16 th October 2014 Ebola virus disease current
16 th October 2014 Ebola virus disease: current epidemiology Dr Chris J Williams Insert name of presentation on Master Consultant Epidemiologist, Public Health Wales Slide
Outline • Aims • What is Ebola virus? • Current Situation: W. Africa, US & EU, forward look • What is the role of LRF • Guidance Ebola epidemiology
Aims and objectives Aims 1. Early case-finding, with appropriate management of cases 2. Avoid inappropriate responses Objectives: 1. Increase awareness in staff 2. Promote knowledge of guidelines and participation in exercises Ebola epidemiology
Main message • There are currently no infectious cases of Ebola in the UK • We are concerned about people who are ill (mainly fever), who have travelled to Guinea, Liberia or Sierra Leone in the past 21 days • All other people have effectively zero risk* *Exceptions: imported blood specimens, bush meat, nurses from Spain or Texas, late-identified source outside the affected area Ebola epidemiology
Ebola virus disease • Filovirus • Infects wide variety of cells including those lining blood vessels • Lymph nodes, liver, adrenal • Immune cascade • Multi-organ failure and death Ebola epidemiology
Course • Symptoms: 8 -12 days after exposure (range 2 -21 days) • Early: Fever (87%), chills, myalgia, malaise • 5 days later: diarrhoea (66%), nausea, vomiting (68%) and abdominal pain • Also red eyes, chest pain, short of breath • Death 6 -16 days (7. 5 days current) Ebola epidemiology
Ebola history • First outbreaks in 1976, East Africa • Gap 1979 -1994 • Always localised and controlled through straightforward measures – Safe healthcare/PPE – Appropriate burial practices – Isolation of cases and contact tracing Ebola epidemiology
7 19 6 7 19 7 7 19 8 7 19 9 8 19 0 8 19 1 8 19 2 8 19 3 8 19 4 8 19 5 8 19 6 8 19 7 8 19 8 8 19 9 9 19 0 9 19 1 9 19 2 9 19 3 9 19 4 9 19 5 9 19 6 9 19 7 9 19 8 9 20 9 0 20 0 0 20 1 0 20 2 0 20 3 0 20 4 0 20 5 0 20 6 0 20 7 0 20 8 0 20 9 1 20 0 1 20 1 12 19 Past outbreaks Outbreaks Ebola (CDC) 3, 5 3 2, 5 2 1, 5 1 0, 5 0 Ebola epidemiology
Transmission: FROM • Sources of virus – – – Blood-stained bodily fluids Saliva, tears Semen Sweat (NO) • From: Live human; dead body; live or dead animal (bat, monkey) Ebola epidemiology
Transmission: VIA • Fomites • Environment • Meat/carcasses • Blood samples • Blood/tissue donations • Medical equipment Ebola epidemiology
Transmission: TO • Direct inoculation – through skin, mucous membranes • Self-inoculation (via hands, PPE) • Sexual contact (semen) • Blood transfusion • Needles/medical equipment Ebola epidemiology
Transmission: main points • Not infectious until symptomatic • Viral load increases after first symptoms, highest near death • Virus can persist on surfaces BUT • Only isolated from visibly bloodstained items in environment Ebola epidemiology
Main routes (Africa) • Community, through contact with an infected person or contaminated fomites • Burials, due to touching dead bodies • Nosocomial, via lack of infection control measures within healthcare facilities Ebola epidemiology
Control • Simple infection control measures to prevent direct contact with body fluids, and appropriate quarantining of ill patients, have been sufficient to contain past outbreaks (Bennett & Brown 1995). Ebola epidemiology
Household risks (DRC, Uganda) • • DRC: 27 households with cases, 28/173 household contacts became ill None of the 78 household members who had no physical contact with the case during the clinical illness were infected (upper 95% CI, 4%). Additional risk in adults, touching cadaver, exposure in late hospital phase. Uganda: 73 contacts; highest risk caring at home in late stages, more than one type of direct contact. Sharing hut, sleeping mat indirect risks. EVD is transmitted principally by direct physical contact with an ill person or their body fluids during the later stages of illness. Ebola epidemiology
Current Situation, W Africa Ebola epidemiology
Economics Country Population (m) GDP/Capita 2013 (USD) Health spending per capita, 2012 (USD) Guinea 12 527 32 Liberia 4 454 65 Nigeria 173 3 006 94 6 809 96 64 39 337 3 647 Sierra Leone UK Ebola epidemiology
Distribution of cases of EVD by week of reporting in Guinea, Sierra Leone, Liberia, Nigeria and Senegal, weeks 48/2013 to 42/2014*, n= 8 994
Epidemiology: descriptive • • The incubation period was estimated to be 11. 4 days with serial interval of 15. 3 days. The case-fatality rate in in Guinea, Liberia and Sierra Leone was 70. 8% (95% CI: 68. 6– 72. 8%) with no noticeable difference between the countries As of 12 October 2014, WHO reported 425 healthcare workers infected with EVD of whom 236 died [10]. HCW account for around 5% of the cases in West Africa Ebola epidemiology
Ebola epidemiology
Imported cases of EVD Case of Ebola treated outside W Africa + gave rise to secondary case(s) + + 31 32 33 34 35 35 36 37 38 39 40 Week number (2014) Countries: USA 6, Germany 3, France 1, Spain 2, Norway 1, UK 1 41
Date of evacuation Source country Recipient country 02 -Aug-14 Liberia USA 05 -Aug-14 Liberia USA 06 -Aug-14 Liberia Spain 24 -Aug-14 Sierra Leone UK 27 -Aug-14 Sierra Leone Germany 04 -Sep-14 09 -Sep-14 Monrovia, Liberia Kenema, Sierra Leone Outcome Nationality Discharged US Death Spanish Stable British Epidemiologist Recovered Senegalese USA Physician (obstetrician) stable US USA Physician stable US Discharged French Death Spanish stable Uganda Stable US not known Norway not known Sudan Death Liberia 19 -Sep-14 Liberia France 22 -Sep-14 Sierra Leone Spain 02 -Oct-14 Sierra Leone Germany 02 -Oct-14 Liberia USA 06 -Oct-14 Sierra Leone Norway 08 -Oct-14 Liberia Germany 20/09/2014 Liberia USA Ebola epidemiology Profession Healthcare worker Healthcare worker Cameraman Healthcare worker Laboratory worker Non-HCW Secondary cases 0 0 0 0 1 0 0 2
Controlling imported Ebola • Challenges and successes Ebola epidemiology
Potential problems in controlling imported EVD
Thomas Duncan • Flew on 20/9; onset 24/9 • First H/C contact 25/9 - Discharged (sinusitis); travel history not passed on. Fever, abdo pain, headache. • Second contact 28/9 – isolated • 76 hospital contacts – 2 cases among these – Contact pre-diagnosis thought to play a role • 48 community contacts – 0 cases to date • Reported difficulties with PPE Ebola epidemiology
Spain • HCW infected despite PPE • Occupational health slow to respond to reported symptoms • Confidence in healthcare system, PPE and procedures Ebola epidemiology
Imported cases VHF to 2012: No evidence flight transmission Year Countries Contacts –All Contacts. High risk Secondary cases Flight exposure? 2008 Netherlands ex Uganda 130 64 0 ? 2008 US ex Uganda 260 ? 1975 S. Africa ex Zimbabwe 35 - 2 ? 2009 Germany ex Cote d’Ivoire 232 30 1 (serol) Y (3 hours) 2009 UK ex Nigeria 328 0 0 Y (ill) 2009 UK ex Mali 125 7 0 Y (ill) 2005 UK ex Sierra Leone 125 0 0 ? Ebola epidemiology
Nigerian experience • 20 cases from 1 index (cared for sibling in Liberia who died; 20/7/2014) • Longest chain of transmission was 3 persons • 62% of cases were in healthcare workers (HCW) • Secondary cases in household contacts of infected HCW Lessons learned • Vigorous management with appropriate resources • EOC had units for case management; epi/contacts; travel/ports; management; community mobilisation • 150 contact tracers; 12 epidemiologists for 850 contacts • Incident management system • Rumour (salt water protects against Ebola) Nigeria declared Ebola free on 17/10/2014 Ebola epidemiology
Fever>38 degrees C
Scenario (a) • Collapsed man (A) of Afro-Caribbean ethnicity in Cardiff city centre • Sweating, bloodshot eyes • Man B (passing by) tries to rouse man A – flags down a passing police officer for help • What should the police officer do now? Ebola epidemiology
Two days later • Partner of man B calls ambulance • One of her children has a fever • Asks why man B has not been isolated and demands care for her child Ebola epidemiology
Scenario (b) • Returned healthcare worker from Liberia living in Merthyr Tydfil • Studying in public library • Member of public calls environmental health concerned about risks to other library users Ebola epidemiology
Learning points • Not infectious until ill • Most Afro-Caribbean men in Cardiff have not come from West Africa in the last 21 days • Immediate contacts are not a risk to anyone unless they are carrying bodily fluids of an infectious case Ebola epidemiology
What can we do? • Know who is at risk • Know how to assess them and pathways for referral • Know the appropriate PPE • Sources of advice • Lines of communication Ebola epidemiology
Initial PPE for assessing those with Symptoms + travel to affected area • • • Non-physical contact (e. g. interviewing people) – no PPE required; Physical contact with mildly symptomatic cases (e. g. with fever) Standard precautions apply: Hand hygiene, gloves, forensic suit; Physical contact with overtly symptomatic cases: Hand hygiene, gloves, forensic suit, fluid repellent surgical facemask, eye protection Physical contact with severely symptomatic patients e. g. those with extensive bruising and/or active bleeding and/or uncontrolled diarrhoea and/or uncontrolled vomiting: Hand hygiene, double gloves, fluid repellent disposable gown/suit, eye protection, FFP 3 respirator. From Ebola risk assessment at custody suites Ebola epidemiology
Initial assessment: commonsense approach • Keep distance (2 m) • Avoid contact with body fluids • Speak to person to assess travel history and symptoms • Then seek healthcare advice (if appropriate) Ebola epidemiology
Ebola preparedness: general briefing • • • Ebola virus disease is a severe infection caused by the Ebola virus. It has caused a number of cases and outbreaks in Africa since 1976, and there are current outbreaks in the three West African countries Guinea (capital Conakry, not Guinea-Bissau or equatorial Guinea), Liberia and Sierra Leone. Two other West African countries with case(s), Senegal and Nigeria, have controlled the spread and are not now included in the list of risk countries, but a further imported case has now been reported in Mali with subsequent contact tracing. The disease is severe, with up to 70% of those infected dying, and is causing great hardship in the affected countries. However, it is not as easy to catch as infections such as influenza or measles, and only direct contact with an infected case who is ill, or some body fluids from such a case, can cause infection. Healthcare workers caring for affected patients have the highest risk of infection, as cases are most infectious when they are most ill. Across Wales the risk of Ebola to the general population is low. To date there have been no persons infected with Ebola in Wales. However, as the situation in West Africa is escalating there is a possibility of infected persons returning to live or work in Wales. The NHS has been preparing for potential cases. In Wales we are asking anyone who becomes unwell with a fever within 21 days of leaving the affected areas to contact NHS Direct Wales (dial 0845 46 47) and tell them their travel history. The current affected areas (as of 17/10/2014 ) are Sierra Leone, Guinea and Liberia. NHS Direct Wales will discuss your symptoms and if your symptoms are thought to require further assessment they will organise for an ambulance to transport you safely to hospital where staff will be prepared to assess you in an appropriate room. Individuals phoning a GP practice for an appointment because they are unwell should be asked if they have travelled to the affected areas of West Africa in the last 3 weeks and if so they can speak to GP on the phone. If an individual attends a GP practice or A&E because they are unwell they should be asked if they have travelled to the affected areas of West Africa in the last 3 weeks, if so they should be directed to a room (with no other patients, which may be easily cleaned) and the GP present communicate preferable by phone with the individual to make an assessment of the patient’s condition and their risk of Ebola. Any concerns relating to a possible case of Ebola presenting to or calling primary care should be discussed with the local health protection team and local infection doctor. Ebola epidemiology
Mid & West Wales Telephone number Local Authority/Local Health Board area 01792 607387 Carmarthenshire, Ceredigion, Pembrokeshire, Powys Swansea Bridgend, Neath Port Talbot, Swansea Cardiff 029 2040 2478 Cardiff, Merthyr Tydfil, Rhondda Cynon Taf, Vale of Glamorgan Gwent 01495 332219 Blaenau Gwent, Caerphilly, Monmouthshire, Newport, Torfaen North Wales 01352 803234 Anglesey, Conwy, Denbighshire, Flintshire, Gwynedd, Wrexham Out of hours please contact Public Health On-call by phoning the following Ambulance Control Centres and requesting the public health doctor on-call. North Wales: Mid & West Wales: South East Wales: 01248 689123 01267 229476 01633 626118 Ebola epidemiology
Guidance • www. publichealthwales. org/ ebola Ebola epidemiology
Response • • • Early case finding Appropriate case management Infection control- universal and specific Contact tracing –community and HCW Information management (epi/surv) Communication (incl. Community) Ebola epidemiology
References • • • http: //jid. oxfordjournals. org/content/179/Supplement_1/S 28. abstract? ijkey=abfe 90425 a 73 c 9 ce 1038 aa 73546 a 1 c 73 d 76 b 556 b&keytype 2=tf_ipsecsha http: //vir. sgmjournals. org/content/95/Pt_8/1619. full http: //jid. oxfordjournals. org/content/196/Supplement_2/S 142. full http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 1997188/pdf/ijexpath 000040005. pdf http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 3035551/ http: //jid. oxfordjournals. org/content/179/Supplement_1/S 87. long http: //www. ncbi. nlm. nih. gov/pubmed/10881895 http: //www. eurosurveillance. org/View. Article. aspx? Article. Id=20920 http: //www. hpsc. ie/AZ/Vectorborne/Viral. Haemorrhagic. Fever/Guidance/VHF 2012/File, 14071, en. pdf http: //www. phac-aspc. gc. ca/lab-bio/res/psds-ftss/ebola-eng. php http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 1675587/pdf/brmedj 014760011. pdf Ebola epidemiology
Virus culture and reverse-transcription polymerase chain reaction (RT-PCR) results from 54 clinical samples collected from 26 patients with laboratory-confirmed Ebola hemorrhagic fever. Bausch D G et al. J Infect Dis. 2007; 196: S 142 -S 147 © 2007 by the Infectious Diseases Society of America
Virus culture and reverse-transcription polymerase chain reaction (RT-PCR) results from 33 environmental samples. Bausch D G et al. J Infect Dis. 2007; 196: S 142 -S 147 © 2007 by the Infectious Diseases Society of America
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