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BACKGROUND: Hemodialysis patients are among high-risk groups for COVID-19. Africa is the continent with the lowest number of cases in the general population but we have little information about the disease burden in dialysis patients. OBJECTIVES: This study aimed to describe the seroprevalence of SARS-CoV-2 antibodies in the hemodialysis population of Senegal. PATIENTS AND METHODS: We conducted a multicenter cross-sectional survey, between June and September 2020 involving 10 public dialysis units randomly selected in eight regions of Senegal. After seeking their consent, we included 303 patients aged ≥ 18 years and hemodialysis for ≥ 3 months. Clinical symptoms and biological parameters were collected from medical records. Patients' blood samples were tested with Abbott SARS-CoV-2 Ig G assay using an Architect system. Statistical tests were performed with STATA 12.0. RESULTS: Seroprevalence of SARS-CoV-2 antibodies was 21.1% (95% CI = 16.7-26.1%). We noticed a wide variability in SARS-CoV-2 seroprevalence between regions ranging from 5.6 to 51.7%. Among the 38 patients who underwent nasal swab testing, only six had a PCR-confirmed infection and all of them did seroconvert. Suggestive clinical symptoms were reported by 28.1% of seropositive patients and the majority of them presented asymptomatic disease. After multivariate analysis, a previous contact with a confirmed case and living in a high population density region were associated with the presence of SARS-CoV-2 antibodies. CONCLUSION: This study presents to our knowledge the first seroprevalence data in African hemodialysis patients. Compared to data from other continents, we found a higher proportion of patients with SARS-CoV-2 antibodies but a lower lethality rate.
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Anticorpos Antivirais/sangue , COVID-19/epidemiologia , Diálise Renal , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , COVID-19/sangue , COVID-19/complicações , Busca de Comunicante , Estudos Transversais , Escolaridade , Feminino , Geografia Médica , Inquéritos Epidemiológicos , Humanos , Imunoglobulina G/sangue , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Densidade Demográfica , Prevalência , Senegal/epidemiologia , Estudos Soroepidemiológicos , Avaliação de Sintomas , Adulto JovemRESUMO
BACKGROUND: Although Schistosoma haematobium infection has been reported to be associated with alterations in immune function, in particular immune hyporesponsiveness, there have been only few studies that have used the approach of removing infection by drug treatment to establish this and to understand the underlying molecular mechanisms. METHODS: Schistosoma haematobium-infected schoolchildren were studied before and after praziquantel treatment and compared with uninfected controls. Cellular responses were characterized by cytokine production and flow cytometry, and in a subset of children RNA sequencing (RNA-Seq) transcriptome profiling was performed. RESULTS: Removal of S haematobium infection resulted in increased schistosome-specific cytokine responses that were negatively associated with CD4+CD25+FOXP3+ T-cells and accompanied by increased frequency of effector memory T-cells. Innate responses to Toll like receptor (TLR) ligation decreased with treatment and showed positive association with CD4+CD25+FOXP3+ T-cells. At the transcriptome level, schistosome infection was associated with enrichment in cell adhesion, whereas parasite removal was associated with a more quiescent profile. Further analysis indicated that alteration in cellular energy metabolism was associated with S haematobium infection and that the early growth response genes 2 and 3 (EGR 2 and EGR3), transcription factors that negatively regulate T-cell activation, may play a role in adaptive immune hyporesponsiveness. CONCLUSIONS: Using a longitudinal study design, we found contrasting effects of schistosome infection on innate and adaptive immune responses. Whereas the innate immune system appears more activated, the adaptive immunity is in a hyporesponsive state reflected in alterations in CD4+CD25+FOXP3+ T-cells, cellular metabolism, and transcription factors involved in anergy.
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Anti-Helmínticos/uso terapêutico , Citocinas/imunologia , Praziquantel/uso terapêutico , Esquistossomose Urinária/imunologia , Transcriptoma , Imunidade Adaptativa , Animais , Criança , Feminino , Citometria de Fluxo , Gabão/epidemiologia , Humanos , Imunidade Inata , Estudos Longitudinais , Masculino , RNA-Seq , Esquistossomose Urinária/tratamento farmacológicoRESUMO
BACKGROUND: Northern Senegal is a zone of very low malaria transmission, with an annual incidence of < 5/1000 inhabitants. This area, where the Senegal National Malaria Control Programme has initiated elimination activities, hosts Fulani, nomadic, pastoralists that spend the dry season in the south where malaria incidence is higher (150-450/1000 inhabitants) and return to the north with the first rains. Previous research demonstrated parasite prevalence of < 1% in this Fulani population upon return from the south, similar to that documented in the north in cross-sectional surveys. METHODS: A modified snowball sampling survey of nomadic pastoralists was conducted in five districts in northern Senegal during September and October 2014. Demographic information and dried blood spots were collected. Multiplex bead-based assays were used to assess antibody responses to merozoite surface protein (MSP-119) antigen of the four primary Plasmodium species, as well as circumsporozoite protein (CSP) and liver stage antigen (LSA-1) of Plasmodium falciparum. RESULTS: In the five study districts, 1472 individuals were enrolled, with a median age of 22 years (range 1 to 80 years). Thirty-two percent of subjects were under 14 years and 57% were male. The overall seroprevalence of P. falciparum MSP-119, CSP and LSA-1 antibodies were 45, 12 and 5%, respectively. Plasmodium falciparum MSP-119 antibody responses increased significantly with age in all study areas, and were significantly higher among males. The highest seroprevalence to P. falciparum antigens was observed in the Kanel district (63%) and the lowest observed in Podor (28%). Low seroprevalence was observed for non-falciparum species in all the study sites: 0.4, 0.7 and 1.8%, respectively, for Plasmodium ovale, Plasmodium vivax and Plasmodium malariae MSP-1. Antibody responses to P. vivax were observed in all study sites except Kanel. CONCLUSION: Prevalence of P. falciparum MSP-119 antibodies and increases by study participant age provided data for low levels of exposure among this transient nomadic population. In addition, antibody responses to P. falciparum short half-life markers (CSP and LSA-1) and non-falciparum species were low. Further investigations are needed to understand the exposure of the Fulani population to P. vivax.
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Anticorpos Antiprotozoários/sangue , Imunoglobulina G/sangue , Malária Falciparum/epidemiologia , Plasmodium falciparum/imunologia , Migrantes , Adolescente , Adulto , Idoso , Animais , Anopheles/parasitologia , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Malária Falciparum/diagnóstico , Malária Falciparum/imunologia , Masculino , Microesferas , Pessoa de Meia-Idade , Mosquitos Vetores/parasitologia , Chuva , Estações do Ano , Senegal/epidemiologia , Estudos Soroepidemiológicos , Adulto JovemRESUMO
The study aimed to estimate the prevalence of Hepatitis B virus (HBV) infection and to describe the HBV virological profiles among Senegalese HIV-1-infected patients. We conducted a retrospective study between 2006 and 2010 among Senegalese HIV-1-infected patients from the antiretroviral therapy cohort. Samples were screened using Determine(®) HBsAg or MONOLISA(®) POC test. The HBsAg positivity status was confirmed by Architect(®) HBsAg. Detection of HBeAg, anti-HBe Ab, and HBV DNA load were done for the HBsAg-positive samples. Then, Anti-HBcAb was tested for the HBsAg-negative samples. Microsoft Excel was used for data collection and statistical analyses were performed using Epi info 3.5.1. Overall, 466 HIV-infected patients were enrolled including 271 women (58.4%), and 193 men (41.6%) with a median age of 39 years (19-74 years). The global prevalence of HIV/HBV coinfection (HBsAg positive) was 8.8% (41/466). For HBsAg positives samples, the prevalence of HBeAg and the anti-HBeAb were, respectively, 24.4 and 69.2% and the median of HBV DNA viral load, for 27 HBsAg-positive samples, was 3.75 log10 copies/ml. The virological profiles were the following: 7, 15, and 5 patients infected, respectively, by a replicative virus, an inactive virus and a probably mutant virus. For HBsAg-negative samples, 83 out of 109 were positive for anti-HBcAb. This study showed a significant decrease of the prevalence of HBV/HIV coinfection between 2004 and 2014 (P = 0.003), which highlighted the performance of the Senegalese HBV vaccine program. However, implementing a systematic quantification of HBV DNA viral load could improve the monitoring of HBV-infected patient.
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Biomarcadores/sangue , Coinfecção/epidemiologia , Infecções por HIV/complicações , HIV-1 , Hepatite B/epidemiologia , Prevalência , Adulto , Idoso , DNA Viral , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Hepatite B/complicações , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Antígenos E da Hepatite B/sangue , Antígenos E da Hepatite B/imunologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Senegal/epidemiologia , Carga Viral , Adulto JovemRESUMO
Differences in lifestyle and break with natural environment appear to be associated with changes in the immune system resulting in various adverse health effects. Although genetics can have a major impact on the immune system and disease susceptibility, the contribution of environmental factors is thought to be substantial. Here, we investigated the immunological profile of healthy volunteers living in a rural and an urban area of a developing African country (Senegal), and in a European country (the Netherlands). Using flow cytometry, we investigated T helper type 1 (Th1), Th2, Th17, Th22 and regulatory T cells, as well as CD4(+) T-cell and B-cell activation markers, and subsets of memory T and B cells in the peripheral blood. Rural Senegalese had significantly higher frequencies of Th1, Th2 and Th22 cells, memory CD4(+) T and B cells, as well as activated CD4(+) T and B cells compared with urban Senegalese and urban Dutch people. Within the Senegalese population, rural paritcipants displayed significantly higher frequencies of Th2 and Th22 cells, as well as higher pro-inflammatory and T-cell activation and memory profiles compared with the urban population. The greater magnitude of immune activation and the enlarged memory pool, together with Th2 polarization, seen in rural participants from Africa, followed by urban Africans and Europeans suggest that environmental changes may define immunological footprints, which could have consequences for disease patterns in general and vaccine responses in particular.
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Adaptação Biológica/imunologia , Sistema Imunitário/fisiologia , Estilo de Vida , Urbanização , Adulto , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Feminino , Humanos , Memória Imunológica , Imunofenotipagem , Mediadores da Inflamação/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Contagem de Linfócitos , Masculino , Países Baixos , População Rural , Senegal , População Urbana , Adulto JovemRESUMO
BACKGROUND: Schistosome infections are often clinically silent, but some individuals develop severe pathological reactions. In several disease processes, T-helper 17 (Th17) cells have been linked to tissue injuries, while regulatory T cells (Tregs) are thought to downmodulate inflammatory reactions. We assessed whether bladder pathology in human Schistosoma haematobium infection is related to the balance of Th17 cells and Tregs. We used a murine model of Schistosoma mansoni infection to further investigate whether the peripheral profiles reflected ongoing events in tissues. METHODS: We characterized T-helper cell subsets in the peripheral blood of children residing in a S. haematobium-endemic area and in the peripheral blood, spleen, and hepatic granulomas of S. mansoni-infected high-pathology CBA mice and low-pathology C57BL/6 mice. RESULTS: S. haematobium-infected children with bladder pathology had a significantly higher percentage of Th17 cells than those without pathology. Moreover, the Th17/Treg ratios were significantly higher in infected children with pathology, compared with infected children without pathology. Percentages of interleukin 17-producing cells were significantly higher in spleen and granulomas of CBA mice, compared with C57BL/6 mice. This difference was also reflected in the peripheral blood. CONCLUSIONS: This is the first study to indicate that Th17 cells may be involved in the pathogenesis of human schistosomiasis.
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Schistosoma haematobium/imunologia , Esquistossomose Urinária/patologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Citocinas/imunologia , Feminino , Granulócitos/patologia , Interações Hospedeiro-Parasita/imunologia , Humanos , Interleucina-17/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Pessoa de Meia-Idade , Schistosoma mansoni/imunologia , Esquistossomose Urinária/parasitologia , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/patologia , Baço/parasitologia , Baço/patologia , Bexiga Urinária/parasitologia , Bexiga Urinária/patologia , Adulto JovemRESUMO
Schistosomiasis treatment entirely relies on a single drug, praziquantel, prompting research into alternative therapeutics. Here we evaluated the efficacy and safety of the antimalarial combination artesunate-mefloquine for the treatment of schistosomiasis in a proof-of-concept, pragmatic, open-label, randomized controlled trial in primary schools of six villages endemic for schistosomiasis in northern Senegal. Children (6-14 years) were eligible if Schistosoma eggs were detected by microscopy in urine and/or stool. In total, 726 children were randomized 1:1 to praziquantel (standard care: 40 mg kg-1 single dose; n = 364) or to artesunate-mefloquine (antimalarial dosage: artesunate 4 mg kg-1 and mefloquine 8 mg kg-1 daily for three consecutive days; n = 362). Eight children not meeting the inclusion criteria were excluded from efficacy analysis. Median age of the remaining 718 participants was 9 years; 399 (55.6%) were male, and 319 (44.4%) female; 99.3% were infected with Schistosoma haematobium and 15.2% with S. mansoni. Primary outcomes were cure rate, assessed by microscopy, and frequency of drug-related adverse effects of artesunate-mefloquine versus praziquantel at 4 weeks after treatment. Cure rate was 59.6% (208/349) in the artesunate-mefloquine arm versus 62.1% (211/340) in the praziquantel arm. The difference of -2.5% (95% confidence interval (CI) -9.8 to 4.8) met the predefined criteria of noninferiority (margin set at 10%). All drug-related adverse events were mild or moderate, and reported in 28/361 children receiving artesunate-mefloquine (7.8%; 95% CI 5.4 to 11.0) versus 8/363 (2.2%; 95% CI 1.1 to 4.3) receiving praziquantel (P < 0.001). Artesunate-mefloquine at antimalarial dosage was moderately safe and noninferior to standard-care praziquantel for the treatment of schistosomiasis, predominantly due to S. haematobium. Multicentric trials in different populations and epidemiological settings are needed to confirm these findings. ClinicalTrials.gov identifier: NCT03893097 .
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Antimaláricos , Esquistossomose , Criança , Feminino , Humanos , Masculino , Antimaláricos/efeitos adversos , Artesunato/efeitos adversos , Mefloquina/efeitos adversos , Praziquantel/efeitos adversos , Esquistossomose/tratamento farmacológico , Resultado do Tratamento , AdolescenteRESUMO
Context: Toxoplasma gondii and rubella virus are microorganisms that can cause intrauterine infections and congenital anomalies in the fetus. Data regarding the simultaneous seroprevalence of these infections are not available in Senegal. Aims: This study aimed to determine for the first time the simultaneous seroprevalence of toxoplasmosis and rubella among pregnant women in Dakar. Materials and Methods: In this retrospective study, anti-Toxoplasma and anti-rubella antibodies were analyzed in the serum samples obtained from pregnant women receiving prenatal care at Military Hospital of Ouakam between 2016 and 2021 using a chemiluminescent microparticle immunoassay for the quantitative determination of immunoglobulin G (IgG) and IgM antibodies to Toxoplasma gondii and rubella in human serum. Results: Overall, data from 2589 women were analyzed. The median age was 29 years (interquartile range: 23.14-34.86). Serum IgG and IgM were positive for T. gondii with 35.84% and 1.66%, respectively. Rubella seroprevalence was 87.14% and 0.35%, respectively, for IgG and IgM. Seroprevalence of toxoplasmosis increases significantly with age and study period. For rubella infection, the highest seroprevalence rates were noted in the youngest age group and at the end of the study period. Conclusions: Data from this first-time study regarding simultaneous seroprevalence of toxoplasmosis and rubella among pregnant women in Senegal indicate a continuing high risk of congenital toxoplasmosis and congenital rubella syndrome in Dakar. Further studies are needed to fully assess the efficacy of rubella vaccination in women of childbearing age.
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This study investigated the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) immunoglobulin G (IgG) during the first pandemic wave in Senegal. The seroprevalence rate of SARS-CoV-2 IgG was assessed in 10 cities in Senegal by testing plasma from volunteers attending healthcare clinics for reasons unrelated to coronavirus disease 2019 (n=3231) between June and October 2020. The overall positivity rate was 20.4% and large geographical differences in seropositivity (6-41.9%) were observed, suggesting that the true number of infections was substantially higher than the official estimate of 8.5%.
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Molecular surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is growing in west Africa, especially in the Republic of Senegal. Here, we present a molecular epidemiology study of the early waves of SARS-CoV-2 infections in this country based on Bayesian phylogeographic approaches. Whereas the first wave in mid-2020 was characterized by a significant diversification of lineages and predominance of B.1.416, the second wave in late 2020 was composed primarily of B.1.1.420. Our results indicate that B.1.416 originated in Senegal and was exported mainly to Europe. In contrast, B.1.1.420 was introduced from Italy, gained fitness in Senegal, and then spread worldwide. Since both B.1.416 and B.1.1.420 lineages carry several positive selected mutations in the spike and nucleocapsid genes, each of which may explain their local dominance, their mutation profiles should be carefully monitored. As the pandemic continues to evolve, molecular surveillance in all regions of Africa will play a key role in stemming its spread.
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â¢Omicron variant continues to progress in Senegal with the appearance of new contaminations.â¢IRESSEF detected the first positive case of the Omicron variant on Friday, December 3, 2021.â¢Since this date, the number of Omicron variant infections has increased over the weeks.â¢Molecular surveillance of the Omicron variant allowed us to identify a strong variation of this variant in our country.
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INTRODUCTION: Alternative drugs and diagnostics are needed for the treatment and control of schistosomiasis. The exclusive use of praziquantel (PZQ) in mass drug administration programmes may result in the emergence of drug resistance. PZQ has little activity against Schistosoma larvae, thus reinfection remains a problem in high-risk communities. Furthermore, the insufficient sensitivity of conventional microscopy hinders therapeutic response assessment. Evaluation of artesunate-mefloquine (AM) as a Novel Alternative Treatment for Schistosomiasis in African Children (SchistoSAM) aims to evaluate the safety and efficacy of the antimalarial combination artesunate-mefloquine, re-purposed for the treatment of schistosomiasis, and to assess the performance of highly sensitive novel antigen-based and DNA-based assays as tools for monitoring treatment response. METHODS AND ANALYSIS: The SchistoSAM study is an open-label, two-arm, individually randomised controlled non-inferiority trial, with a follow-up of 48 weeks. Primary school-aged children from the Richard Toll district in northern Senegal, an area endemic for Schistosoma mansoni and Schistosoma haematobium, are allocated to the AM intervention arm (3-day courses at 6-week intervals) or the PZQ control arm (single dose of 40 mg/kg). The trial's primary endpoints are the efficacy (cure rate (CR), assessed by microscopy) and safety (frequency and pattern of drug-related adverse events) of one AM course versus PZQ at 4 weeks after treatment. Secondary endpoints include (1) cumulative CR, egg reduction rate and safety after each additional course of AM, and at weeks 24 and 48, (2) prevalence and severity of schistosomiasis-related morbidity and (3) malaria prevalence, incidence and morbidity, both after 24 and 48 weeks. CRs and intensity reduction rates are also assessed by antigen-based and DNA-based diagnostic assays, for which performance for treatment monitoring is evaluated. ETHICS AND DISSEMINATION: Ethics approval was obtained both in Belgium and Senegal. Oral assent from the children and signed informed consent from their legal representatives was obtained, prior to enrolment. The results will be disseminated in peer-reviewed journals and at international conferences. TRIAL REGISTRATION NUMBER: NCT03893097; pre-results.
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Anti-Helmínticos , Esquistossomose , Anti-Helmínticos/uso terapêutico , Artesunato , Criança , Humanos , Mefloquina , Ensaios Clínicos Controlados Aleatórios como Assunto , Esquistossomose/tratamento farmacológico , Senegal , Resultado do TratamentoRESUMO
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineages that carry mutations in the spike gene are of concern for potential impact to treatment and prevention efforts. To monitor for new SARS-CoV-2 mutations, a panel of specimens were sequenced from both wave one (N = 96), and wave two (N = 117) of the pandemic in Senegal by whole genome next generation sequencing. Amongst these genomes, new combinations of SARS-CoV-2 spike mutations were identified, with E484K + N501T, L452R + N501Y, and L452M + S477N exclusively found in second wave specimens. These sequences are evidence of local diversification over the course of the pandemic and parallel evolution of escape mutations in different lineages.
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COVID-19/patologia , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , COVID-19/virologia , Humanos , Mutação , Ligação Proteica , Domínios Proteicos/genética , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Senegal , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
Helminth infections induce strong type 2 and regulatory responses, but the degree of heterogeneity of such cells is not well characterized. Using mass cytometry, we profiled these cells in Europeans and Indonesians not exposed to helminths and in Indonesians residing in rural areas infected with soil-transmitted helminths. To assign immune alteration to helminth infection, the profiling was performed before and 1 year after deworming. Very distinct signatures were found in Europeans and Indonesians, showing expanded frequencies of T helper 2 cells, particularly CD161+ cells and ILC2s in helminth-infected Indonesians, which was confirmed functionally through analysis of cytokine-producing cells. Besides ILC2s and CD4+ T cells, CD8+ T cells and γδ T cells in Indonesians produced type 2 cytokines. Regulatory T cells were also expanded in Indonesians, but only those expressing CTLA-4, and some coexpressed CD38, HLA-DR, ICOS, or CD161. CD11c+ B cells were found to be the main IL-10 producers among B cells in Indonesians, a subset that was almost absent in Europeans. A number of the distinct immune profiles were driven by helminths as the profiles reverted after clearance of helminth infections. Moreover, Indonesians with no helminth infections residing in an urban area showed immune profiles that resembled Europeans rather than rural Indonesians, which excludes a major role for ethnicity. Detailed insight into the human type 2 and regulatory networks could provide opportunities to target these cells for more precise interventions.
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Helmintíase/imunologia , Helmintos/fisiologia , Linfócitos T Reguladores/imunologia , Células Th2/imunologia , Animais , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Europa (Continente) , Helmintíase/tratamento farmacológico , Humanos , Indonésia , Interleucina-10/metabolismo , Subfamília B de Receptores Semelhantes a Lectina de Células NK/metabolismo , População RuralRESUMO
The COVID-19 pandemic is shining a spotlight on the field of immunology like never before. To appreciate the diverse ways in which immunologists have contributed, Nature Reviews Immunology invited the president of the International Union of Immunological Societies and the presidents of 15 other national immunology societies to discuss how they and their members responded following the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
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COVID-19/epidemiologia , Infecções por Coronavirus/epidemiologia , Cooperação Internacional , Pandemias , Pneumonia Viral/epidemiologia , Síndrome Respiratória Aguda Grave/epidemiologia , Sociedades Científicas/organização & administração , Antivirais/síntese química , Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/terapia , Vacinas contra COVID-19 , Relações Comunidade-Instituição , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Saúde Global/tendências , Humanos , Educação de Pacientes como Assunto/organização & administração , Equipamento de Proteção Individual/provisão & distribuição , Pneumonia Viral/imunologia , Pneumonia Viral/terapia , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/terapia , Vacinas Virais/biossínteseRESUMO
Schistosomiasis is widely distributed along the Senegal River Basin (SRB), affecting both the human population and their livestock. Damming of the Senegal River for irrigation purposes in the 1980s induced ecological changes that resulted in a large outbreak of Schistosoma mansoni, followed a few years later by an increase and spread of Schistosoma haematobium infections. The presence of hybrid crosses between the human and cattle schistosomes, S. haematobium and Schistosoma bovis, respectively, is adding complexity to the disease epidemiology in this area, and questions the strength of the species boundary between these two species. This study aimed to investigate the epidemiology of S. haematobium, S. bovis and their hybrids along the Senegal River basin using both microsatellite genetic markers and analysis of mitochondrial and nuclear DNA markers. Human schistosome populations with a S. haematobium cox1 mtDNA profile and those with a S. bovis cox1 mtDNA profile (the so-called hybrids) appear to belong to a single randomly mating population, strongly differentiated from the pure S. bovis found in cattle. These results suggest that, in northern Senegal, a strong species boundary persists between human and cattle schistosome species and there is no prolific admixing of the populations. In addition, we found that in the SRB S. haematobium was spatially more differentiated in comparison to S. mansoni. This may be related either to the presence and susceptibility of the intermediate snail hosts, or to the colonisation history of the parasite.
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Doenças dos Bovinos/parasitologia , Quimera/classificação , Variação Genética , Schistosoma/classificação , Schistosoma/isolamento & purificação , Esquistossomose/parasitologia , Esquistossomose/veterinária , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Quimera/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , Surtos de Doenças , Complexo IV da Cadeia de Transporte de Elétrons/genética , Humanos , Repetições de Microssatélites , Schistosoma/genética , Esquistossomose/epidemiologia , Senegal/epidemiologia , Análise de Sequência de DNARESUMO
INTRODUCTION: Hepatitis B virus (HBV) infection is highly endemic in Senegal. HBV vaccine of all children has been introduced in 1999 and included in the Expanded Programme on Immunization in 2004. The aim of this study was to assess the HBV prevalence and immunity status against HBV amongst children in Senegal. METHODS: Between March and August 2016, consecutive children aged from 6 months to 16 years old were recruited in outpatient department of three main children hospitals in Senegal. Serum samples were analyzed for HBV serology (HBsAg, HBcAb, HBsAb) using ARCHITECT analyzer. Children with HBsAb levels ≥ 10 IU/l) were considered as seroprotected against HBV. RESULTS: During the study period, 295 children fulfilled the criteria for the study and were further analyzed. Three children were HBsAg positive giving a seroprevalence at 1.1% (95% CI: 0.2-3.3), 12/267 (4.5%, 95% CI=2.3-7.7) had positive HBcAb and 226/295 (76.6%, 71.4-81.3) had positive HBsAb including 191 (77.3%, 71.6-82.4) with isolated HBsAb related to previous active immunization. However only 165 children (56%, CI 50-62) had seroprotective HBsAb levels (HBsAb ≥ 10 UI/L) and 63 (21.4, 16.8-26) had a strong seroprotectiondefined by HBsAb ≥ 100 IU/L. CONCLUSION: Our results suggest that although HBV prevalence has significantly decreased in children in Senegal following a better HBV vaccine coverage, the number of children correctly seroprotected is insufficient (56%). Assessing the levels of HBsAb and providing HBV vaccine boosters should be considered in children in Senegal.
Assuntos
Vacinas contra Hepatite B/administração & dosagem , Vírus da Hepatite B/isolamento & purificação , Hepatite B/epidemiologia , Cobertura Vacinal , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Hepatite B/prevenção & controle , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Humanos , Programas de Imunização , Lactente , Masculino , Prevalência , Senegal/epidemiologia , Estudos SoroepidemiológicosRESUMO
Here we assess the role of parasite genetic variation in host disease phenotype in human schistosomiasis by implementing concepts and techniques from environmental association analysis in evolutionary epidemiology. Schistosomiasis is a tropical disease that affects more than 200 million people worldwide and is caused by parasitic flatworms belonging to the genus Schistosoma. While the role of host genetics has been extensively studied and demonstrated, nothing is yet known on the contribution of parasite genetic variation to host disease phenotype in human schistosomiasis. In this study microsatellite genotypes of 1561 Schistosoma mansoni larvae collected from 44 human hosts in Senegal were linked to host characteristics such as age, gender, infection intensity, liver and bladder morbidity by means of multivariate regression methods (on each parasite locus separately). This revealed a highly significant association between allelic variation at the parasite locus L46951 and host infection intensity and bladder morbidity. Locus L46951 is located in the 3' untranslated region of the cGMP-dependent protein kinase gene that is expressed in reproductive organs of adult schistosome worms and appears to be linked to egg production. This putative link between parasite genetic variation and schistosomiasis disease phenotype sets the stage for further functional research.
Assuntos
Schistosoma mansoni/genética , Esquistossomose mansoni/patologia , Esquistossomose mansoni/parasitologia , Adolescente , Animais , Criança , Feminino , Variação Genética , Humanos , Masculino , Repetições de Microssatélites , Epidemiologia Molecular , Fenótipo , Schistosoma mansoni/classificação , Esquistossomose mansoni/epidemiologia , Senegal/epidemiologia , Adulto JovemRESUMO
Background. Management of clinical malaria requires the development of reliable diagnostic methods and efficient biomarkers for follow-up of patients. Protection is partly based on IgG responses to parasite antigens exposed at the surface of infected erythrocytes (iRBCs). These IgG responses appeared low during clinical infection, particularly in severe disease. Methods. We analyzed the IgG binding capacity to the surface of live erythrocytes infected by knob positive FCR3 strain. Sera from 69 cerebral malaria (CM) and 72 mild malaria (MM) cases were analyzed by ELISA for IgG responses to five antigens from iRBC and by flow cytometry for IgG binding as expressed in labeling index ratio (LIR). The relationship between IgG levels, LIR, parasitemia, age, and the clinical outcomes was evaluated. Results. We found a significant decrease of LIR in adult CM fatal cases compared to surviving patients (p = 0.019). In MM, LIRs were correlated to IgG anti-iRBC and anti-PfEMP3/5 levels. In CM, no correlation was found between LIR, IgG levels, and parasitemia. Conclusion. The IgG binding assay was able to discriminate outcome of cerebral malaria cases and it deserves further development as a potential functional-associated assay for symptomatic malaria analysis.