RESUMO
Zaire ebolavirus (EBOV) is a highly pathogenic filovirus which can result in Ebola virus disease (EVD); a serious medical condition that presents as flu like symptoms but then often leads to more serious or fatal outcomes. The 2013-16 West Africa epidemic saw an unparalleled number of cases. Here we show characterisation and identification of T cell epitopes in surviving patients from Guinea to the EBOV glycoprotein. We perform interferon gamma (IFNγ) ELISpot using a glycoprotein peptide library to identify T cell epitopes and determine the CD4+ or CD8+ T cell component response. Additionally, we generate data on the T cell phenotype and measure polyfunctional cytokine secretion by these antigen specific cells. We show candidate peptides able to elicit a T cell response in EBOV survivors and provide inferred human leukocyte antigen (HLA) allele restriction. This data informs on the long-term T cell response to Ebola virus disease and highlights potentially important immunodominant peptides.
Assuntos
Ebolavirus/imunologia , Epitopos de Linfócito T/imunologia , Glicoproteínas/imunologia , Doença pelo Vírus Ebola/imunologia , Linfócitos T/imunologia , África Ocidental/epidemiologia , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Ebolavirus/genética , ELISPOT , Epidemias , Glicoproteínas/genética , Doença pelo Vírus Ebola/epidemiologia , Humanos , Imunidade Celular , Interferon gama , SobreviventesRESUMO
After the large-scale outbreak of Ebola hemorrhagic fever (EHF) in Bandundu region, Democratic Republic of the Congo, a program was developed to help detect and prevent future outbreaks of EHF in the region. The long-term surveillance and prevention strategy is based on early recognition by physicians, immediate initiation of enhanced barrier-nursing practices, and the use of an immunohistochemical diagnostic test performed on formalin-fixed skin specimens of patients who die of suspected viral hemorrhagic fever. The program was implemented in September 1995 during a 4-day workshop with 28 local physicians representing 17 of 22 health zones in the region. Specimen collection kits were distributed to clinics in participating health zones, and a follow-up evaluation was conducted after 6 months. The use of a formalin-fixed skin specimen for laboratory confirmation of EHF can provide an appropriate method for EHF surveillance when linked with physician training, use of viral hemorrhagic fever isolation precautions, and follow-up investigation.
Assuntos
Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/epidemiologia , Vigilância da População/métodos , Adulto , República Democrática do Congo/epidemiologia , Surtos de Doenças/prevenção & controle , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Imuno-Histoquímica/métodos , Controle de Infecções , Modelos Teóricos , Pele/virologia , Design de Software , Fatores de TempoRESUMO
Three outbreaks of meningitis caused by Neisseria meningitidis serogroup A (subgroup III) are described: Niger (1991), Burundi (1992), and Guinea (1993). These outbreaks showed unusual characteristics: a shorter inter-epidemic interval (Niger), unusual geographical location outside the meningitis belt (Burundi and Guinea), and high age-specific attack rates in all age groups (Burundi and Guinea). Mass immunization campaigns mobilized considerable human and financial means (US $322,000 and 3000 person-days of work for health personnel to immunize 629,000 people in Guinea). The vaccination coverage was over 80% in densely populated areas (Burundi and urban Guinea), but below 50% in less populated areas (24/27 and 26/30 sub-districts in Niger and Guinea, respectively). The preventive fraction (proportion of cases prevented by vaccination) was substantial in Guinea (35% for a vaccine efficacy of 85%) and was higher where the campaign was initiated earlier. An 'alert' threshold indicating the onset of an epidemic of 15/100,000 cases in one week showed good sensitivity (94%), specificity (98%) and positive predictive value (89%) in Burundi, permitting quick decision making outside the meningitis belt. These 3 meningococcal meningitis outbreaks show the need for epidemic emergency preparedness and for vigilance on the whole African continent.
Assuntos
Surtos de Doenças/prevenção & controle , Meningite Meningocócica/epidemiologia , Meningite Meningocócica/prevenção & controle , Vacinação , Adolescente , Adulto , Distribuição por Idade , Burundi/epidemiologia , Criança , Pré-Escolar , Previsões/métodos , Guiné/epidemiologia , Humanos , Incidência , Lactente , Recém-Nascido , Meningite Meningocócica/mortalidade , Neisseria meningitidis/classificação , Neisseria meningitidis/isolamento & purificação , Níger/epidemiologia , Sensibilidade e Especificidade , Vacinação/economiaRESUMO
It is commonly assumed in public health practice that households in developing country settings are relatively homogeneous with respect to nutritional status. To the extent that this assumption is valid, nutritional assessments of mothers or individual children would provide an effective screening mechanism for household-level maternal-child nutritional risk. However, there has been no confirmation of the strength of intra-household correlations in nutritional status among women and children. Using data from a cross-sectional survey undertaken in 1990 in rural central Guinea, the present study investigates the nature of within-household relationships in maternal and child nutritional status and considers the implications for programme screening strategies. Mothers and their surviving children under 5 years of age are the focus of the analysis. Correlations between maternal and child nutritional levels are assessed and the performance of maternal-child nutritional indicators as screening tools for household nutritional risk are formally evaluated by analysing the sensitivity, specificity, and positive-negative predictive values of various indicators.
PIP: The authors explore to what extent households may be identified as being at risk of maternal-childhood malnutrition on the basis of a nutritional assessment of one household member. Cross-sectional survey data collected in 1990 from the central Guinean provinces of Labe, Tougue, Lelouma, Dolaba, and Pita, on 780 mothers and their 1118 surviving children under 5 years of age are the focus of the analysis. The survey had been conducted to obtain baseline data on nutrition and health problems in the region. Investigators assessed correlations between maternal and child nutrition, and formally evaluated the performance of maternal-child nutritional indicators as screening tools for household nutrition risk. Although significant intra-households correlations were found with regard to nutritional status among women and children, the data clearly indicate the inefficiency of screening for household-level maternal-child nutritional risk on the basis of anthropometric indicators for mothers and/or individual children under age five years.
Assuntos
Fenômenos Fisiológicos da Nutrição Infantil , Estado Nutricional , Mulheres , Adulto , Antropometria , Pré-Escolar , Estudos Transversais , Demografia , Feminino , Guiné/epidemiologia , Humanos , Lactente , Masculino , Distúrbios Nutricionais/epidemiologia , Inquéritos Nutricionais , População Rural , Estudos de AmostragemRESUMO
Measles immunization with the Edmonston Zagreb stain was carried out in 71 six-month-old infants. Proportions of subjects with immunity were 91% among the 47 subjects retested before one year of age and 100% among the 28 subjects retested between two and three years of age. These results support the WHO recommendation that measles immunization should be given at the age of six months. The concerns expressed by some about possible adverse effects of early measles immunization (decreased immune defenses) are discussed, as well as the transfer of maternal antibodies and persistence of these antibodies in the child. The obstacles to such studies in developing countries, including the need for repeated phlebotomies with centrifugation of specimens and freezing of sera, could be circumvented by the use of filter paper dried blood spot samples which seem to provide reliable results although with values somewhat lower than those found in frozen sera.