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1.
Emerg Infect Dis ; 28(2): 457-460, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34906290

RESUMEN

This overview of severe acute respiratory syndrome coronavirus 2 circulation over 1.5 years in Guinea demonstrates that virus clades and variants of interest and concern were progressively introduced, mostly by travellers through Conakry, before spreading through the country. Sequencing is key to following virus evolution and establishing efficient control strategies.


Asunto(s)
COVID-19 , SARS-CoV-2 , Guinea/epidemiología , Humanos
2.
Nature ; 524(7563): 102-4, 2015 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-26106863

RESUMEN

An epidemic of Ebola virus disease of unprecedented scale has been ongoing for more than a year in West Africa. As of 29 April 2015, there have been 26,277 reported total cases (of which 14,895 have been laboratory confirmed) resulting in 10,899 deaths. The source of the outbreak was traced to the prefecture of Guéckédou in the forested region of southeastern Guinea. The virus later spread to the capital, Conakry, and to the neighbouring countries of Sierra Leone, Liberia, Nigeria, Senegal and Mali. In March 2014, when the first cases were detected in Conakry, the Institut Pasteur of Dakar, Senegal, deployed a mobile laboratory in Donka hospital to provide diagnostic services to the greater Conakry urban area and other regions of Guinea. Through this process we sampled 85 Ebola viruses (EBOV) from patients infected from July to November 2014, and report their full genome sequences here. Phylogenetic analysis reveals the sustained transmission of three distinct viral lineages co-circulating in Guinea, including the urban setting of Conakry and its surroundings. One lineage is unique to Guinea and closely related to the earliest sampled viruses of the epidemic. A second lineage contains viruses probably reintroduced from neighbouring Sierra Leone on multiple occasions, while a third lineage later spread from Guinea to Mali. Each lineage is defined by multiple mutations, including non-synonymous changes in the virion protein 35 (VP35), glycoprotein (GP) and RNA-dependent RNA polymerase (L) proteins. The viral GP is characterized by a glycosylation site modification and mutations in the mucin-like domain that could modify the outer shape of the virion. These data illustrate the ongoing ability of EBOV to develop lineage-specific and potentially phenotypically important variation.


Asunto(s)
Ebolavirus/genética , Variación Genética/genética , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/virología , Mutación/genética , Filogenia , Ebolavirus/aislamiento & purificación , Evolución Molecular , Genoma Viral/genética , Glicoproteínas/genética , Glicoproteínas/metabolismo , Glicosilación , Guinea/epidemiología , Fiebre Hemorrágica Ebola/transmisión , Humanos , Malí/epidemiología , Datos de Secuencia Molecular , Mucinas/química , Proteínas de la Nucleocápside , Nucleoproteínas/genética , Estructura Terciaria de Proteína/genética , ARN Polimerasa Dependiente del ARN/genética , Sierra Leona/epidemiología , Proteínas del Núcleo Viral/genética
3.
Emerg Infect Dis ; 26(2): 206-211, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31961292

RESUMEN

At the end of the 2013-2016 Ebola virus disease outbreak in Guinea, we implemented an alert system for early detection of Ebola resurgence among survivors. Survivors were asked to report health alerts in their household and provide body fluid specimens for laboratory testing. During April-September 2016, a total of 1,075 (88%) of 1,215 survivors participated in the system; follow up occurred at a median of 16 months after discharge (interquartile range 14-18 months). Of these, 784 acted as focal points and reported 1,136 alerts (including 4 deaths among survivors). A total of 372 (91%) of 408 eligible survivors had >1 semen specimen tested; of 817 semen specimens, 5 samples from 4 survivors were positive up to 512 days after discharge. No lochia (0/7) or breast milk (0/69) specimens tested positive. Our findings underscore the importance of long-term monitoring of survivors' semen samples in an Ebola-affected country.


Asunto(s)
Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/epidemiología , Adolescente , Adulto , Líquidos Corporales/virología , Niño , Preescolar , Brotes de Enfermedades/prevención & control , Composición Familiar , Femenino , Guinea/epidemiología , Fiebre Hemorrágica Ebola/prevención & control , Fiebre Hemorrágica Ebola/virología , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Salud Pública , Recurrencia , Semen/virología , Sobrevivientes , Adulto Joven
5.
Emerg Infect Dis ; 25(2): 249-255, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30500321

RESUMEN

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.


Asunto(s)
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 Joven
6.
J Infect Dis ; 218(suppl_5): S287-S291, 2018 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-29920602

RESUMEN

The 2014-2016 Ebola virus (EBOV) disease outbreak affected over 29000 people and left behind the biggest cohort (over 17000 individuals) of Ebola survivors in history. Although the persistence of EBOV in body fluids of survivors was reported before the recent outbreak, new evidence revealed that the virus can be detected up to 18 months in the semen, which represents the biggest risk of Ebola resurgence in affected communities. In this study, we review the knowledge on the Ebola flare-ups that occurred after the peak of the 2014-2016 Ebola epidemic in West Africa.


Asunto(s)
Ebolavirus/patogenicidad , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/transmisión , África Occidental/epidemiología , Líquidos Corporales/virología , Brotes de Enfermedades , Epidemias , Fiebre Hemorrágica Ebola/virología , Humanos , Semen/virología , Sobrevivientes
7.
Emerg Infect Dis ; 24(1): 9-14, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29260687

RESUMEN

Rapid early detection and control of Ebola virus disease (EVD) is contingent on accurate case definitions. Using an epidemic surveillance dataset from Guinea, we analyzed an EVD case definition developed by the World Health Organization (WHO) and used in Guinea. We used the surveillance dataset (March-October 2014; n = 2,847 persons) to identify patients who satisfied or did not satisfy case definition criteria. Laboratory confirmation determined cases from noncases, and we calculated sensitivity, specificity and predictive values. The sensitivity of the defintion was 68.9%, and the specificity of the definition was 49.6%. The presence of epidemiologic risk factors (i.e., recent contact with a known or suspected EVD case-patient) had the highest sensitivity (74.7%), and unexplained deaths had the highest specificity (92.8%). Results for case definition analyses were statistically significant (p<0.05 by χ2 test). Multiple components of the EVD case definition used in Guinea contributed to improved overall sensitivity and specificity.


Asunto(s)
Epidemias , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/epidemiología , Adolescente , Adulto , Niño , Preescolar , Femenino , Guinea/epidemiología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Organización Mundial de la Salud , Adulto Joven
8.
Lancet ; 389(10068): 505-518, 2017 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-28017403

RESUMEN

BACKGROUND: rVSV-ZEBOV is a recombinant, replication competent vesicular stomatitis virus-based candidate vaccine expressing a surface glycoprotein of Zaire Ebolavirus. We tested the effect of rVSV-ZEBOV in preventing Ebola virus disease in contacts and contacts of contacts of recently confirmed cases in Guinea, west Africa. METHODS: We did an open-label, cluster-randomised ring vaccination trial (Ebola ça Suffit!) in the communities of Conakry and eight surrounding prefectures in the Basse-Guinée region of Guinea, and in Tomkolili and Bombali in Sierra Leone. We assessed the efficacy of a single intramuscular dose of rVSV-ZEBOV (2×107 plaque-forming units administered in the deltoid muscle) in the prevention of laboratory confirmed Ebola virus disease. After confirmation of a case of Ebola virus disease, we definitively enumerated on a list a ring (cluster) of all their contacts and contacts of contacts including named contacts and contacts of contacts who were absent at the time of the trial team visit. The list was archived, then we randomly assigned clusters (1:1) to either immediate vaccination or delayed vaccination (21 days later) of all eligible individuals (eg, those aged ≥18 years and not pregnant, breastfeeding, or severely ill). An independent statistician generated the assignment sequence using block randomisation with randomly varying blocks, stratified by location (urban vs rural) and size of rings (≤20 individuals vs >20 individuals). Ebola response teams and laboratory workers were unaware of assignments. After a recommendation by an independent data and safety monitoring board, randomisation was stopped and immediate vaccination was also offered to children aged 6-17 years and all identified rings. The prespecified primary outcome was a laboratory confirmed case of Ebola virus disease with onset 10 days or more from randomisation. The primary analysis compared the incidence of Ebola virus disease in eligible and vaccinated individuals assigned to immediate vaccination versus eligible contacts and contacts of contacts assigned to delayed vaccination. This trial is registered with the Pan African Clinical Trials Registry, number PACTR201503001057193. FINDINGS: In the randomised part of the trial we identified 4539 contacts and contacts of contacts in 51 clusters randomly assigned to immediate vaccination (of whom 3232 were eligible, 2151 consented, and 2119 were immediately vaccinated) and 4557 contacts and contacts of contacts in 47 clusters randomly assigned to delayed vaccination (of whom 3096 were eligible, 2539 consented, and 2041 were vaccinated 21 days after randomisation). No cases of Ebola virus disease occurred 10 days or more after randomisation among randomly assigned contacts and contacts of contacts vaccinated in immediate clusters versus 16 cases (7 clusters affected) among all eligible individuals in delayed clusters. Vaccine efficacy was 100% (95% CI 68·9-100·0, p=0·0045), and the calculated intraclass correlation coefficient was 0·035. Additionally, we defined 19 non-randomised clusters in which we enumerated 2745 contacts and contacts of contacts, 2006 of whom were eligible and 1677 were immediately vaccinated, including 194 children. The evidence from all 117 clusters showed that no cases of Ebola virus disease occurred 10 days or more after randomisation among all immediately vaccinated contacts and contacts of contacts versus 23 cases (11 clusters affected) among all eligible contacts and contacts of contacts in delayed plus all eligible contacts and contacts of contacts never vaccinated in immediate clusters. The estimated vaccine efficacy here was 100% (95% CI 79·3-100·0, p=0·0033). 52% of contacts and contacts of contacts assigned to immediate vaccination and in non-randomised clusters received the vaccine immediately; vaccination protected both vaccinated and unvaccinated people in those clusters. 5837 individuals in total received the vaccine (5643 adults and 194 children), and all vaccinees were followed up for 84 days. 3149 (53·9%) of 5837 individuals reported at least one adverse event in the 14 days after vaccination; these were typically mild (87·5% of all 7211 adverse events). Headache (1832 [25·4%]), fatigue (1361 [18·9%]), and muscle pain (942 [13·1%]) were the most commonly reported adverse events in this period across all age groups. 80 serious adverse events were identified, of which two were judged to be related to vaccination (one febrile reaction and one anaphylaxis) and one possibly related (influenza-like illness); all three recovered without sequelae. INTERPRETATION: The results add weight to the interim assessment that rVSV-ZEBOV offers substantial protection against Ebola virus disease, with no cases among vaccinated individuals from day 10 after vaccination in both randomised and non-randomised clusters. FUNDING: WHO, UK Wellcome Trust, the UK Government through the Department of International Development, Médecins Sans Frontières, Norwegian Ministry of Foreign Affairs (through the Research Council of Norway's GLOBVAC programme), and the Canadian Government (through the Public Health Agency of Canada, Canadian Institutes of Health Research, International Development Research Centre and Department of Foreign Affairs, Trade and Development).


Asunto(s)
Vacunas contra el Virus del Ébola , Fiebre Hemorrágica Ebola/prevención & control , Adolescente , Adulto , Niño , Análisis por Conglomerados , Trazado de Contacto , Ebolavirus , Femenino , Guinea , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/transmisión , Humanos , Masculino , Glicoproteínas de Membrana , Persona de Mediana Edad , Resultado del Tratamiento , Vesiculovirus , Adulto Joven
9.
Euro Surveill ; 23(12)2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29589579

RESUMEN

On 11 May 2015, the Dubréka prefecture, Guinea, reported nine laboratory-confirmed cases of Ebola virus disease (EVD). None could be epidemiologically linked to cases previously reported in the prefecture. We describe the epidemiological and molecular investigations of this event. We used the Dubréka EVD registers and the Ebola treatment centre's (ETC) records to characterise chains of transmission. Real-time field Ebola virus sequencing was employed to support epidemiological results. An epidemiological cluster of 32 cases was found, of which 27 were laboratory confirmed, 24 were isolated and 20 died. Real-time viral sequencing on 12 cases demonstrated SL3 lineage viruses with sequences differing by one to three nt inside a single phylogenetic cluster. For isolated cases, the average time between symptom onset and ETC referral was 2.8 days (interquartile range (IQR): 1-4). The average time between sample collection and molecular results' availability was 3 days (IQR: 2-5). In an area with scarce resources, the genetic characterisation supported the outbreak investigations in real time, linking cases where epidemiological investigation was limited and reassuring that the responsible strain was already circulating in Guinea. We recommend coupling thorough epidemiological and genomic investigations to control EVD clusters.


Asunto(s)
ADN Viral/genética , Ebolavirus/genética , Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/transmisión , Trazado de Contacto , Brotes de Enfermedades/prevención & control , Genómica , Guinea/epidemiología , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/virología , Humanos , Filogenia , Reacción en Cadena en Tiempo Real de la Polimerasa
10.
J Infect Dis ; 215(12): 1799-1806, 2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-28520958

RESUMEN

Background: The international impact, rapid widespread transmission, and reporting delays during the 2014 Ebola outbreak in West Africa highlighted the need for a global, centralized database to inform outbreak response. The World Health Organization and Emerging and Dangerous Pathogens Laboratory Network addressed this need by supporting the development of a global laboratory database. Methods: Specimens were collected in the affected countries from patients and dead bodies meeting the case definitions for Ebola virus disease. Test results were entered in nationally standardized spreadsheets and consolidated onto a central server. Results: From March 2014 through August 2016, 256343 specimens tested for Ebola virus disease were captured in the database. Thirty-one specimen types were collected, and a variety of diagnostic tests were performed. Regular analysis of data described the functionality of laboratory and response systems, positivity rates, and the geographic distribution of specimens. Conclusion: With data standardization and end user buy-in, the collection and analysis of large amounts of data with multiple stakeholders and collaborators across various user-access levels was made possible and contributed to outbreak response needs. The usefulness and value of a multifunctional global laboratory database is far reaching, with uses including virtual biobanking, disease forecasting, and adaption to other disease outbreaks.


Asunto(s)
Bancos de Muestras Biológicas/normas , Bases de Datos Factuales/normas , Brotes de Enfermedades/estadística & datos numéricos , Ebolavirus/fisiología , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/virología , África Occidental/epidemiología , Salud Global , Humanos , Laboratorios , Organización Mundial de la Salud
12.
Emerg Infect Dis ; 23(13)2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29155674

RESUMEN

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.


Asunto(s)
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 Calidad
13.
N Engl J Med ; 371(15): 1418-25, 2014 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-24738640

RESUMEN

In March 2014, the World Health Organization was notified of an outbreak of a communicable disease characterized by fever, severe diarrhea, vomiting, and a high fatality rate in Guinea. Virologic investigation identified Zaire ebolavirus (EBOV) as the causative agent. Full-length genome sequencing and phylogenetic analysis showed that EBOV from Guinea forms a separate clade in relationship to the known EBOV strains from the Democratic Republic of Congo and Gabon. Epidemiologic investigation linked the laboratory-confirmed cases with the presumed first fatality of the outbreak in December 2013. This study demonstrates the emergence of a new EBOV strain in Guinea.


Asunto(s)
Brotes de Enfermedades , Ebolavirus/genética , Fiebre Hemorrágica Ebola/epidemiología , Adolescente , Adulto , Secuencia de Bases , Niño , Ebolavirus/clasificación , Ebolavirus/aislamiento & purificación , Femenino , Guinea/epidemiología , Fiebre Hemorrágica Ebola/virología , Humanos , Masculino , Filogenia , ARN Viral/análisis , Adulto Joven
14.
N Engl J Med ; 371(16): 1481-95, 2014 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-25244186

RESUMEN

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.


Asunto(s)
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 Joven
15.
J Infect Dis ; 214(suppl 3): S229-S233, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27481863

RESUMEN

To strengthen the laboratory diagnostic capacity for Ebola virus disease (EVD) in the remote areas of Guinea, we deployed a mobile field laboratory and implemented reverse transcription loop-mediated isothermal amplification (RT-LAMP) for postmortem testing. We tested 896 oral swab specimens and 21 serum samples, using both RT-LAMP and reverse transcription-polymerase chain reaction (RT-PCR). Neither test yielded a positive result, and the results from RT-LAMP and RT-PCR were consistent. More than 95% of the samples were tested within 2 days of sample collection. These results highlight the usefulness of the RT-LAMP assay as an EVD diagnostic testing method in the field or remote areas.


Asunto(s)
Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/diagnóstico , Técnicas de Amplificación de Ácido Nucleico/métodos , Sistemas de Atención de Punto , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Ebolavirus/genética , Guinea/epidemiología , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/virología , Humanos , ARN Viral/análisis , ARN Viral/genética , Sensibilidad y Especificidad
16.
Clin Infect Dis ; 63(10): 1353-1356, 2016 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-27585800

RESUMEN

We report on an Ebola virus disease (EVD) survivor who showed Ebola virus in seminal fluid 531 days after onset of disease. The persisting virus was sexually transmitted in February 2016, about 470 days after onset of symptoms, and caused a new cluster of EVD in Guinea and Liberia.


Asunto(s)
Brotes de Enfermedades , Ebolavirus/genética , Fiebre Hemorrágica Ebola , Semen/virología , Enfermedades Virales de Transmisión Sexual , Ebolavirus/aislamiento & purificación , Femenino , Guinea , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Humanos , Masculino , Reacción en Cadena de la Polimerasa , ARN Viral/análisis , Enfermedades Virales de Transmisión Sexual/transmisión , Enfermedades Virales de Transmisión Sexual/virología , Sobrevivientes
17.
Emerg Infect Dis ; 22(2): 178-83, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26812047

RESUMEN

In 2014, Ebola virus disease (EVD) in West Africa was first reported during March in 3 southeastern prefectures in Guinea; from there, the disease rapidly spread across West Africa. We describe the epidemiology of EVD cases reported in Guinea's capital, Conakry, and 4 surrounding prefectures (Coyah, Dubreka, Forecariah, and Kindia), encompassing a full year of the epidemic. A total of 1,355 EVD cases, representing ≈40% of cases reported in Guinea, originated from these areas. Overall, Forecariah had the highest cumulative incidence (4× higher than that in Conakry). Case-fatality percentage ranged from 40% in Conakry to 60% in Kindia. Cumulative incidence was slightly higher among male than female residents, although incidences by prefecture and commune differed by sex. Over the course of the year, Conakry and neighboring prefectures became the EVD epicenter in Guinea.


Asunto(s)
Fiebre Hemorrágica Ebola/epidemiología , Adulto , Brotes de Enfermedades , Femenino , Guinea/epidemiología , Fiebre Hemorrágica Ebola/historia , Historia del Siglo XXI , Humanos , Incidencia , Masculino , Vigilancia de la Población , Adulto Joven
18.
Emerg Infect Dis ; 22(9): 1653-5, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27268508

RESUMEN

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.


Asunto(s)
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 Población
19.
PLoS Med ; 13(11): e1002170, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27846234

RESUMEN

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.


Asunto(s)
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/epidemiología
20.
Lancet ; 386(9996): 857-66, 2015 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-26248676

RESUMEN

BACKGROUND: A recombinant, replication-competent vesicular stomatitis virus-based vaccine expressing a surface glycoprotein of Zaire Ebolavirus (rVSV-ZEBOV) is a promising Ebola vaccine candidate. We report the results of an interim analysis of a trial of rVSV-ZEBOV in Guinea, west Africa. METHODS: For this open-label, cluster-randomised ring vaccination trial, suspected cases of Ebola virus disease in Basse-Guinée (Guinea, west Africa) were independently ascertained by Ebola response teams as part of a national surveillance system. After laboratory confirmation of a new case, clusters of all contacts and contacts of contacts were defined and randomly allocated 1:1 to immediate vaccination or delayed (21 days later) vaccination with rVSV-ZEBOV (one dose of 2 × 10(7) plaque-forming units, administered intramuscularly in the deltoid muscle). Adults (age ≥18 years) who were not pregnant or breastfeeding were eligible for vaccination. Block randomisation was used, with randomly varying blocks, stratified by location (urban vs rural) and size of rings (≤20 vs >20 individuals). The study is open label and masking of participants and field teams to the time of vaccination is not possible, but Ebola response teams and laboratory workers were unaware of allocation to immediate or delayed vaccination. Taking into account the incubation period of the virus of about 10 days, the prespecified primary outcome was laboratory-confirmed Ebola virus disease with onset of symptoms at least 10 days after randomisation. The primary analysis was per protocol and compared the incidence of Ebola virus disease in eligible and vaccinated individuals in immediate vaccination clusters with the incidence in eligible individuals in delayed vaccination clusters. This trial is registered with the Pan African Clinical Trials Registry, number PACTR201503001057193. FINDINGS: Between April 1, 2015, and July 20, 2015, 90 clusters, with a total population of 7651 people were included in the planned interim analysis. 48 of these clusters (4123 people) were randomly assigned to immediate vaccination with rVSV-ZEBOV, and 42 clusters (3528 people) were randomly assigned to delayed vaccination with rVSV-ZEBOV. In the immediate vaccination group, there were no cases of Ebola virus disease with symptom onset at least 10 days after randomisation, whereas in the delayed vaccination group there were 16 cases of Ebola virus disease from seven clusters, showing a vaccine efficacy of 100% (95% CI 74·7-100·0; p=0·0036). No new cases of Ebola virus disease were diagnosed in vaccinees from the immediate or delayed groups from 6 days post-vaccination. At the cluster level, with the inclusion of all eligible adults, vaccine effectiveness was 75·1% (95% CI -7·1 to 94·2; p=0·1791), and 76·3% (95% CI -15·5 to 95·1; p=0·3351) with the inclusion of everyone (eligible or not eligible for vaccination). 43 serious adverse events were reported; one serious adverse event was judged to be causally related to vaccination (a febrile episode in a vaccinated participant, which resolved without sequelae). Assessment of serious adverse events is ongoing. INTERPRETATION: The results of this interim analysis indicate that rVSV-ZEBOV might be highly efficacious and safe in preventing Ebola virus disease, and is most likely effective at the population level when delivered during an Ebola virus disease outbreak via a ring vaccination strategy. FUNDING: WHO, with support from the Wellcome Trust (UK); Médecins Sans Frontières; the Norwegian Ministry of Foreign Affairs through the Research Council of Norway; and the Canadian Government through the Public Health Agency of Canada, Canadian Institutes of Health Research, International Development Research Centre, and Department of Foreign Affairs, Trade and Development.


Asunto(s)
Vacunas contra el Virus del Ébola , Fiebre Hemorrágica Ebola/prevención & control , Adulto , Ebolavirus/inmunología , Femenino , Vectores Genéticos , Guinea/epidemiología , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Incidencia , Estimación de Kaplan-Meier , Masculino , Glicoproteínas de Membrana/metabolismo , Persona de Mediana Edad , Vacunación/métodos , Vesiculovirus/metabolismo , Adulto Joven
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