RESUMEN
BACKGROUND: Long-term persistence of Ebola virus (EBOV) in immunologically privileged sites has been implicated in recent outbreaks of Ebola virus disease (EVD) in Guinea and the Democratic Republic of Congo. This study was designed to understand how the acute course of EVD, convalescence, and host immune and genetic factors may play a role in prolonged viral persistence in semen. METHODS: A cohort of 131 male EVD survivors in Liberia were enrolled in a case-case study. "Early clearers" were defined as those with 2 consecutive negative EBOV semen test results by real-time reverse-transcription polymerase chain reaction (rRT-PCR) ≥2 weeks apart within 1 year after discharge from the Ebola treatment unit or acute EVD. "Late clearers" had detectable EBOV RNA by rRT-PCR >1 year after discharge from the Ebola treatment unit or acute EVD. Retrospective histories of their EVD clinical course were collected by questionnaire, followed by complete physical examinations and blood work. RESULTS: Compared with early clearers, late clearers were older (median, 42.5 years; P < .001) and experienced fewer severe clinical symptoms (median 2, P = .006). Late clearers had more lens opacifications (odds ratio, 3.9 [95% confidence interval, 1.1-13.3]; P = .03), after accounting for age, higher total serum immunoglobulin G3 (IgG3) titers (P = .005), and increased expression of the HLA-C*03:04 allele (0.14 [.02-.70]; P = .007). CONCLUSIONS: Older age, decreased illness severity, elevated total serum IgG3 and HLA-C*03:04 allele expression may be risk factors for the persistence of EBOV in the semen of EVD survivors. EBOV persistence in semen may also be associated with its persistence in other immunologically protected sites, such as the eye.
Asunto(s)
Ebolavirus , Fiebre Hemorrágica Ebola , Humanos , Masculino , Ebolavirus/genética , Fiebre Hemorrágica Ebola/epidemiología , Semen , Liberia/epidemiología , Estudios Retrospectivos , Antígenos HLA-C , Sobrevivientes , Factores de RiesgoRESUMEN
BACKGROUND: In the immediate aftermath of a 14-year civil conflict that disrupted the health system, Liberia adopted the internationally recommended integrated disease surveillance and response (IDSR) strategy in 2004. Despite this, Liberia was among the three West African countries ravaged by the worst Ebola epidemic in history from 2014 to 2016. This paper describes successes, failures, strengths, and weaknesses in the development, adoption, and implementation of IDSR following the civil war and up until the outbreak of Ebola, from 2004 to early 2014. METHODS: We reviewed 112 official Government documents and peer-reviewed articles and conducted 29 in-depth interviews with key informants from December 2021 to March 2022 to gain perspectives on IDSR in the post-conflict and pre-Ebola era in Liberia. We assessed the core and supportive functions of IDSR, such as notification of priority diseases, confirmation, reporting, analysis, investigation, response, feedback, monitoring, staff training, supervision, communication, and financial resources. Data were triangulated and presented via emerging themes and in-depth accounts to describe the context of IDSR introduction and implementation, and the barriers surrounding it. RESULTS: Despite the adoption of the IDSR framework, Liberia failed to secure the resources-human, logistical, and financial-to support effective implementation over the 10-year period. Documents and interview reports demonstrate numerous challenges prior to Ebola: the surveillance system lacked key components of IDSR including laboratory testing capacity, disease reporting, risk communication, community engagement, and staff supervision systems. Insufficient financial support and an abundance of vertical programs further impeded progress. In-depth accounts by donors and key governmental informants demonstrate that although the system had a role in detecting Ebola in Liberia, it could not respond effectively to control the disease. CONCLUSION: Our findings suggest that post-war, Liberia's health system intended to prioritize epidemic preparedness and response with the adoption of IDSR. However, insufficient investment and systems development meant IDSR was not well implemented, leaving the country vulnerable to the devastating impact of the Ebola epidemic.
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Epidemias , Fiebre Hemorrágica Ebola , Humanos , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Liberia/epidemiología , Vigilancia en Salud Pública , Brotes de Enfermedades/prevención & control , Epidemias/prevención & controlRESUMEN
INTRODUCTION: Ebola virus (EBOV), species Zaire ebolavirus, may persist in the semen of male survivors of Ebola virus disease (EVD). We conducted a study of male survivors of the 2014-2016 EVD outbreak in Liberia and evaluated their immune responses to EBOV. We report here findings from the serologic testing of blood for EBOV-specific antibodies, molecular testing for EBOV in blood and semen, and serologic testing of peripheral blood mononuclear cells (PBMCs) in a subset of study participants. METHODS: We tested for EBOV RNA in blood by quantitative reverse transcription polymerase chain reaction (qRT-PCR), and for anti-EBOV-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies by enzyme-linked immunosorbent assay (ELISA) for 126 study participants. We performed PBMC analysis on a subgroup of 26 IgG-negative participants. RESULTS: All 126 participants tested negative for EBOV RNA in blood by qRT-PCR. The blood of 26 participants tested negative for EBOV-specific IgG antibodies by ELISA. PBMCs were collected from 23/26 EBOV IgG-negative participants. Of these, 1/23 participants had PBMCs that produced anti-EBOV-specific IgG antibodies upon stimulation with EBOV-specific glycoprotein (GP) and nucleoprotein (NP) antigens. CONCLUSIONS: The blood of EVD survivors, collected when they did not have symptoms meeting the case definition for acute or relapsed EVD, is unlikely to pose a risk for EBOV transmission. We identified 1 IgM/IgG negative participant who had PBMCs that produced anti-EBOV-specific antibodies upon stimulation. Immunogenicity following acute EBOV infection may exist along a spectrum, and absence of antibody response should not be exclusionary in determining an individual's status as a survivor of EVD.
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Ebolavirus , Fiebre Hemorrágica Ebola , Anticuerpos Antivirales , Ebolavirus/genética , Humanos , Leucocitos Mononucleares , Liberia/epidemiología , Masculino , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción Reversa , Semen , SobrevivientesRESUMEN
BACKGROUND: The safety and efficacy of vaccines to prevent Ebola virus disease (EVD) were unknown when the incidence of EVD was peaking in Liberia. METHODS: We initiated a randomized, placebo-controlled, phase 3 trial of the chimpanzee adenovirus 3 vaccine (ChAd3-EBO-Z) and the recombinant vesicular stomatitis virus vaccine (rVSV∆G-ZEBOV-GP) in Liberia. A phase 2 subtrial was embedded to evaluate safety and immunogenicity. Because the incidence of EVD declined in Liberia, the phase 2 component was expanded and the phase 3 component was eliminated. RESULTS: A total of 1500 adults underwent randomization and were followed for 12 months. The median age of the participants was 30 years; 36.6% of the participants were women. During the week after the administration of vaccine or placebo, adverse events occurred significantly more often with the active vaccines than with placebo; these events included injection-site reactions (in 28.5% of the patients in the ChAd3-EBO-Z group and 30.9% of those in the rVSV∆G-ZEBOV-GP group, as compared with 6.8% of those in the placebo group), headache (in 25.1% and 31.9%, vs. 16.9%), muscle pain (in 22.3% and 26.9%, vs. 13.3%), feverishness (in 23.9% and 30.5%, vs. 9.0%), and fatigue (in 14.0% and 15.4%, vs. 8.8%) (P<0.001 for all comparisons); these differences were not seen at 1 month. Serious adverse events within 12 months after injection were seen in 40 participants (8.0%) in the ChAd3-EBO-Z group, in 47 (9.4%) in the rVSV∆G-ZEBOV-GP group, and in 59 (11.8%) in the placebo group. By 1 month, an antibody response developed in 70.8% of the participants in the ChAd3-EBO-Z group and in 83.7% of those in the rVSV∆G-ZEBOV-GP group, as compared with 2.8% of those in the placebo group (P<0.001 for both comparisons). At 12 months, antibody responses in participants in the ChAd3-EBO-Z group (63.5%) and in those in the rVSV∆G-ZEBOV-GP group (79.5%) remained significantly greater than in those in the placebo group (6.8%, P<0.001 for both comparisons). CONCLUSIONS: A randomized, placebo-controlled phase 2 trial of two vaccines that was rapidly initiated and completed in Liberia showed the capability of conducting rigorous research during an outbreak. By 1 month after vaccination, the vaccines had elicited immune responses that were largely maintained through 12 months. (Funded by the National Institutes of Allergy and Infectious Diseases and the Liberian Ministry of Health; PREVAIL I ClinicalTrials.gov number, NCT02344407 .).
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Vacunas contra el Virus del Ébola/efectos adversos , Vacunas contra el Virus del Ébola/inmunología , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/prevención & control , Adenoviridae , Adulto , Animales , Brotes de Enfermedades , Método Doble Ciego , Femenino , Fiebre/etiología , Seropositividad para VIH/complicaciones , Cefalea/etiología , Fiebre Hemorrágica Ebola/complicaciones , Fiebre Hemorrágica Ebola/inmunología , Humanos , Inyecciones Intramusculares/efectos adversos , Liberia , Masculino , Mialgia/etiología , Pan troglodytes , ARN Viral/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , VesiculovirusRESUMEN
Ebola virus (EBOV) can persist in immunologically protected body sites in survivors of Ebola virus disease, creating the potential to initiate new chains of transmission. From the outbreak in West Africa during 2014-2016, we identified 13 possible events of viral persistence-derived transmission of EBOV (VPDTe) and applied predefined criteria to classify transmission events based on the strength of evidence for VPDTe and source and route of transmission. For 8 events, a recipient case was identified; possible source cases were identified for 5 of these 8. For 5 events, a recipient case or chain of transmission could not be confidently determined. Five events met our criteria for sexual transmission (male-to-female). One VPDTe event led to at least 4 generations of cases; transmission was limited after the other events. VPDTe has increased the importance of Ebola survivor services and sustained surveillance and response capacity in regions with previously widespread transmission.
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Brotes de Enfermedades , Ebolavirus , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/transmisión , Sobrevivientes , Adolescente , Adulto , África Occidental/epidemiología , Ebolavirus/clasificación , Ebolavirus/genética , Ebolavirus/aislamiento & purificación , Femenino , Fiebre Hemorrágica Ebola/virología , Humanos , Masculino , Persona de Mediana Edad , Vigilancia en Salud Pública , Adulto JovenRESUMEN
BACKGROUND: Rubella is an RNA virus in the genus Rubivirus within the Matonaviridae family. Rubella remains a leading vaccine-preventable cause of birth defects. Most African countries including Liberia do not currently provide rubella-containing vaccine (RCV) in their immunization program. We analyzed the existing surveillance data to describe rubella cases and identify the at-risk population. METHODS: We conducted a retrospective descriptive statistics on the suspected-measles case-based surveillance data that obtained from the national database. Suspected-measles cases who were negative and indeterminate for measles IgM and tested for rubella IgM were extracted from the database. We used only rubella IgM positive cases to calculate trends and percentages by person, place and time. The cumulative-percent curve was used to visually describe the age distribution of rubella cases. RESULTS: During 2017-2018, a total of 2027 suspected-measles cases with known laboratory results were reported; of which, 1307 were tested for rubella IgM. Among tested cases, 472 (36%) were positive, 769 (59%) were negative and 66 (5%) were indeterminate for rubella IgM. Female contributed 269 (57%) of the confirmed rubella cases respectively. The median age was 7 years with an interquartile range of 5-10 years. From the total rubella cases, 6 (1%) were under 1 year, 109 (23%) were 1-4 years, 207 (44%) were 5-9 years, 87 (18%) were 10-14 years and 56 (12%) were more than or equal to 15 years. Women in their reproductive-age contributed 23 (5%) of rubella cases with 17% positivity rate. Two-thirds or 307 (65%) of the cases were reported from February to May which is dry season in Liberia. CONCLUSIONS: Our analysis revealed that rubella was widely circulating in Liberia. Majority of the cases were reported among children < 15 years. However, rubella was also reported among women of reproductive age and infants < 1 year with no report of congenital rubella syndrome (CRS). Detail investigation of rubella cases among infants of < 1 year and women of reproductive age is important to uncover CRS. Establishment of CRS surveillance and the introduction of RCV in the immunization program are crucial to prevent rubella infection and avert the risk of CRS.
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Síndrome de Rubéola Congénita/diagnóstico , Vacuna contra la Rubéola/inmunología , Adolescente , Adulto , Niño , Preescolar , Bases de Datos Factuales , Femenino , Humanos , Programas de Inmunización , Inmunoglobulina M/sangre , Lactante , Liberia/epidemiología , Masculino , Sarampión/epidemiología , Estudios Retrospectivos , Síndrome de Rubéola Congénita/epidemiología , Síndrome de Rubéola Congénita/transmisión , Virus de la Rubéola/inmunología , Estaciones del Año , Adulto JovenRESUMEN
A suspected case of sexual transmission from a male survivor of Ebola virus disease (EVD) to his female partner (the patient in this report) occurred in Liberia in March 2015. Ebola virus (EBOV) genomes assembled from blood samples from the patient and a semen sample from the survivor were consistent with direct transmission. The genomes shared three substitutions that were absent from all other Western African EBOV sequences and that were distinct from the last documented transmission chain in Liberia before this case. Combined with epidemiologic data, the genomic analysis provides evidence of sexual transmission of EBOV and evidence of the persistence of infective EBOV in semen for 179 days or more after the onset of EVD. (Funded by the Defense Threat Reduction Agency and others.).
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Ebolavirus/genética , Fiebre Hemorrágica Ebola/transmisión , Semen/virología , Adulto , Coito , Ebolavirus/aislamiento & purificación , Femenino , Genoma Viral , Fiebre Hemorrágica Ebola/virología , Humanos , Liberia , Masculino , ARN Viral/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sexo InseguroRESUMEN
Events such as the 2014-2015 West Africa epidemic of Ebola virus disease highlight the importance of the capacity to detect and respond to public health threats. We describe capacity-building efforts during and after the Ebola epidemic in Liberia, Sierra Leone, and Guinea and public health progress that was made as a result of the Ebola response in 4 key areas: emergency response, laboratory capacity, surveillance, and workforce development. We further highlight ways in which capacity-building efforts such as those used in West Africa can be accelerated after a public health crisis to improve preparedness for future events.
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Fiebre Hemorrágica Ebola/epidemiología , Vigilancia en Salud Pública , Programas Médicos Regionales , África Occidental/epidemiología , Creación de Capacidad , Brotes de Enfermedades , Urgencias Médicas , Fiebre Hemorrágica Ebola/historia , Historia del Siglo XXI , Humanos , Evaluación de Resultado en la Atención de Salud , Salud Pública , Mejoramiento de la CalidadRESUMEN
Ebola virus is known to persist in semen of male survivors of Ebola virus disease (EVD). However, maximum duration of, or risk factors for, virus persistence are unknown. We report an EVD survivor with preexisting HIV infection, whose semen was positive for Ebola virus RNA 565 days after recovery from EVD.
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Ebolavirus/aislamiento & purificación , Infecciones por VIH/complicaciones , Fiebre Hemorrágica Ebola/virología , ARN Viral/aislamiento & purificación , Semen/virología , Humanos , Masculino , Persona de Mediana Edad , ARN Viral/química , Factores de Tiempo , Proteínas del Núcleo Viral/química , Proteínas de la Matriz Viral/químicaRESUMEN
Alison Galvani and colleagues describe a community-based protocol to improve cooperation with Ebola testing as well as contact tracing, quarantining, and treatment.
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Protocolos Clínicos , Participación de la Comunidad , Fiebre Hemorrágica Ebola/diagnóstico , Sistemas de Atención de Punto/estadística & datos numéricos , Vigilancia de la Población , Participación de la Comunidad/estadística & datos numéricos , Humanos , LiberiaRESUMEN
BACKGROUND: On March 23, 2014, the World Health Organization (WHO) was notified of an outbreak of Ebola virus disease (EVD) in Guinea. On August 8, the WHO declared the epidemic to be a "public health emergency of international concern." METHODS: By September 14, 2014, a total of 4507 probable and confirmed cases, including 2296 deaths from EVD (Zaire species) had been reported from five countries in West Africa--Guinea, Liberia, Nigeria, Senegal, and Sierra Leone. We analyzed a detailed subset of data on 3343 confirmed and 667 probable Ebola cases collected in Guinea, Liberia, Nigeria, and Sierra Leone as of September 14. RESULTS: The majority of patients are 15 to 44 years of age (49.9% male), and we estimate that the case fatality rate is 70.8% (95% confidence interval [CI], 69 to 73) among persons with known clinical outcome of infection. The course of infection, including signs and symptoms, incubation period (11.4 days), and serial interval (15.3 days), is similar to that reported in previous outbreaks of EVD. On the basis of the initial periods of exponential growth, the estimated basic reproduction numbers (R0 ) are 1.71 (95% CI, 1.44 to 2.01) for Guinea, 1.83 (95% CI, 1.72 to 1.94) for Liberia, and 2.02 (95% CI, 1.79 to 2.26) for Sierra Leone. The estimated current reproduction numbers (R) are 1.81 (95% CI, 1.60 to 2.03) for Guinea, 1.51 (95% CI, 1.41 to 1.60) for Liberia, and 1.38 (95% CI, 1.27 to 1.51) for Sierra Leone; the corresponding doubling times are 15.7 days (95% CI, 12.9 to 20.3) for Guinea, 23.6 days (95% CI, 20.2 to 28.2) for Liberia, and 30.2 days (95% CI, 23.6 to 42.3) for Sierra Leone. Assuming no change in the control measures for this epidemic, by November 2, 2014, the cumulative reported numbers of confirmed and probable cases are predicted to be 5740 in Guinea, 9890 in Liberia, and 5000 in Sierra Leone, exceeding 20,000 in total. CONCLUSIONS: These data indicate that without drastic improvements in control measures, the numbers of cases of and deaths from EVD are expected to continue increasing from hundreds to thousands per week in the coming months.
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Epidemias/estadística & datos numéricos , Fiebre Hemorrágica Ebola/epidemiología , Adolescente , Adulto , África Occidental/epidemiología , Niño , Ebolavirus , Femenino , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/transmisión , Humanos , Incidencia , Periodo de Incubación de Enfermedades Infecciosas , Masculino , Persona de Mediana Edad , Mortalidad , Adulto JovenRESUMEN
On April 25, 2017, a cluster of unexplained illness and deaths among persons who had attended a funeral during April 21-22 was reported in Sinoe County, Liberia (1). Using a broad initial case definition, 31 cases were identified, including 13 (42%) deaths. Twenty-seven cases were from Sinoe County (1), and two cases each were from Grand Bassa and Monsterrado counties, respectively. On May 5, 2017, initial multipathogen testing of specimens from four fatal cases using the Taqman Array Card (TAC) assay identified Neisseria meningitidis in all specimens. Subsequent testing using direct real-time polymerase chain reaction (PCR) confirmed N. meningitidis in 14 (58%) of 24 patients with available specimens and identified N. meningitidis serogroup C (NmC) in 13 (54%) patients. N. meningitidis was detected in specimens from 11 of the 13 patients who died; no specimens were available from the other two fatal cases. On May 16, 2017, the National Public Health Institute of Liberia and the Ministry of Health of Liberia issued a press release confirming serogroup C meningococcal disease as the cause of this outbreak in Liberia.
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Brotes de Enfermedades , Meningitis Meningocócica/epidemiología , Meningitis Meningocócica/microbiología , Neisseria meningitidis Serogrupo C/aislamiento & purificación , Servicios de Laboratorio Clínico/estadística & datos numéricos , Análisis por Conglomerados , Humanos , Liberia/epidemiología , Meningitis Meningocócica/mortalidad , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de TiempoRESUMEN
The development of point-of-care clinical chemistry analyzers has enabled the implementation of these ancillary tests in field laboratories in resource-limited outbreak areas. The Eternal Love Winning Africa (ELWA) outbreak diagnostic laboratory, established in Monrovia, Liberia, to provide Ebola virus and Plasmodium spp. diagnostics during the Ebola epidemic, implemented clinical chemistry analyzers in December 2014. Clinical chemistry testing was performed for 68 patients in triage, including 12 patients infected with Ebola virus and 18 infected with Plasmodium spp. The main distinguishing feature in clinical chemistry of Ebola virus-infected patients was the elevation in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyltransferase levels and the decrease in calcium. The implementation of clinical chemistry is probably most helpful when the medical supportive care implemented at the Ebola treatment unit allows for correction of biochemistry derangements and on-site clinical chemistry analyzers can be used to monitor electrolyte balance.
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Brotes de Enfermedades , Epidemias , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Malaria/diagnóstico , Adolescente , Alanina Transaminasa/análisis , Fosfatasa Alcalina/análisis , Aspartato Aminotransferasas/análisis , Química Clínica , Servicios de Laboratorio Clínico , Ebolavirus/inmunología , Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/virología , Humanos , Liberia/epidemiología , Pruebas de Función Hepática , Malaria/epidemiología , Malaria/parasitología , Masculino , Plasmodium/aislamiento & purificación , Plasmodium/metabolismo , Sistemas de Atención de Punto , gamma-Glutamiltransferasa/análisisRESUMEN
West Africa experienced the first epidemic of Ebola virus infection, with by far the greatest number of cases in Guinea, Sierra Leone, and Liberia. The unprecedented epidemic triggered an unparalleled response, including the deployment of multiple Ebola treatment units and mobile/field diagnostic laboratories. The National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention deployed a joint laboratory to Monrovia, Liberia, in August 2014 to support the newly founded Ebola treatment unit at the Eternal Love Winning Africa (ELWA) campus. The laboratory operated initially out of a tent structure but quickly moved into a fixed-wall building owing to severe weather conditions, the need for increased security, and the high sample volume. Until May 2015, when the laboratory closed, the site handled close to 6000 clinical specimens for Ebola virus diagnosis and supported the medical staff in case patient management. Laboratory operation and safety, as well as Ebola virus diagnostic assays, are described and discussed; in addition, lessons learned for future deployments are reviewed.
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Servicios de Laboratorio Clínico/organización & administración , Ebolavirus/aislamiento & purificación , Epidemias/prevención & control , Fiebre Hemorrágica Ebola/epidemiología , África Occidental/epidemiología , Centers for Disease Control and Prevention, U.S. , Femenino , Guinea/epidemiología , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Humanos , Cooperación Internacional , Liberia/epidemiología , Masculino , National Institute of Allergy and Infectious Diseases (U.S.) , Seguridad , Sierra Leona/epidemiología , Estados UnidosRESUMEN
BACKGROUND: The ongoing Ebola outbreak in West Africa has resulted in 28 646 suspected, probable, and confirmed Ebola virus infections. Nevertheless, malaria remains a large public health burden in the region affected by the outbreak. A joint Centers for Disease Control and Prevention/National Institutes of Health diagnostic laboratory was established in Monrovia, Liberia, in August 2014, to provide laboratory diagnostics for Ebola virus. METHODS: All blood samples from suspected Ebola virus-infected patients admitted to the Médecins Sans Frontières ELWA3 Ebola treatment unit in Monrovia were tested by quantitative real-time polymerase chain reaction for the presence of Ebola virus and Plasmodium species RNA. Clinical outcome in laboratory-confirmed Ebola virus-infected patients was analyzed as a function of age, sex, Ebola viremia, and Plasmodium species parasitemia. RESULTS: The case fatality rate of 1182 patients with laboratory-confirmed Ebola virus infections was 52%. The probability of surviving decreased with increasing age and decreased with increasing Ebola viral load. Ebola virus-infected patients were 20% more likely to survive when Plasmodium species parasitemia was detected, even after controlling for Ebola viral load and age; those with the highest levels of parasitemia had a survival rate of 83%. This effect was independent of treatment with antimalarials, as this was provided to all patients. Moreover, treatment with antimalarials did not affect survival in the Ebola virus mouse model. CONCLUSIONS: Plasmodium species parasitemia is associated with an increase in the probability of surviving Ebola virus infection. More research is needed to understand the molecular mechanism underlying this remarkable phenomenon and translate it into treatment options for Ebola virus infection.
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Coinfección , Ebolavirus , Fiebre Hemorrágica Ebola/complicaciones , Fiebre Hemorrágica Ebola/mortalidad , Malaria/complicaciones , Malaria/parasitología , Parasitemia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Modelos Animales de Enfermedad , Ebolavirus/genética , Femenino , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Lactante , Recién Nacido , Malaria/diagnóstico , Malaria/epidemiología , Masculino , Ratones , Persona de Mediana Edad , Carga de Parásitos , Plasmodium/genética , Tasa de Supervivencia , Carga Viral , Adulto JovenRESUMEN
The severe epidemic of Ebola virus disease in Liberia started in March 2014. On May 9, 2015, the World Health Organization declared Liberia free of Ebola, 42 days after safe burial of the last known case-patient. However, another 6 cases occurred during June-July; on September 3, 2015, the country was again declared free of Ebola. Liberia had by then reported 10,672 cases of Ebola and 4,808 deaths, 37.0% and 42.6%, respectively, of the 28,103 cases and 11,290 deaths reported from the 3 countries that were heavily affected at that time. Essential components of the response included government leadership and sense of urgency, coordinated international assistance, sound technical work, flexibility guided by epidemiologic data, transparency and effective communication, and efforts by communities themselves. Priorities after the epidemic include surveillance in case of resurgence, restoration of health services, infection control in healthcare settings, and strengthening of basic public health systems.
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Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Manejo de la Enfermedad , Comunicación en Salud , Personal de Salud , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/historia , Historia del Siglo XXI , Humanos , Liberia/epidemiología , Aislamiento de Pacientes , Vigilancia de la PoblaciónRESUMEN
Malaria is a major public health concern in the countries affected by the Ebola virus disease epidemic in West Africa. We determined the feasibility of using molecular malaria diagnostics during an Ebola virus disease outbreak and report the incidence of Plasmodium spp. parasitemia in persons with suspected Ebola virus infection.
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Coinfección , Brotes de Enfermedades , Ebolavirus , Fiebre Hemorrágica Ebola/epidemiología , Malaria/diagnóstico , Malaria/parasitología , Humanos , Malaria Falciparum/diagnóstico , Malaria Falciparum/parasitología , Carga de Parásitos , Plasmodium falciparum/clasificación , Plasmodium falciparum/genética , PrevalenciaRESUMEN
Persons who died of Ebola virus disease at home in rural communities in Liberia and Guinea resulted in more secondary infections than persons admitted to Ebola treatment units. Intensified monitoring of contacts of persons who died of this disease in the community is an evidence-based approach to reduce virus transmission in rural communities.
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Coinfección/epidemiología , Ebolavirus , Fiebre Hemorrágica Ebola/epidemiología , Población Rural , Coinfección/historia , Coinfección/transmisión , Coinfección/virología , Guinea/epidemiología , Fiebre Hemorrágica Ebola/historia , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Historia del Siglo XXI , Hospitalización , Humanos , Liberia/epidemiología , Vigilancia de la PoblaciónRESUMEN
BACKGROUND: The ongoing West African Ebola epidemic began in December 2013 in Guinea, probably from a single zoonotic introduction. As a result of ineffective initial control efforts, an Ebola outbreak of unprecedented scale emerged. As of 4 May 2015, it had resulted in more than 19,000 probable and confirmed Ebola cases, mainly in Guinea (3,529), Liberia (5,343), and Sierra Leone (10,746). Here, we present analyses of data collected during the outbreak identifying drivers of transmission and highlighting areas where control could be improved. METHODS AND FINDINGS: Over 19,000 confirmed and probable Ebola cases were reported in West Africa by 4 May 2015. Individuals with confirmed or probable Ebola ("cases") were asked if they had exposure to other potential Ebola cases ("potential source contacts") in a funeral or non-funeral context prior to becoming ill. We performed retrospective analyses of a case line-list, collated from national databases of case investigation forms that have been reported to WHO. These analyses were initially performed to assist WHO's response during the epidemic, and have been updated for publication. We analysed data from 3,529 cases in Guinea, 5,343 in Liberia, and 10,746 in Sierra Leone; exposures were reported by 33% of cases. The proportion of cases reporting a funeral exposure decreased over time. We found a positive correlation (r = 0.35, p < 0.001) between this proportion in a given district for a given month and the within-district transmission intensity, quantified by the estimated reproduction number (R). We also found a negative correlation (r = -0.37, p < 0.001) between R and the district proportion of hospitalised cases admitted within ≤4 days of symptom onset. These two proportions were not correlated, suggesting that reduced funeral attendance and faster hospitalisation independently influenced local transmission intensity. We were able to identify 14% of potential source contacts as cases in the case line-list. Linking cases to the contacts who potentially infected them provided information on the transmission network. This revealed a high degree of heterogeneity in inferred transmissions, with only 20% of cases accounting for at least 73% of new infections, a phenomenon often called super-spreading. Multivariable regression models allowed us to identify predictors of being named as a potential source contact. These were similar for funeral and non-funeral contacts: severe symptoms, death, non-hospitalisation, older age, and travelling prior to symptom onset. Non-funeral exposures were strongly peaked around the death of the contact. There was evidence that hospitalisation reduced but did not eliminate onward exposures. We found that Ebola treatment units were better than other health care facilities at preventing exposure from hospitalised and deceased individuals. The principal limitation of our analysis is limited data quality, with cases not being entered into the database, cases not reporting exposures, or data being entered incorrectly (especially dates, and possible misclassifications). CONCLUSIONS: Achieving elimination of Ebola is challenging, partly because of super-spreading. Safe funeral practices and fast hospitalisation contributed to the containment of this Ebola epidemic. Continued real-time data capture, reporting, and analysis are vital to track transmission patterns, inform resource deployment, and thus hasten and maintain elimination of the virus from the human population.
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Brotes de Enfermedades , Ebolavirus/fisiología , Fiebre Hemorrágica Ebola/epidemiología , Guinea/epidemiología , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Humanos , Liberia/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Sierra Leona/epidemiologíaRESUMEN
According to World Health Organization (WHO) data, the Ebola virus disease (Ebola) outbreak that began in West Africa in 2014 has resulted in 28,603 cases and 11,301 deaths (1). In March 2015, epidemiologic investigation and genetic sequencing in Liberia implicated sexual transmission from a male Ebola survivor, with Ebola virus detected by reverse transcription-polymerase chain reaction (RT-PCR) 199 days after symptom onset (2,3), far exceeding the 101 days reported from an earlier Ebola outbreak (4). In response, WHO released interim guidelines recommending that all male survivors, in addition to receiving condoms and sexual risk reduction counseling at discharge from an Ebola treatment unit (ETU), be offered semen testing for Ebola virus RNA by RT-PCR 3 months after disease onset, and every month thereafter until two consecutive semen specimens collected at least 1 week apart test negative for Ebola virus RNA (5). Male Ebola survivors should also receive counseling to promote safe sexual practices until their semen twice tests negative. When these recommendations were released, testing of semen was not widely available in Liberia. Challenges in establishing and operating the first nationwide semen testing and counseling program for male Ebola survivors included securing sufficient resources for the program, managing a public health semen testing program in the context of ongoing research studies that were also collecting and screening semen, identification of adequate numbers of trained counselors and appropriate health communication messages for the program, overcoming Ebola survivor-associated stigma, identification and recruitment of male Ebola survivors, and operation of mobile teams.