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1.
Open Forum Infect Dis ; 6(3): ofz068, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30949523

RESUMEN

The clinical, virologic, and immunologic findings in a female Ebola virus disease patient are described. During the long-term follow-up, Ebola virus RNA was detectable in vaginal fluid before 36 days after symptom onset, with nearly an identical genome sequence as in acute phase blood. Ebola-specific T cells retained activation at 56 days after disease onset.

2.
PLoS Negl Trop Dis ; 11(9): e0005827, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28892490

RESUMEN

BACKGROUND: During the 2014-2016 West Africa Ebola Virus Disease (EVD) epidemic, the public health community had concerns that sexual transmission of the Ebola virus (EBOV) from EVD survivors was a risk, due to EBOV persistence in body fluids of EVD survivors, particularly semen. The Sierra Leone Ebola Virus Persistence Study was initiated to investigate this risk by assessing EBOV persistence in numerous body fluids of EVD survivors and providing risk reduction counseling based on test results for semen, vaginal fluid, menstrual blood, urine, rectal fluid, sweat, tears, saliva, and breast milk. This publication describes implementation of the counseling protocol and the key lessons learned. METHODOLOGY/PRINCIPAL FINDINGS: The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol was developed from a framework used to prevent transmission of HIV and other sexually transmitted infections. The framework helped to identify barriers to risk reduction and facilitated the development of a personalized risk-reduction plan, particularly around condom use and abstinence. Pre-test and post-test counseling sessions included risk reduction guidance, and post-test counseling was based on the participants' individual test results. The behavioral counseling protocol enabled study staff to translate the study's body fluid test results into individualized information for study participants. CONCLUSIONS/SIGNIFICANCE: The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol provided guidance to mitigate the risk of EBOV transmission from EVD survivors. It has since been shared with and adapted by other EVD survivor body fluid testing programs and studies in Ebola-affected countries.


Asunto(s)
Terapia Conductista , Consejo , Transmisión de Enfermedad Infecciosa/prevención & control , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Asunción de Riesgos , Conducta Sexual , Femenino , Humanos , Masculino , Sierra Leona/epidemiología , Sobrevivientes
3.
PLoS Negl Trop Dis ; 11(9): e0005723, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28892501

RESUMEN

BACKGROUND: The 2013-2016 West African Ebola virus disease epidemic was unprecedented in terms of the number of cases and survivors. Prior to this epidemic there was limited data available on the persistence of Ebola virus in survivors' body fluids and the potential risk of transmission, including sexual transmission. METHODOLOGY/PRINCIPAL FINDINGS: Given the urgent need to determine the persistence of Ebola virus in survivors' body fluids, an observational cohort study was designed and implemented during the epidemic response operation in Sierra Leone. This publication describes study implementation methodology and the key lessons learned. Challenges encountered during implementation included unforeseen duration of follow-up, complexity of interpreting and communicating laboratory results to survivors, and the urgency of translating research findings into public health practice. Strong community engagement helped rapidly implement the study during the epidemic. The study was conducted in two phases. The first phase was initiated within five months of initial protocol discussions and assessed persistence of Ebola virus in semen of 100 adult men. The second phase assessed the persistence of virus in multiple body fluids (semen or vaginal fluid, menstrual blood, breast milk, and urine, rectal fluid, sweat, saliva, tears), of 120 men and 120 women. CONCLUSION/SIGNIFICANCE: Data from this study informed national and global guidelines in real time and demonstrated the need to implement semen testing programs among Ebola virus disease survivors. The lessons learned and study tools developed accelerated the implementation of such programs in Ebola virus disease affected countries, and also informed studies examining persistence of Zika virus. Research is a vital component of the public health response to an epidemic of a poorly characterized disease. Adequate resources should be rapidly made available to answer critical research questions, in order to better inform response efforts.


Asunto(s)
Líquidos Corporales/virología , Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/virología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sierra Leona , Sobrevivientes , Factores de Tiempo , Adulto Joven
4.
N Engl J Med ; 377(15): 1428-1437, 2017 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-26465681

RESUMEN

BACKGROUND: Ebola virus has been detected in the semen of men after their recovery from Ebola virus disease (EVD). We report the presence of Ebola virus RNA in semen in a cohort of survivors of EVD in Sierra Leone. METHODS: We enrolled a convenience sample of 220 adult male survivors of EVD in Sierra Leone, at various times after discharge from an Ebola treatment unit (ETU), in two phases (100 participants were in phase 1, and 120 in phase 2). Semen specimens obtained at baseline were tested by means of a quantitative reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay with the use of the target sequences of NP and VP40 (in phase 1) or NP and GP (in phase 2). This study did not evaluate directly the risk of sexual transmission of EVD. RESULTS: Of 210 participants who provided an initial semen specimen for analysis, 57 (27%) had positive results on quantitative RT-PCR. Ebola virus RNA was detected in the semen of all 7 men with a specimen obtained within 3 months after ETU discharge, in 26 of 42 (62%) with a specimen obtained at 4 to 6 months, in 15 of 60 (25%) with a specimen obtained at 7 to 9 months, in 4 of 26 (15%) with a specimen obtained at 10 to 12 months, in 4 of 38 (11%) with a specimen obtained at 13 to 15 months, in 1 of 25 (4%) with a specimen obtained at 16 to 18 months, and in no men with a specimen obtained at 19 months or later. Among the 46 participants with a positive result in phase 1, the median baseline cycle-threshold values (higher values indicate lower RNA values) for the NP and VP40 targets were lower within 3 months after ETU discharge (32.4 and 31.3, respectively; in 7 men) than at 4 to 6 months (34.3 and 33.1; in 25), at 7 to 9 months (37.4 and 36.6; in 13), and at 10 to 12 months (37.7 and 36.9; in 1). In phase 2, a total of 11 participants had positive results for NP and GP targets (samples obtained at 4.1 to 15.7 months after ETU discharge); cycle-threshold values ranged from 32.7 to 38.0 for NP and from 31.1 to 37.7 for GP. CONCLUSIONS: These data showed the long-term presence of Ebola virus RNA in semen and declining persistence with increasing time after ETU discharge. (Funded by the World Health Organization and others.).


Asunto(s)
Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/virología , Semen/virología , Adulto , Estudios de Cohortes , Estudios Transversales , Ebolavirus/genética , Fiebre Hemorrágica Ebola/terapia , Humanos , Masculino , ARN Viral/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sierra Leona , Sobrevivientes , Factores de Tiempo , Adulto Joven
5.
BMC Pediatr ; 14: 92, 2014 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-24708735

RESUMEN

BACKGROUND: Vitamin A supplementation significantly reduces all-cause mortality when given between 6-59 months of age, but has a null or detrimental effect when given between 1-5 months. Studies of neonatal vitamin A supplementation conducted across Africa and South Asia have produced conflicting findings. These age-pattern variations might result from immunological interactions between vitamin A supplementation and vaccines. Knowledge on the potential immunological sequelae of human neonatal vitamin A supplementation is so scarce that the foremost aim of this study is to seek indicative data on aspects of immunity likely to be affected by neonatal vitamin A supplementation. The objective of this trial is to test whether human neonatal vitamin A supplementation modulates immune function including improved thymic maturation in infancy and improved systemic immune responses to routine immunization. METHODS/DESIGN: In an area of moderate vitamin A deficiency in a peri-urban area of The Gambia, 200 mother-infant pairs were enrolled in a double-blind randomised controlled trial. Within 48 hours of birth, neonates were randomised with stratification by birth weight and sex to receive either an oral dose of 50,000 IU vitamin A or placebo. Expanded Programme of Immunisation birth vaccinations were administered after supplementation, with subsequent vaccinations administered at 8, 12 and 16 weeks of age. A range of immunological outcomes were examined up to 17 weeks of age, with additional morbidity and anthropometry follow-up carried out throughout the first year of life. The primary endpoint of this trial is the frequency of circulating T regulatory (Treg) cells expressing gut homing receptors in infants at 17 week post-supplementation, with secondary outcomes including thymus maturation and B cell immune responses. DISCUSSION: Indicative immunological data from this trial (and its Bangladeshi counterpart), will complement the larger randomised controlled trials (conducted in India, Tanzania and Ghana), on the effectiveness and safety of neonatal vitamin A supplementation in improving infant survival. Combined these trials, in addition to the existing trials, will inform policy. TRIAL REGISTRATION: clinicaltrials.gov NCT01476358.


Asunto(s)
Antioxidantes/administración & dosificación , Suplementos Dietéticos , Vitamina A/análogos & derivados , Linfocitos B/metabolismo , Diterpenos , Método Doble Ciego , Citometría de Flujo , Gambia , Anticuerpos contra la Hepatitis B/sangre , Humanos , Programas de Inmunización , Lactante , Recién Nacido , Intestinos/inmunología , Receptores Mensajeros de Linfocitos/metabolismo , Ésteres de Retinilo , Linfocitos T Reguladores/metabolismo , Timo/crecimiento & desarrollo , Vacunación , Vitamina A/administración & dosificación
6.
Infect Immun ; 74(1): 257-64, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16368979

RESUMEN

The isotype/subclass of immunoglobulin determines antibody function, but rather little is known about factors that direct class switching in vivo. To evaluate factors that might influence the maturation of the antibody response during infection, we conducted a seroepidemiological study of the immunoglobulin G (IgG) subclass response to four merozoite-associated antigens of Plasmodium falciparum in a mountainous region of northeastern Tanzania, where malaria endemicity declines with increasing altitudes. We found that IgG1/IgG3 class switching is independently affected by the nature of the antigen, cumulative exposure to the antigen, and the maturity of the immune system (i.e., the age of the individual). These observations provide insights into the effects of immune system maturity, the duration and intensity of antigen exposure, and inherent characteristics of individual antigens on the process of class switching in human B cells. Our data also throw light on the consequences of class switch decisions on the gradual acquisition of antimalarial immunity.


Asunto(s)
Envejecimiento/inmunología , Antígenos de Protozoos/fisiología , Cambio de Clase de Inmunoglobulina/fisiología , Inmunoglobulina G/biosíntesis , Inmunoglobulina G/clasificación , Malaria Falciparum/inmunología , Plasmodium falciparum/inmunología , Adolescente , Adulto , Animales , Linfocitos B/inmunología , Niño , Preescolar , Relación Dosis-Respuesta Inmunológica , Humanos , Inmunoglobulina G/genética , Malaria Falciparum/epidemiología , Prevalencia , Tanzanía/epidemiología , Factores de Tiempo
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