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1.
J Bacteriol ; 205(3): e0045822, 2023 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-36852982

RESUMEN

Neisseria meningitidis exhibits a general O-linked protein glycosylation system in which pili and other extracytoplasmic proteins are glycosylated. To investigate glycan antigenicity in humans and the significance of high glycan diversity on immune escape mechanisms, we exploited serogroup A meningococcal strains and serum samples obtained from laboratory-confirmed Ethiopian patients with meningococcal disease. The 37 meningococcal isolates were sequenced, and their protein glycosylation (pgl) genotypes and protein glycosylation phenotypes were investigated in detail. An insertion sequence (IS1655) element in pglH reduced glycan variability in the majority of isolates, while phase variation strengthened glycan variability and microheterogeneity. Homologous recombination events within the pgl genes were identified in eight of the 37 isolates, and the phenotypic consequences ranged from none detected to altered glycoforms in two of the isolates in which the whole pgl locus was exchanged. Immunoblotting of sera against a complete panel of glycan-expressing mutant strains demonstrated that most of these patient sera had IgG antibodies against various neisserial protein glycan antigens. Furthermore, using a bactericidal assay comparing a wild-type meningococcal A strain and a glycosylation-null variant strain, we showed that these protein glycan antigens interfere with bactericidal killing by antibodies in patient sera. Altogether, we were largely able to link pgl genotype with glycosylation phenotype. Our study reveals that protein glycans seem to contribute to the ability of N. meningitidis to resist the bactericidal activity of human serum, possibly by masking protein epitopes important for bactericidal killing and thus protection against meningococcal disease. IMPORTANCE Bacterial meningitis is a serious global health problem, and one of the major causative organisms is Neisseria meningitidis. Extensive variability in protein glycan structure and antigenicity is due to phase variation of protein glycosylation genes and polymorphic gene content and function. The exact role(s) of glycosylation in Neisseria remains to be determined, but increasing evidence, supported by this study, suggests that glycan variability can be a strategy to escape the human immune system. The complexity of the O-linked protein glycosylation system requires further studies to fully comprehend how these bacteria utilize variation in pgl genes to produce such high glycoform diversity and to evade the human immune response.


Asunto(s)
Infecciones Meningocócicas , Vacunas Meningococicas , Neisseria meningitidis , Humanos , Glicosilación , Neisseria meningitidis/genética , Neisseria meningitidis/metabolismo , Proteínas Bacterianas/metabolismo , Serogrupo , Polisacáridos/metabolismo , Vacunas Meningococicas/metabolismo
2.
Bull World Health Organ ; 101(11): 717-722, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37961059

RESUMEN

The importance of strong coordination for research on public health and social measures was highlighted at the Seventy-fourth World Health Assembly in 2021. This article describes efforts undertaken by the World Health Organization (WHO) to develop a global research agenda on the use of public health and social measures during health emergencies. This work includes a multistep process that started with a global technical consultation convened by WHO in September 2021. The consultation included experts from around the world and from a wide range of disciplines, such as public health, education, tourism, finance and social sciences, and aimed to identify research and implementation approaches based on lessons learnt during the coronavirus disease 2019 pandemic. To prepare for future epidemics and pandemics, it is essential to adopt a more robust, comparable and systematic research approach to public health and social measures. Such comprehensive approach will better inform agile, balanced and context-specific implementation decisions during future emergencies. This article describes the methods used to develop global research priorities for public health and social measures and the next steps needed.


La soixante-quatorzième Assemblée mondiale de la Santé en 2021 a souligné l'importance d'une coordination solide pour la recherche sur la santé publique et les mesures sociales. Le présent article décrit les efforts entrepris par l'Organisation mondiale de la santé (OMS) pour élaborer un programme de recherche mondial sur l'utilisation des mesures de santé publique et des mesures sociales lors de situations d'urgence sanitaire. Ce travail comprend un processus en plusieurs étapes qui a commencé par une consultation technique mondiale organisée par l'OMS en septembre 2021. La consultation a réuni des experts du monde entier issus d'un large éventail de disciplines telles que la santé publique, l'éducation, le tourisme, la finance et les sciences sociales. Elle visait à identifier des approches de recherche et de mise en œuvre fondées sur les enseignements tirés de la pandémie de maladie à coronavirus de 2019. Pour se préparer aux futures épidémies et pandémies, il est essentiel d'adopter une approche de recherche plus solide, comparable et systématique en matière de santé publique et de mesures sociales. Cette approche globale permettra de mieux éclairer les décisions de mise en œuvre agiles, équilibrées et adaptées au contexte lors des futures situations d'urgence. Le présent article décrit les méthodes appliquées pour définir les priorités mondiales de recherche en matière de santé publique et de mesures sociales, ainsi que les prochaines étapes à franchir.


En la 74.ª Asamblea Mundial de la Salud, celebrada en 2021, se destacó la importancia de una sólida coordinación en la investigación sobre salud pública y medidas sociales. Este artículo describe los esfuerzos que ha emprendido la Organización Mundial de la Salud (OMS) para desarrollar un programa mundial de investigación sobre el uso de medidas sociales y de salud pública durante las emergencias sanitarias. Este trabajo incluye un proceso de varios pasos que comenzó con una consulta técnica mundial que convocó la OMS en septiembre de 2021. La consulta incluyó a expertos de todo el mundo y de una gran variedad de disciplinas, como la salud pública, la educación, el turismo, las finanzas y las ciencias sociales, y tuvo como objetivo identificar enfoques de investigación y aplicación basados en las lecciones aprendidas durante la pandemia de la enfermedad por coronavirus de 2019. Para prepararse ante futuras epidemias y pandemias, es esencial adoptar un enfoque de investigación más sólido, comparable y sistemático en materia de salud pública y medidas sociales. Este enfoque integral informará mejor las decisiones de aplicación ágiles, equilibradas y adaptadas al contexto durante futuras emergencias. En este artículo se describen los métodos utilizados para elaborar las prioridades mundiales de investigación sobre salud pública y medidas sociales, así como los próximos pasos necesarios.


Asunto(s)
COVID-19 , Salud Pública , Humanos , Salud Pública/métodos , Urgencias Médicas , COVID-19/epidemiología , Organización Mundial de la Salud , Salud Global , Pandemias
3.
Ann Hepatol ; 28(1): 100770, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36220615

RESUMEN

INTRODUCTION AND OBJECTIVES: Chronic hepatitis D infection contributes substantially to the progression of chronic liver disease, especially in most low and middle-income countries, where hepatitis B virus-related chronic liver disease is endemic. Therefore, this study aimed to determine the magnitude and genotype of hepatitis delta virus (HDV) among patients with chronic hepatitis B (CHB)-related liver diseases in Ethiopia. PATIENTS AND METHODS: In this cross-sectional study, 323 known HBsAg positive individuals comprising 220 patients with CHB-related liver diseases [121 advanced liver diseases (hepatocellular carcinoma /HCC/ and non-HCC) and 99 chronic hepatitis (CH)], and 103 symptomless blood donors (BD) were enrolled. An ELISA kit was employed to determine HDV infection, and quantitative real-time PCR was used to detect HDV RNA. In addition, a non-coding genomic RNA region was sequenced for genotyping and phylogenetic analysis. RESULTS: Irrespective of the stage of liver disease, the overall magnitude of HDV was 7.7% (25/323). The frequency of anti-HDV increases with the severity of liver disease, 1.9%, 4%, 10%, and 21.3% among BD, CH, non-HCC, and HCC patients, respectively. HDV RNA has been detected in 1.54 %(5/323) cases with a mean viral load of 4,010,360 IU/ml. All isolates were found to be HDV genotype 1. CONCLUSIONS: The magnitude of HDV infection increased with the severity of liver disease, indicating HDV infection is more common among patients with CHB-related liver diseases in Ethiopia.


Asunto(s)
Carcinoma Hepatocelular , Coinfección , Hepatitis B Crónica , Hepatitis B , Neoplasias Hepáticas , Humanos , Virus de la Hepatitis Delta/genética , Hepatitis B Crónica/diagnóstico , Hepatitis B Crónica/epidemiología , Etiopía/epidemiología , Filogenia , Estudios Transversales , Virus de la Hepatitis B , Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/genética , Genotipo , ARN Viral/genética , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/genética , Hepatitis B/epidemiología , Antígenos de Superficie de la Hepatitis B , Coinfección/epidemiología
4.
Adv Exp Med Biol ; 1370: 91-102, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36318402

RESUMEN

Background Extended-spectrum ß-lactamases (ESBLs)-producing Klebsiella pneumoniae is reported worldwide increasingly. However, studies on ESBLs are still scarce in Ethiopia. Therefore, the current study aimed to determine the magnitude and resistance patterns of ESBL-producing K. pneumoniae as well as the frequency of ESBL-encoding genes.Methods A cross-sectional study was conducted from September 2018 to February 2019 at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia among a total of 132 non-duplicate K. pneumoniae isolates. Phenotypic detection of ESBL production was done using Combined Disc Test. ESBL-encoding genes of blaCTX-M, blaTEM, and blaSHV were detected through multiplex PCR.Results The magnitude of ESBL production was 102/132 (77.3%). ESBL positive isolates were 100% resistant to ceftriaxone, cefotaxime, and cefuroxime. Co-resistance of ESBL-positive isolates to other non ß-lactam antimicrobials was high to trimethoprim-sulfamethoxazole (96.1%) followed by tetracycline (75.5%) and gentamicin (73.5%). However, these isolates showed high susceptibility to amikacin (96.1%) and meropenem (89.2%). From the total ESBL-positive isolates, 82.6%, 73.5%, and 75% carried blaCTX-M, blaTEM, and blaSHV genes, respectively. The majority 78/102 (76.5%) of ESBL-positive isolates harbored all three types of ESBL genes simultaneously.Conclusions The magnitude of ESBL-producing K. pneumoniae isolates was very alarming in the study area. The co-occurrence of blaCTX-M, blaTEM, and blaSHV genes is high, demanding large-scale studies to evaluate the presence of antimicrobial resistance super-clones. ESBL-producing isolates showed high resistance to most of the antimicrobials, needing phenotypic detection of ESBL regularly for better management of patients.


Asunto(s)
Infecciones por Klebsiella , Klebsiella pneumoniae , Humanos , Klebsiella pneumoniae/genética , Centros de Atención Terciaria , beta-Lactamasas/genética , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/genética , Etiopía/epidemiología , Estudios Transversales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pruebas de Sensibilidad Microbiana
5.
Dev World Bioeth ; 23(1): 50-58, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35247023

RESUMEN

Few studies in sub-Saharan Africa evaluate Institutional Review Boards (IRBs) capacity. The study aims to explore the composition of IRBs, training, and challenges experienced in the ethics review processes by members of research institutions and universities in Addis Ababa, Ethiopia. Our findings indicate that most IRBs members were trained on research ethics and good clinical practice. However, majority perceived the trainings as basic. IRB members faced several challenges including: investigators wanting rapid review; time pressure; investigators not following checklists; limited expertise in reviewing clinical trials, studies on genetics, and traditional medicine; lack of IRB offices for administrative work; competing tasks; limited staffing and the lack of a standardized review system. There is need for advanced training on research ethics to meet the evolving research needs. In addition, investments in IRBs are needed in terms of funding, and physical and human resources in Addis Ababa and Ethiopia in general.


Asunto(s)
Comités de Ética en Investigación , Ética en Investigación , Humanos , Etiopía , Investigación Cualitativa , Encuestas y Cuestionarios
6.
Antimicrob Agents Chemother ; 66(8): e0053422, 2022 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-35876577

RESUMEN

Sepsis due to carbapenemase-producing and colistin-resistant Enterobacteriaceae is a global health threat. A multicenter study was conducted between October 2019 and September 2020 at four hospitals located in different parts of Ethiopia. From a total of 1,416 sepsis patients, blood culture was performed. Enterobacteriaceae were confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Carbapenem and colistin susceptibility testing was performed using disk diffusion, broth microdilution, and Etest strip. Enterobacteriaceae isolates (n = 301) were subjected to whole-genome sequencing using Illumina HiSeq 2500. SPAdes version 3.9 was used for genome assembly. Carbapenem and colistin resistance genes, chromosomal point mutations, sequence types, and plasmid replicons were identified using tools at the Center for Genomic Epidemiology. Phylogeny structure was constructed using CSI Phylogeny 1.4. Visualization of trees and metadata was done using iTOL v6.5.2. Among 301 Enterobacteriaceae, 22 Klebsiella pneumoniae, 2 Klebsiella variicola, and 3 Enterobacter cloacae isolates showed reduced susceptibility to meropenem (7% of tested isolates). blaNDM-1, blaNDM-5, and blaOXA-181 were variants of carbapenemase genes detected. Co-occurrence of blaNDM-5 and blaOXA-181 was detected with 4 K. pneumoniae strains. K. pneumoniae and K. variicola showed chromosomal alterations of ompK36 and ompk37. Plasmid incompatibility (Inc) groups Col, IncC, IncHI, IncF, IncFII, IncR, and IncX3 were identified among carbapenem-resistant K. pneumoniae and E. cloacae isolates. Two mcr-9 genes were detected from Salmonella species and K. pneumoniae. The dissemination of carbapenemase-producing Enterobacteriaceae in all hospitals is worrying. Multiple carbapenemase genes were detected, with blaNDM variants the most frequent. The occurrence of colistin-resistant Enterobacteriaceae among sepsis patients is critical. Implementation of effective antimicrobial stewardship is urgently needed.


Asunto(s)
Colistina , Sepsis , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Proteínas Bacterianas/genética , Carbapenémicos , Colistina/farmacología , Enterobacteriaceae/genética , Etiopía/epidemiología , Genómica , Humanos , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana , beta-Lactamasas/genética
7.
BMC Infect Dis ; 22(1): 766, 2022 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-36184614

RESUMEN

BACKGROUND: We aimed to assess the prevalence of Salmonella Typhi through DNA and IgM-antibody detection methods as a prelude to extended surveillance activities at sites in Ghana, Madagascar, and Ethiopia. METHODS: We performed species-specific real-time polymerase reaction (RT-PCR) to identify bacterial nucleic acid, and enzyme-linked immunosorbent assay (ELISA) for detecting HlyE/STY1498-, CdtB/STY1886-, pilL/STY4539- and Vi-antigens in blood and biopsy specimens of febrile and non-febrile subjects. We generated antigen-specific ELISA proxy cut-offs by change-point analyses, and utilized cumulative sum as detection method coupled with 1000 repetitive bootstrap analyses. We computed prevalence rates in addition to odds ratios to assess correlations between ELISA outcomes and participant characteristics. RESULTS: Definitive positive RT-PCR results were obtained from samples of febrile subjects originating from Adama Zuria/Ethiopia (1.9%, 2/104), Wolayita Sodo/Ethiopia (1.0%, 1/100), Diego/Madagascar (1.0%, 1/100), and Kintampo/Ghana (1.0%, 1/100), and from samples of non-febrile subjects from Wolayita Sodo/Ethiopia (1%, 2/201). While IgM antibodies against all antigens were identified across all sites, prevalence rates were highest at all Ethiopian sites, albeit in non-febrile populations. Significant correlations in febrile subjects aged < 15 years versus ≥ 15 years were detected for Vi (Odds Ratio (OR): 8.00, p = 0.034) in Adama Zuria/Ethiopia, STY1498 (OR: 3.21, p = 0.008), STY1886 (OR: 2.31, p = 0.054) and STY4539 (OR: 2.82, p = 0.022) in Diego/Madagascar, and STY1498 (OR: 2.45, p = 0.034) in Kintampo/Ghana. We found statistical significance in non-febrile male versus female subjects for STY1498 (OR: 1.96, p = 0.020) in Adama Zuria/Ethiopia, Vi (OR: 2.84, p = 0.048) in Diego/Madagascar, and STY4539 (OR: 0.46, p = 0.009) in Kintampo/Ghana. CONCLUSIONS: Findings indicate non-discriminatory stages of acute infections, though with site-specific differences. Immune responses among non-febrile, presumably healthy participants may mask recall and/or reporting bias leading to misclassification, or asymptomatic, subclinical infection signs induced by suppression of inflammatory responses. As most Ethiopian participants were ≥ 15 years of age and not at high-risk, the true S. Typhi burden was likely missed. Change-point analyses for generating ELISA proxy cut-offs appeared robust, though misclassification is possible. Our findings provided important information that may be useful to assess sites prior to implementing surveillance for febrile illness including Salmonella disease.


Asunto(s)
Ácidos Nucleicos , Fiebre Tifoidea , Adolescente , Distrofias Hereditarias de la Córnea , Ensayo de Inmunoadsorción Enzimática , Etiopía/epidemiología , Femenino , Fiebre/microbiología , Ghana/epidemiología , Humanos , Inmunoglobulina M , Madagascar , Masculino , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Salmonella , Salmonella typhi/genética , Fiebre Tifoidea/diagnóstico , Fiebre Tifoidea/epidemiología , Fiebre Tifoidea/microbiología
8.
J Water Health ; 20(6): 903-914, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35768966

RESUMEN

Carbapenemase-producing Aeromonas species are an emerging health threat. This study aimed to determine carbapenemase-mediated resistance among Aeromonas isolates from the Akaki river, Ethiopia during the dry and wet seasons in 2019-2020. Antimicrobial susceptibility to carbapenems and cephalosporins was determined and carbapenemase production was confirmed. Of 163 isolates, the majority were human pathogens Aeromonas caviae (62), Aeromonas hydrophila (33) and Aeromonas veronii (49). These isolates were resistant to carbapenem and cephalosporin antibiotics, with the highest resistance to cefotaxime 86 (59.7%), ertapenem 71 (49.3%) and imipenem 65 (45.1%). Resistance to carbapenem antibiotics varied between species, where most A. veronii 37 (75.5%) and A. hydrophila 28 (84.8%) were resistant to imipenem and all A. caviae were sensitive. A. veronii, A. caviae and A. hydrophila resistance to meropenem was 31 (63.3%), 3 (4.8%) and 19 (57.6%), respectively. Of isolates resistant to carbapenem, 82.1% A. hydrophila and 94.4% A. veronii were carbapenemase producers. Cephalosporin resistance also varied among the different species. The highest resistance to carbapenem antibiotics was in isolates collected during the wet season (p<0.05); however, it was not consistent across all classes of antibiotics tested. The rivers in megacities could be reservoirs of carbapenemase-producing Aeromonas spp.


Asunto(s)
Aeromonas , Antibacterianos/farmacología , Proteínas Bacterianas , Carbapenémicos/farmacología , Etiopía , Humanos , Imipenem , Pruebas de Sensibilidad Microbiana , Ríos , beta-Lactamasas
9.
Environ Monit Assess ; 194(5): 349, 2022 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-35394223

RESUMEN

Pollution of the aquatic environment is a global problem, with industrial waste, farming effluents, sewage, and wastewater as the main contributors. Many pollutants are biologically active at low concentrations, resulting in sublethal effects, which makes it a highly complex situation and difficult to assess. In many places, such as the Akaki river in Ethiopia, the pollution situation has resulted in streams with minimal presence of invertebrates or vertebrates. As it is difficult to perform a complete chemical analysis of the waters, the present study focused on using gene expression analysis as a biological end point to determine the effects of Akaki river contaminants. The present study was conducted using the small planktonic crustacean Daphnia magna with toxicogenomic molecular markers. Daphnia magna neonates were exposed to Akaki water samples collected from two different sites on the river and analyzed for mortality and expression of genes involved in different biological pathways. Despite the poor quality of Akaki river water, 48 h acute toxicity tests showed no mortality. Interestingly, analysis of sublethal toxicogenomic responses showed that exposure to Akaki water altered the expression of 25 out of 37 genes involved in metal regulation, immune response, oxidative stress, respiration, reproduction, and development. The toxicogenomic data gives insight into the mechanisms involved in causing potential adverse effects to aquatic biota harboring the Akaki river system.


Asunto(s)
Daphnia , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente/métodos , Ríos/química , Agua/análisis , Contaminantes Químicos del Agua/análisis
10.
BMC Immunol ; 22(1): 9, 2021 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-33509080

RESUMEN

BACKGROUND: Understanding immune mechanisms, particularly the role of innate immune markers during latent TB infection remains elusive. The main objective of this study was to evaluate mRNA gene expression patterns of toll-like receptors (TLRs) as correlates of immunity during latent TB infection and further infer their roles as potential diagnostic biomarkers. METHODS: Messenger RNA (mRNA) levels were analysed in a total of 64 samples collected from apparently healthy children and adolescents latently infected with tuberculosis (n = 32) or non-infected (n = 32). Relative expression in peripheral blood of selected genes encoding TLRs (TLR-1, TLR-2, TLR-4, TLR-6 and TLR-9) was determined with a quantitative real-time polymerase chain reaction (qRT-PCR) using specific primers and florescent labelled probes and a comparative threshold cycle method to define fold change. Data were analysed using Graph-Pad Prism 7.01 for Windows and a p-value less than 0.05 was considered statistically significant. RESULTS: An increased mean fold change in the relative expression of TLR-2 and TLR-6 mRNA was observed in LTBI groups relative to non-LTBI groups (p < 0.05), whereas a slight fold decrease was observed for TLR-1 gene. CONCLUSIONS: An increased mRNA expression of TLR-2 and TLR-6 was observed in latently infected individuals relative to those non-infected, possibly indicating the roles these biomarkers play in sustenance of the steady state interaction between the dormant TB bacilli and host immunity.


Asunto(s)
Tuberculosis Latente/inmunología , ARN Mensajero/metabolismo , Receptores Toll-Like/genética , Adolescente , Biomarcadores/metabolismo , Niño , Diagnóstico Precoz , Femenino , Humanos , Inmunidad Innata , Tuberculosis Latente/diagnóstico , Masculino , Mycobacterium tuberculosis , ARN Mensajero/genética
11.
Cytokine ; 145: 155289, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-32951968

RESUMEN

The clinical course and outcome of cutaneous leishmaniasis (CL) vary due to the infecting Leishmania species and host genetic makeup that result in different immune responses against the parasites. The host immune response to Leishmania aethiopica (L.aethiopica), the causative agent of CL in Ethiopia, is poorly understood. To contribute to the understanding of the protective immune response in CL due to L.aethiopica, we characterized the cytokine response to L. aethiopica in patients with the localized form of CL (LCL) and age-and sex-matched apparently healthy controls. By applying a whole blood based in vitro culture we found enhanced release of TNF, IL-6, MCP-1 or CCL2, IP-10 or CXCL10, MIP-1ß or CCL4 and IL-8 or CXCL8- but not of IL-10CL patients in response to L. aethiopica compared to the controls. No difference was observed between LCL cases and controls in the secretion of these cytokines and chemokines in whole blood cultures treated with the TLR-ligands LPS, MALP-2 or polyI: C. The observed increased secretion of the pro-inflammatory cytokines/chemokines reflects an enhanced response against the parasites by LCL patients as compared to healthy controls rather than a generally enhanced ability of blood leukocytes from LCL patients to respond to microbial constituents. Our findings suggest that the enhanced production of pro-inflammatory cytokines/chemokines is associated with localized cutaneous leishmaniasis caused by L.aethiopica.


Asunto(s)
Quimiocinas/inmunología , Citocinas/inmunología , Inflamación/inmunología , Leishmania/inmunología , Leishmaniasis Cutánea/inmunología , Etiopía , Humanos , Inmunidad/inmunología , Inflamación/parasitología , Leishmaniasis Cutánea/parasitología , Leucocitos/inmunología , Leucocitos/parasitología
12.
Cytokine ; 145: 155246, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-32828639

RESUMEN

The likelihood of being bitten by sand flies infected with Leishmania (L.) donovani is considered to be high for all inhabitants living in the endemic areas, but only a small ratio of the population develop symptomatic visceral leishmanisis (VL). Since adequate activation of antimicrobial immune response plays a key role in control of pathogens early after infection we hypothesized that a dysfunction of essential cells of the immune system is associated with disease development after infection with L. donovani. In order to obtain insights into the capacity of leukocytes to respond to L. donovani, a whole blood based assay was applied to evaluate the production of cytokines and chemokines in clinical VL versus Ethiopian endemic healthy control (EHC). In response to L. donovani, VL blood cultures showed significantly lower secretion of IL-12p70, IL-6, IL-17, IL-8 and IP-10 compared to EHC. On the contrary, there was a significantly higher secretion of IL-10 observed in VL compared to EHC. In response to LPS also a lower IL-1ß, IL-12p70 and IL-6 secretion was observed in VL as compared to EHC. The data clearly indicate a diminished ability of blood leukocytes in VL to respond to L. donovani and to the TLR ligand LPS. This compromised response in VL may contribute to the severe disease development and enhanced susceptibility to secondary infections in VL.


Asunto(s)
Quimiocinas/inmunología , Citocinas/inmunología , Inflamación/inmunología , Leishmania donovani/inmunología , Leishmaniasis Visceral/inmunología , Adulto , Cultivo de Sangre/métodos , Estudios Transversales , Humanos , Sistema Inmunológico/inmunología , Inflamación/parasitología , Leishmaniasis Visceral/parasitología , Leucocitos/inmunología , Leucocitos/parasitología , Masculino
13.
Lipids Health Dis ; 20(1): 129, 2021 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-34602073

RESUMEN

Mycobacterium tuberculosis (Mtb), the main etiology of tuberculosis (TB), is predominantly an intracellular pathogen that has caused infection, disease and death in humans for centuries. Lipid droplets (LDs) are dynamic intracellular organelles that are found across the evolutionary tree of life. This review is an evaluation of the current state of knowledge regarding Mtb-LD formation and associated Mtb transcriptome directly from sputa.Based on the LD content, Mtb in sputum may be classified into three groups: LD positive, LD negative and LD borderline. However, the clinical and evolutionary importance of each state is not well elaborated. Mounting evidence supports the view that the presence of LD positive Mtb bacilli in sputum is a biomarker of slow growth, low energy state, towards lipid degradation, and drug tolerance. In Mtb, LD may serve as a source of chemical energy, scavenger of toxic compounds, prevent destruction of Mtb through autophagy, delay trafficking of lysosomes towards the phagosome, and contribute to Mtb persistence. It is suggest that LD is a key player in the induction of a spectrum of phenotypic and metabolic states of Mtb in the macrophage, granuloma and extracellular sputum microenvironment. Tuberculosis patients with high proportion of LD positive Mtb in pretreatment sputum was associated with higher rate of poor treatment outcome, indicating that LD may have a clinical application in predicting treatment outcome.The propensity for LD formation among Mtb lineages is largely unknown. The role of LD on Mtb transmission and disease phenotype (pulmonary TB vs extra-pulmonary TB) is not well understood. Thus, further studies are needed to understand the relationships between LD positivity and Mtb lineage, Mtb transmission and clinical types.


Asunto(s)
Gotas Lipídicas , Mycobacterium tuberculosis/metabolismo , Transcriptoma , Tuberculosis/metabolismo , Interacciones Huésped-Patógeno , Humanos , Macrófagos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/fisiología , Esputo/microbiología , Resultado del Tratamiento , Tuberculosis/tratamiento farmacológico , Tuberculosis/transmisión
14.
BMC Infect Dis ; 20(1): 528, 2020 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-32698884

RESUMEN

BACKGROUND: Hepatitis B virus (HBV) infection is one of the major public health problems worldwide. Limited information exists about the epidemiology of HBV infection in Ethiopia. This study aimed to assess sero-prevalence of HBV markers and associated factors in children living in Hawassa City, southern Ethiopia. METHODS: A community-based cross-sectional study was conducted among 471 children in Hawassa City, southern Ethiopia from May to September, 2018. A total of 471 children were included in the study using a multistage sampling technique. Data on demographic and risk factors were gathered using structured questionnaires. Blood samples were collected and sera were screened for hepatitis B surface antigen (HBsAg), antibody to core antigen (anti-HBc), and antibody against surface antigen (anti-HBs) using enzyme-linked immunosorbent assay. RESULTS: The sero-prevalence of HBsAg, anti-HBc, and anti-HBs markers among children were 4.4, 19.5 and 20.0%, respectively. Children at higher risk of having HBsAg marker were those who had a history of injectable medications (AOR 5.02, 95% CI: 1.14, 22.07), a family history of liver disease (AOR 6.37, 95% CI: 1.32, 30.74), a HBsAg seropositive mothers, (AOR 11.19, (95% CI: 3.15, 39.67), and had no vaccination history for HBV (AOR, 6.37, 95% CI: 1.32, 30.74). Children from families with low monthly income, who were home delivered, unvaccinated for HBV or with HBsAg seropositive mother had increased risk of having anti-HBc. CONCLUSIONS: The study findings showed an intermediate endemicity of HBV infection in the study setting. The observed rate of residual HBV infection with low rate of immunized children after HBV vaccination was high. Hence, introducing birth dose vaccine, safe injection practice and improving immunization coverage during pregnancy as part of the antenatal care package should be considered. Furthermore, governmental and non-governmental organizations should give attention on timely measures for the prevention of ongoing vertical transmission from mother to child as well as early horizontal transmission of HBV in Hawassa City, Ethiopia.


Asunto(s)
Virus de la Hepatitis B/inmunología , Hepatitis B/sangre , Hepatitis B/epidemiología , Complicaciones Infecciosas del Embarazo/epidemiología , Biomarcadores/sangre , Niño , Preescolar , Estudios Transversales , Etiopía/epidemiología , Femenino , Hepatitis B/prevención & control , Hepatitis B/transmisión , Anticuerpos contra la Hepatitis B/sangre , Antígenos de Superficie de la Hepatitis B/sangre , Vacunas contra Hepatitis B/administración & dosificación , Humanos , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Masculino , Embarazo , Complicaciones Infecciosas del Embarazo/sangre , Complicaciones Infecciosas del Embarazo/prevención & control , Complicaciones Infecciosas del Embarazo/virología , Atención Prenatal/métodos , Prevalencia , Factores de Riesgo , Encuestas y Cuestionarios , Vacunación/métodos
15.
BMC Public Health ; 20(1): 631, 2020 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-32375716

RESUMEN

BACKGROUND: Ethiopia is among the 14 high TB, TB/HIV and MDR-TB burden countries globally. Prior studies indicate students attending universities in Ethiopia may be at increased risk for active tuberculosis (TB) relative to the general population, mainly due to the dramatic increase in expansion of the enrollment scale of universities.This study sought to gain insight about non-health science university students' TB knowledge and attitudes to help develop a strategy for TB education in this population. METHODS: A cross-sectional study was conducted from October to December 2018 among non-health science university students at three eastern Ethiopia public universities. Participants were considered having 'good' knowledge on TB when they correctly mentioned the communicability, means of transmission and prevention methods of TB and recognized modern medicine as the best treatment for TB. Participants were considered as having 'acceptable' attitude towards TB when they indicated they would seek immediate care for TB diagnosis, not hide a TB diagnosis and feel compassion to help people with TB. RESULTS: A total of 1720 non-health science university students participated. Only 614 (35.7%) of the students had 'good' knowledge on TB. This differed significantly between universities, with students from Haramaya and Dire Dawa universities more likely to have 'good' TB knowledge than their counterparts from Jigjiga University [COR (Crude Odds Ratio):1.62 and 1.94, respectively; and 95% Confidence Interval (CI): (1.236, 2.079) and (1.511, 2.483), respectively]. Only a third of students, 555 (32.3%) mentioned 'bacteria' as causing TB, and 836 students (48.6%) had ever heard of Multi Drug Resistant-TB (MDR-TB). An 'acceptable' attitude towards people with TB was observed in 666 students (38.7%). Even though 739 students (43%) felt compassion and desire to help TB patients, 213 (12%) and 382 (22%) mentioned they fear and tend to stay away from TB patients, respectively. CONCLUSIONS: The present study revealed that non-health science university students lack important TB knowledge and have misconceptions about TB in eastern Ethiopia. University administrators and other stakeholders striving against TB should provide due attention to university settings and consider development of student education programs to improve awareness and knowledge of TB disease.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Estudiantes/psicología , Tuberculosis/psicología , Adolescente , Adulto , Estudios Transversales , Etiopía/epidemiología , Femenino , Humanos , Masculino , Oportunidad Relativa , Encuestas y Cuestionarios , Tuberculosis/epidemiología , Universidades , Adulto Joven
16.
J Infect Dis ; 220(11): 1738-1749, 2019 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-30668735

RESUMEN

The Horn of Africa harbors the largest reservoir of Plasmodium vivax in the continent. Most of sub-Saharan Africa has remained relatively vivax-free due to a high prevalence of the human Duffy-negative trait, but the emergence of strains able to invade Duffy-negative reticulocytes poses a major public health threat. We undertook the first population genomic investigation of P. vivax from the region, comparing the genomes of 24 Ethiopian isolates against data from Southeast Asia to identify important local adaptions. The prevalence of the Duffy binding protein amplification in Ethiopia was 79%, potentially reflecting adaptation to Duffy negativity. There was also evidence of selection in a region upstream of the chloroquine resistance transporter, a putative chloroquine-resistance determinant. Strong signals of selection were observed in genes involved in immune evasion and regulation of gene expression, highlighting the need for a multifaceted intervention approach to combat P. vivax in the region.


Asunto(s)
Genotipo , Malaria Vivax/parasitología , Plasmodium vivax/genética , Plasmodium vivax/aislamiento & purificación , Selección Genética , Adaptación Biológica , Adolescente , Animales , Niño , Preescolar , Etiopía , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Plasmodium vivax/clasificación , Prevalencia
17.
Clin Infect Dis ; 69(Suppl 6): S483-S491, 2019 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-31665778

RESUMEN

BACKGROUND: Clearly differentiating causes of fever is challenging where diagnostic capacities are limited, resulting in poor patient management. We investigated acute febrile illness in children aged ≤15 years enrolled at healthcare facilities in Butajira, Ethiopia, during January 2012 to January 2014 for the Typhoid Fever Surveillance in Africa Program. METHODS: Blood culture, malaria microscopy, and blood analyses followed by microbiological, biochemical, and antimicrobial susceptibility testing of isolates were performed. We applied a retrospectively developed scheme to classify children as malaria or acute respiratory, gastrointestinal or urinary tract infection, or other febrile infections and syndromes. Incidence rates per 100 000 population derived from the classification scheme and multivariate logistic regression to determine fever predictors were performed. RESULTS: We rarely observed stunting (4/513, 0.8%), underweight (1/513, 0.2%), wasting (1/513, 0.2%), and hospitalization (21/513, 4.1%) among 513 children with mild transient fever and a mean disease severity score of 12 (95% confidence interval [CI], 11-13). Blood cultures yielded 1.6% (8/513) growth of pathogenic agents; microscopy detected 13.5% (69/513) malaria with 20 611/µL blood (95% CI, 15 352-25 870) mean parasite density. Incidences were generally higher in children aged ≤5 years than >5 to ≤15 years; annual incidences in young children were 301.3 (95% CI, 269.2-337.2) for malaria and 1860.1 (95% CI, 1778.0-1946.0) for acute respiratory and 379.9 (95% CI, 343.6-420.0) for gastrointestinal tract infections. CONCLUSIONS: We could not detect the etiological agents in all febrile children. Our findings may prompt further investigations and the reconsideration of policies and frameworks for the management of acute febrile illness.


Asunto(s)
Monitoreo Epidemiológico , Fiebre/epidemiología , Fiebre/etiología , Fiebre Tifoidea/epidemiología , Enfermedad Aguda , Adolescente , Cultivo de Sangre , Niño , Preescolar , Etiopía/epidemiología , Femenino , Enfermedades Gastrointestinales/epidemiología , Enfermedades Gastrointestinales/microbiología , Instituciones de Salud , Humanos , Lactante , Malaria/epidemiología , Masculino , Estudios Prospectivos , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/microbiología , Estudios Retrospectivos , Fiebre Tifoidea/sangre
18.
BMC Immunol ; 20(1): 35, 2019 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-31601184

RESUMEN

BACKGROUND: HIV-infected individuals with latent TB infection are at increased risk of developing active TB. HAART greatly reduces the incidence rate of TB in HIV-infected patients and reconstitutes Mycobacterium tuberculosis (M. tuberculosis)-specific immune response in the first 12 months of therapy. The durability of the anti-mycobacterial immune restoration after a year of HAART however remains less investigated. METHOD: A cross-sectional study was conducted to evaluate M. tuberculosis-specific functional immune responses in HIV/latent TB co-infected patients who were on HAART for at least 1.5 up to 9 years as compared to HAART-naïve patients. Three-hundred sixteen HIV-infected patients without active TB were screened by tuberculin skin testing for M. tuberculosis infection and peripheral blood mononuclear cells (PBMCs) were isolated from 61 HIV/latent TB co-infected patients (30 HAART-naïve and 31 HAART-treated). IFN-γ and IL-2 ELISPOT as well as CFSE cell proliferation assays were performed after stimulation with M. tuberculosis antigens PPD and ESAT-6. RESULT: The median frequency of PPD and ESAT-6 specific IFN-γ secreting cells was significantly higher in the HAART-treated patients as compared to HAART-naïve patients, p = 0.0021 and p = 0.0081 respectively. However, there was no significant difference in the median frequency of IL-2 secreting cells responding to PPD (p = 0.5981) and ESAT-6 (p = 0.3943) antigens between HAART-naïve and-treated groups. Both IFN-γ and IL-2 responses were independent of CD4+ T cell count regardless of the HAART status. Notably, the frequency of PPD and ESAT-6 specific IL-2 secreting cells was positively associated with CD4+ T cell proliferation while inversely correlated with duration of HAART, raising the possibility that M. tuberculosis-specific IL-2 response that promote the antigen-specific CD4+ T cell proliferation diminish with time on antiretroviral therapy in HIV/latent TB co-infected patients. CONCLUSION: This study shows an increased M. tuberculosis-specific IFN-γ, but not IL-2, response in HIV/latent TB co-infected patients with long-term HAART, consistent with only partial immune restoration. Future studies should, therefore, be done to prospectively define the rate and extent to which functional immune responses to M. tuberculosis are restored after long-term HAART.


Asunto(s)
Antígenos Bacterianos/inmunología , Coinfección , Infecciones por VIH/inmunología , Infecciones por VIH/metabolismo , Interferón gamma/metabolismo , Interleucina-2/metabolismo , Tuberculosis Latente/inmunología , Tuberculosis Latente/metabolismo , Adulto , Terapia Antirretroviral Altamente Activa , Recuento de Linfocito CD4 , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Estudios Transversales , Citocinas/metabolismo , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Humanos , Tuberculosis Latente/microbiología , Masculino
19.
BMC Med ; 17(1): 151, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-31366382

RESUMEN

BACKGROUND: Malaria causes a reduction in haemoglobin that is compounded by primaquine, particularly in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The aim of this study was to determine the relative contributions to red cell loss of malaria and primaquine in patients with uncomplicated Plasmodium vivax. METHODS: A systematic review identified P. vivax efficacy studies of chloroquine with or without primaquine published between January 2000 and March 2017. Individual patient data were pooled using standardised methodology, and the haematological response versus time was quantified using a multivariable linear mixed effects model with non-linear terms for time. Mean differences in haemoglobin between treatment groups at day of nadir and day 42 were estimated from this model. RESULTS: In total, 3421 patients from 29 studies were included: 1692 (49.5%) with normal G6PD status, 1701 (49.7%) with unknown status and 28 (0.8%) deficient or borderline individuals. Of 1975 patients treated with chloroquine alone, the mean haemoglobin fell from 12.22 g/dL [95% CI 11.93, 12.50] on day 0 to a nadir of 11.64 g/dL [11.36, 11.93] on day 2, before rising to 12.88 g/dL [12.60, 13.17] on day 42. In comparison to chloroquine alone, the mean haemoglobin in 1446 patients treated with chloroquine plus primaquine was - 0.13 g/dL [- 0.27, 0.01] lower at day of nadir (p = 0.072), but 0.49 g/dL [0.28, 0.69] higher by day 42 (p < 0.001). On day 42, patients with recurrent parasitaemia had a mean haemoglobin concentration - 0.72 g/dL [- 0.90, - 0.54] lower than patients without recurrence (p < 0.001). Seven days after starting primaquine, G6PD normal patients had a 0.3% (1/389) risk of clinically significant haemolysis (fall in haemoglobin > 25% to < 7 g/dL) and a 1% (4/389) risk of a fall in haemoglobin > 5 g/dL. CONCLUSIONS: Primaquine has the potential to reduce malaria-related anaemia at day 42 and beyond by preventing recurrent parasitaemia. Its widespread implementation will require accurate diagnosis of G6PD deficiency to reduce the risk of drug-induced haemolysis in vulnerable individuals. TRIAL REGISTRATION: This trial was registered with PROSPERO: CRD42016053312. The date of the first registration was 23 December 2016.


Asunto(s)
Anemia Hemolítica/etiología , Antimaláricos/efectos adversos , Malaria Vivax/complicaciones , Malaria Vivax/tratamiento farmacológico , Primaquina/efectos adversos , Adulto , Cloroquina/uso terapéutico , Femenino , Deficiencia de Glucosafosfato Deshidrogenasa/complicaciones , Deficiencia de Glucosafosfato Deshidrogenasa/diagnóstico , Hemólisis/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Plasmodium vivax/efectos de los fármacos
20.
Trop Med Int Health ; 24(2): 143-154, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30461138

RESUMEN

OBJECTIVE: To review the findings of studies of pharyngeal carriage of Neisseria meningitidis and related species conducted in the African meningitis belt since a previous review published in 2007. METHODS: PubMed and Web of Science were searched in July 2018 using the terms 'meningococcal OR Neisseria meningitidis OR lactamica AND carriage AND Africa', with the search limited to papers published on or after 1st January 2007. We conducted a narrative review of these publications. RESULTS: One hundred and thirteen papers were identified using the search terms described above, 20 of which reported new data from surveys conducted in an African meningitis belt country. These papers described 40 surveys conducted before the introduction of the group A meningococcal conjugate vaccine (MenAfriVacR ) during which 66 707 pharyngeal swabs were obtained. Carriage prevalence of N. meningitidis varied substantially by time and place, ranging from <1% to 24%. The mean pharyngeal carriage prevalence of N. meningitidis across all surveys was 4.5% [95% CI: 3.4%, 6.8%] and that of capsulated N. meningitidis was 2.8% [95% CI: 1.9%; 5.2%]. A study of households provided strong evidence for meningococcal transmission within and outside households. The introduction of MenAfriVac® led to marked reductions in carriage of the serogroup A meningococcus in Burkina Faso and Chad. CONCLUSIONS: Recent studies employing standardised methods confirm the findings of older studies that carriage of N. meningitidis in the African meningitis belt is highly variable over time and place, but generally occurs with a lower prevalence and shorter duration than reported from industrialised countries.


Asunto(s)
Portador Sano/epidemiología , Meningitis Meningocócica/epidemiología , Neisseria meningitidis/aislamiento & purificación , África , Humanos , Vacunación Masiva , Meningitis Meningocócica/prevención & control , Vacunas Meningococicas/administración & dosificación , Neisseria meningitidis Serogrupo A
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