance protein A (MxA) levels in peripheral blood mononuclear cells (PBMCs) during primary and chronic HIV-1 infection, with chronic infection samples being matched PBMCs and central nervous system (CNS)-derived cells. Associations with biomarkers of disease progression were explored. The impact of IFN-I, select proinflammatory cytokines, and HIV on TRIM E3 ligase-specific expression was investigated. PBMCs from individuals with primary and chronic HIV-1 infection had significantly higher levels of MxA and TRIM22 than did PBMCs from HIV-1-negative individuals (P < 0.05 for all comparisons). PBMCs from chronic infection had lower levels of TRIM5α than did PBMCs from primary infection or HIV-1-uninfected PBMCs (P = 0.0001 for both). In matched CNS-derived samples and PBMCs, higher levels of MxA (P = 0.001) and TRIM5α (P = 0.0001) in the CNS were noted. There was a negative correlation between TRIM22 levels in PBMCs and plasma viral load (r = -0.40; P = 0.04). In vitro, IFN-I and, rarely, proinflammatory cytokines induced TRIM5α and TRIM22 in a cell type-dependent manner, and the knockdown of either protein in CD4(+) lymphocytes resulted in increased HIV-1 infection. These data suggest that there are infection-phase-specific and anatomically compartmentalized differences in TRIM5α and TRIM22 regulation involving primarily IFN-I and specific cell types and indicate subtle differences in the antiviral roles and transcriptional regulation of TRIM E3 ligases in vivo. IMPORTANCE: Type I interferon-inducible TRIM E3 ligases are a family of intracellular proteins with potent antiviral activities mediated through diverse mechanisms. However, little is known about the contribution of these proteins to antiviral immunity in vivo and how their expression is regulated. We show here that TRIM5α and TRIM22, two prominent members of the family, have different expression patterns in vivo and that the expression pattern depends on HIV-1 infection status and phase. Furthermore, expression differs in peripheral blood versus central nervous system anatomical sites of infection. Only TRIM22 expression correlated negatively with HIV-1 viral load, but gene silencing of both proteins enhances HIV-1 infection of target cells. We report subtle differences in TRIM5α and TRIM22 gene induction by IFN-I and proinflammatory cytokines in CD4(+) lymphocytes, monocytes, and neuronal cells. This study enhances our understanding of antiviral immunity by intrinsic antiviral factors and how their expression is determined.


Assuntos
Proteínas de Transporte/metabolismo , Infecções por HIV/metabolismo , HIV-1/fisiologia , Proteínas Repressoras/metabolismo , Adolescente , Adulto , Fatores de Restrição Antivirais , Proteínas de Transporte/genética , Criança , Estudos de Coortes , Feminino , Regulação da Expressão Gênica , Infecções por HIV/genética , Infecções por HIV/virologia , HIV-1/genética , Humanos , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Antígenos de Histocompatibilidade Menor , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , Proteínas Repressoras/genética , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Replicação Viral , Adulto Jovem
8.
BMC Med Genomics ; 17(1): 14, 2024 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-38184575

RESUMO

BACKGROUND: Though persons of African descent have one of the widest genetic variability, genetic polymorphisms of drug-metabolising enzymes such as N-Acetyltransferase-2 (NAT2) are understudied. This study aimed to identify prevalent NAT2 single nucleotide polymorphisms (SNPs) and infer their potential effects on enzyme function among Kenyan volunteers with tuberculosis (TB) infection. Genotypic distribution at each SNP and non-random association of alleles were evaluated by testing for Hardy-Weinberg Equilibrium (HWE) and Linkage Disequilibrium (LD). METHODS: We isolated genomic DNA from cryopreserved Peripheral Blood Mononuclear Cells of 79 volunteers. We amplified the protein-coding region of the NAT2 gene by polymerase chain reaction (PCR) and sequenced PCR products using the Sanger sequencing method. Sequencing reads were mapped and aligned to the NAT2 reference using the Geneious software (Auckland, New Zealand). Statistical analyses were performed using RStudio version 4.3.2 (2023.09.1 + 494). RESULTS: The most frequent haplotype was the wild type NAT2*4 (37%). Five genetic variants: 282C > T (NAT2*13), 341 T > C (NAT2*5), 803A > G (NAT2*12), 590G > A (NAT2*6) and 481C > T (NAT2*11) were observed with allele frequencies of 29%, 18%, 6%, 6%, and 4% respectively. According to the bimodal distribution of acetylation activity, the predicted phenotype was 76% rapid (mainly consisting of the wildtype NAT2*4 and the NAT2*13A variant). A higher proportion of rapid acetylators were female, 72% vs 28% male (p = 0.022, odds ratio [OR] 3.48, 95% confidence interval [CI] 1.21 to 10.48). All variants were in HWE. NAT2 341 T > C was in strong complete LD with the 590G > A variant (D' = 1.0, r2 = - 0.39) but not complete LD with the 282C > T variant (D' = 0.94, r2 = - 0.54). CONCLUSION: The rapid acetylation haplotypes predominated. Despite the LD observed, none of the SNPs could be termed tag SNP. This study adds to the genetic characterisation data of African populations at NAT2, which may be useful for developing relevant pharmacogenomic tools for TB therapy. To support optimised, pharmacogenomics-guided TB therapy, we recommend genotype-phenotype studies, including studies designed to explore gender-associated differences.


Assuntos
Arilamina N-Acetiltransferase , Etnicidade , Feminino , Masculino , Humanos , Quênia , Leucócitos Mononucleares , Farmacogenética , Genótipo , Acetiltransferases , Arilamina N-Acetiltransferase/genética
9.
Front Vet Sci ; 11: 1379907, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38966562

RESUMO

Introduction: Animal health surveillance systems in Kenya have undergone significant changes and faced various challenges throughout the years. Methods: In this article, we present a comprehensive overview of the Kenya animal health surveillance system (1944 to 2024), based on a review of archived documents, a scoping literature review, and an examination of past surveillance assessments and evaluation reports. Results: The review of archived documents revealed key historical events that have shaped the surveillance system. These include the establishment of the Directorate of Veterinary Services in 1895, advancements in livestock farming, the implementation of mandatory disease control interventions in 1944, the growth of veterinary services from a section to a ministry in 1954, the disruption caused by the Mau Mau insurrection from 1952 to 1954, which led to the temporary halt of agriculture in certain regions until 1955, the transition of veterinary clinical services from public to private, and the progressive privatization plan for veterinary services starting in 1976. Additionally, we highlight the development of electronic surveillance from 2003 to 2024. The scoping literature review, assessments and evaluation reports uncovered several strengths and weaknesses of the surveillance system. Among the strengths are a robust legislative framework, the adoption of technology in surveillance practices, the existence of a formal intersectoral coordination platform, the implementation of syndromic, sentinel, and community-based surveillance methods, and the presence of a feedback mechanism. On the other hand, the system's weaknesses include the inadequate implementation of strategies and enforcement of laws, the lack of standard case definitions for priority diseases, underutilization of laboratory services, the absence of formal mechanisms for data sharing across sectors, insufficient resources for surveillance and response, limited integration of surveillance and laboratory systems, inadequate involvement of private actors and communities in disease surveillance, and the absence of a direct supervisory role between the national and county veterinary services. Discussion and recommendations: To establish an effective early warning system, we propose the integration of surveillance systems and the establishment of formal data sharing mechanisms. Furthermore, we recommend enhancing technological advancements and adopting artificial intelligence in surveillance practices, as well as implementing risk-based surveillance to optimize the allocation of surveillance resources.

10.
Microbiol Spectr ; 12(4): e0357023, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38364104

RESUMO

Phenotypic changes and functional impairment of natural killer (NK) cells occur early in HIV-1 infection. Antiretroviral therapy (ART) effectively restores CD4+ T cell counts and suppresses HIV-1 to undetectable levels. The role and efficacy of immediate ART initiation in mitigating NK cell aberrations remain to be elucidated comprehensively. This study hypothesized that HIV-1 infection negatively influences NK cell evolution and that early ART initiation restores these perturbations. Blood samples were collected longitudinally from five acutely HIV-1 infected men who have sex with men in Nairobi, Kenya. Participants were immediately initiated on ART after HIV-1 diagnosis. Blood samples were drawn pre-infection and at sequential bi-weekly post-infection time points. Peripheral blood mononuclear cells were stained with panel NK cells surface markers to assess HIV-induced phenotypic changes by flow cytometry. Some cells were also stimulated overnight with K562 cell line, IL-2, and IL-15 and stained for flow cytometry functionality. HIV-1 infection was associated with significant reductions in the production of IFN-γ (P = 0.0264), expression of CD69 (P = 0.0110), and expression of NK cell inhibitory receptor Siglec7 (P = 0.0418). We observed an increased NK cell degranulation (P = 0.0100) and an upregulated expression of cell exhaustion marker PD-1 (P = 0.0513) at post-infection time points. These changes mainly were restored upon immediate initiation of ART, except for Siglec7 expression, whose reduced expression persisted despite ART. Some HIV-associated changes in NK cells may persist despite the immediate initiation of ART in acute HIV-1 infections. Our findings suggest that understanding NK cell dynamics and their restoration after ART can offer insights into optimizing HIV-1 treatment and potentially slowing disease progression.IMPORTANCENatural killer (NK) cells play a crucial role in controlling of HIV-1 replication and progression to disease. Perturbations of their functionality may therefore result in deleterious disease outcomes. Previous studies have demonstrated reduced NK cell functionality in chronic HIV-1 infection that positively correlated to HIV-1 viral load. This may suggest that control of HIV-1 viremia in acute HIV-1 infection may aid in enhancing NK cell response boosting the inate immunity hence effective control of viral spread and establishment of viral reservoir. Antiretroviral therapy (ART) effectively supresses HIV-1 viremia to undectable levels and restores CD4+ T cell counts. Our study highlights the significant role of early ART initiation in mitigating NK cell disruptions caused by acute HIV-1 infection. Our results suggest that early initiation of ART could have benefits beyond suppressing viral load and restoring CD4+ T cell counts. In addition, it could boost the innate immunity necessary to control disease progression.


Assuntos
Infecções por HIV , HIV-1 , Minorias Sexuais e de Gênero , Masculino , Humanos , Projetos Piloto , Estudos Transversais , Leucócitos Mononucleares , Viremia , Homossexualidade Masculina , Quênia , Antirretrovirais/uso terapêutico , Células Matadoras Naturais , Progressão da Doença , Carga Viral , Linfócitos T CD4-Positivos
11.
medRxiv ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38798521

RESUMO

Background: Recent epidemiology of Rift Valley fever (RVF) disease in Africa suggests growing frequency and expanding geographic range of small disease clusters in regions that previously had not reported the disease. We investigated factors associated with the phenomenon by characterizing recent RVF disease events in East Africa. Methods: Data on 100 disease events (2008 - 2022) from Kenya, Uganda, and Tanzania were obtained from public databases and institutions, and modeled against possible geo-ecological risk factors of occurrence including altitude, soil type, rainfall/precipitation, temperature, normalized difference vegetation index (NDVI), livestock production system, land-use change, and long-term climatic variations. Decadal climatic variations between 1980-2022 were evaluated for association with the changing disease pattern. Results: Of 100 events, 91% were small RVF clusters with a median of one human (IQR, 1-3) and 3 livestock cases (IQR, 2-7). These clusters exhibited minimal human mortality (IQR 0-1), and occurred primarily in highlands (67%), with 35% reported in areas that had never reported RVF disease. Multivariate regression analysis of geo-ecological variables showed a positive correlation between occurrence and increasing temperature and rainfall. A 1oC increase in temperature and 1-unit increase in NDVI, 1-3 months prior were associated with increased RVF incidence rate ratios (IRR) of 1.20 (95% CI 1.1,1.2) and 9.88 (95% CI 0.85, 119.52), respectively. Long-term climatic trends showed significant decadal increase in annual mean temperature (0.12 to 0.3oC/decade, P<0.05), associated with decreasing rainfall in arid and semi-arid lowlands but increasing rainfall trends in highlands (P<0.05). These hotter and wetter highlands showed increasing frequency of RVF clusters, accounting for 76% and 43% in Uganda and Kenya, respectively. Conclusion: These findings demonstrate the changing epidemiology of RVF disease. The widening geographic range of disease is associated with climatic variations, with the likely impact of wider dispersal of virus to new areas of endemicity and future epidemics. Key questions: What is already known on this topic?: Rift Valley fever is recognized for its association with heavy rainfall, flooding, and El Niño rains in the East African region. A growing body of recent studies has highlighted a shifting landscape of the disease, marked by an expanding geographic range and an increasing number of small RVF clusters.What this study adds: This study challenges previous beliefs about RVF, revealing that it predominantly occurs in small clusters rather than large outbreaks, and its association with El Niño is not as pronounced as previously thought. Over 65% of these clusters are concentrated in the highlands of Kenya and Uganda, with 35% occurring in previously unaffected regions, accompanied by an increase in temperature and total rainfall between 1980 and 2022, along with a rise in the annual number of rainy days. Notably, the observed rainfall increases are particularly significant during the short-rains season (October-December), aligning with a secondary peak in RVF incidence. In contrast, the lowlands of East Africa, where typical RVF epidemics occur, display smaller and more varied trends in annual rainfall.How this study might affect research, practice, or policy: The worldwide consequence of the expanding RVF cluster is the broader dispersion of the virus, leading to the establishment of new regions with virus endemicity. This escalation heightens the risk of more extensive extreme-weather-associated RVF epidemics in the future. Global public health institutions must persist in developing preparedness and response strategies for such scenarios. This involves the creation and approval of human RVF vaccines and therapeutics, coupled with a rapid distribution plan through regional banks.

12.
BMJ Glob Health ; 9(6)2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38857944

RESUMO

BACKGROUND: Recent epidemiology of Rift Valley fever (RVF) disease in Africa suggests growing frequency and expanding geographic range of small disease clusters in regions that previously had not reported the disease. We investigated factors associated with the phenomenon by characterising recent RVF disease events in East Africa. METHODS: Data on 100 disease events (2008-2022) from Kenya, Uganda and Tanzania were obtained from public databases and institutions, and modelled against possible geoecological risk factors of occurrence including altitude, soil type, rainfall/precipitation, temperature, normalised difference vegetation index (NDVI), livestock production system, land-use change and long-term climatic variations. Decadal climatic variations between 1980 and 2022 were evaluated for association with the changing disease pattern. RESULTS: Of 100 events, 91% were small RVF clusters with a median of one human (IQR, 1-3) and three livestock cases (IQR, 2-7). These clusters exhibited minimal human mortality (IQR, 0-1), and occurred primarily in highlands (67%), with 35% reported in areas that had never reported RVF disease. Multivariate regression analysis of geoecological variables showed a positive correlation between occurrence and increasing temperature and rainfall. A 1°C increase in temperature and a 1-unit increase in NDVI, one months prior were associated with increased RVF incidence rate ratios of 1.20 (95% CI 1.1, 1.2) and 1.93 (95% CI 1.01, 3.71), respectively. Long-term climatic trends showed a significant decadal increase in annual mean temperature (0.12-0.3°C/decade, p<0.05), associated with decreasing rainfall in arid and semi-arid lowlands but increasing rainfall trends in highlands (p<0.05). These hotter and wetter highlands showed increasing frequency of RVF clusters, accounting for 76% and 43% in Uganda and Kenya, respectively. CONCLUSION: These findings demonstrate the changing epidemiology of RVF disease. The widening geographic range of disease is associated with climatic variations, with the likely impact of wider dispersal of virus to new areas of endemicity and future epidemics.


Assuntos
Mudança Climática , Febre do Vale de Rift , Febre do Vale de Rift/epidemiologia , Humanos , Animais , África Oriental/epidemiologia , Gado , Fatores de Risco , Uganda/epidemiologia , Análise por Conglomerados , Surtos de Doenças , Quênia/epidemiologia
13.
J Pers Med ; 13(2)2023 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-36836473

RESUMO

Inherited retinal dystrophies (IRDs) are a global problem that is largely unaddressed, especially in Africa. Black indigenous Africans are rarely represented in research that develops genetic tests and genetic therapies for IRDs, yet their genomes are more diverse. The aim of this literature review is to synthesize information on the IRD genetic research conducted among indigenous black Africans to identify challenges and opportunities for progress. PubMed was searched to identify empirical publications reporting the genetic analysis of IRDs among indigenous Africans. A total of 11 articles were selected for the review. Based on the information in the articles, the main genetic testing methods in use include next-generation, whole exome, and Sanger sequencing. The main IRDs characterized by the genetic tests include retinitis pigmentosa, Leber Congenital Amaurosis, Stagardt disease, and cone dystrophy. Examples of implicated genes include MERTK, GUCY2D, ABCA4, and KCNV2 for the four IRDs, respectively. Research activities on the genetics of IRDs are generally scanty in Africa. Even in South Africa and North Africa where some research activities were noted, only a few indigenous black Africans were included in the study cohorts. There is an urgent need for genetic research on IRDs, especially in East, Central, and West Africa.

14.
BMJ Open Respir Res ; 10(1)2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37197794

RESUMO

BACKGROUND: Tuberculosis (TB) disease is the leading cause of mortality among people living with HIV (PLHIV). Interferon-gamma release assays (IGRAs) are approved for TB infection ascertainment. However, current IGRA data on the prevalence of TB infection in the context of near-universal access to antiretroviral therapy (ART) and TB preventive therapy (TPT) are lacking. We estimated the prevalence and determinants of TB infection among PLHIV within a high TB and HIV burden context. METHODS: This cross-sectional study included data from adult PLHIV age ≥18 years in whom QuantiFERON-TB Gold Plus (QFT-Plus) assay, an IGRA, was performed. TB infection was defined as a positive or indeterminate QFT-Plus test. Participants with TB and those who had previously used TPT were excluded. Regression analysis was performed to identify independent predictors of TB infection. RESULTS: Of 121 PLHIV with QFT-Plus test results, females were 74.4% (90/121), and the mean age was 38.4 (SD 10.8) years. Overall, 47.9% (58/121) were classified as TB infection (QFT-Plus test positive and indeterminate results were 39.7% (48/121) and 8.3% (10/121), respectively). Being obese/overweight (body mass index ≥25 kg/m2; p=0.013, adjusted OR (aOR) 2.90, 95% CI 1.25 to 6.74) and ART usage for >3 years (p=0.013, aOR 3.99, 95% CI 1.55 to 10.28) were independently associated with TB infection. CONCLUSION: There was a high TB infection prevalence among PLHIV. A longer period of ART and obesity were independently associated with TB infection. The relationship between obesity/overweight and TB infection may be related to ART use and immune reconstitution and requires further investigation. Given the known benefit of test-directed TPT among PLHIV never exposed to TPT, its clinical and cost implications for low and middle-income countries should be explored further.


Assuntos
Infecções por HIV , Tuberculose Latente , Tuberculose , Adulto , Feminino , Humanos , Adolescente , Prevalência , Estudos Transversais , Sobrepeso/complicações , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/complicações , Tuberculose Latente/diagnóstico , Tuberculose Latente/epidemiologia , Tuberculose Latente/complicações , Infecções por HIV/complicações , Infecções por HIV/epidemiologia
15.
South Afr J HIV Med ; 24(1): 1508, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928501

RESUMO

Background: High-risk human papillomavirus (HR-HPV) is the primary cause of cervical cancer, leading to over 311 000 global deaths, mainly in low- and middle-income countries. Kenyan women living with HIV (WLHIV) face a disproportionate burden of HR-HPV. Objectives: We determined the prevalence of HR-HPV infections and their association with cervical cytology findings among Kenyan WLHIV. Method: We conducted a cross-sectional study among WLHIV attending the HIV care and treatment clinic at the Kenyatta National Hospital (KNH), Kenya's national referral hospital. Study nurses collected a cervical sample with a cytobrush for HR-HPV genotyping using Gene Xpert® assays and HPV Genotypes 14 Real-TM Quant V67-100FRT. Bivariate analysis explored the associations. Results: We enrolled 647 WLHIV (mean age of 42.8 years), with 97.2% on antiretroviral therapy (ART) and 79% with a suppressed viral load (< 50 copies/mL plasma). The prevalence of any and vaccine-preventable HR-HPV was 34.6% and 29.4%, respectively, with HPV 52 being the most common genotype (13.4%). Among WLHIV with HR-HPV infections, 21.4% had abnormal cervical cytology. Women with multiple HR-HPV infections were more likely to have abnormal cytology compared to those with single HR-HPV infections (34.9 vs 9.3%, adjusted odds ratio [aOR] = 6.2, 95% confidence interval [CI]: 2.7-14.1, P = 0.001). Women with HR-HPV infection (single or multiple) were more likely to be on the second-line ART regimen compared to those without HR-HPV infections (53.1% vs 46.7%, aOR = 2.3, 95% CI: 1.3-4.1, P = 0.005). Conclusion: Among WLHIV at KNH, abnormal cytology was common and more frequent among women with multiple HR-HPV infections.

16.
PLoS One ; 18(10): e0286436, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37816026

RESUMO

BACKGROUND: For optimal functionality, immune cells require a robust and adaptable metabolic program that is fueled by dynamic mitochondrial activity. In this study, we investigate the metabolic alterations occurring in immune cells during HIV infection and antiretroviral therapy by analyzing the uptake of metabolic substrates and mitochondrial phenotypes. By delineating changes in immune cell metabolic programming during HIV, we may identify novel potential therapeutic targets to improve anti-viral immune responses. METHODS: After consent and voluntary participation was confirmed, whole blood was drawn from HIV uninfected women and women with chronic HIV infection on long-term combination antiretroviral therapy (HIV/cART). Peripheral blood mononuclear cells-derived immune cells were directly incubated with different fluorescently tagged metabolites and markers of mitochondrial activity: FITC-2-NBDG (2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose), FITC-BODIPY (4,4-Difluoro-5,7-Dimethyl-4-Bora-3a,4a-Diaza-s-Indacene-3-Hexadecanoic Acid), FITC-MitoTracker Green and APC-MitoTracker Deep Red. The uptake of glucose and fats and the mitochondrial mass and potential were measured using flow cytometry. All values are reported quantitatively as geometric means of fluorescence intensity. RESULTS: During chronic HIV infection, cellular uptake of glucose increases in HIV+ dendritic cells in particular. CD4+ T cells had the lowest uptake of glucose and fats compared to all other cells regardless of HIV status, while CD8+ T cells took up more fatty acids. Interestingly, despite the lower utilization of glucose and fats in CD4+ T cells, mitochondrial mass increased in HIV+ CD4+ T cells compared to HIV negative CD4+ T-cells. HIV+ CD4+ T cells also had the highest mitochondrial potential. CONCLUSIONS: Significant disparities in the utilization of substrates by leukocytes during chronic HIV/cART exist. Innate immune cells increased utilization of sugars and fats while adaptive immune cells displayed lower glucose and fat utilization despite having a higher mitochondrial activity. Our findings suggest that cART treated HIV-infected CD4+ T cells be dysfunctional or may prefer alternative fuel sources not included in these studies. This underscores the importance of understanding the metabolic effects of HIV treatment on immune function.


Assuntos
Linfócitos T CD4-Positivos , Infecções por HIV , Humanos , Feminino , Leucócitos Mononucleares/metabolismo , Fluoresceína-5-Isotiocianato/metabolismo , Linfócitos T CD8-Positivos , Glucose/metabolismo , Terapia Antirretroviral de Alta Atividade
17.
PLoS Negl Trop Dis ; 17(10): e0011682, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37844102

RESUMO

BACKGROUND: Brucellosis is a neglected zoonotic disease that affects both animals and humans, causing debilitating illness in humans and socio-economic losses in livestock-keeping households globally. The disease is endemic in many developing countries, including Kenya, but measures to prevent and control the disease are often inadequate among high-risk populations. This study aimed to investigate the human and livestock seroprevalence of brucellosis and associated risk factors of Brucella spp. in a pastoralist region of northern Kenya. METHODS: A cross-sectional survey was conducted using a two-stage cluster sampling method to select households, livestock, and humans for sampling. Blood samples were collected from 683 humans and 2157 animals, and Brucella immunoglobulin G (IgG) antibodies were detected using enzyme-linked immunosorbent assays. A structured questionnaire was used to collect data on potential risk factors associated with human and animal exposures. Risk factors associated with Brucella spp. exposures in humans and livestock were identified using Multivariate logistic regression. RESULTS: The results indicated an overall livestock Brucella spp. seroprevalence of 10.4% (95% Confidence Interval (CI): 9.2-11.7). Camels had the highest exposure rates at 19.6% (95% CI: 12.4-27.3), followed by goats at 13.2% (95% CI: 9.3-17.1), cattle at 13.1% (95% CI: 11.1-15.3) and sheep at 5.4% (95% CI: 4.0-6.9). The herd-level seroprevalence was 51.7% (95% CI: 47.9-55.7). Adult animals (Adjusted Odds Ratio (aOR) = 2.3, CI: 1.3-4.0), female animals (aOR = 1.7, CI: 1.1-2.6), and large herd sizes (aOR = 2.3, CI: 1.3-4.0) were significantly associated with anti-brucella antibody detection while sheep had significantly lower odds of Brucella spp. exposure compared to cattle (aOR = 1.3, CI: 0.8-2.1) and camels (aOR = 2.4, CI: 1.2-4.8). Human individual and household seroprevalences were 54.0% (95% CI: 50.2-58.0) and 86.4% (95% CI: 84.0-89.0), respectively. Significant risk factors associated with human seropositivity included being male (aOR = 2.1, CI:1.3-3.2), residing in Sericho ward (aOR = 1.6, CI:1.1-2.5) and having no formal education (aOR = 3.0, CI:1.5-5.9). There was a strong correlation between human seropositivity and herd exposure (aOR = 1.6, CI:1.2-2.3). CONCLUSIONS: The study provides evidence of high human and livestock exposures to Brucella spp. and identifies important risk factors associated with disease spread. These findings emphasize the need for targeted prevention and control measures to curb the spread of brucellosis and implement a One Health surveillance to ensure early detection of the disease in Isiolo County, Northern Kenya.


Assuntos
Brucella , Brucelose , Adulto , Bovinos , Humanos , Animais , Masculino , Feminino , Ovinos , Gado , Estudos Soroepidemiológicos , Quênia/epidemiologia , Estudos Transversais , Camelus , Brucelose/epidemiologia , Brucelose/veterinária , Fatores de Risco , Anticorpos Antibacterianos , Cabras
18.
Wellcome Open Res ; 8: 154, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37502177

RESUMO

Background: Maternal respiratory syncytial virus (RSV) vaccines that are likely to be implementable in low- and middle-income countries (LMICs) are in final stages of clinical trials. Data on the number of women presenting for antenatal care (ANC) per day and proportion attending within the proposed gestational window for vaccine delivery, is a prerequisite to guide development of vaccine vial size and inform vaccine uptake in this setting. Methods: We undertook administrative review and abstraction of ANC attendance records from 2019 registers of 24 selected health facilities, stratified by the level of care, from Kilifi, Siaya and Nairobi counties in Kenya. Additional data were obtained from Mother and Child Health (MCH) booklets of women in each of the Health and Demographic Surveillance System (HDSS) areas of Kilifi, Nairobi and Siaya. Data analysis involved descriptive summaries of the number (mean, median) and proportion of women attending ANC within the gestational window period of 28-32 weeks and 24-36 weeks. Results: A total of 62,153 ANC records were abstracted, 33,872 from Kilifi, 19,438 from Siaya and 8,943 from Nairobi Counties. The median (Interquartile range, IQR) number of women attending ANC per day at a gestational age window of 28-32 and 24-36 weeks, respectively, were: 4 (2-6) and 7 (4-12) in dispensaries, 5 (2-9) and 10 (4-19) in health centres and 6 (4-11) and 16 (10-26) in county referral hospitals. In the HDSS areas of Kilifi, Siaya and Nairobi, pregnant women attending at least one ANC visit, within a window of 28-32 weeks, were: 77% (360/470), 75% (590/791) and 67% (547/821), respectively. Conclusions: About 70% of pregnant women across three distinct geographical regions in Kenya, attend ANC within 28-32 weeks of gestation. A multidose vial size with about five doses per vial, approximates daily ANC attendance and would not incur possible wastage in similar settings.

19.
AAS Open Res ; 5: 12, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38323170

RESUMO

Introduction: The human-restricted sexually transmitted Neisseria gonorrhoeae (NG) has been shown to modulate the immune response against it and consequently the cytokines produced. The levels of cytokines in NG infection in the African population have not been well described. We aimed to quantify the systemic and mucosal cytokines in NG infection. Methods: This was a comparative cross-sectional study. Levels of nine cytokines (IL-1ß, IL-2, IL-4, 1L-6, 1L-10, 1L-12p70, IL-17A, TNF-α and INF-γ) were measured from plasma and genital samples (urethral swabs in men and cervicovaginal lavage in women) from 61 Neisseria gonorrhoeae infected individuals seeking treatment for sexually transmitted infections (STIs) at Casino Health Centre in Nairobi, Kenya. A comparative group of 61 NG-uninfected individuals, seeking treatment at the same facility but with laboratory-confirmed negative Neisseria gonorrhoeae, Chlamydia trachomatis (CT), Mycoplasma genitalium (MG) and Trichomonas vaginalis(TV) was also included. The Mann-Whitney U test was used to compare the cytokine levels between NG-infected and uninfected individuals. Data was analyzed using STATA ver. 15.1. Results: Overall, systemic IL-6, TNF-α and IL-10 were elevated while genital IL-10 and TNF-α were lower in NG positive participants. On subgroup analysis by sex, the levels of genital IL-1ß and IL-6 and systemic IL-6 were elevated in NG-infected men. None of the genital cytokines were elevated in NG-infected women, while all systemic cytokines, except INF-γ, were elevated in NG-infected women. Conclusions: Neisseria gonorrhoeae induced the production of different cytokines in men and women, with men having a pro-inflammatory genital response. These differences should be taken into consideration during development of various interventions e.g. vaccine development.

20.
F1000Res ; 11: 962, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37224326

RESUMO

BACKGROUND: Non-tuberculous mycobacteria (NTM) treatment constitutes a macrolide-based antibiotic regimen in combination with aminoglycosides for Rapid-Growing Mycobacteria (RGM), and rifampicin for Slow-Growing Mycobacteria (SGM). Mutations in the anti-NTM drug target regions promote NTM evolution to mutant strains that are insusceptible to NTM drugs leading to treatment failure. We, therefore, described the mutation patterns of anti-NTM drug target genes including rrl, rrs, and rpoB in NTM isolates from Kenya.  Methods: We carried out a cross-sectional study that included 122 NTM obtained from the sputum of symptomatic tuberculosis-negative patients in Kenya. All 122 NTM underwent targeted sequencing of the rrl gene. The 54 RGM were also sequenced for rrs, and the 68 SGM were sequenced for rpoB genes using ABI 3730XL analyzer. The obtained sequences were aligned to their wild-type reference sequences for each gene using Geneious then mutations were identified. Pearson chi-square at a 95% confidence interval tested the association of NTM to mutation patterns for each gene. RESULTS: NTM harboring mutations associated with resistance to at least one of the antibiotics used in the macrolide-based therapy were 23% (28/122). Of these NTM, 10.4% (12/122) had mutations in the rrl gene with 58.3% (7/12) comprising RGM and 41.7% (5/12) being SGM. Mutation at position 2058 (A2058G, A2058C, A2058T) of the rrl gene was seen for 83.3% (10/12) of NTM, while 16.6% (2/12) harbored a A2059G mutation. Of the 54 RGM included for rrs characterization, 11.1% (6/54) exhibited mutations  at position 1408(A1408G), while 14.7% (10/68) of the SGM had mutations in the rpoB gene at positions S531W, S531L, S531Y, F506L, E509H with M.gastri having multiple mutations at positions D516V, H526D and, S531F. CONCLUSION: We demonstrated a significant level of mutations associated with drug resistance for macrolides, aminoglycosides, and rifampicin in NTM isolated from symptomatic TB negative patients in Kenya.


Assuntos
Aminoglicosídeos , Rifampina , Humanos , Aminoglicosídeos/farmacologia , Aminoglicosídeos/uso terapêutico , Rifampina/farmacologia , Rifampina/uso terapêutico , Micobactérias não Tuberculosas/genética , Quênia , Macrolídeos/farmacologia , Macrolídeos/uso terapêutico , Estudos Transversais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Mutação
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