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1.
Clin Infect Dis ; 66(9): 1467-1469, 2018 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-29177461

RESUMEN

Randomized clinical trials are the most reliable approaches to evaluating the effects of new treatments and vaccines. During the 2014-2015 West African Ebola epidemic, many argued that such trials were neither ethical nor feasible in an environment of limited health infrastructure and severe disease with a high fatality rate. Consensus among the numerous organizations providing help to the affected areas was never achieved, resulting in fragmented collaboration, delayed study initiation, and ultimately failure to provide definitive evidence on the efficacy of treatments and vaccines. Randomized trials were in fact approved by local ethics boards and initiated, demonstrating that randomized trials, even in such difficult circumstances, are feasible. Improved planning and collaboration among research and humanitarian organizations, and affected communities, in the interepidemic periods are needed to ensure that questions regarding the efficacy of vaccines and treatments can be definitively answered during future public health emergencies.


Asunto(s)
Brotes de Enfermedades , Urgencias Médicas , Ética en Investigación , Salud Pública , Ensayos Clínicos Controlados Aleatorios como Asunto/normas , Proyectos de Investigación/normas , África Occidental/epidemiología , Grupos Control , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Fiebre Hemorrágica Ebola/epidemiología , Humanos
5.
Nat Med ; 10(4): 406-10, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15034567

RESUMEN

Many human T-cell responses specific for epitopes in Plasmodium falciparum have been described, but none has yet been shown to be predictive of protection against natural malaria infection. Here we report a peptide-specific T-cell assay that is strongly associated with protection of humans in The Gambia, West Africa, from both malaria infection and disease. The assay detects interferon-gamma-secreting CD4(+) T cells specific for a conserved sequence from the circumsporozoite protein, which binds to many human leukocyte antigen (HLA)-DR types. The correlation was observed using a cultured, rather than an ex vivo, ELISPOT assay that measures central memory-'type T cells rather than activated effector T cells. These findings provide direct evidence for a protective role for CD4(+) T cells in humans, and a precise target for the design of improved vaccines against P. falciparum.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Epítopos/inmunología , Malaria Falciparum/prevención & control , Proteínas Protozoarias/inmunología , Adolescente , Adulto , Secuencia de Aminoácidos , Secuencia Conservada , Ensayo de Inmunoadsorción Enzimática , Humanos , Memoria Inmunológica , Malaria Falciparum/inmunología , Persona de Mediana Edad , Datos de Secuencia Molecular
6.
J Multidiscip Healthc ; 14: 2195-2204, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34421303

RESUMEN

PURPOSE: Music and memory are inextricably linked, and the recollection of music varies according to age. In order to create personalized music playlists tailored for people living with dementia, this study aimed to determine the age at which healthy individuals could best recall music that was popular at the time. METHODS: A survey was designed asking participants to identify the number of songs they recalled from a random selection of 10 from the 100 most popular songs from each year, presented in random order of years, from 1945 to 2015. Of the 311 individuals born between 1929 and 2002, who responded to the survey, 157 met the inclusion criteria. RESULTS: The median peak of recollection was between the ages of 13 and 19 across all age-cohorts, with participants recalling a maximum median number of 6-8 songs in all of the age-cohorts. There was no evidence of a difference in the peak age of recollection between those who recognized seven or more songs in at least 1 year and those who recognized fewer than seven songs in all years. CONCLUSION: The peak of recollection of popular music occurs in the teenage years, regardless of era of birth. Music from this "reminiscence bump" provides a rich source of retained music that should be tapped when creating playlists of meaningful music for people living with dementia.

7.
Hum Resour Health ; 7: 76, 2009 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-19698146

RESUMEN

BACKGROUND: To increase access to antiretroviral therapy in resource-limited settings, several experts recommend "task shifting" from doctors to clinical officers, nurses and midwives. This study sought to identify task shifting that has already occurred and assess the antiretroviral therapy training needs among clinicians to whom tasks have shifted. METHODS: The Infectious Diseases Institute, in collaboration with the Ugandan Ministry of Health, surveyed health professionals and heads of antiretroviral therapy clinics at a stratified random sample of 44 health facilities accredited to provide this therapy. A sample of 265 doctors, clinical officers, nurses and midwives reported on tasks they performed, previous human immunodeficiency virus training, and self-assessment of knowledge of human immunodeficiency virus and antiretroviral therapy. Heads of the antiretroviral therapy clinics reported on clinic characteristics. RESULTS: Thirty of 33 doctors (91%), 24 of 40 clinical officers (60%), 16 of 114 nurses (14%) and 13 of 54 midwives (24%) who worked in accredited antiretroviral therapy clinics reported that they prescribed this therapy (p<0.001). Sixty-four percent of the people who prescribed antiretroviral therapy were not doctors. Among professionals who prescribed it, 76% of doctors, 62% of clinical officers, 62% of nurses and 51% of midwives were trained in initiating patients on antiretroviral therapy (p=0.457); 73%, 46%, 50% and 23%, respectively, were trained in monitoring patients on the therapy (p=0.017). Seven percent of doctors, 42% of clinical officers, 35% of nurses and 77% of midwives assessed that their overall knowledge of antiretroviral therapy was lower than good (p=0.001). CONCLUSION: Training initiatives should be an integral part of the support for task shifting and ensure that antiretroviral therapy is used correctly and that toxicity or drug resistance do not reverse accomplishments to date.

8.
Am J Respir Crit Care Med ; 178(2): 203-7, 2008 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-18420963

RESUMEN

RATIONALE: Tuberculosis remains a major cause of morbidity and mortality in the developing world. A better understanding of the mechanisms of disease protection could allow novel strategies to disease management and control. OBJECTIVES: To identify human genomic loci with evidence of linkage to tuberculosis susceptibility and, within these loci, to identify individual genes influencing tuberculosis susceptibility. METHODS: Affected sibling pair analysis in South African and Malawian populations. Independent case-control study in West Africa. MEASUREMENTS AND MAIN RESULTS: Two novel putative loci for tuberculosis susceptibility are identified: chromosome 6p21-q23 and chromosome 20q13.31-33--the latter with the strongest evidence for any locus reported to date in human tuberculosis (single point LOD score of 3.1, P = 10(-4), with a maximum likelihood score [MLS] of 2.8). An independent, multistage genetic association study in West African populations mapped this latter region in detail, finding evidence that variation in the melanocortin 3 receptor (MC3R) and cathepsin Z (CTSZ) genes play a role in the pathogenesis of tuberculosis. CONCLUSIONS: These results demonstrate how a genomewide approach to the complex phenotype of human tuberculosis can identify novel targets for further research.


Asunto(s)
Catepsinas/genética , Polimorfismo Genético , Receptor de Melanocortina Tipo 3/genética , Tuberculosis Pulmonar/etnología , Tuberculosis Pulmonar/genética , África Occidental/epidemiología , Población Negra/genética , Estudios de Casos y Controles , Catepsina K , Catepsina Z , Ligamiento Genético , Predisposición Genética a la Enfermedad/etnología , Predisposición Genética a la Enfermedad/genética , Humanos , Funciones de Verosimilitud , Malaui/epidemiología , Repeticiones de Microsatélite , Linaje , Análisis de Regresión , Hermanos , Sudáfrica/epidemiología
9.
Artículo en Inglés | MEDLINE | ID: mdl-17989427

RESUMEN

This article describes immunological HIV progression, mortality, and its predictors in 974 Zambian adults. During 3138 person-years of follow-up, 281 deaths occurred, and the overall mortality rate was 9.0 per 100 person-years. Thirty-six percent of patients were dead within 5 years of enrollment. The median survival in patients with baseline CD4 count ≥500 cells/mm³ was 5.62 years, with CD4 count between 200 and 499 cells/mm³ 5.46 years, and with CD4 count <200 cells/mm³ 3.89 years. The mortality rate increased significantly with older age (6.9 in patients <25 years, 9.3 in individuals aged 25-39 years, 10.2 in patients ≥40 years) and was higher in women (rate ratio 1.29). The median annual change of progression markers was -29.6 cells/mm³ for CD4 count, -3.0% for CD4 count percentage, 1.2 nmol/L for neopterin, -1.9 g/L for hemoglobin, and -70 cells/mm³ for total lymphocyte count. Hemoglobin and neopterin were as accurate as CD4 count to predict mortality.


Asunto(s)
Progresión de la Enfermedad , Infecciones por VIH/inmunología , Infecciones por VIH/mortalidad , Adulto , Distribución por Edad , Anemia/sangre , Biomarcadores , Recuento de Linfocito CD4 , Estudios de Cohortes , Femenino , Infecciones por VIH/diagnóstico , Humanos , Estimación de Kaplan-Meier , Masculino , Neopterin/sangre , Pronóstico , Distribución por Sexo , Zambia/epidemiología
10.
PLoS Med ; 4(6): e192, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17564487

RESUMEN

BACKGROUND: Very little longitudinal information is available regarding the performance of T cell-based tests for Mycobacterium tuberculosis infection. To address this deficiency, we conducted a longitudinal assessment of the enzyme-linked immunosorbent spot test (ELISPOT) test in comparison to the standard tuberculin skin test (TST). METHODS AND FINDINGS: In tuberculosis (TB) contacts we repeated ELISPOT tests 3 mo (n = 341) and 18 mo (n = 210) after recruitment and TSTs at 18 mo (n = 130). We evaluated factors for association with conversion and reversion and investigated suspected cases of TB. Of 207 ELISPOT-negative contacts, 51 (24.6%) had 3-mo ELISPOT conversion, which was associated with a positive recruitment TST (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.0-5.0, p = 0.048) and negatively associated with bacillus Calmette-Guérin (BCG) vaccination (OR 0.5, 95% CI 0.2-1.0, p = 0.06). Of 134 contacts, 54 (40.2%) underwent 3-mo ELISPOT reversion, which was less likely in those with a positive recruitment TST (OR 0.3, 95% CI 0.1-0.8, p = 0.014). Between 3 and 18 mo, 35/132 (26.5%) contacts underwent ELISPOT conversion and 28/78 (35.9%) underwent ELISPOT reversion. Of the 210 contacts with complete results, 73 (34.8%) were ELISPOT negative at all three time points; 36 (17.1%) were positive at all three time points. Between recruitment and 18 mo, 20 (27%) contacts had ELISPOT conversion; 37 (50%) had TST conversion, which was associated with a positive recruitment ELISPOT (OR 7.2, 95% CI 1.4-37.1, p = 0.019); 18 (32.7%) underwent ELISPOT reversion; and five (8.9%) underwent TST reversion. Results in 13 contacts diagnosed as having TB were mixed, but suggested higher TST sensitivity. CONCLUSIONS: Both ELISPOT conversion and reversion occur after M. tuberculosis exposure. Rapid ELISPOT reversion may reflect M. tuberculosis clearance or transition into dormancy and may contribute to the relatively low reported ELISPOT conversion rate. Therefore, a negative ELISPOT test for M. tuberculosis infection should be interpreted with caution.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática , Interferón gamma/análisis , Mycobacterium tuberculosis/aislamiento & purificación , Linfocitos T/metabolismo , Tuberculosis/diagnóstico , Adolescente , Adulto , Anciano , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Estudios de Cohortes , Trazado de Contacto , ADN Bacteriano/genética , Bases de Datos Factuales , Reacciones Falso Negativas , Femenino , Estudios de Seguimiento , Gambia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/inmunología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Esputo/microbiología , Linfocitos T/inmunología , Factores de Tiempo , Prueba de Tuberculina , Tuberculosis/epidemiología , Tuberculosis/inmunología , Tuberculosis/microbiología
11.
J Clin Invest ; 111(11): 1747-55, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12782677

RESUMEN

Immunization of newborns against viral infections may be hampered by ineffective CD8(+) T cell responses. To characterize the function of CD8(+) T lymphocytes in early life, we studied newborns with congenital human cytomegalovirus (HCMV) infection. We demonstrate that HCMV infection in utero leads to the expansion and the differentiation of mature HCMV-specific CD8(+) T cells, which have similar characteristics to those detected in adults. High frequencies of HCMV-specific CD8(+) T cells were detected by ex vivo tetramer staining as early as after 28 weeks of gestation. During the acute phase of infection, these cells had an early differentiation phenotype (CD28(-)CD27(+)CD45RO(+), perforin(low)), and they acquired a late differentiation phenotype (CD28(-)CD27(-)CD45RA(+), perforin(high)) during the course of the infection. The differentiated cells showed potent perforin-dependent cytolytic activity and produced antiviral cytokines. The finding of a mature and functional CD8(+) T cell response to HCMV suggests that the machinery required to prime such responses is in place during fetal life and could be used to immunize newborns against viral pathogens.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Feto/inmunología , Feto/virología , Antígenos CD28/biosíntesis , Linfocitos T CD8-positivos/metabolismo , Diferenciación Celular , Infecciones por Citomegalovirus/inmunología , Infecciones por Citomegalovirus/prevención & control , Femenino , Citometría de Flujo , Antígenos de Histocompatibilidad/química , Humanos , Memoria Inmunológica/inmunología , Inmunofenotipificación , Recién Nacido , Antígenos Comunes de Leucocito/biosíntesis , Glicoproteínas de Membrana/biosíntesis , Péptidos/química , Perforina , Fenotipo , Reacción en Cadena de la Polimerasa , Proteínas Citotóxicas Formadoras de Poros , Embarazo , Factores de Tiempo , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/biosíntesis
12.
Trans R Soc Trop Med Hyg ; 101(7): 691-8, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17434194

RESUMEN

Commercial tests measuring IFN-gamma responses to ESAT-6 and CFP-10 are available for diagnosing Mycobacterium tuberculosis infection. Measures that minimize cost and complexity will facilitate their application in less-developed countries. We investigated whether overlapping peptides representing both ESAT-6 and CFP-10 are required to detect M. tuberculosis infection in a high TB-burden country, and whether they can be combined in a single pool. ESAT-6 and CFP-10 peptides were compared in IFN-gamma enzyme-linked immunospot (ELISPOT) in 183 HIV-negative smear-positive TB cases and 1673 HIV-negative household contacts. Separate peptide pools for each antigen were compared with a combined pool in 498 contacts. Forty per cent of responsive contacts recognized both antigens, 51% only ESAT-6 and 10% only CFP-10, whereas 56% of responsive cases recognized both antigens, 30% only ESAT-6 and 13% only CFP-10. Accordingly, CFP-10 response rates were higher for TB cases (odds ratio 2.409, P<0.001). Low purified protein derivative response rates indicated that responses to CFP-10 only were non-specific in contacts. Agreement between peptides in separate versus combined pools was good (kappa=0.758, r=0.840). Therefore a combined ESAT-6/CFP-10 peptide pool provided maximum sensitivity and efficiency, but CFP-10 was mainly required to detect active disease.


Asunto(s)
Antígenos Bacterianos/análisis , Proteínas Bacterianas/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Mycobacterium tuberculosis/inmunología , Tuberculosis Pulmonar/diagnóstico , Adolescente , Adulto , Niño , Femenino , Gambia , Humanos , Masculino , Sensibilidad y Especificidad , Prueba de Tuberculina , Tuberculosis Pulmonar/transmisión
13.
Trans R Soc Trop Med Hyg ; 101(6): 594-601, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17368495

RESUMEN

Contact investigation is a key component of tuberculosis (TB) control in developed, but not developing, countries. We aimed to measure the prevalence of TB among household contacts of sputum-smear-positive TB cases in The Gambia and to assess the sensitivity of an enzyme-linked immunospot (ELISPOT) assay in this regard. Household contacts of adult smear-positive TB patients were assessed by questionnaire, purified protein derivative (PPD) skin test, ELISPOT assay, physical examination, chest X-ray and sputum/gastric aspirate. Thirty-three TB cases were identified from 2174 of 2381 contacts of 317 adult smear-positive pulmonary TB patients, giving a prevalence of 1518/100000. The cases identified tended to have milder disease than those passively detected. The sensitivity of ESAT-6/CFP-10 ELISPOT test as a screening test for TB disease was estimated as 71%. Fifty-six per cent of contacts with a PPD skin test result >or=10mm induration had detectable responses to ESAT-6/CFP-10 by ELISPOT; 11% with a negative PPD skin test (<10mm) had a positive ESAT-6/CFP-10 response. Active screening for TB among contacts of TB patients may have a role in TB control in The Gambia. These individuals are a high-risk group, and the disease identified is less advanced than that found through passive case detection. An ELISPOT assay was relatively insensitive as a screening test for TB.


Asunto(s)
Trazado de Contacto/métodos , Tuberculosis Pulmonar/epidemiología , Adolescente , Adulto , Anciano , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/normas , Composición Familiar , Femenino , Gambia/epidemiología , Humanos , Lactante , Masculino , Tamizaje Masivo/métodos , Persona de Mediana Edad , Prevalencia , Sensibilidad y Especificidad , Pruebas Cutáneas/métodos , Esputo/microbiología , Prueba de Tuberculina , Tuberculosis Pulmonar/diagnóstico
14.
BMC Infect Dis ; 6: 66, 2006 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-16573826

RESUMEN

BACKGROUND: New tools are required to improve tuberculosis (TB) diagnosis and treatment, including enhanced ability to compare new treatment strategies. The ELISPOT assay uses Mycobacterium tuberculosis-specific antigens to produce a precise quantitative readout of the immune response to pathogen. We hypothesized that TB patients in The Gambia would have reduced ELISPOT counts after successful treatment. METHODS: We recruited Gambian adults with sputum smear and culture positive tuberculosis for ELISPOT assay and HIV test, and followed them up one year later to repeat testing and document treatment outcome. We used ESAT-6, CFP-10 and Purified Protein Derivative (PPD) as stimulatory antigens. We confirmed the reliability of our assay in 23 volunteers through 2 tests one week apart, comparing within and between subject variation. RESULTS: We performed an ELISPOT test at diagnosis and 12 months later in 89 patients. At recruitment, 70/85 HIV-negative patients (82%) were ESAT-6 or CFP-10 (EC) ELISPOT positive, 77 (90%) were PPD ELISPOT positive. Eighty-two cases (96%) successfully completed treatment: 44 (55%; p < 0.001) were EC ELISPOT negative at 12 months, 17 (21%; p = 0.051) were PPD ELISPOT negative. Sixty (73%) cured cases had a CFP-10 ELISPOT count decrease, 64 (78%) had an ESAT-6 ELISPOT count decrease, 58 (70%) had a PPD ELISPOT count decrease. There was a mean decline of 25, 44 and 47 SFU/2 x 105 cells for CFP-10, ESAT-6 and PPD respectively (p < 0.001 for all). Three of 4 HIV positive patients were cured, all 3 underwent ELISPOT reversion; all 4 not cured subjects (3 HIV-negative, 1 HIV positive) were ESAT-6, CFP-10 and PPD ELISPOT positive at 12 months. CONCLUSION: Successful tuberculosis treatment is accompanied by a significant reduction in the M. tuberculosis-specific antigen ELISPOT count. The ELISPOT has potential as a proxy measure of TB treatment outcome. Further investigation into the decay kinetics of T-cells with treatment is warranted.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática/métodos , Mycobacterium tuberculosis/inmunología , Tuberculosis/tratamiento farmacológico , Tuberculosis/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos Bacterianos/inmunología , Femenino , Gambia/epidemiología , Humanos , Interferón gamma/inmunología , Masculino , Persona de Mediana Edad , Esputo/microbiología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Tuberculosis/sangre , Tuberculosis/microbiología
15.
Stroke ; 36(7): 1388-93, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15947255

RESUMEN

BACKGROUND AND PURPOSE: Despite increasing burden of stroke in Africa, prospective descriptive data are rare. Our objective was to describe, in The Gambia, the clinical outcome of stroke patients admitted to the Royal Victoria Teaching Hospital in the capital Banjul, to assess mortality and morbidity, and propose preventive and therapeutic measures. METHODS: Prospective data were collected on consecutive patients older than 15 years old admitted between February 2000 and February 2001 with the diagnosis of nonsubarachnoid stroke. Risk factors, clinical characteristics, and social consequences were assessed using a modified National Institutes of Health Stroke Scale (mNIHSS), the Barthel Activity in Daily Living scale, the Siriraj score for subtypes, and the Bamford criteria for location/extension. Patients were followed-up at home up to 1 year after discharge. RESULTS: Ninety-one percent (148/162) of eligible patients were enrolled and followed-up. Hypertension and smoking were the most prevalent risk factors. Severity was high at admission, especially in women, and was strongly correlated to the outcome. mNIHSS and consciousness level on admission were strong predictors of the mortality risk. Swallowing difficulties at admission, fever, lung infection, and no aspirin treatment were, independently, risk factors for a lethal outcome susceptible to being addressed by treatment. Mortality was 41% in-hospital and 62% after 1 year. In survivors, autonomy levels improved over time. Drug compliance was poor. At home, family members provided care. Long-term socioeconomic and cultural activities were affected in most patients. CONCLUSIONS: Case-fatality was high compared with Western cohorts. Preventive measures can be developed. Rational treatment, in the absence of head imaging for initial assessment, requires adapted protocols. Providers should be trained, both at hospital and community levels.


Asunto(s)
Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/patología , Actividades Cotidianas , Adulto , Anciano , Anciano de 80 o más Años , Infarto Cerebral , Estudios de Cohortes , Servicios de Salud Comunitaria , Países en Desarrollo , Femenino , Estudios de Seguimiento , Gambia , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Recuperación de la Función , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores Socioeconómicos , Accidente Cerebrovascular/epidemiología , Factores de Tiempo , Resultado del Tratamiento
16.
Clin Infect Dis ; 40(2): 273-8, 2005 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-15655747

RESUMEN

BACKGROUND: Currently, reliable efficacy markers for assessment of new interventions against tuberculosis (TB) are limited to disease and death. More precise measurement of the human immune response to Mycobacterium tuberculosis infection may be important. A qualitative enzyme-linked immunospot assay (ELISPOT) result for early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) offers improved specificity over the purified protein derivative (PPD) skin test reaction in the detection of M. tuberculosis infection. We evaluated the quantitative ELISPOT and PPD skin test responses to recent M. tuberculosis exposure. METHODS: We studied quantitative PPD skin test and PPD ELISPOT results in 1052 healthy household contacts of index patients with cases of sputum smear-positive and culture-positive TB in The Gambia, according to a positive or negative ex vivo interferon gamma ELISPOT response to M. tuberculosis-specific antigens (ESAT-6/CFP-10). We then studied the quantitative PPD skin test and PPD ELISPOT results in patient contacts who had positive ESAT-6/CFP-10 results against a natural exposure gradient according to sleeping proximity to a patient with TB. RESULTS: The number of positive results was significantly greater for both PPD skin test and PPD ELISPOT in ESAT-6/CFP-10-positive subjects, compared with others (P<.0001). However, when quantitative PPD skin test and PPD ELISPOT results were compared in ESAT-6/CFP-10-positive subjects, only the ELISPOT count was sensitive to the exposure gradient, increasing significantly according to exposure (P=.009). CONCLUSIONS: The quantitative ELISPOT response to PPD in specific-antigen-positive contacts of patients with TB reflects the infectious load of M. tuberculosis as a result of recent exposure. This finding offers new possibilities for assessment of the efficacy of new interventions, and adjustment should be made for it when relating the early immune response to progression to disease.


Asunto(s)
Trazado de Contacto , Mycobacterium tuberculosis/aislamiento & purificación , Linfocitos T/inmunología , Tuberculosis/microbiología , Tuberculosis/transmisión , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Gambia/epidemiología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/inmunología , Prueba de Tuberculina , Tuberculosis/epidemiología , Tuberculosis/inmunología
17.
J Endotoxin Res ; 11(5): 281-6, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16263000

RESUMEN

To determine whether variation in two interleukin 1 family genes (IL1B and interleukin 1 receptor antagonist, IL1RN) is associated with pulmonary tuberculosis (TB), two published polymorphisms at nucleotide positions -511 and +3953 in IL1B and one in the IL1RN 86 bp VNTR were genotyped in 335 smear positive Gambian TB patients, and 298 ethnically matched controls. All individuals were HIV negative. Decreased risk of pulmonary TB was associated with both heterozygosity and homozygosity for the IL1B-511-C allele (OR 0.66, P = 0.027, and OR 0.58, P = 0.015, respectively). Nonetheless, the C allele was present at a frequency of 0.66 in TB cases suggesting that whilst IL-1beta contributes to disease susceptibility, it is not the major factor. There was no association between the IL1B+3953-T/C polymorphism or the 86 bp IL1RN pentallelic repeat and TB in this population. Using an ex-vivo whole blood assay, healthy Gambian individuals who are homozygous for the IL1B-511-T allele failed to exhibit a significant increase in IL-1beta production in response to LPS after IFN-gamma priming.


Asunto(s)
Interleucina-1/genética , Tuberculosis Pulmonar/genética , Adolescente , Adulto , Anciano , Alelos , Estudios de Casos y Controles , Femenino , Gambia , Humanos , Interferón gamma/fisiología , Lipopolisacáridos/farmacología , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Receptores de Interleucina-1/antagonistas & inhibidores , Tuberculosis Pulmonar/microbiología
18.
Lancet ; 363(9415): 1093-8, 2004 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-15064026

RESUMEN

BACKGROUND: Eye-seeking flies have received much attention as possible trachoma vectors, but this remains unproved. We aimed to assess the role of eye-seeking flies as vectors of trachoma and to test provision of simple pit latrines, without additional health education, as a sustainable method of fly control. METHODS: In a community-based, cluster-randomised controlled trial, we recruited seven sets of three village clusters and randomly assigned them to either an intervention group that received regular insecticide spraying or provision of pit latrines (without additional health education) to each household, or to a control group with no intervention. Our primary outcomes were fly-eye contact and prevalence of active trachoma. Frequency of child fly-eye contact was monitored fortnightly. Whole communities were screened for clinical signs of trachoma at baseline and after 6 months. Analysis was per protocol. FINDINGS: Of 7080 people recruited, 6087 (86%) were screened at follow-up. Baseline community prevalence of active trachoma was 6%. The number of Musca sorbens flies caught from children's eyes was reduced by 88% (95% CI 64-100; p<0.0001) by insecticide spraying and by 30% (7-52; p=0.04) by latrine provision by comparison with controls. Analysis of age-standardised trachoma prevalence rates at the cluster level (n=14) showed that spraying was associated with a mean reduction in trachoma prevalence of 56% (19-93; p=0.01) and 30% with latrines (-81 to 22; p=0.210) by comparison with the mean rate change in the controls. INTERPRETATION: Fly control with insecticide is effective at reducing the number of flies caught from children's eyes and is associated with substantially lower trachoma prevalence compared with controls. Such a finding is consistent with flies being important vectors of trachoma. Since latrine provision without health education was associated with a significant reduction in fly-eye contact by M sorbens, studies of their effect when combined with other trachoma control measures are warranted.


Asunto(s)
Dípteros/microbiología , Control de Insectos/métodos , Cuartos de Baño/normas , Tracoma/prevención & control , Administración de Residuos/métodos , Adolescente , Animales , Niño , Preescolar , Chlamydia trachomatis/aislamiento & purificación , Dípteros/efectos de los fármacos , Gambia/epidemiología , Humanos , Lactante , Insectos Vectores/microbiología , Insecticidas/uso terapéutico , Evaluación de Resultado en la Atención de Salud , Prevalencia , Tracoma/epidemiología
19.
Clin Infect Dis ; 38(7): 966-73, 2004 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-15034828

RESUMEN

The purified protein derivative (PPD) skin test for Mycobacterium tuberculosis infection lacks specificity. We assessed 2 more specific M. tuberculosis antigens (ESAT-6 and CFP-10) by enzyme-linked immunospot assay (ELISPOT) compared with PPD by ELISPOT and skin test in The Gambia. Of 735 household contacts of 130 sputum smear-positive tuberculosis cases, 476 (65%) tested positive by PPD ELISPOT, 300 (41%) tested positive by PPD skin test, and 218 (30%) tested positive by ESAT-6/CFP-10 ELISPOT. Only 15 (2%) had positive ESAT-6/CFP-10 results and negative PPD results by ELISPOT. With increasing M. tuberculosis exposure, the percentage of subjects who were PPD skin test positive/ESAT-6/CFP-10 ELISPOT negative increased (P<.001), whereas the percentage of subjects who were PPD skin test negative/PPD ELISPOT positive decreased (P=.011). Eighteen (31%) ESAT-6/CFP-10 ELISPOT-positive subjects in the lowest exposure category had negative PPD skin test results. ESAT-6/CFP-10 ELISPOT probably offers increased specificity in the diagnosis of M. tuberculosis infection in this tropical setting of endemicity, at the cost of some sensitivity.


Asunto(s)
Antígenos Bacterianos/análisis , Proteínas Bacterianas/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Pruebas Cutáneas/métodos , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Gambia , Humanos , Lactante , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Tuberculina/análisis
20.
Pediatr Infect Dis J ; 21(10): 940-7, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12394817

RESUMEN

BACKGROUND: Pneumococcal polysaccharide/protein conjugate vaccines (PnCV) are immunogenic and effective in infancy. However, an addition to the nine currently recommended vaccine injections during the first year of life of African children may be a deterrent to participation in a PnCV program. Thus we have evaluated the safety and immunogenicity of a 9-valent PnCV (Wyeth Lederle Pediatrics and Vaccines) mixed with diphtheria, tetanus toxoid, cell pertussis and type b (TETRAMUNE). METHODS: Healthy Gambian infants were randomized at the age of 2 months to receive three doses 1 month apart of either (1) placebo reconstituted in TETRAMUNE in the right thigh (control) or (2) PnCV in the left thigh and TETRAMUNE in the right thigh (separate) or (3) PnCV reconstituted in TETRAMUNE as a single injection in the right thigh (combined). The vaccines were given together with routine Expanded Program on Immunization vaccines. Adverse reactions were recorded after vaccination, and antibody concentrations were measured by enzyme-linked immunosorbent assays. RESULTS: Local induration and tenderness were observed more commonly at the site of injection of TETRAMUNE than at the site of injection with PnCV after each dose of vaccination. Swelling at the site of injection was encountered more frequently at the site of administration of TETRAMUNE than at the site of administration PnCV ( P< 0.00001 for Doses 1 and 2 and P< 0.0009 for Dose 3). Swelling at the site of administration of TETRAMUNE mixed with PnCV was comparable with that observed for TETRAMUNE alone. Although most mothers reported that the babies "felt hot" 24 h after each injection, febrile reactions (temperature, >or=38 degrees C) were infrequent and resolved with antipyretics. Geometric mean titer for anti-polyribosylribitol phosphate antibody was 11.6 microg/ml [95% confidence limits (95% CI), 9.2, 14.6] in the control group and comparable with 13.3 microg/ml (95% CI 11.0, 16.0) in the combined group and significantly higher at 17.9 microg/ml (95% CI 14.7, 21.9; P= 0.01) in the separate group. Geometric mean concentrations of serotype-specific pneumococcal antibodies were higher in the combined group than the separate group for all nine serotypes. Antibody responses to diphtheria and pertussis antigens were similar in all groups. Anti-tetanus toxoid antibody concentrations were lowest in the combined group (6.66 IU/ml, 95% CI 5.77, 7.68 in the control group; 5.15 IU/ml, 95% CI 4.39, 6.03 in the combined group; P= 0.02). However, all vaccinees achieved protective antibody values. CONCLUSION: The combination of TETRAMUNE and PnCV is safe and immunogenic.


Asunto(s)
Vacuna contra Difteria, Tétanos y Tos Ferina/administración & dosificación , Vacunas contra Haemophilus/administración & dosificación , Inmunidad/fisiología , Polisacáridos Bacterianos/administración & dosificación , Vacunación/métodos , Cápsulas Bacterianas , Intervalos de Confianza , Países en Desarrollo , Femenino , Gambia , Humanos , Programas de Inmunización/organización & administración , Esquemas de Inmunización , Lactante , Masculino , Probabilidad , Valores de Referencia , Seguridad , Vacunas Combinadas/administración & dosificación , Vacunas Conjugadas/administración & dosificación
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