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Prasad AN, Agans KN, Geisbert JB, Borisevich V, Deer DJ, Dobias NS, Comer JE, Woolsey C, Fenton KA, Geisbert TW, Cross RW. Natural History of Nonhuman Primates After Oral Exposure to Ebola Virus Variant Makona. J Infect Dis 2023; 228:S571-S581. [PMID: 37348509 PMCID: PMC10651204 DOI: 10.1093/infdis/jiad225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/03/2023] [Accepted: 06/21/2023] [Indexed: 06/24/2023] Open
Abstract
BACKGROUND The primary route of infection by Ebola virus (EBOV) is through contact of mucosal surfaces. Few studies have explored infection of nonhuman primates (NHPs) via the oral mucosa, which is a probable portal of natural infection in humans. METHODS To further characterize the pathogenesis of EBOV infection via the oral exposure route, we challenged cohorts of cynomolgus monkeys with low doses of EBOV variant Makona. RESULTS Infection with 100 or 50 PFU of EBOV Makona via the oral route resulted in 50% and 83% lethality, respectively. Animals that progressed to fatal disease exhibited lymphopenia, marked coagulopathy, high viral loads, and increased levels of serum markers of inflammation and hepatic/renal injury. Survival in these cohorts was associated with milder fluctuations in leukocyte populations, lack of coagulopathy, and reduced or absent serum markers of inflammation and/or hepatic/renal function. Surprisingly, 2 surviving animals from the 100- and 50-PFU cohorts developed transient low-level viremia in the absence of other clinical signs of disease. Conversely, all animals in the 10 PFU cohort remained disease free and survived to the study end point. CONCLUSIONS Our observations highlight the susceptibility of NHPs, and by extension, likely humans, to relatively low doses of EBOV via the oral route.
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Affiliation(s)
- Abhishek N Prasad
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Krystle N Agans
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Joan B Geisbert
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Viktoriya Borisevich
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Daniel J Deer
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Natalie S Dobias
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jason E Comer
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Courtney Woolsey
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Karla A Fenton
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Thomas W Geisbert
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Robert W Cross
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
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2
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Prasad AN, Fenton KA, Agans KN, Borisevich V, Woolsey C, Comer JE, Dobias NS, Peel JE, Deer DJ, Geisbert JB, Lawrence WS, Cross RW, Geisbert TW. Pathogenesis of Aerosolized Ebola Virus Variant Makona in Nonhuman Primates. J Infect Dis 2023; 228:S604-S616. [PMID: 37145930 PMCID: PMC10651212 DOI: 10.1093/infdis/jiad137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/25/2023] [Accepted: 05/02/2023] [Indexed: 05/07/2023] Open
Abstract
BACKGROUND Highly pathogenic filoviruses such as Ebola virus (EBOV) hold capacity for delivery by artificial aerosols, and thus potential for intentional misuse. Previous studies have shown that high doses of EBOV delivered by small-particle aerosol cause uniform lethality in nonhuman primates (NHPs), whereas only a few small studies have assessed lower doses in NHPs. METHODS To further characterize the pathogenesis of EBOV infection via small-particle aerosol, we challenged cohorts of cynomolgus monkeys with low doses of EBOV variant Makona, which may help define risks associated with small particle aerosol exposures. RESULTS Despite using challenge doses orders of magnitude lower than previous studies, infection via this route was uniformly lethal across all cohorts. Time to death was delayed in a dose-dependent manner between aerosol-challenged cohorts, as well as in comparison to animals challenged via the intramuscular route. Here, we describe the observed clinical and pathological details including serum biomarkers, viral burden, and histopathological changes leading to death. CONCLUSIONS Our observations in this model highlight the striking susceptibility of NHPs, and likely humans, via small-particle aerosol exposure to EBOV and emphasize the need for further development of diagnostics and postexposure prophylactics in the event of intentional release via deployment of an aerosol-producing device.
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Affiliation(s)
- Abhishek N Prasad
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Karla A Fenton
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Krystle N Agans
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Viktoriya Borisevich
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Courtney Woolsey
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jason E Comer
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Natalie S Dobias
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jennifer E Peel
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Daniel J Deer
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Joan B Geisbert
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - William S Lawrence
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Robert W Cross
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Thomas W Geisbert
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
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3
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Duffy N, Bruden D, Thomas H, Nichols E, Knust B, Hennessy T, Reichler MR. Risk factors for Ebola virus disease among household care providers, Sierra Leone, 2015. Int J Epidemiol 2022; 51:1457-1468. [PMID: 35441222 DOI: 10.1093/ije/dyac081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/04/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Household contacts who provide care to an Ebola virus disease (EVD) case have a 3-fold higher risk of EVD compared with contacts who do not provide care. METHODS We enrolled persons with confirmed EVD from December 2014 to April 2015 in Freetown, Sierra Leone, and their household contacts. Index cases and contacts were interviewed, and contacts were followed for 21 days to identify secondary cases. Epidemiological data were analysed to describe household care and to identify risk factors for developing EVD. RESULTS Of 838 contacts in 147 households, 156 (17%) self-reported providing care to the index case; 56 households had no care provider, 52 a single care provider and 39 multiple care providers. The median care provider age was 29 years, 68% were female and 32% were the index case's spouse. Care providers were more likely to report physical contact, contact with body fluids or sharing clothing, bed linens or utensils with an index case, compared with non-care providers (P <0.01). EVD risk among non-care providers was greater when the number of care providers in the household increased (odds ratio: 1.61; 95% confidence interval: 1.1, 2.4). In multivariable analysis, factors associated with care provider EVD risk included no piped water access and absence of index case fever, and protective factors included age <20 years and avoiding the index case. CONCLUSIONS Limiting the number of care providers in a household could reduce the risk of EVD transmission to both care providers and non-care providers. Strategies to protect care providers from EVD exposure are needed.
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Affiliation(s)
- Nadezhda Duffy
- Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Dana Bruden
- Division of Preparedness and Emerging Infections, National Center for Emerging and Zoonotic diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA
| | - Harold Thomas
- Directorate of Health Security and Emergencies, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Erin Nichols
- National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD, USA
| | - Barbara Knust
- Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Thomas Hennessy
- Division of Preparedness and Emerging Infections, National Center for Emerging and Zoonotic diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA
| | - Mary R Reichler
- Division of Tuberculosis Elimination, National Center for HIV/AIDS, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA
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4
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Abstract
Prevention of emerging infections in children is a dynamic arena where substantial medical advances have enabled intervention and prevention of infection outbreaks. This article discusses 5 infections causing significant morbidity and mortality across Asia, Latin America, and Africa. Avian influenza and the Middle East respiratory syndrome are highly contagious zoonoses spread through aerosol and droplets, affecting predominantly Asia. Dengue infection and chikungunya are endemic mosquito-borne viruses in tropical regions across Asia, Latin America, and Africa. Ebola is a highly contagious virus spread through human-to-human contact. The latest information in clinical manifestations, infection, prevention control, chemoprophylaxis, vaccination, and public health measures is reviewed.
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Affiliation(s)
- Thanyawee Puthanakit
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, 9th Floor, Sor Kor Building, Rama 4 Road, Patumwan, Bangkok 10330, Thailand.
| | | | - Watsamon Jantarabenjakul
- Center of Excellence for Pediatric Infectious Diseases, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand
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5
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Exploration of alternate therapeutic remedies in Ebola virus disease: the case of reported antiviral phytochemical derived from the leaves Spondias Mombin Linn. ADVANCES IN TRADITIONAL MEDICINE 2021. [DOI: 10.1007/s13596-021-00603-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Development of a Well-Characterized Rhesus Macaque Model of Ebola Virus Disease for Support of Product Development. Microorganisms 2021; 9:microorganisms9030489. [PMID: 33652589 PMCID: PMC7996724 DOI: 10.3390/microorganisms9030489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 11/17/2022] Open
Abstract
Ebola virus (EBOV) is a negative-sense RNA virus that can infect humans and nonhuman primates with severe health consequences. Development of countermeasures requires a thorough understanding of the interaction between host and pathogen, and the course of disease. The goal of this study was to further characterize EBOV disease in a uniformly lethal rhesus macaque model, in order to support development of a well-characterized model following rigorous quality standards. Rhesus macaques were intramuscularly exposed to EBOV and one group was euthanized at predetermined time points to characterize progression of disease. A second group was not scheduled for euthanasia in order to analyze survival, changes in physiology, clinical pathology, terminal pathology, and telemetry kinetics. On day 3, sporadic viremia was observed and pathological evidence was noted in lymph nodes. By day 5, viremia was detected in all EBOV exposed animals and pathological evidence was noted in the liver, spleen, and gastrointestinal tissues. These data support the notion that EBOV infection in rhesus macaques is a rapid systemic disease similar to infection in humans, under a compressed time scale. Biomarkers that correlated with disease progression at the earliest stages of infection were observed thereby identifying potential "trigger-to-treat" for use in therapeutic studies.
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7
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Kelly JD, Hoff NA, Spencer D, Musene K, Bramble MS, McIlwain D, Okitundu D, Porco TC, Rutherford GW, Glymour MM, Bjornson Z, Mukadi P, Okitolonda-Wemakoy E, Nolan GP, Muyembe-Tamfum JJ, Rimoin AW. Neurological, Cognitive, and Psychological Findings Among Survivors of Ebola Virus Disease From the 1995 Ebola Outbreak in Kikwit, Democratic Republic of Congo: A Cross-sectional Study. Clin Infect Dis 2020; 68:1388-1393. [PMID: 30107392 PMCID: PMC6452000 DOI: 10.1093/cid/ciy677] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/08/2018] [Indexed: 11/12/2022] Open
Abstract
Background Clinical sequelae of Ebola virus disease (EVD) have not been described more than 3 years postoutbreak. We examined survivors and close contacts from the 1995 Ebola outbreak in Kikwit, Democratic Republic of Congo (DRC), and determined prevalence of abnormal neurological, cognitive, and psychological findings and their association with EVD survivorship. Methods From August to September 2017, we conducted a cross-sectional study in Kikwit, DRC. Over 2 decades after the EVD outbreak, we recruited EVD survivors and close contacts from the outbreak to undergo physical examination and culturally adapted versions of the Folstein mini-mental status exam (MMSE) and Goldberg anxiety and depression scale (GADS). We estimated the strength of relationships between EVD survivorship and health outcomes using linear regression models by comparing survivors versus close contacts, adjusting for age, sex, educational level, marital status, and healthcare worker status. Results We enrolled 20 EVD survivors and 187 close contacts. Among the 20 EVD survivors, 4 (20%) reported at least 1 abnormal neurological symptom, and 3 (15%) had an abnormal neurological examination. Among the 187 close contacts, 14 (11%) reported at least 1 abnormal neurologic symptom, and 9 (5%) had an abnormal neurological examination. EVD survivors had lower mean MMSE and higher mean GADS scores as compared to close contacts (MMSE: adjusted coefficient: −1.85; 95% confidence interval [CI]: −3.63, −0.07; GADS: adjusted coefficient: 3.91; 95% CI: 1.76, 6.04). Conclusions EVD survivors can have lower cognitive scores and more symptoms of depression and anxiety than close contacts more than 2 decades after Ebola virus outbreaks.
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Affiliation(s)
- J Daniel Kelly
- School of Medicine, University of California, San Francisco
| | - Nicole A Hoff
- School of Public Health, University of California, Los Angeles
| | - D'Andre Spencer
- School of Public Health, University of California, Los Angeles
| | - Kamy Musene
- School of Public Health, University of California, Los Angeles
| | - Matthew S Bramble
- School of Public Health, University of California, Los Angeles.,Department of Genetic Medicine Research, Children's Research Institute, Children's National Medical Center, Washington, D.C
| | - David McIlwain
- Department of Microbiology and Immunology, Stanford University, California
| | - Daniel Okitundu
- Institut National de Recherche Biomédicale, Université de Kinshasa, Democratic Republic of Congo.,Faculté de Médecine, Université de Kinshasa, Democratic Republic of Congo
| | - Travis C Porco
- School of Medicine, University of California, San Francisco
| | | | | | - Zach Bjornson
- Department of Microbiology and Immunology, Stanford University, California
| | - Patrick Mukadi
- Institut National de Recherche Biomédicale, Université de Kinshasa, Democratic Republic of Congo.,Faculté de Médecine, Université de Kinshasa, Democratic Republic of Congo
| | | | - Garry P Nolan
- Department of Microbiology and Immunology, Stanford University, California
| | | | - Anne W Rimoin
- School of Public Health, University of California, Los Angeles
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8
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Jacob ST, Crozier I, Fischer WA, Hewlett A, Kraft CS, Vega MADL, Soka MJ, Wahl V, Griffiths A, Bollinger L, Kuhn JH. Ebola virus disease. Nat Rev Dis Primers 2020; 6:13. [PMID: 32080199 PMCID: PMC7223853 DOI: 10.1038/s41572-020-0147-3] [Citation(s) in RCA: 296] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/10/2020] [Indexed: 12/16/2022]
Abstract
Ebola virus disease (EVD) is a severe and frequently lethal disease caused by Ebola virus (EBOV). EVD outbreaks typically start from a single case of probable zoonotic transmission, followed by human-to-human transmission via direct contact or contact with infected bodily fluids or contaminated fomites. EVD has a high case-fatality rate; it is characterized by fever, gastrointestinal signs and multiple organ dysfunction syndrome. Diagnosis requires a combination of case definition and laboratory tests, typically real-time reverse transcription PCR to detect viral RNA or rapid diagnostic tests based on immunoassays to detect EBOV antigens. Recent advances in medical countermeasure research resulted in the recent approval of an EBOV-targeted vaccine by European and US regulatory agencies. The results of a randomized clinical trial of investigational therapeutics for EVD demonstrated survival benefits from two monoclonal antibody products targeting the EBOV membrane glycoprotein. New observations emerging from the unprecedented 2013-2016 Western African EVD outbreak (the largest in history) and the ongoing EVD outbreak in the Democratic Republic of the Congo have substantially improved the understanding of EVD and viral persistence in survivors of EVD, resulting in new strategies toward prevention of infection and optimization of clinical management, acute illness outcomes and attendance to the clinical care needs of patients.
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Affiliation(s)
- Shevin T Jacob
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Global Health Security Department, Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Ian Crozier
- Integrated Research Facility at Fort Detrick, Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research supported by the National Cancer Institute, Frederick, MD, USA
| | - William A Fischer
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, Chapel Hill, NC, USA
| | - Angela Hewlett
- Nebraska Biocontainment Unit, Division of Infectious Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - Colleen S Kraft
- Microbiology Section, Emory Medical Laboratory, Emory University School of Medicine, Atlanta, GA, USA
| | - Marc-Antoine de La Vega
- Department of Microbiology, Immunology & Infectious Diseases, Université Laval, Quebec City, QC, Canada
| | - Moses J Soka
- Partnership for Ebola Virus Disease Research in Liberia, Monrovia Medical Units ELWA-2 Hospital, Monrovia, Liberia
| | - Victoria Wahl
- National Biodefense Analysis and Countermeasures Center, Fort Detrick, Frederick, MD, USA
| | - Anthony Griffiths
- Department of Microbiology and National Emerging Infectious Diseases Laboratories, Boston University School of Medicine, Boston, MA, USA
| | - Laura Bollinger
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD, USA.
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Lalle E, Biava M, Nicastri E, Colavita F, Di Caro A, Vairo F, Lanini S, Castilletti C, Langer M, Zumla A, Kobinger G, Capobianchi MR, Ippolito G. Pulmonary Involvement during the Ebola Virus Disease. Viruses 2019; 11:E780. [PMID: 31450596 PMCID: PMC6784166 DOI: 10.3390/v11090780] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/20/2019] [Accepted: 08/22/2019] [Indexed: 12/16/2022] Open
Abstract
Filoviruses have become a worldwide public health concern, especially during the 2013-2016 Western Africa Ebola virus disease (EVD) outbreak-the largest outbreak, both by number of cases and geographical extension, recorded so far in medical history. EVD is associated with pathologies in several organs, including the liver, kidney, and lung. During the 2013-2016 Western Africa outbreak, Ebola virus (EBOV) was detected in the lung of infected patients suggesting a role in lung pathogenesis. However, little is known about lung pathogenesis and the controversial issue of aerosol transmission in EVD. This review highlights the pulmonary involvement in EVD, with a special focus on the new data emerging from the 2013-2016 Ebola outbreak.
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Affiliation(s)
- Eleonora Lalle
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
| | - Mirella Biava
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
| | - Emanuele Nicastri
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
| | - Francesca Colavita
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
| | - Antonino Di Caro
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
- International Public Health Crisis Group, 00149 Rome, Italy
| | - Francesco Vairo
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
- International Public Health Crisis Group, 00149 Rome, Italy
| | - Simone Lanini
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
| | - Concetta Castilletti
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
| | - Martin Langer
- EMERGENCY Onlus NGO, Via Santa Croce 19, 20122 Milan, Italy
| | - Alimuddin Zumla
- International Public Health Crisis Group, London WC1E 6BT, UK
- Division of Infection and Immunity, National Institute for Health Research Biomedical Research Centre at University College London Hospitals NHS Foundation Trust, London WC1E 6BT, UK
| | - Gary Kobinger
- International Public Health Crisis Group, Quebec City, PQ G1V 0A6, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- Département de microbiologie-infectiologie et d'immunologie, Université Laval, Québec, PQ G1V 0A6, Canada
| | - Maria R Capobianchi
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy
| | - Giuseppe Ippolito
- National Institute for Infectious Diseases 'Lazzaro Spallanzani' IRCCS, 00149 Rome, Italy.
- International Public Health Crisis Group, 00149 Rome, Italy.
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10
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Halfmann PJ, Eisfeld AJ, Watanabe T, Maemura T, Yamashita M, Fukuyama S, Armbrust T, Rozich I, N’jai A, Neumann G, Kawaoka Y, Sahr F. Serological analysis of Ebola virus survivors and close contacts in Sierra Leone: A cross-sectional study. PLoS Negl Trop Dis 2019; 13:e0007654. [PMID: 31369554 PMCID: PMC6692041 DOI: 10.1371/journal.pntd.0007654] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 08/13/2019] [Accepted: 07/23/2019] [Indexed: 11/18/2022] Open
Abstract
The 2013–2016 Ebola virus outbreak in West Africa was the largest and deadliest outbreak to date. Here we conducted a serological study to examine the antibody levels in survivors and the seroconversion in close contacts who took care of Ebola-infected individuals, but did not develop symptoms of Ebola virus disease. In March 2017, we collected blood samples from 481 individuals in Makeni, Sierra Leone: 214 survivors and 267 close contacts. Using commercial, quantitative ELISAs, we tested the plasma for IgG-specific antibodies against three major viral antigens: GP, the only viral glycoprotein expressed on the virus surface; NP, the most abundant viral protein; and VP40, a major structural protein of Zaire ebolavirus. We also determined neutralizing antibody titers. In the cohort of Ebola survivors, 97.7% of samples (209/214) had measurable antibody levels against GP, NP, and/or VP40. Of these positive samples, all but one had measurable neutralizing antibody titers against Ebola virus. For the close contacts, up to 12.7% (34/267) may have experienced a subclinical virus infection as indicated by detectable antibodies against GP. Further investigation is warranted to determine whether these close contacts truly experienced subclinical infections and whether these asymptomatic infections played a role in the dynamics of transmission. As the causative agent of an often lethal hemorrhagic fever disease in humans and nonhuman primates, Zaire ebolavirus typically causes high fever, severe diarrhea, and vomiting which results in case fatality rates as high as 90%. The 2013–2016 outbreak in West Africa was the largest and most devastating Ebola outbreak to date resulting in over 28,600 identified human cases and 11,300 deaths. Though our knowledge of virus transmission is incomplete, we do know that transmission occurs through direct contact with virus-contaminated body fluids (blood, secretions, or other body fluids), materials such as bedding contaminated with these fluids, and through the handling and preparation of contaminated food. Asymptomatic Ebola virus infections that result in seroconversion in the absence of disease symptoms have been observed both in humans and experimentally in animal models. In the present serology study, we determined a majority of Ebola survivors in our cohort had measurable antibody levels against at least one viral antigen, as expected. In our cohort of close contacts, relatives and health care workers who took care of Ebola-infected individuals during the outbreak, we observed a rate of seroprevalence of 12.7% as indicated by detectable GP antibody levels. Given that Ebola virus is typically associated with a highly lethal disease in humans, it is of great interest to determine the host-virus interactions and transmission dynamics associated with asymptomatic cases.
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Affiliation(s)
- Peter J. Halfmann
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail: (PJH); (YK)
| | - Amie J. Eisfeld
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Tokiko Watanabe
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Tadashi Maemura
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | | | | | - Tammy Armbrust
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Isaiah Rozich
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Alhaji N’jai
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Biological Sciences, Fourah Bay College, University of Sierra Leone, Freetown, Sierra Leone
| | - Gabriele Neumann
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Yoshihiro Kawaoka
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
- Institute of Medical Science, University of Tokyo, Tokyo, Japan
- * E-mail: (PJH); (YK)
| | - Foday Sahr
- 34 Regimental Military Hospital at Wilberforce, Freetown, Sierra Leone
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11
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Ponce J, Zheng Y, Lin G, Feng Z. Assessing the effects of modeling the spectrum of clinical symptoms on the dynamics and control of Ebola. J Theor Biol 2019; 467:111-122. [PMID: 30735738 DOI: 10.1016/j.jtbi.2019.01.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 10/27/2018] [Accepted: 01/08/2019] [Indexed: 10/27/2022]
Abstract
Mathematical modelers have attempted to capture the dynamics of Ebola transmission and to evaluate the effectiveness of control measures, as well as to make predictions about ongoing outbreaks. Many of their models consider only infections with typical symptoms, but Ebola presents clinically in a more complicated way. Even the most common symptom, fever, is not experienced by 13% of patients. This suggests that infected individuals could be asymptomatic or have moderately symptomatic infections as reported during previous Ebola outbreaks. To account crudely for the spectrum of clinical symptoms that characterizes Ebola infection, we developed a model including moderate and severe symptoms. Our model captures the dynamics of the recent outbreak of Ebola in Liberia. Our estimate of the basic reproduction number is 1.83 (CI: 1.72, 1.86), consistent with the WHO response team's estimate using early outbreak case data. We also estimate the effectiveness of interventions using observations before and after their introduction. As the final epidemic size is linked to the timing of interventions in an exponential fashion, a simple empirical formula is provided to guide policy-making. It suggests that early implementation could significantly decrease final size. We also compare our model to one with typical symptoms by excluding moderate ones. The model with only typical symptoms overestimates the basic reproduction number and effectiveness of control measures, and exaggerates changes in peak size attributable to the timing of interventions. In addition, uncertainty about how moderate symptoms affect the basic reproduction number is considered, and PRCC (Partial rank correlation coefficient) is used to analyze the global sensitivity of relevant parameters. Possible control strategies are evaluated through numerical simulations and sensitivity analysis, indicating that simultaneously strengthening contact-tracing and effectiveness of isolation in hospital would be most effective. In this study, we show that asymptomatic Ebola infections may have implications for policy-making.
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Affiliation(s)
- Joan Ponce
- Department of Mathematics, Purdue University, West Lafayette, IN 47907, USA.
| | - Yiqiang Zheng
- Department of Mathematics, Purdue University, West Lafayette, IN 47907, USA.
| | - Guang Lin
- Department of Mathematics, Purdue University, West Lafayette, IN 47907, USA; School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA.
| | - Zhilan Feng
- Department of Mathematics, Purdue University, West Lafayette, IN 47907, USA.
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12
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Hoff NA, Mukadi P, Doshi RH, Bramble MS, Lu K, Gadoth A, Sinai C, Spencer D, Nicholson BP, Williams R, Mossoko M, Ilunga-Kebela B, Wasiswa J, Okitolonda-Wemakoy E, Alfonso VH, Steffen I, Muyembe-Tamfum JJ, Simmons G, Rimoin AW. Serologic Markers for Ebolavirus Among Healthcare Workers in the Democratic Republic of the Congo. J Infect Dis 2019; 219:517-525. [PMID: 30239838 PMCID: PMC6350949 DOI: 10.1093/infdis/jiy499] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 08/18/2018] [Indexed: 12/17/2022] Open
Abstract
Healthcare settings have played a major role in propagation of Ebola virus (EBOV) outbreaks. Healthcare workers (HCWs) have elevated risk of contact with EBOV-infected patients, particularly if safety precautions are not rigorously practiced. We conducted a serosurvey to determine seroprevalence against multiple EBOV antigens among HCWs of Boende Health Zone, Democratic Republic of the Congo, the site of a 2014 EBOV outbreak. Interviews and specimens were collected from 565 consenting HCWs. Overall, 234 (41.4%) of enrolled HCWs were reactive to at least 1 EBOV protein: 159 (28.1%) were seroreactive for anti-glycoprotein immunoglobulin G (IgG), 89 (15.8%) were seroreactive for anti-nucleoprotein IgG, and 54 (9.5%) were VP40 positive. Additionally, sera from 16 (2.8%) HCWs demonstrated neutralization capacity. These data demonstrate that a significant proportion of HCWs have the ability to neutralize virus, despite never having developed Ebola virus disease symptoms, highlighting an important and poorly documented aspect of EBOV infection and progression.
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Affiliation(s)
- Nicole A Hoff
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles
| | - Patrick Mukadi
- Institut National de Recherche Biomédicale, Washington, District of Columbia
- Faculté de Médecine, Université de Kinshasa, Democratic Republic of the Congo (DRC), Washington, District of Columbia
| | - Reena H Doshi
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles
| | - Matthew S Bramble
- Department of Genetic Medicine Research, Children’s Research Institute, Children’s National Medical Center, Washington, District of Columbia
| | - Kai Lu
- Blood Systems Research Institute, San Francisco
- Department of Laboratory Medicine, University of California, San Francisco
| | - Adva Gadoth
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles
| | - Cyrus Sinai
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles
| | - D’Andre Spencer
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles
| | - Bradley P Nicholson
- Molecular Epidemiology Research Laboratory, Veterans Affairs Medical Center, Durham, North Carolina
| | | | - Matthias Mossoko
- Direction de lutte contre la Maladie, Ministère de la Santé Publique
| | | | - Joseph Wasiswa
- University of California, Los Angeles-DRC Research Program
- Direction de lutte contre la Maladie, Ministère de la Santé Publique
| | | | - Vivian H Alfonso
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles
| | - Imke Steffen
- Blood Systems Research Institute, San Francisco
- Department of Laboratory Medicine, University of California, San Francisco
| | - Jean-Jacques Muyembe-Tamfum
- Institut National de Recherche Biomédicale, Washington, District of Columbia
- Faculté de Médecine, Université de Kinshasa, Democratic Republic of the Congo (DRC), Washington, District of Columbia
| | - Graham Simmons
- Blood Systems Research Institute, San Francisco
- Department of Laboratory Medicine, University of California, San Francisco
| | - Anne W Rimoin
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles
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13
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Jacobsen KA, Burch MG, Tien JH, Rempała GA. The large graph limit of a stochastic epidemic model on a dynamic multilayer network. JOURNAL OF BIOLOGICAL DYNAMICS 2018; 12:746-788. [PMID: 30175687 DOI: 10.1080/17513758.2018.1515993] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/17/2018] [Indexed: 06/08/2023]
Abstract
We consider a Markovian SIR-type (Susceptible → Infected → Recovered) stochastic epidemic process with multiple modes of transmission on a contact network. The network is given by a random graph following a multilayer configuration model where edges in different layers correspond to potentially infectious contacts of different types. We assume that the graph structure evolves in response to the epidemic via activation or deactivation of edges of infectious nodes. We derive a large graph limit theorem that gives a system of ordinary differential equations (ODEs) describing the evolution of quantities of interest, such as the proportions of infected and susceptible vertices, as the number of nodes tends to infinity. Analysis of the limiting system elucidates how the coupling of edge activation and deactivation to infection status affects disease dynamics, as illustrated by a two-layer network example with edge types corresponding to community and healthcare contacts. Our theorem extends some earlier results describing the deterministic limit of stochastic SIR processes on static, single-layer configuration model graphs. We also describe precisely the conditions for equivalence between our limiting ODEs and the systems obtained via pair approximation, which are widely used in the epidemiological and ecological literature to approximate disease dynamics on networks. The flexible modeling framework and asymptotic results have potential application to many disease settings including Ebola dynamics in West Africa, which was the original motivation for this study.
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Affiliation(s)
- Karly A Jacobsen
- a College of Public Health, Department of Mathematics and Mathematical Biosciences Institute , The Ohio State University , Columbus , OH , USA
| | - Mark G Burch
- a College of Public Health, Department of Mathematics and Mathematical Biosciences Institute , The Ohio State University , Columbus , OH , USA
| | - Joseph H Tien
- a College of Public Health, Department of Mathematics and Mathematical Biosciences Institute , The Ohio State University , Columbus , OH , USA
| | - Grzegorz A Rempała
- a College of Public Health, Department of Mathematics and Mathematical Biosciences Institute , The Ohio State University , Columbus , OH , USA
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14
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Golding H, Khurana S, Zaitseva M. What Is the Predictive Value of Animal Models for Vaccine Efficacy in Humans? The Importance of Bridging Studies and Species-Independent Correlates of Protection. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a028902. [PMID: 28348035 DOI: 10.1101/cshperspect.a028902] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Animal models have played a pivotal role in all stages of vaccine development. Their predictive value for vaccine effectiveness depends on the pathogen, the robustness of the animal challenge model, and the correlates of protection (if known). This article will cover key questions regarding bridging animal studies to efficacy trials in humans. Examples include human papillomavirus (HPV) vaccine in which animal protection after vaccination with heterologous prototype virus-like particles (VLPs) predicted successful efficacy trials in humans, and a recent approval of anthrax vaccine in accordance with the "Animal Rule." The establishment of animal models predictive of vaccine effectiveness in humans has been fraught with difficulties with low success rate to date. Challenges facing the use of animal models for vaccine development against Ebola and HIV will be discussed.
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Affiliation(s)
- Hana Golding
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993
| | - Surender Khurana
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993
| | - Marina Zaitseva
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993
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15
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Singh RK, Dhama K, Malik YS, Ramakrishnan MA, Karthik K, Khandia R, Tiwari R, Munjal A, Saminathan M, Sachan S, Desingu PA, Kattoor JJ, Iqbal HMN, Joshi SK. Ebola virus - epidemiology, diagnosis, and control: threat to humans, lessons learnt, and preparedness plans - an update on its 40 year's journey. Vet Q 2017; 37:98-135. [PMID: 28317453 DOI: 10.1080/01652176.2017.1309474] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Ebola virus (EBOV) is an extremely contagious pathogen and causes lethal hemorrhagic fever disease in man and animals. The recently occurred Ebola virus disease (EVD) outbreaks in the West African countries have categorized it as an international health concern. For the virus maintenance and transmission, the non-human primates and reservoir hosts like fruit bats have played a vital role. For curbing the disease timely, we need effective therapeutics/prophylactics, however, in the absence of any approved vaccine, timely diagnosis and monitoring of EBOV remains of utmost importance. The technologically advanced vaccines like a viral-vectored vaccine, DNA vaccine and virus-like particles are underway for testing against EBOV. In the absence of any effective control measure, the adaptation of high standards of biosecurity measures, strict sanitary and hygienic practices, strengthening of surveillance and monitoring systems, imposing appropriate quarantine checks and vigilance on trade, transport, and movement of visitors from EVD endemic countries remains the answer of choice for tackling the EBOV spread. Herein, we converse with the current scenario of EBOV giving due emphasis on animal and veterinary perspectives along with advances in diagnosis and control strategies to be adopted, lessons learned from the recent outbreaks and the global preparedness plans. To retrieve the evolutionary information, we have analyzed a total of 56 genome sequences of various EBOV species submitted between 1976 and 2016 in public databases.
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Affiliation(s)
- Raj Kumar Singh
- a ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Kuldeep Dhama
- b Division of Pathology, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Yashpal Singh Malik
- c Division of Biological Standardization, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | | | - Kumaragurubaran Karthik
- e Divison of Bacteriology and Mycology, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Rekha Khandia
- f Department of Biochemistry and Genetics , Barkatullah University , Bhopal , India
| | - Ruchi Tiwari
- g Department of Veterinary Microbiology and Immunology , College of Veterinary Sciences, Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwavidyalay Evum Go-Anusandhan Sansthan (DUVASU) , Mathura , India
| | - Ashok Munjal
- f Department of Biochemistry and Genetics , Barkatullah University , Bhopal , India
| | - Mani Saminathan
- b Division of Pathology, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Swati Sachan
- h Immunology Section, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | | | - Jobin Jose Kattoor
- c Division of Biological Standardization, ICAR-Indian Veterinary Research Institute , Bareilly , India
| | - Hafiz M N Iqbal
- i School of Engineering and Science, Tecnologico de Monterrey , Monterrey , Mexico
| | - Sunil Kumar Joshi
- j Cellular Immunology Lab , Frank Reidy Research Center for Bioelectrics , School of Medical Diagnostics & Translational Sciences, Old Dominion University , Norfolk , VA , USA
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16
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Alfson KJ, Avena LE, Worwa G, Carrion R, Griffiths A. Development of a Lethal Intranasal Exposure Model of Ebola Virus in the Cynomolgus Macaque. Viruses 2017; 9:E319. [PMID: 29109373 PMCID: PMC5707526 DOI: 10.3390/v9110319] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 10/23/2017] [Accepted: 10/26/2017] [Indexed: 11/24/2022] Open
Abstract
Ebola virus (EBOV) is a filovirus that can cause Ebola virus disease (EVD). No approved vaccines or therapies exist for filovirus infections, despite an urgent need. The development and testing of effective countermeasures against EBOV requires use of animal models and a thorough understanding of how the model aligns with EVD in humans. The majority of published studies report outcomes of parenteral exposures for emulating needle stick transmission. However, based on data from EVD outbreaks, close contact exposures to infected bodily fluid seems to be one of the primary routes of EBOV transmission. Thus, further work is needed to develop models that represent mucosal exposure. To characterize the outcome of mucosal exposure to EBOV, cynomolgus macaques were exposed to EBOV via intranasal (IN) route using the LMA® mucosal atomization device (LMA® MAD). For comparison, four non-human primates (NHPs) were exposed to EBOV via intramuscular (IM) route. This IN exposure model was uniformly lethal and correlated with a statistically significant delay in time to death when compared to exposure via the IM route. This more closely reflects the timeframes observed in human infections. An IN model of exposure offers an attractive alternative to other models as it can offer insight into the consequences of exposure via a mucosal surface and allows for screening countermeasures via a different exposure route.
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Affiliation(s)
- Kendra J Alfson
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX 78227, USA.
| | - Laura E Avena
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX 78227, USA.
- Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
| | - Gabriella Worwa
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX 78227, USA.
| | - Ricardo Carrion
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX 78227, USA.
| | - Anthony Griffiths
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX 78227, USA.
- Graduate School of Biomedical Sciences, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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17
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The perspective of gender on the Ebola virus using a risk management and population health framework: a scoping review. Infect Dis Poverty 2017; 6:135. [PMID: 29017587 PMCID: PMC5635524 DOI: 10.1186/s40249-017-0346-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 08/07/2017] [Indexed: 11/13/2022] Open
Abstract
Background In the three decades since the first reported case of Ebola virus, most known index cases have been consistently traced to the hunting of “bush meat”, and women have consistently recorded relatively high fatality rates in most catastrophic outbreaks. This paper discusses Ebola-related risk factors, which constantly interact with cultural values, and provides an insight into the link between gender and the risk of contracting infectious diseases, using Ebola virus as an example within Africa. Method A comprehensive search of the literature was conducted using the PubMed, Ovid Medline and Global Health CABI databases as well as CAB Abstracts, including gray literature. We used a descriptive and sex- and gender-based analysis to revisit previous studies on Ebola outbreaks since 1976 to 2014, and disaggregated the cases and fatality rates according to gender and the sources of known index cases based on available data. Results In total, approximately 1530 people died in all previous Ebola outbreaks from 1976 to 2012 compared with over 11,310 deaths from the 2014 outbreak. Women’s increased exposure can be attributed to time spent at home and their responsibility for caring for the sick, while men’s increased vulnerability to the virus can be attributed to their responsibility for caring for livestock and to time spent away from home, as most known sources of the index cases have been infected in the process of hunting. We present a conceptual model of a circle of interacting risk factors for Ebola in the African context. Conclusion There is currently no evidence related to biological differences in female or male sex that increases Ebola virus transmission and vulnerability; rather, there are differences in the level of exposure between men and women. Gender is therefore an important risk factor to consider in the design of health programs. Building the capacity for effective risk communication is a worthwhile investment in public and global health for future emergency responses. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0346-7) contains supplementary material, which is available to authorized users.
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18
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Walldorf JA, Cloessner EA, Hyde TB, MacNeil A. Considerations for use of Ebola vaccine during an emergency response. Vaccine 2017; 37:7190-7200. [PMID: 28890191 DOI: 10.1016/j.vaccine.2017.08.058] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/21/2017] [Accepted: 08/24/2017] [Indexed: 10/18/2022]
Abstract
Vaccination against Ebola virus disease is a tool that may limit disease transmission and deaths in future outbreaks, integrated within traditional Ebola outbreak prevention and control measures. Although a licensed Ebolavirus vaccine (EV) is not yet available, the 2014-2016 West African Ebola outbreak has accelerated EV clinical trials and given public health authorities in Guinea, Liberia, and Sierra Leone experience with implementation of emergency ring vaccination. As evidence supporting the use of EV during an outbreak response has become available, public health authorities in at-risk countries are considering how to integrate EV into future emergency Ebola responses and for prevention in high-risk groups, such as healthcare workers and frontline workers (HCW/FLWs), even before an EV is licensed. This review provides an overview of Ebola epidemiology, immunology, and evidence to inform regional and country-level decisions regarding EV delivery during an emergency response and to at-risk populations before a licensed vaccine is available and beyond. Countries or regions planning to use EV will need to assess factors such as the likelihood of a future Ebolavirus outbreak, the most likely species to cause an outbreak, the availability of a safe and effective EV (unlicensed or licensed) for the affected population, capacity to implement Ebola vaccination in conjunction with standard Ebola outbreak control measures, and availability of minimum essential resources and regulatory requirements to implement emergency Ebola vaccination. Potential emergency vaccination strategies for consideration include ring or geographically targeted community vaccination, HCW/FLW vaccination, and mass vaccination. The development of guidelines and protocols for Ebola vaccination will help ensure that activities are standardized, evidence-based, and well-coordinated with overall Ebola outbreak response efforts in the future.
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Affiliation(s)
- Jenny A Walldorf
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, United States.
| | - Emily A Cloessner
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, United States; Association of Schools and Programs of Public Health, 1900 M St NW Suite 710, Washington, DC 20036, United States.
| | - Terri B Hyde
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, United States.
| | - Adam MacNeil
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, United States.
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D'Silva JP, Eisenberg MC. Modeling spatial invasion of Ebola in West Africa. J Theor Biol 2017; 428:65-75. [PMID: 28551366 DOI: 10.1016/j.jtbi.2017.05.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 05/22/2017] [Accepted: 05/23/2017] [Indexed: 10/19/2022]
Abstract
The 2014-2016 Ebola Virus Disease (EVD) epidemic in West Africa was the largest ever recorded, representing a fundamental shift in Ebola epidemiology with unprecedented spatiotemporal complexity. To understand the spatiotemporal dynamics of EVD in West Africa, we developed spatial transmission models using a gravity-model framework at both the national and district-level scales, which we used to compare effectiveness of local interventions (e.g. local quarantine) and long-range interventions (e.g. border-closures). The country-level gravity model captures the epidemic data, including multiple waves of initial epidemic growth observed in Guinea. We found that local-transmission reductions were most effective in Liberia, while long-range transmission was dominant in Sierra Leone. Both models illustrated that interventions in one region result in an amplified protective effect on other regions by preventing spatial transmission. In the district-level model, interventions in the strongest of these amplifying regions reduced total cases in all three countries by over 20%, in spite of the region itself generating only ∼0.1% of total cases. This model structure and associated intervention analysis provide information that can be used by public health policymakers to assist planning and response efforts for future epidemics.
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Affiliation(s)
- Jeremy P D'Silva
- Departments of Epidemiology and Mathematics, School of Public Health, University of Michigan, Ann Arbor, United States
| | - Marisa C Eisenberg
- Departments of Epidemiology and Mathematics, School of Public Health, University of Michigan, Ann Arbor, United States.
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20
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Palich R, Irenge LM, Barte de Sainte Fare E, Augier A, Malvy D, Gala JL. Ebola virus RNA detection on fomites in close proximity to confirmed Ebola patients; N'Zerekore, Guinea, 2015. PLoS One 2017; 12:e0177350. [PMID: 28493945 PMCID: PMC5426669 DOI: 10.1371/journal.pone.0177350] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/26/2017] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Health care workers (HCWs) in contact with patients with Ebola virus disease (EVD) are exposed to a risk of viral contamination. Fomites contaminated with the patient's blood or body fluids represents this risk. Our study aims to detect Ebola virus (EBOV) RNA within the high- and low-risk areas of an Ebola treatment unit (ETU) located in inland Guinea during the 2014-2015 West African Ebola epidemics. For samples from patients' immediate vicinity, we aim to seek an association between viral RNA detectability and level of plasma viral load of patients (intermediate to high, or very high). METHODS Swabbing was performed on immediate vicinity of Ebola patients, on surfaces of an ETU, and on personal protective equipment (PPE) of HCWs after patient care and prior to doffing. All samples were assessed by quantitative reverse-transcribed PCR (RT-qPCR). RESULTS 32% (22/68) of swabs from high-risk areas were tested positive for EBOV RNA, including 42% (18/43) from patients' immediate vicinity, and 16% (4/25) from HCWs PPE. None of specimens from low-risk areas were tested positive (0/19). Swabs were much more often viral RNA positive in the vicinity of patients with a very high plasma viral load (OR 6.7, 95% CI [1.7-23.4]). CONCLUSION Our findings show the persistence of EBOV RNA in the environment of Ebola patients and of HCWs, in a Guinean ETU, despite strict infection prevention and control measures. This detection raises the possibility that patients' environment could be a potential source of contamination with the virus.
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Affiliation(s)
- Romain Palich
- Alliance for International Medical Action, Dakar, Senegal
- * E-mail:
| | - Leonid M. Irenge
- Center for Applied Molecular Technologies, Louvain Catholic University, Brussels, Belgium
| | | | | | - Denis Malvy
- Department of Tropical Medicine and Clinical International Health, Division of Infectious and Tropical Diseases, University Hospital of Bordeaux, Bordeaux, France
- INSERM1219, University of Bordeaux, Bordeaux, France
| | - Jean-Luc Gala
- Center for Applied Molecular Technologies, Louvain Catholic University, Brussels, Belgium
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21
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Houlihan CF, McGowan CR, Dicks S, Baguelin M, Moore DAJ, Mabey D, Roberts CH, Kumar A, Samuel D, Tedder R, Glynn JR. Ebola exposure, illness experience, and Ebola antibody prevalence in international responders to the West African Ebola epidemic 2014-2016: A cross-sectional study. PLoS Med 2017; 14:e1002300. [PMID: 28510604 PMCID: PMC5433702 DOI: 10.1371/journal.pmed.1002300] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 04/04/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Healthcare and other front-line workers are at particular risk of infection with Ebola virus (EBOV). Despite the large-scale deployment of international responders, few cases of Ebola virus disease have been diagnosed in this group. Since asymptomatic or pauci-symptomatic infection has been described, it is plausible that infections have occurred in healthcare workers but have escaped being diagnosed. We aimed to assess the prevalence of asymptomatic or pauci-symptomatic infection, and of exposure events, among returned responders to the West African Ebola epidemic 2014-2016. METHODS AND FINDINGS We used snowball sampling to identify responders who had returned to the UK or Ireland, and used an online consent and questionnaire to determine their exposure to EBOV and their experience of illness. Oral fluid collection devices were sent and returned by post, and samples were tested using an EBOV IgG capture assay that detects IgG to Ebola glycoprotein. Blood was collected from returnees with reactive samples for further testing. Unexposed UK controls were also recruited. In all, 300 individuals consented, of whom 268 (89.3%) returned an oral fluid sample (OFS). The majority had worked in Sierra Leone in clinical, laboratory, research, and other roles. Fifty-three UK controls consented and provided samples using the same method. Of the returnees, 47 (17.5%) reported that they had had a possible EBOV exposure. Based on their free-text descriptions, using a published risk assessment method, we classified 43 (16%) as having had incidents with risk of Ebola transmission, including five intermediate-risk and one high-risk exposure. Of the returnees, 57 (21%) reported a febrile or diarrhoeal illness in West Africa or within 1 mo of return, of whom 40 (70%) were not tested at the time for EBOV infection. Of the 268 OFSs, 266 were unreactive. Two returnees, who did not experience an illness in West Africa or on return, had OFSs that were reactive on the EBOV IgG capture assay, with similar results on plasma. One individual had no further positive test results; the other had a positive result on a double-antigen bridging assay but not on a competitive assay or on an indirect EBOV IgG ELISA. All 53 controls had non-reactive OFSs. While the participants were not a random sample of returnees, the number participating was high. CONCLUSIONS This is the first study, to our knowledge, of the prevalence of EBOV infection in international responders. More than 99% had clear negative results. Sera from two individuals had discordant results on the different assays; both were negative on the competitive assay, suggesting that prior infection was unlikely. The finding that a significant proportion experienced "near miss" exposure events, and that most of those who experienced symptoms did not get tested for EBOV at the time, suggests a need to review and standardise protocols for the management of possible exposure to EBOV, and for the management of illness, across organisations that deploy staff to outbreaks.
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Affiliation(s)
- Catherine F. Houlihan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Faculty of Medical Sciences, University College London, London, United Kingdom
| | - Catherine R. McGowan
- Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Humanitarian Public Health Technical Unit, Save the Children UK, London, United Kingdom
| | - Steve Dicks
- Transfusion Microbiology, National Health Service Blood and Transplant, London, United Kingdom
- NHSBT/PHE Blood Borne Virus Unit, Serology Development Unit, Public Health England, London, United Kingdom
| | - Marc Baguelin
- Centre of Infectious Disease Surveillance and Control, Public Health England, London, United Kingdom
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David A. J. Moore
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David Mabey
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Chrissy h. Roberts
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Alex Kumar
- Department of Infection and Tropical Medicine, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Dhan Samuel
- NHSBT/PHE Blood Borne Virus Unit, Serology Development Unit, Public Health England, London, United Kingdom
| | - Richard Tedder
- Transfusion Microbiology, National Health Service Blood and Transplant, London, United Kingdom
- NHSBT/PHE Blood Borne Virus Unit, Serology Development Unit, Public Health England, London, United Kingdom
| | - Judith R. Glynn
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
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22
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Non-biomedical factors in the Ebola virus disease outbreak in West Africa. Uirusu 2017; 65:83-8. [PMID: 26923961 DOI: 10.2222/jsv.65.83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The outbreak of Ebola virus disease, reported in West Africa in 2014, has become the largest ever one in the history. Tremendous efforts by all the parties concerned are now bringing this epidemic closer to the end, while observing a large number of cases and deaths, including health care workers.This paper features five questions:1. Why did it emerge in West Africa?2. Why has it spread so wide and intensely?3. Why were so many health care workers infected?4. Why is it being brought under control?5. Would it emerge and spread in Japan in the same way?Ebola virus transmits through human acts such as caregiving of the sick and attending a funeral, therefore an epidemic is not likely to subside naturally, but intentional interventions are needed to terminate its transmission. Who the outbreak response is meant for, either patients, the general public in the affected countries, or international communities, also determines its success or failure.
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Lamunu M, Olu OO, Bangura J, Yoti Z, Samba TT, Kargbo DK, Dafae FM, Raja MA, Sempira N, Ivan ML, Sing A, Kurti-George F, Worku N, Mitula P, Ganda L, Samupindi R, Conteh R, Kamara KB, Muraguri B, Kposowa M, Charles J, Mugaga M, Dye C, Banerjee A, Formenty P, Kargbo B, Aylward RB. Epidemiology of Ebola Virus Disease in the Western Area Region of Sierra Leone, 2014-2015. Front Public Health 2017; 5:33. [PMID: 28303239 PMCID: PMC5332373 DOI: 10.3389/fpubh.2017.00033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 02/15/2017] [Indexed: 11/15/2022] Open
Abstract
Introduction Western Area (WA) of Sierra Leone including the capital, Freetown, experienced an unprecedented outbreak of Ebola from 2014 to 2015. At the onset of the epidemic, there was little information about the epidemiology, transmission dynamics, and risk factors in urban settings as previous outbreaks were limited to rural/semi-rural settings. This study, therefore, aimed to describe the epidemiology of the outbreak and the factors which had most impact on the transmission of the epidemic and whether there were different drivers from those previously described in rural settings. Methods We conducted a descriptive epidemiology study in WA, Sierra Leone using secondary data from the National Ebola outbreak database. We also reviewed the Ebola situation reports, response strategy documents, and other useful documents. Results A total of 4,955 Ebola cases were identified between June 2014 and November 2015, although there were reports of cases occurring in WA toward end of May. All wards were affected, and Waterloo Area I (Ward 330), the capital city of Western Area Rural District, recorded the highest numbers of cases (580) and deaths (236). Majority of cases (63.4%) and deaths (66.8%) were in WA Urban District (WAU); 44 cases were imported from other provinces. Only 20% of cases had a history of contact with an Ebola case, and more than 30% were death alerts. Equal numbers of males and females were infected, and very few cases (3.2%) were health workers. Overall, transmission was through contact with infected individuals, and intense transmission occurred at the community level. In WAU, transmission was mostly between neighbors and among inhabitants of shared accommodations. The drivers of transmission included high population movement to and from WA, overcrowding, fear and lack of trust in the response, and negative community behaviors. Transmission was mostly through contact and with limited transmission through sex and breast milk. Conclusion The unprecedented outbreak in WA was attributed to delayed detection, inadequate preparedness and response, intense population movements, overcrowding, and unresponsive communities. Anticipation, strengthening preparedness for early detection, and swift and effective response remains critical in mitigating a potential urban explosion of similar future outbreaks.
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Affiliation(s)
- Margaret Lamunu
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | | | - James Bangura
- Ministry of Health and Sanitation , Freetown , Sierra Leone
| | - Zabulon Yoti
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | | | | | | | - Muhammad Ali Raja
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Noah Sempira
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Michael Lyazi Ivan
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Aarti Sing
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | | | - Negusu Worku
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Pamela Mitula
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Louisa Ganda
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Robert Samupindi
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Roland Conteh
- Ministry of Health and Sanitation , Freetown , Sierra Leone
| | - Kande-Bure Kamara
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Beatrice Muraguri
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | | | - Joseph Charles
- Ministry of Health and Sanitation , Freetown , Sierra Leone
| | - Malimbo Mugaga
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Christopher Dye
- World Health Organization (WHO) Headquarters , Geneva , Switzerland
| | - Anshu Banerjee
- World Health Organization (WHO) Country Office , Freetown , Sierra Leone
| | - Pierre Formenty
- World Health Organization (WHO) Headquarters , Geneva , Switzerland
| | - Brima Kargbo
- Ministry of Health and Sanitation , Freetown , Sierra Leone
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Lawrence P, Danet N, Reynard O, Volchkova V, Volchkov V. Human transmission of Ebola virus. Curr Opin Virol 2016; 22:51-58. [PMID: 28012412 DOI: 10.1016/j.coviro.2016.11.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/25/2016] [Accepted: 11/29/2016] [Indexed: 12/11/2022]
Abstract
Ever since the first recognised outbreak of Ebolavirus in 1976, retrospective epidemiological analyses and extensive studies with animal models have given us insight into the nature of the pathology and transmission mechanisms of this virus. In this review focusing on Ebolavirus, we present an outline of our current understanding of filovirus human-to-human transmission and of our knowledge concerning the molecular basis of viral transmission and potential for adaptation, with particular focus on what we have learnt from the 2014 outbreak in West Africa. We identify knowledge gaps relating to transmission and pathogenicity mechanisms, molecular adaptation and filovirus ecology.
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Affiliation(s)
- Philip Lawrence
- Molecular Basis of Viral Pathogenicity, International Centre for Research in Infectiology (CIRI), INSERM U1111 - CNRS UMR5308, Université Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France; Université de Lyon, UMRS 449, Laboratoire de Biologie Générale, Université Catholique de Lyon - EPHE, Lyon 69288, France
| | - Nicolas Danet
- Molecular Basis of Viral Pathogenicity, International Centre for Research in Infectiology (CIRI), INSERM U1111 - CNRS UMR5308, Université Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France
| | - Olivier Reynard
- Molecular Basis of Viral Pathogenicity, International Centre for Research in Infectiology (CIRI), INSERM U1111 - CNRS UMR5308, Université Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France
| | - Valentina Volchkova
- Molecular Basis of Viral Pathogenicity, International Centre for Research in Infectiology (CIRI), INSERM U1111 - CNRS UMR5308, Université Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France
| | - Viktor Volchkov
- Molecular Basis of Viral Pathogenicity, International Centre for Research in Infectiology (CIRI), INSERM U1111 - CNRS UMR5308, Université Lyon 1, Ecole Normale Supérieure de Lyon, Lyon 69007, France.
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25
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Agua-Agum J, Ariyarajah A, Aylward B, Bawo L, Bilivogui P, Blake IM, Brennan RJ, Cawthorne A, Cleary E, Clement P, Conteh R, Cori A, Dafae F, Dahl B, Dangou JM, Diallo B, Donnelly CA, Dorigatti I, Dye C, Eckmanns T, Fallah M, Ferguson NM, Fiebig L, Fraser C, Garske T, Gonzalez L, Hamblion E, Hamid N, Hersey S, Hinsley W, Jambei A, Jombart T, Kargbo D, Keita S, Kinzer M, George FK, Godefroy B, Gutierrez G, Kannangarage N, Mills HL, Moller T, Meijers S, Mohamed Y, Morgan O, Nedjati-Gilani G, Newton E, Nouvellet P, Nyenswah T, Perea W, Perkins D, Riley S, Rodier G, Rondy M, Sagrado M, Savulescu C, Schafer IJ, Schumacher D, Seyler T, Shah A, Van Kerkhove MD, Wesseh CS, Yoti Z. Exposure Patterns Driving Ebola Transmission in West Africa: A Retrospective Observational Study. PLoS Med 2016; 13:e1002170. [PMID: 27846234 PMCID: PMC5112802 DOI: 10.1371/journal.pmed.1002170] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 10/07/2016] [Indexed: 11/18/2022] Open
Abstract
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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Affiliation(s)
| | | | | | | | - Luke Bawo
- Ministry of Health, Monrovia, Liberia
| | | | - Isobel M. Blake
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | | | | | | | | | - Anne Cori
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | - Benjamin Dahl
- Centers for Disease Control and Prevention, Conakry, Guinea
| | | | | | - Christl A. Donnelly
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Ilaria Dorigatti
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | - Tim Eckmanns
- World Health Organization, Geneva, Switzerland
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | | | - Neil M. Ferguson
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Lena Fiebig
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - Christophe Fraser
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
- Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Tini Garske
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | | | - Nuha Hamid
- World Health Organization, Monrovia, Liberia
| | - Sara Hersey
- Centers for Disease Control and Prevention, Freetown, Sierra Leone
| | - Wes Hinsley
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | - Thibaut Jombart
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | | | - Michael Kinzer
- Centers for Disease Control and Prevention, Conakry, Guinea
| | | | | | | | | | - Harriet L. Mills
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
- MRC Integrative Epidemiology Unit, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
- School of Veterinary Sciences, University of Bristol, Bristol, United Kingdom
| | - Thomas Moller
- European Centre for Disease Prevention and Control, Conakry, Guinea
| | | | | | - Oliver Morgan
- Centers for Disease Control and Prevention, Freetown, Sierra Leone
| | - Gemma Nedjati-Gilani
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | - Pierre Nouvellet
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | | | | | - Steven Riley
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | | | | | | | - Ilana J. Schafer
- Centers for Disease Control and Prevention, Freetown, Sierra Leone
| | - Dirk Schumacher
- World Health Organization, Geneva, Switzerland
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | | | - Anita Shah
- World Health Organization, Geneva, Switzerland
| | - Maria D. Van Kerkhove
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | | | - Zabulon Yoti
- World Health Organization, Freetown, Sierra Leone
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Bower H, Johnson S, Bangura MS, Kamara AJ, Kamara O, Mansaray SH, Sesay D, Turay C, Checchi F, Glynn JR. Exposure-Specific and Age-Specific Attack Rates for Ebola Virus Disease in Ebola-Affected Households, Sierra Leone. Emerg Infect Dis 2016; 22:1403-11. [PMID: 27144428 PMCID: PMC4982163 DOI: 10.3201/eid2208.160163] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Using histories of household members of Ebola virus disease (EVD) survivors in Sierra Leone, we calculated risk of EVD by age and exposure level, adjusting for confounding and clustering, and estimated relative risks. Of 937 household members in 94 households, 448 (48%) had had EVD. Highly correlated with exposure, EVD risk ranged from 83% for touching a corpse to 8% for minimal contact and varied by age group: 43% for children <2 years of age; 30% for those 5-14 years of age; and >60% for adults >30 years of age. Compared with risk for persons 20-29 years of age, exposure-adjusted relative risks were lower for those 5-9 (0.70), 10-14 (0.64), and 15-19 (0.71) years of age but not for children <2 (0.92) or 2-4 (0.97) years of age. Lower risk for 5-19-year-olds, after adjustment for exposure, suggests decreased susceptibility in this group.
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27
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Hewlett BL, Hewlett BS. Providing Care and Facing Death: Nursing During Ebola Outbreaks in Central Africa. J Transcult Nurs 2016; 16:289-97. [PMID: 16160191 DOI: 10.1177/1043659605278935] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Few studies have focused on describing the experiences of health care workers during rapid killing epidemics. In this article, the views and experiences of nurses during three outbreaks of Ebola hemorrhagic fever (EHF) in Central Africa are examined. These three outbreaks occurred in Kikwit, Democratic Republic of Congo (DRC, 1995); Gulu, Uganda (2000-2001); and Republic of Congo (ROC, 2003). Open-ended and semistructured interviews with individuals and small groups were conducted during the outbreaks in Uganda and ROC; data from DRC are extracted from published sources. Three key themes emerged from the interviews: (a) lack of protective gear, basic equipment, and other resources necessary to provide care, especially during the early phases of the outbreaks; (b) stigmatization by family, coworkers, and community; and (c) exceptional commitment to the nursing profession in a context where the lives of the health care workers were in jeopardy.
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28
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CHUGHTAI AA, BARNES M, MACINTYRE CR. Persistence of Ebola virus in various body fluids during convalescence: evidence and implications for disease transmission and control. Epidemiol Infect 2016; 144:1652-60. [PMID: 26808232 PMCID: PMC4855994 DOI: 10.1017/s0950268816000054] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 12/22/2015] [Accepted: 01/06/2016] [Indexed: 11/06/2022] Open
Abstract
The aim of this study was to review the current evidence regarding the persistence of Ebola virus (EBOV) in various body fluids during convalescence and discuss its implication on disease transmission and control. We conducted a systematic review and searched articles from Medline and EMBASE using key words. We included studies that examined the persistence of EBOV in various body fluids during the convalescent phase. Twelve studies examined the persistence of EBOV in body fluids, with around 800 specimens tested in total. Available evidence suggests that EBOV can persist in some body fluids after clinical recovery and clearance of virus from the blood. EBOV has been isolated from semen, aqueous humor, urine and breast milk 82, 63, 26 and 15 days after onset of illness, respectively. Viral RNA has been detectable in semen (day 272), aqueous humor (day 63), sweat (day 40), urine (day 30), vaginal secretions (day 33), conjunctival fluid (day 22), faeces (day 19) and breast milk (day 17). Given high case fatality and uncertainties around the transmission characteristics, patients should be considered potentially infectious for a period of time after immediate clinical recovery. Patients and their immediate contacts should be informed about these risks. Convalescent patients may need to abstain from sex for at least 9 months or should use condoms until their semen tests are negative. Breastfeeding should be avoided during the convalescent phase. There is a need for more research on persistence, and a uniform approach to infection control guidelines in convalescence.
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Affiliation(s)
- A. A. CHUGHTAI
- School of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - M. BARNES
- School of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - C. R. MACINTYRE
- School of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales, Sydney, Australia
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29
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Mekibib B, Ariën KK. Aerosol Transmission of Filoviruses. Viruses 2016; 8:v8050148. [PMID: 27223296 PMCID: PMC4885103 DOI: 10.3390/v8050148] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 05/18/2016] [Accepted: 05/20/2016] [Indexed: 12/30/2022] Open
Abstract
Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire) and Sudan, the 2013–2015 western African Ebola virus disease (EVD) outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s) in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses.
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Affiliation(s)
- Berhanu Mekibib
- Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp B-2000, Belgium.
- School of Veterinary Medicine, College of Natural and Computational Sciences, Hawassa University, P.O. Box 05, Hawassa, Ethiopia.
| | - Kevin K Ariën
- Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp B-2000, Belgium.
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30
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Edmunds KL, Elrahman SA, Bell DJ, Brainard J, Dervisevic S, Fedha TP, Few R, Howard G, Lake I, Maes P, Matofari J, Minnigh H, Mohamedani AA, Montgomery M, Morter S, Muchiri E, Mudau LS, Mutua BM, Ndambuki JM, Pond K, Sobsey MD, van der Es M, Zeitoun M, Hunter PR. Recommendations for dealing with waste contaminated with Ebola virus: a Hazard Analysis of Critical Control Points approach. Bull World Health Organ 2016; 94:424-32. [PMID: 27274594 PMCID: PMC4890207 DOI: 10.2471/blt.15.163931] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 01/02/2016] [Accepted: 01/12/2016] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To assess, within communities experiencing Ebola virus outbreaks, the risks associated with the disposal of human waste and to generate recommendations for mitigating such risks. METHODS A team with expertise in the Hazard Analysis of Critical Control Points framework identified waste products from the care of individuals with Ebola virus disease and constructed, tested and confirmed flow diagrams showing the creation of such products. After listing potential hazards associated with each step in each flow diagram, the team conducted a hazard analysis, determined critical control points and made recommendations to mitigate the transmission risks at each control point. FINDINGS The collection, transportation, cleaning and shared use of blood-soiled fomites and the shared use of latrines contaminated with blood or bloodied faeces appeared to be associated with particularly high levels of risk of Ebola virus transmission. More moderate levels of risk were associated with the collection and transportation of material contaminated with bodily fluids other than blood, shared use of latrines soiled with such fluids, the cleaning and shared use of fomites soiled with such fluids, and the contamination of the environment during the collection and transportation of blood-contaminated waste. CONCLUSION The risk of the waste-related transmission of Ebola virus could be reduced by the use of full personal protective equipment, appropriate hand hygiene and an appropriate disinfectant after careful cleaning. Use of the Hazard Analysis of Critical Control Points framework could facilitate rapid responses to outbreaks of emerging infectious disease.
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Affiliation(s)
- Kelly L Edmunds
- Centre for Ecology, Evolution and Conservation, University of East Anglia, Norwich, England
| | - Samira Abd Elrahman
- Department of Family and Community Medicine, University of Gezira, Gezira, Sudan
| | - Diana J Bell
- Centre for Ecology, Evolution and Conservation, University of East Anglia, Norwich, England
| | - Julii Brainard
- Norwich Medical School, University of East Anglia, Norwich, NR4 7TJ, England
| | - Samir Dervisevic
- Norwich Medical School, University of East Anglia, Norwich, NR4 7TJ, England
| | - Tsimbiri P Fedha
- Reproductive Health Department, Egerton University, Egerton, Kenya
| | - Roger Few
- School of International Development, University of East Anglia, Norwich, England
| | - Guy Howard
- Department for International Development, East Kilbride, Scotland
| | - Iain Lake
- School of Environmental Sciences, University of East Anglia, Norwich, England
| | - Peter Maes
- Médecins Sans Frontières, Bruxelles, Belgium
| | - Joseph Matofari
- Department of Dairy, Food Science and Technology, Egerton University, Egerton, Kenya
| | - Harvey Minnigh
- Centro de Educación, Conservación, e Interpretación Ambiental, Inter American University of Puerto Rico, San Germán, Puerto Rico
| | | | - Maggie Montgomery
- Water, Sanitation, Hygiene and Health Unit, World Health Organization, Geneva, Switzerland
| | - Sarah Morter
- Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, England
| | - Edward Muchiri
- Faculty of Engineering and Technology, Egerton University, Egerton, Kenya
| | | | - Benedict M Mutua
- Faculty of Engineering and Technology, Egerton University, Egerton, Kenya
| | - Julius M Ndambuki
- Faculty of Engineering and Technology, Egerton University, Egerton, Kenya
| | - Katherine Pond
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, England
| | - Mark D Sobsey
- Gillings School of Global Public Health, University of North Carolina, Chapel Hill, United States of America
| | - Mike van der Es
- Norwich Medical School, University of East Anglia, Norwich, NR4 7TJ, England
| | - Mark Zeitoun
- Water Security Research Centre, University of East Anglia, Norwich, England
| | - Paul R Hunter
- Norwich Medical School, University of East Anglia, Norwich, NR4 7TJ, England
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Dean NE, Halloran ME, Yang Y, Longini IM. Transmissibility and Pathogenicity of Ebola Virus: A Systematic Review and Meta-analysis of Household Secondary Attack Rate and Asymptomatic Infection. Clin Infect Dis 2016; 62:1277-1286. [PMID: 26932131 DOI: 10.1093/cid/ciw114] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/19/2016] [Indexed: 11/14/2022] Open
Abstract
Factors affecting our ability to control an Ebola outbreak include transmissibility of the virus and the proportion of transmissions occurring asymptomatically. We performed a meta-analysis of Ebola household secondary attack rate (SAR), disaggregating by type of exposure (direct contact, no direct contact, nursing care, direct contact but no nursing care). The estimated overall household SAR is 12.5% (95% confidence interval [CI], 8.6%-16.3%). Transmission was driven by direct contact, with little transmission occurring in its absence (SAR, 0.8% [95% CI, 0%-2.3%]). The greatest risk factor was the provision of nursing care (SAR, 47.9% [95% CI, 23.3%-72.6%]). There was evidence of a decline in household SAR for direct contact between 1976 and 2014 (P = .018). We estimate that 27.1% (95% CI, 14.5%-39.6%) of Ebola infections are asymptomatic. Our findings suggest that surveillance and containment measures should be effective for controlling Ebola.
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Affiliation(s)
- Natalie E Dean
- Department of Biostatistics, University of Florida, Gainesville
| | - M Elizabeth Halloran
- Department of Biostatistics, University of Washington.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Yang Yang
- Department of Biostatistics, University of Florida, Gainesville
| | - Ira M Longini
- Department of Biostatistics, University of Florida, Gainesville
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Brainard J, Hooper L, Pond K, Edmunds K, Hunter PR. Risk factors for transmission of Ebola or Marburg virus disease: a systematic review and meta-analysis. Int J Epidemiol 2016; 45:102-16. [PMID: 26589246 PMCID: PMC4795563 DOI: 10.1093/ije/dyv307] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The Ebola virus disease outbreak that started in Western Africa in 2013 was unprecedented because it spread within densely populated urban environments and affected many thousands of people. As a result, previous advice and guidelines need to be critically reviewed, especially with regard to transmission risks in different contexts. METHODS Scientific and grey literature were searched for articles about any African filovirus. Articles were screened for information about transmission (prevalence or odds ratios especially). Data were extracted from eligible articles and summarized narratively with partial meta-analysis. Study quality was also evaluated. RESULTS A total of 31 reports were selected from 6552 found in the initial search. Eight papers gave numerical odds for contracting filovirus illness; 23 further articles provided supporting anecdotal observations about how transmission probably occurred for individuals. Many forms of contact (conversation, sharing a meal, sharing a bed, direct or indirect touching) were unlikely to result in disease transmission during incubation or early illness. Among household contacts who reported directly touching a case, the attack rate was 32% [95% confidence interval (CI) 26-38%]. Risk of disease transmission between household members without direct contact was low (1%; 95% CI 0-5%). Caring for a case in the community, especially until death, and participation in traditional funeral rites were strongly associated with acquiring disease, probably due to a high degree of direct physical contact with case or cadaver. CONCLUSIONS Transmission of filovirus is unlikely except through close contact, especially during the most severe stages of acute illness. More data are needed about the context, intimacy and timing of contact required to raise the odds of disease transmission. Risk factors specific to urban settings may need to be determined.
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Affiliation(s)
- Julii Brainard
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Lee Hooper
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Katherine Pond
- Robens Centre for Public and Environmental Health, University of Surrey, Guildford, UK
| | - Kelly Edmunds
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Paul R Hunter
- Norwich Medical School, University of East Anglia, Norwich, UK
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Mann E, Streng S, Bergeron J, Kircher A. A Review of the Role of Food and the Food System in the Transmission and Spread of Ebolavirus. PLoS Negl Trop Dis 2015; 9:e0004160. [PMID: 26633305 PMCID: PMC4669147 DOI: 10.1371/journal.pntd.0004160] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The current outbreak of Ebola virus disease (EVD) centered in West Africa is the largest in history, with nearly ten times more individuals contracting the disease than all previous outbreaks combined. The details of human-to-human and zoonotic ebolavirus transmission have justifiably received the largest share of research attention, and much information exists on these topics. However, although food processing-in the form of slaughtering and preparing wildlife for consumption (referred to as bushmeat)-has been implicated in EVD outbreaks, the full role of food in EVD spread is poorly understood and has been little studied. A literature search was undertaken to assess the current state of knowledge regarding how food can or may transmit ebolaviruses and how the food system contributes to EVD outbreak and spread. The literature reveals surprising preliminary evidence that food and the food system may be more implicated in ebolavirus transmission than expected and that further research is urgently needed.
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Affiliation(s)
- Erin Mann
- Food Protection and Defense Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Stephen Streng
- Food Protection and Defense Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Justin Bergeron
- Food Protection and Defense Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
| | - Amy Kircher
- Food Protection and Defense Institute, University of Minnesota, Saint Paul, Minnesota, United States of America
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Missair A, Marino MJ, Vu CN, Gutierrez J, Missair A, Osman B, Gebhard RE. Anesthetic Implications of Ebola Patient Management: A Review of the Literature and Policies. Anesth Analg 2015; 121:810-821. [PMID: 25551317 DOI: 10.1213/ane.0000000000000573] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
As of mid-October 2014, the ongoing Ebola epidemic in Western Africa has affected approximately 10,000 patients, approached a 50% mortality rate, and crossed political and geographic borders without precedent. The disease has spread throughout Liberia, Guinea, and Sierra Leone. Isolated cases have arrived in urban centers in Europe and North America. The exponential growth, currently unabated, highlights the urgent need for effective and immediate management protocols for the various health care subspecialties that may care for Ebola virus disease patients. We conducted a comprehensive review of the literature to identify key areas of anesthetic care affected by this disease. The serious potential for "high-risk exposure" and "direct contact" (as defined by the Centers for Disease Control and Prevention) of anesthesiologists caring for Ebola patients prompted this urgent investigation. A search was conducted using MEDLINE/PubMed, MeSH, Cochrane Review, and Google Scholar. Key words included "anesthesia" and/or "ebola" combined with "surgery," "intubation," "laryngoscopy," "bronchoscopy," "stethoscope," "ventilation," "ventilator," "phlebotomy," "venous cannulation," "operating room," "personal protection," "equipment," "aerosol," "respiratory failure," or "needle stick." No language or date limits were applied. We also included secondary-source data from government organizations and scientific societies such as the Centers for Disease Control and Prevention, World Health Organization, American Society of Anesthesiologists, and American College of Surgeons. Articles were reviewed for primary-source data related to inpatient management of Ebola cases as well as evidence-based management guidelines and protocols for the care of Ebola patients in the operative room, infection control, and health care worker personal protection. Two hundred thirty-six articles were identified using the aforementioned terminology in the scientific database search engines. Twenty articles met search criteria for information related to inpatient Ebola virus disease management or animal virology studies as primary or secondary sources. In addition, 9 articles met search criteria as tertiary sources, representing published guidelines. The recommendations developed in this article are based on these 29 source documents. Anesthesia-specific literature regarding the care of Ebola patients is very limited. Secondary-source guidelines and policies represent the majority of available information. Data from controlled animal experiments and tuberculosis patient research provide some evidence for the existing recommendations and identify future guideline considerations.
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Affiliation(s)
- Andres Missair
- From the Department of Anesthesiology, Perioperative Medicine, and Pain, University of Miami, Miller School of Medicine, Miami, Florida; United Nations Development Programme, New York, New York; and Beth Israel Deaconess Medical Center, Boston, Massachusetts
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Abstract
Ebola virus, the virus responsible for Ebola virus disease, has spawned several epidemics during the past 38 years. In 2014, an Ebola epidemic spread from Africa to other continents, becoming a pandemic. The virus's relatively unique structure, its infectivity and lethality, the difficulty in stopping its spread, and the lack of an effective treatment captured the world's attention. This article provides a brief review of the known history of Ebola virus disease, its etiology, epidemiology, and pathophysiology and a review of the limited information on managing patients with Ebola virus disease.
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37
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The Role of Cytokines and Chemokines in Filovirus Infection. Viruses 2015; 7:5489-507. [PMID: 26512687 PMCID: PMC4632400 DOI: 10.3390/v7102892] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/09/2015] [Accepted: 10/14/2015] [Indexed: 01/11/2023] Open
Abstract
Ebola- and marburgviruses are highly pathogenic filoviruses and causative agents of viral hemorrhagic fever. Filovirus disease is characterized by a dysregulated immune response, severe organ damage, and coagulation abnormalities. This includes modulation of cytokines, signaling mediators that regulate various components of the immune system as well as other biological processes. Here we examine the role of cytokines in filovirus infection, with an emphasis on understanding how these molecules affect development of the antiviral immune response and influence pathology. These proteins may present targets for immune modulation by therapeutic agents and vaccines in an effort to boost the natural immune response to infection and/or reduce immunopathology.
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38
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Ocular Manifestations of Ebola Virus Disease: An Ophthalmologist's Guide to Prevent Infection and Panic. BIOMED RESEARCH INTERNATIONAL 2015; 2015:487073. [PMID: 26557674 PMCID: PMC4628748 DOI: 10.1155/2015/487073] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/11/2015] [Indexed: 11/27/2022]
Abstract
Ebola virus disease (EVD—formerly known as Ebola hemorrhagic fever) is a severe hemorrhagic fever caused by lipid-enveloped, nonsegmented, negative-stranded RNA viruses belonging to the genus Ebolavirus. Case fatality rates may reach up to 76% of infected individuals, making this infection a deadly health problem in the sub-Saharan population. At the moment, there are still no indications on ophthalmological clinical signs and security suggestions for healthcare professionals (doctors and nurses or cooperative persons). This paper provides a short but complete guide to reduce infection risks.
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Fischer WA, Weber D, Wohl DA. Personal Protective Equipment: Protecting Health Care Providers in an Ebola Outbreak. Clin Ther 2015; 37:2402-2410. [PMID: 26452427 PMCID: PMC4661082 DOI: 10.1016/j.clinthera.2015.07.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 07/10/2015] [Indexed: 11/29/2022]
Abstract
Purpose The recent Ebola epidemic that devastated West Africa has infected and killed more health care providers than any other outbreak in the history of this virus. An improved understanding of pathogen transmission and the institution of strategies to protect health care providers against infection are needed in infectious disease outbreaks. This review connects what is known about Ebola virus transmission with personal protective equipment (PPE) designed to arrest nosocomial transmission. Methods Articles pertaining to filovirus transmission and PPE in filovirus outbreaks were reviewed and findings are presented. In addition, studies that evaluated PPE and donning and doffing strategies are presented. Findings PPE is one step in a comprehensive infection prevention and control strategy that is required to protect health care providers. Given that the Ebola virus is primarily transmitted through direct contact of mucous membranes and cuts in the skin with infected patients and/or their bodily fluids, it is necessary to cover these potential portals of infection with PPE as part of a structured and instructed donning and doffing procedure. Implications Current recommendations about PPE and the donning and doffing processes are based on anecdotal experience. However, the use of non-human viruses can help provide evidence-based guidelines on both PPE and donning and doffing processes.
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Affiliation(s)
- William A Fischer
- Division of Pulmonary and Critical Care Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - David Weber
- Division of Infectious Diseases, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - David A Wohl
- Division of Infectious Diseases, The University of North Carolina at Chapel Hill, Chapel Hill, NC
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40
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Bibby K, Fischer RJ, Casson LW, Stachler E, Haas C, Munster VJ. Persistence of Ebola Virus in Sterilized Wastewater. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2015; 2:245-249. [PMID: 26523283 PMCID: PMC4613737 DOI: 10.1021/acs.estlett.5b00193] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 08/17/2015] [Accepted: 08/17/2015] [Indexed: 05/13/2023]
Abstract
In the wake of the ongoing 2014/2015 Ebola virus outbreak, significant questions regarding the appropriate handling of Ebola virus-contaminated liquid waste remain, including the persistence of Ebola virus in wastewater. To address these uncertainties, we evaluated the persistence of Ebola virus spiked in sterilized domestic sewage. The viral titer decreased approximately 99% within the first test day from an initial viral titer of 106 TCID50 mL-1; however, it could not be determined if this initial rapid decrease was due to aggregation or inactivation of the viral particles. The subsequent viral titer decrease was less rapid, and infectious Ebola virus particles persisted for all 8 days of the test. The inactivation constant (k) was determined to be -1.08 (2.1 days for a 90% viral titer decrease). Due to experimental conditions, we believe these results to be an upper bound for Ebola virus persistence in wastewater. Wastewater composition is inherently heterogeneous; subsequently, we caution that interpretation of these results should be made within a holistic assessment, including the effects of wastewater composition, dilution, and potential exposure routes within wastewater infrastructure. While it remains unknown if Ebola virus may be transmitted via wastewater, these data demonstrate a potential exposure route to infectious Ebola virus via wastewater and emphasize the value of a precautionary approach to wastewater handling in an epidemic response.
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Affiliation(s)
- Kyle Bibby
- Department of Civil and Environmental Engineering and Department of Computational and
Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Robert J. Fischer
- Laboratory
of Virology, Division of Intramural Research, National Institute of
Allergy and Infectious Diseases, National
Institutes of Health, Hamilton, Montana 59840, United States
| | - Leonard W. Casson
- Department of Civil and Environmental Engineering and Department of Computational and
Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Elyse Stachler
- Department of Civil and Environmental Engineering and Department of Computational and
Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Charles
N. Haas
- Department
of Civil, Architectural & Environmental Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Vincent J. Munster
- Laboratory
of Virology, Division of Intramural Research, National Institute of
Allergy and Infectious Diseases, National
Institutes of Health, Hamilton, Montana 59840, United States
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Abstract
Ebola virus disease (EVD) is a zoonotic disease that causes severe haemorrhagic fever, with high fatality rates of up to 90% in humans. Today, there is no effective treatment available. Person-to-person transmission occurs through exposure to blood or body fluids, which can threaten other household members and first-line healthcare workers. The first cases of EVD in Guinea were identified on 22 March 2014. It was initially believed that this like previous outbreaks would be self-limiting. However, lack of public health infrastructure, delays in virus detection and late implementation of control interventions contributed to widespread transmission of EVD in a region inexperienced in dealing with the disease. Socio-cultural and economic factors probably also played a key role in the spread of the disease, resulting in the current large-scale outbreak. Some promising candidate treatments for this disease are now being developed.
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Affiliation(s)
- A Mirazimi
- Department of Clinical Microbiology, Karolinska Institutet, Stockholm, Sweden
- National Veterinary Institute, Uppsala, Sweden
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42
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Atherstone C, Smith E, Ochungo P, Roesel K, Grace D. Assessing the Potential Role of Pigs in the Epidemiology of Ebola Virus in Uganda. Transbound Emerg Dis 2015; 64:333-343. [PMID: 26310206 DOI: 10.1111/tbed.12394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Indexed: 12/24/2022]
Abstract
Uganda has experienced 4 Ebola outbreaks since the discovery of the virus. Recent epidemiological work has shown pigs are hosts for Ebola viruses. Due to their high reproduction rates, rapid weight gain, potential to provide quick financial returns and rising demand for pork, pig production in Uganda has undergone massive expansion. The combination of pork sector growth supported by development programmes and Ebola virus risk prompted a foresight exercise using desk, interview and spatial methods. The study found that the lack of serological evidence for specific reservoir species, the number of human index cases unable to account for their source of infection, domestic pig habitat overlap with potential Ebola virus zoonotic host environments, reported interactions at the human-pig-wildlife interface that could support transmission, fever in pigs as a commonly reported problem by pig farmers and temporal correlation of outbreaks with peak pork consumption periods warrants further research into potential zoonotic transmission in Uganda from pigs.
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Affiliation(s)
- C Atherstone
- International Livestock Research Institute, Kampala, Uganda
| | - E Smith
- International Livestock Research Institute, Kampala, Uganda
| | - P Ochungo
- International Livestock Research Institute, Nairobi, Kenya
| | - K Roesel
- International Livestock Research Institute, Kampala, Uganda
| | - D Grace
- International Livestock Research Institute, Nairobi, Kenya
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43
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Tang JW, Wilson P, Shetty N, Noakes CJ. Aerosol-Transmitted Infections-a New Consideration for Public Health and Infection Control Teams. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2015; 7:176-201. [PMID: 32226323 PMCID: PMC7100085 DOI: 10.1007/s40506-015-0057-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Since the emergence of the 2003 severe acute respiratory syndrome (SARS), the 2003 reemergence of avian A/H5N1, the emergence of the 2009 pandemic influenza A/H1N1, the 2012 emergence of Middle East respiratory syndrome (MERS), the 2013 emergence of avian A/H7N9 and the 2014 Ebola virus outbreaks, the potential for the aerosol transmission of infectious agents is now routinely considered in the investigation of any outbreak. Although many organisms have traditionally been considered to be transmitted by only one route (e.g. direct/indirect contact and/or faecal-orally), it is now apparent that the aerosol transmission route is also possible and opportunistic, depending on any potentially aerosol-generating procedures, the severity of illness and the degree and duration of pathogen-shedding in the infected patient, as well as the environment in which these activities are conducted.This article reviews the evidence and characteristics of some of the accepted (tuberculosis, measles, chickenpox, whooping cough) and some of the more opportunistic (influenza, Clostridium difficile, norovirus) aerosol-transmitted infectious agents and outlines methods of detecting and quantifying transmission.
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Affiliation(s)
- Julian W. Tang
- Clinical Microbiology, Leicester Royal Infirmary, University Hospitals Leicester, Leicester NHS Trust, Leicester, LE1 5WW UK
| | - Peter Wilson
- Clinical Microbiology, University College London Hospitals NHS Trust, London, UK
| | - Nandini Shetty
- Clinical Microbiology, University College London Hospitals NHS Trust, London, UK
| | - Catherine J. Noakes
- Institute for Public Health and Environmental Engineering, School of Civil Engineering, University of Leeds, Leeds, UK
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Abstract
Clinicians caring for patients infected with Ebola virus must be familiar not only with screening and infection control measures but also with management of severe disease. By integrating experience from several Ebola epidemics with best practices for managing critical illness, this report focuses on the clinical presentation and management of severely ill infants, children, and adults with Ebola virus disease. Fever, fatigue, vomiting, diarrhea, and anorexia are the most common symptoms of the 2014 West African outbreak. Profound fluid losses from the gastrointestinal tract result in volume depletion, metabolic abnormalities (including hyponatremia, hypokalemia, and hypocalcemia), shock, and organ failure. Overt hemorrhage occurs infrequently. The case fatality rate in West Africa is at least 70%, and individuals with respiratory, neurological, or hemorrhagic symptoms have a higher risk of death. There is no proven antiviral agent to treat Ebola virus disease, although several experimental treatments may be considered. Even in the absence of antiviral therapies, intensive supportive care has the potential to markedly blunt the high case fatality rate reported to date. Optimal treatment requires conscientious correction of fluid and electrolyte losses. Additional management considerations include searching for coinfection or superinfection; treatment of shock (with intravenous fluids and vasoactive agents), acute kidney injury (with renal replacement therapy), and respiratory failure (with invasive mechanical ventilation); provision of nutrition support, pain and anxiety control, and psychosocial support; and the use of strategies to reduce complications of critical illness. Cardiopulmonary resuscitation may be appropriate in certain circumstances, but extracorporeal life support is not advised. Among other ethical issues, patients' medical needs must be carefully weighed against healthcare worker safety and infection control concerns. However, meticulous attention to the use of personal protective equipment and strict adherence to infection control protocols should permit the safe provision of intensive treatment to severely ill patients with Ebola virus disease.
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45
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Gesser-Edelsburg A, Shir-Raz Y, Hayek S, Sassoni-Bar Lev O. What does the public know about Ebola? The public's risk perceptions regarding the current Ebola outbreak in an as-yet unaffected country. Am J Infect Control 2015; 43:669-75. [PMID: 25920703 DOI: 10.1016/j.ajic.2015.03.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/05/2015] [Accepted: 03/09/2015] [Indexed: 11/25/2022]
Abstract
BACKGROUND The unexpected developments surrounding the Ebola virus in the United States provide yet another warning that we need to establish communication preparedness. This study examines what the Israeli public knew about Ebola after the initial stages of the outbreak in a country to which Ebola has not spread and assesses the association between knowledge versus worries and concerns about contracting Ebola. METHODS Online survey using Google Docs (Google, Mountain View, CA) of Israeli health care professionals and the general public (N = 327). RESULTS The Israeli public has knowledge about Ebola (mean ± SD, 4.18 ± 0.83), despite the fact that the disease has not spread to Israel. No statistically significant difference was found between health care workers versus non-health care workers in the knowledge score. Additionally, no statistically significant association was found between knowledge and worry levels. The survey indicated that Israelis expect information about Ebola from the health ministry, including topics of uncertainty. More than half of the participants thought the information provided by the health ministry on Ebola and Ebola prevention was insufficient (50.5% and 56.4%, respectively), and almost half (45.2% and 41.1%, respectively) were unsure if the information was sufficient. CONCLUSION The greatest challenges that the organizations face is not only to convey knowledge, but also to find ways to convey comprehensive information that reflects uncertainty and empowers the public to make fact-based decisions about health.
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Nguyen C, Kaku S, Tutera D, Kuschner WG, Barr J. Viral Respiratory Infections of Adults in the Intensive Care Unit. J Intensive Care Med 2015; 31:427-41. [PMID: 25990273 DOI: 10.1177/0885066615585944] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 03/16/2015] [Indexed: 12/12/2022]
Abstract
Viral lower respiratory tract infections (LRTIs) are an underappreciated cause of critical illness in adults. Recent advances in viral detection techniques over the past decade have demonstrated viral LRTIs are associated with rates of morbidity, mortality, and health care utilization comparable to those of seen with bacterial community acquired and nosocomial pneumonias. In this review, we describe the relationship between viral LRTIs and critical illness, as well as discuss relevant clinical features and management strategies for the more prevalent respiratory viral pathogens.
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Affiliation(s)
- Christopher Nguyen
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Shawn Kaku
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Dominic Tutera
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Ware G Kuschner
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA Pulmonary Section, Medicine Service, VA Palo Alto Health Care System, Palo Alto, CA, USA
| | - Juliana Barr
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA Anesthesiology and Perioperative Care Service, VA Palo Alto Health Care System, Palo Alto, CA, USA
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47
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Elshabrawy HA, Erickson TB, Prabhakar BS. Ebola virus outbreak, updates on current therapeutic strategies. Rev Med Virol 2015; 25:241-53. [PMID: 25962887 PMCID: PMC7169053 DOI: 10.1002/rmv.1841] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/30/2015] [Accepted: 04/01/2015] [Indexed: 12/26/2022]
Abstract
Filoviruses are enveloped negative‐sense single‐stranded RNA viruses, which include Ebola and Marburg viruses, known to cause hemorrhagic fever in humans with a case fatality of up to 90%. There have been several Ebola virus outbreaks since the first outbreak in the Democratic Republic of Congo in 1976 of which, the recent 2013–2015 epidemic in Guinea, Liberia, and Sierra Leone is the largest in recorded history. Within a few months of the start of the outbreak in December 2013, thousands of infected cases were reported with a significant number of deaths. As of March 2015, according to the Centers for Disease Control and Prevention, there have been nearly 25 000 suspected cases, with 15 000 confirmed by laboratory testing, and over 10 000 deaths. The large number of cases and the high mortality rate, combined with the lack of effective Food and Drug Administration‐approved treatments, necessitate the development of potent and safe therapeutic measures to combat the current and future outbreaks. Since the beginning of the outbreak, there have been considerable efforts to develop and characterize protective measures including vaccines and antiviral small molecules, and some have proven effective in vitro and in animal models. Most recently, a cocktail of monoclonal antibodies has been shown to be highly effective in protecting non‐human primates from Ebola virus infection. In this review, we will discuss what is known about the nature of the virus, phylogenetic classification, genomic organization and replication, disease transmission, and viral entry and highlight the current approaches and efforts, in the development of therapeutics, to control the outbreak. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Hatem A Elshabrawy
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, USA.,Department of Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Timothy B Erickson
- Department of Emergency Medicine, University of Illinois College of Medicine, Chicago, IL, USA.,Center for Global Health, University of Illinois at Chicago, Chicago, IL, USA
| | - Bellur S Prabhakar
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, USA.,Center for Global Health, University of Illinois at Chicago, Chicago, IL, USA
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48
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MacIntyre CR, Chughtai AA, Seale H, Richards GA, Davidson PM. Uncertainty, risk analysis and change for Ebola personal protective equipment guidelines. Int J Nurs Stud 2015; 52:899-903. [PMID: 25575750 PMCID: PMC7130314 DOI: 10.1016/j.ijnurstu.2014.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/03/2014] [Indexed: 12/03/2022]
Affiliation(s)
- C Raina MacIntyre
- School of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
| | - Abrar Ahmad Chughtai
- School of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Holly Seale
- School of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Guy A Richards
- University of the Witwatersrand Johannesburg, Johannesburg, South Africa; Critical Care Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa
| | - Patricia M Davidson
- Johns Hopkins University, Baltimore, ML, USA; University of Technology, Sydney, Australia
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Ebola virus disease in nonendemic countries. J Formos Med Assoc 2015; 114:384-98. [PMID: 25882189 PMCID: PMC7135111 DOI: 10.1016/j.jfma.2015.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 01/22/2015] [Accepted: 01/24/2015] [Indexed: 12/20/2022] Open
Abstract
The 2014 West African outbreak of Ebola virus disease was unprecedented in its scale and has resulted in transmissions outside endemic countries. Clinicians in nonendemic countries will most likely face the disease in returning travelers, either among healthcare workers, expatriates, or visiting friends and relatives. Clinical suspicion for the disease must be heightened for travelers or contacts presenting with compatible clinical syndromes, and strict infection control measures must be promptly implemented to minimize the risk of secondary transmission within healthcare settings or in the community. We present a concise review on human filoviral disease with an emphasis on issues that are pertinent to clinicians practicing in nonendemic countries.
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Craig AT, Ronsse A, Hardie K, Pavlin BI, Biaukula V, Nilles EJ. Risk posed by the Ebola epidemic to the Pacific islands: findings of a recent World Health Organization assessment. Western Pac Surveill Response J 2015; 6:45-50. [PMID: 26306216 PMCID: PMC4542486 DOI: 10.5365/wpsar.2015.6.1.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVE To assess the public health risk posed by the ongoing Ebola virus disease (EVD) epidemic in West Africa to Pacific island countries and areas and to highlight priority risk management actions for preparedness and response. METHOD The likelihood of EVD importation and the magnitude of public health impact in Pacific island countries and areas were assessed to determine overall risk. Literature about the hazard, epidemiology, exposure and contextual factors associated with EVD was collected and reviewed. Epidemiological information from the current EVD outbreak was assessed. RESULTS As of 11 March 2015, there have been more than 24,200 reported cases of EVD and at least 9976 deaths in six West African countries. Three EVD cases have been infected outside of the West African region, and all have epidemiological links to the outbreak in West Africa. Pacific island countries' and areas' relative geographic isolation and lack of travel or trade links between countries with transmission means that EVD importation is very unlikely. However, should a case be imported, the health and non-health consequences would be major. The capacity of Pacific island countries and areas to respond adequately varies greatly between (and within) states but in general is limited. DISCUSSION This risk assessment highlights the needs to enhance preparedness for EVD in the Pacific by strengthening the capacities outlined in the World Health Organization Framework for Action on Ebola. Priority areas include the ability to detect and respond to suspected EVD cases quickly, isolation and management of cases in appropriately resourced facilities and the prevention of further cases through infection prevention and control. These efforts for Ebola should enhance all-hazards public health preparedness in line with the International Health Regulations (2005).
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Affiliation(s)
- Adam T Craig
- Emerging Disease Surveillance and Response Unit, Division of Pacific Technical Support, World Health Organization, Suva, Fiji
- The University of Newcastle, Callaghan, New South Wales, Australia
| | - Axelle Ronsse
- Emerging Disease Surveillance and Response Unit, Division of Pacific Technical Support, World Health Organization, Suva, Fiji
| | - Kate Hardie
- Emerging Disease Surveillance and Response Unit, Division of Pacific Technical Support, World Health Organization, Suva, Fiji
| | - Boris I Pavlin
- Office of the WHO Representative, Papua New Guinea Country Office, Port Moresby, Papua New Guinea
| | - Viema Biaukula
- Emerging Disease Surveillance and Response Unit, Division of Pacific Technical Support, World Health Organization, Suva, Fiji
| | - Eric J Nilles
- Emerging Disease Surveillance and Response Unit, Division of Pacific Technical Support, World Health Organization, Suva, Fiji
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