Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
BMC Public Health ; 23(1): 1164, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328849

RESUMO

BACKGROUND: In Ghana, Hepatitis B virus (HBV) infection remains a major public health threat as in many parts of the world. Even with an effective vaccine, there are shortfalls with low vaccine coverage among adults. To create awareness and encourage vaccination, community engagement and public-private partnerships are needed in endemic settings to help fund campaigns and offer screening and vaccinations at no cost to under privileged people. OBJECTIVES: An awareness and screening exercise was scheduled by University of Ghana-based Hepatitis-Malaria (HEPMAL) project team to coincide with the World Hepatitis Day (WHD) 2021. It was to engage the community in creating awareness of the menace and offer diagnostic services to ascertain prevalence levels and provide needed clinical support. METHODS: Participants from the University of Ghana community and its immediate environs were registered, taken through pre-counselling sessions where they were educated on hepatitis transmission and prevention before consenting. Eligible participants were screened for HBV markers (HBsAg, HBeAg, HBsAb, HBcAb,HbcAg) with a rapid test kit. All HBsAb-negative participants were recommended for initial vaccination at the event, whilst the subsequent shots were administered at the University Hospital Public Health Department. Hepatitis B surface Antigen-positive participants were counselled and referred for appropriate care. RESULTS: / Outcomes: A total of 297 people, comprising of 126 (42%) males and 171 (58%) females aged between 17 and 67 years were screened during the exercise. Amongst these, 246 (82.8%) showed no detectable protective antibodies against HBV and all of them agreed to and were given the first dose HBV vaccine. Additionally, 19 (6.4%) individuals tested positive for HBsAg and were counselled and referred to specialists from the University Hospital for further assessment and management. We found that 59 (19.9%) of our participants had previously initiated HBV vaccination and had taken at least one dose of the vaccine more than 6 months prior to this screening, 3 of whom tested positive for HBsAg. For the three-dose HBV vaccines deployed, a little over 20% (50/246) and a further 17% (33/196) did not return for the second and the third doses respectively, resulting in an overall 66% (163/246) of persons who completed all three vaccinations. CONCLUSIONS: / Lessons learnt: Our medical campaign exercise established an active case prevalence rate of 6.4% and achieved a full vaccination success rate of 66% which is critical in the induction of long-term immunity in the participants. Aside these achievements, we would like to reiterate the importance of the use of different approaches including educational events and WHD activities to target groups and communities to raise awareness. Additionally, home and school vaccination programmes may be adopted to enhance vaccine uptake and adherence to the vaccination schedule. We plan to extend this screening exercise to deprived and/or rural communities where HBV incidence may be higher than in urban communities.


Assuntos
Hepatite A , Hepatite B , Adulto , Masculino , Feminino , Humanos , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Vírus da Hepatite B , Antígenos de Superfície da Hepatite B , Gana/epidemiologia , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Vacinas contra Hepatite B , Anticorpos Anti-Hepatite B , Vacinação
2.
Front Cell Infect Microbiol ; 12: 901433, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35811678

RESUMO

Sepsis defined as a dysregulated immune response is a major cause of morbidity in children. In sub-Saharan Africa, the clinical features of sepsis overlap with other frequent infections such as malaria, thus sepsis is usually misdiagnosed in the absence of confirmatory tests. Therefore, it becomes necessary to identify biomarkers that can be used to distinguish sepsis from other infectious diseases. We measured and compared the plasma levels of 18 cytokines (Th1 [GM-CSF, IFN-γ, TNF-α, IL-1ß, 1L-2, IL-6, IL-8, IL-12/IL-23p40, IL-15], Th2[IL-4, IL-5, IL-13), Th17 [IL17A], Regulatory cytokine (IL-10) and 7 chemokines (MCP-1/CCL2, MIP-1α/CCL3, MIP-1ß/CCL4, RANTES/CCL5, Eotaxin/CCL11, MIG/CXCL9 and IP-10/CXCL10 using the Human Cytokine Magnetic 25-Plex Panel in plasma samples obtained from children with sepsis, clinical malaria and other febrile conditions. Children with sepsis had significantly higher levels of IL-1ß, IL-12 and IL-17A compared to febrile controls but lower levels of MIP1-ß/CCL4, RANTES/CCL5 and IP10/CXCL10 when compared to children with malaria and febrile controls. Even though levels of most inflammatory responses were higher in malaria compared to sepsis, children with sepsis had a higher pro-inflammatory to anti-inflammatory ratio which seemed to be mediated by mostly monocytes. A principal component analysis and a receiver operator characteristic curve analysis, identified seven potential biomarkers; IL-1ß, IL-7, IL-12, IL-1RA, RANTES/CCL5, MIP1ß/CCL4 and IP10/CXCL10 that could discriminate children with sepsis from clinical malaria and other febrile conditions. The data suggests that sepsis is associated with a higher pro-inflammatory environment. These pro-inflammatory cytokines/chemokines could further be evaluated for their diagnostic potential to differentiate sepsis from malaria and other febrile conditions in areas burdened with infectious diseases.


Assuntos
Citocinas , Sepse , Biomarcadores , Quimiocina CCL5 , Quimiocina CXCL10 , Criança , Diagnóstico Diferencial , Humanos , Interleucina-12 , Sepse/diagnóstico
3.
J Blood Med ; 13: 151-164, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35330697

RESUMO

Purpose: The severity of Plasmodium falciparum infections is associated with the ability of the infected red blood cells to cytoadhere to host vascular endothelial surfaces and to uninfected RBCs. Host blood group antigens and two serum proteins α2-macroglobulin (α2M) and IgM have been implicated in rosette formation in laboratory-adapted P. falciparum. However, there is only limited information about these phenotypes in clinical isolates. Methods: This was a hospital-based study involving children under 12 years-of-age reporting to the Hohoe Municipal Hospital with different clinical presentations of malaria. Parasite isolates were grown and rosette capabilities and characteristics were investigated by fluorescence microscopy. α2M and IgM were detected by ELISA. Results: Rosette formation was observed in 46.8% (75/160) of the parasite isolates from all the blood groups tested. Rosettes were more prevalent (55%) among isolates from patients with severe malaria compared to isolates from patients with uncomplicated malaria (45%). Rosette prevalence was highest (30%) among patients with blood group O (30%) and B (29%), while the mean rosette frequency was higher in isolates from patients with blood group A (28.7). Rosette formation correlated negatively with age (r = -0.09, P= 0.008). Participants with severe malaria had a lower IgM concentration (3.683±3.553) than those with uncomplicated malaria (5.256±4.294) and the difference was significant (P= 0.0228). The mean concentrations of anti-parasite IgM measured among the clinical isolates which formed rosettes was lower (4.2 ±3.930 mg/mL), than that in the non rosetting clinical isolates (4.604 ±4.159 mg/mL) but the difference was not significant (P=0.2733). There was no significant difference in plasma α2M concentration between rosetting and non rosetting isolates (P=0.442). Conclusion: P. falciparum parasite rosette formation was affected by blood group type and plasma concentration of IgM. A lower IgM concentration was associated with severe malaria whilst a higher α2M concentration was associated with uncomplicated malaria.

4.
PLoS Negl Trop Dis ; 16(3): e0010115, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35263327

RESUMO

BACKGROUND: Evidence from recent studies in Schistosoma mansoni-endemic areas show an age-associated immunity that is positively correlated with IgE titres to Schistosoma mansoni-specific tegumental allergen-like protein 1 (SmTAL1). The structural homology between SmTAL1 and the S. haematobium-specific TAL1 (ShTAL1) has been verified, yet it remains unclear whether similar age- and immune-associated trends characterize ShTAL1. This community-based intervention study was conducted to assess whether ShTAL1IgE responses post-treatment with praziquantel (PZQ) might be associated with a reduced risk to re-infection with S. haematobium. METHODOLOGY/PRINCIPAL FINDINGS: This study was conducted at Agona Abodom, Central Region, Ghana, and involved 114 participants aged 6 to 55 years. EDTA blood samples were collected at baseline and 7 weeks after PZQ treatment (Follow-up). Baseline and Follow-up titres of specific IgG1, IgG4, and IgE antibodies to the S. haematobium-specific adult worm antigen (ShAWA), the Sh-specific soluble egg antigen (ShSEA), and the Sh-specific tegumental-allergen-like 1 protein (ShTAL1) in plasma samples were measured using sandwich ELISA. Participants at both time points also provided stool and urine for helminth egg detection by microscopy. Prevalence of S. haematobium at baseline was 22.80%, and decreased to 3.50% at Follow-up. The egg reduction rate (ERR) was 99.87%. Overall plasma levels of ShTAL1-IgE increased 7 weeks post-PZQ treatment, and with increasing age; whiles S. haematobium infection prevalence and intensity decreased. For S. haematobium-infected participants who were egg-negative at Follow-up (N = 23), minimal median levels of ShTAL1-IgE were observed for all age groups prior to treatment, whilst median levels increased considerably among participants aged 12 years and older at Follow-up; and remained minimal among participants aged 11 years or less. In the univariate analysis, being aged 12 years or older implied an increased likelihood for ShTAL1-IgE positivity [12-14 years (cOR = 9.64, 95% CI = 2.09-44.51; p = 0.004); 15+ years (cOR = 14.26, 95% CI = 3.10-65.51; p = 0.001)], and this remained significant after adjusting for confounders [12-14 years (aOR = 22.34, 95% CI = 2.77-180.14; p = 0.004); ≥15 years (aOR = 51.82, 95% CI = 6.44-417.17; p < 0.001)]. Conversely, median ShTAL1-IgG4 titres were hardly detectible at Follow-up. CONCLUSIONS/SIGNIFICANCE: These findings demonstrate that increased IgE levels to ShTAL1 7 weeks after PZQ treatment could be associated with a reduced risk to re-infection, and adds to the large body of evidence suggesting a protective role of the treatment-induced ShTAL1 antigen in schistosomiasis infections. It was also quite clear from this work that apart from being persistently S. haematobium-positive, elevated ShTAL1-IgG4 levels at Follow-up could be indicative of susceptibility to re-infection. These outcomes have important implications in vaccine development, and in shifting the paradigm in mass chemotherapy programmes from a 'one-size-fits-all' approach to more sub-group-/participant-specific strategies in endemic areas.


Assuntos
Anti-Helmínticos , Esquistossomose Urinária , Alérgenos , Animais , Anti-Helmínticos/uso terapêutico , Feminino , Gana/epidemiologia , Humanos , Imunoglobulina E , Imunoglobulina G , Masculino , Praziquantel/uso terapêutico , Reinfecção , Schistosoma haematobium , Schistosoma mansoni , Esquistossomose Urinária/tratamento farmacológico , Esquistossomose Urinária/epidemiologia , Resultado do Tratamento
5.
Malar J ; 19(1): 362, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33032607

RESUMO

BACKGROUND: The pathogenesis of Plasmodium falciparum malaria is related to the ability of parasite­infected erythrocytes (IEs) to adhere to the vascular endothelium (cytoadhesion/sequestration) or to surrounding uninfected erythrocytes (rosetting). Both processes are mediated by the expression of members of the clonally variant PfEMP1 parasite protein family on the surface of the IEs. Recent evidence obtained with laboratory-adapted clones indicates that P. falciparum can exploit human serum factors, such as IgM and α2-macroglobulin (α2M), to increase the avidity of PfEMP1-mediated binding to erythrocyte receptors, as well as to evade host PfEMP1-specific immune responses. It has remained unclear whether PfEMP1 variants present in field isolates share these characteristics, and whether they are associated with clinical malaria severity. These issues were investigated here. METHODS: Children 1-12 years reporting with P. falciparum malaria to Hohoe Municipal Hospital, Ghana were enrolled in the study. Parasites from children with uncomplicated (UM) and severe malaria (SM) were collected. Binding of α2M and IgM from non-immune individuals to erythrocytes infected by P. falciparum isolates from 34 children (UM and SM) were analysed by flow cytometry. Rosetting in the presence of IgM or α2M was also evaluated. Experimental results were analysed according to the clinical presentation of the patients. RESULTS: Clinical data from 108 children classified as UM (n = 54) and SM cases (n = 54) were analysed. Prostration, severe malaria anaemia, and hyperparasitaemia were the most frequent complications. Three children were diagnosed with cerebral malaria, and one child died. Parasite isolates from UM (n = 14) and SM (n = 20) children were analysed. Most of the field isolates bound non-immune IgM (33/34), whereas the α2M-binding was less common (23/34). Binding of both non-immune IgM and α2M was higher but not significant in IEs from children with SM than from children with UM. In combination, IgM and α2M supported rosette formation at levels similar to that observed in the presence of 10% human serum. CONCLUSIONS: The results support the hypothesis that binding of non-immune IgM and/or α2M to IEs facilitates rosette formation and perhaps contributes to P. falciparum malaria severity.


Assuntos
Proteínas Sanguíneas/metabolismo , Eritrócitos/parasitologia , Malária Falciparum/complicações , Malária Falciparum/fisiopatologia , Plasmodium falciparum/fisiologia , Criança , Pré-Escolar , Eritrócitos/metabolismo , Feminino , Gana , Humanos , Lactente , Malária Falciparum/diagnóstico , Malária Falciparum/parasitologia , Masculino
6.
Sci Rep ; 10(1): 12871, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732983

RESUMO

Plasmodium falciparum causes the most severe form of malaria in humans. The adhesion of the infected erythrocytes (IEs) to endothelial receptors (sequestration) and to uninfected erythrocytes (rosetting) are considered major elements in the pathogenesis of the disease. Both sequestration and rosetting appear to involve particular members of several IE variant surface antigens (VSAs) as ligands, interacting with multiple vascular host receptors, including the ABO blood group antigens. In this study, we subjected genetically distinct P. falciparum parasites to in vitro selection for increased IE adhesion to ABO antigens in the absence of potentially confounding receptors. The selection resulted in IEs that adhered stronger to pure ABO antigens, to erythrocytes, and to various human cell lines than their unselected counterparts. However, selection did not result in marked qualitative changes in transcript levels of the genes encoding the best-described VSA families, PfEMP1 and RIFIN. Rather, overall transcription of both gene families tended to decline following selection. Furthermore, selection-induced increases in the adhesion to ABO occurred in the absence of marked changes in immune IgG recognition of IE surface antigens, generally assumed to target mainly VSAs. Our study sheds new light on our understanding of the processes and molecules involved in IE sequestration and rosetting.


Assuntos
Sistema ABO de Grupos Sanguíneos/metabolismo , Eritrócitos , Regulação da Expressão Gênica , Malária Falciparum/metabolismo , Proteínas de Membrana/biossíntese , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/biossíntese , Animais , Células CHO , Cricetulus , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA