Epidemiological features and control of Ebola virus disease

1. “ Infection Preventionists: Ready for Disasters ”
Ebola Virus Disease: The Outbreak
Professor Tarek Tawfik Amin
Epidemiology and Public Health
Faculty of Medicine, Cairo University
amin55@myway.com
The 22nd Annual Conference of the Egyptian Society for Infection Control (ESIC)
(APIC/Egypt Chapter)
& The 5th Conference of the Eastern Mediterranean Regional Network for Infection
Control (EMRNIC)
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2. Objectives
Recognize the epidemiological features of Ebola Virus
Disease (EVD).
 Appreciate the role of infection control procedures in
controlling EVD.
Recognize the guidelines and procedures implied for
infection control at different stages of patient’s
management.
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3. Causative agents 1
Family Filoviridae, three genera: Cuevavirus, Marburgvirus,
and Ebolavirus.
Five species of Ebola:
- Zaire, Bundibugyo, Sudan, Reston (Philippines) and Taï
Forest (Cote de Ivories) .
- Bundibugyo, Zaire, and Sudan associated with large
outbreaks in Africa.
- The 2014 West African outbreak belongs to the Zaire.
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6. Reservoirs
Non-human primates, duikers, bats, small rodents, and
shrews.
Past outbreaks, human contact with wild animals
hunting, butchering and preparing meat from infected
wild animals (“bush meat”).
In 2014 epidemic the majority of cases are a result of
human to human transmission.
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9. Transmission 2
Fruit bats (Pteropodidae family) are natural hosts.
Contact with blood, bodily fluids: chimpanzees, gorillas,
fruit bats, monkeys, forest antelope and porcupines “ ill or
dead or in the rainforest”.
Human-to-human transmission via direct contact with
blood, bodily fluids, or contaminated surfaces and
materials.
HCPs infected while treating patients through close
contact.
Burial ceremonies, Corpse remains infectious for six days.
 Semen for up to seven weeks 3 .
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10. Hypothesis: Ebola transmission
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11. Hypothesis : Marburg transmission
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12. Historical outbreaks 4
EVD in 1976 in two simultaneous outbreaks, Nzara, Sudan, and
Yambuku, DR Congo (former Zaire), near Ebola river.
West African is the largest and most complex outbreak (2014).
Started in Guinea then spreading across borders to Sierra Leone
and Liberia, air to Nigeria, and land to Senegal.
Guinea, Sierra Leone and Liberia: weak health systems, lacking
human and infrastructural resources, and facing long of conflict
and instability.
On August 8th , the WHO Director-General declared this
outbreak a Public Health Emergency of International Concern.
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13. Year Country Ebola virus species Cases Deaths Case fatality
2012 DR Congo Bundibugyo 57 29 51%
2012 Uganda Sudan 7 4 57%
2012 Uganda Sudan 24 17 71%
2008 DR Congo Zaire 32 14 44%
2007 Uganda Bundibugyo 149 37 25%
2007 DR Congo Zaire 264 187 71%
2005 Congo Zaire 12 10 83%
2004 Sudan Sudan 17 7 41%
2003 Congo Zaire 35 29 83%
2003 Congo Zaire 143 128 90%
2001-2002 Congo Zaire 59 44 75%
2001-2002 Gabon Zaire 65 53 82%
2000 Uganda Sudan 425 224 53%
1996 Gabon Zaire 60 45 75%
1996 Gabon Zaire 31 21 68%
1995 DR Congo Zaire 315 254 81%
1994 Cote d'Ivoire Taï Forest 1 0 0%
1994 Gabon Zaire 52 31 60%
1979 Sudan Sudan 34 22 65%
1976 Sudan Sudan 284 151 53%
1976 DR Congo Zaire 318 280 88%
10/28/14
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14. Ebola and Health care settings:
Of the 2 870 Marburg and Ebola cases
documented between June 1967 and June 2011,
270 (9%) were health-care providers.3
Started as small scattered outbreaks, usually
spread within health care facility
‘Amplification”
Family members and HCPs are at the highest
risk of infection.
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15. 24th of October 2014, CDC, Current situation
Country Total Cases
Nigeria ! 20* 19* 8
Spain 1 1 0
United States 4 4 1
Total 25 24 9
Country Total Cases
Laboratory-
Confirmed Cases Total Deaths
Mali 1 1 1
Senegal ! 1* 1* 0
Total 2 2 1
Country Total Cases
Laboratory-
Confirmed Cases Total Deaths
Laboratory-
Confirmed
Cases Total Deaths
Guinea 1553 1312 926
Liberia 4665 965 2705
Sierra Leone 3896 3389 1281
Total 10114 5666 4912
•Countries with Travel-associated
Cases
•Countries with Travel-associated
Cases and Localized
Transmission
•Countries with Widespread
Transmission
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http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/case-counts.html

16. Case
definition 3
Routine surveillance:
Suspect case:
Fever and no response to
treatment for usual causes in
the area, and at least one:
bloody diarrhea, bleeding
gums, purpura, bleeding into
eyes, or hematuria.
Confirmed Ebola :
Laboratory confirmation
(Ve+ IgM antibody, Ve+
PCR or viral isolation)
Community-based
surveillance:
Pre-epidemic phase
and outbreak.
Alert case: fever and
no response to
treatment of usual
causes of in the area,
OR bleeding, bloody
diarrhea, hematuria
OR any sudden death.
During outbreak:
SUSPECT CASE:
Alive or dead, high fever and
contacted a suspected,
probable or confirmed case;
dead or sick animal.
OR: sudden onset of high
fever + at least 3: • headaches
• vomiting • anorexia / loss of
appetite • diarrhea •
lethargy • stomach pain •
aching muscles or joints •
difficulty breathing or
swallowing • hiccup
OR: inexplicable bleeding
OR: sudden, inexplicable
death.
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18. Case definition for exclusive use by hospitals and
surveillance teams 3:
PROBABLE CASE:
Any suspected case
evaluated by a clinician
OR: Deceased suspected
case having an
epidemiological link with a
confirmed case
LABORATORY
CONFIRMED CASE:
Any suspected or probable cases
with a positive laboratory
result.
- Virus RNA by RT- PCR,
- IgM antibodies.
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19. Case contacts: With case in the Contacts 4
last 21 days preceding the onset of symptoms:
 Slept in the same household
 Physical contact with case
 Physical contact at the funeral,
 Touched blood or body fluids
 Touched his/her clothes or linens
 Breastfed by the patient
Dead or sick animals:
With sick or dead animal in the 21 days
preceding:
 Physical contact with the animal
 Animal’s blood or body fluids
 Carved up the animal
 Eaten raw bush-meat
Laboratory contacts: Worked in a laboratory 21 days preceding onset
of symptoms:
 Direct contact with specimens collected from suspected Ebola patients
 Direct contact with specimens collected from suspected Ebola animal
 Contact with a hospital where Ebola cases being treated the 21 days.
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21. Timeline of Infection Diagnostic tests available
- Within a few days after symptoms ® Antigen-capture enzyme-linked
immunosorbent assay (ELISA) testing
® IgM ELISA
® RT Polymerase chain reaction (RT- PCR)
® Virus isolation
- Later in disease course or
recovery · IgM and IgG antibodies
- Deceased patients · Immunohistochemistry testing
· PCR
· Virus isolation
Laboratory diagnosis 5
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22. Blood sampling: BSL4* 6
 Acute phase: whole blood obtained within 7 days of onset.
 Convalescent sera: collected at least 14 days after onset.
Paired serum samples are ideal, usually collected 7-20 days
apart.
*Bio-safety level 4: level required for work with dangerous and exotic agents that pose a high individual risk of
aerosol-transmitted laboratory infections, agents which cause severe to fatal disease in humans for which
vaccines or other treatments are not available, such as Bolivian and Argentine hemorrhagic fevers, Marburg
virus, Ebola virus, Lassa virus, Crimean-Congo hemorrhagic fever, and others.
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23. Safety precautions: Category A, BSL4 facilities 7.
Do not separate acute phase sera from blood clots .
Sealed sterile dry Vacutainer tubes.
In their original tube and stored at 4 ˚C for PCR /
virus isolation
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24. Phases: opportunity for control
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25. Outbrea measures
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27. Controlling Infection in Health Care Setting: rules 1,2
Strict standard precautions, regardless of diagnosis.
Basic hand, respiratory hygiene, PPE, safe injection practices
and safe burial practices.
Extra infection control measures to prevent contact with
patient’s blood and body fluids and contaminated surfaces or
materials.
In close encounter (1 m) face protection (face shield or
medical mask and goggles), a clean, non-sterile long-sleeved
gown, and gloves (sterile gloves for some procedures).
Human and animal samples for investigations handled by
trained staff and processed in suitably equipped laboratories.
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30. DIRECT PATIENT CARE (FOR
SUSPECTED OR CONFIRMED
PATIENTS) 1,8
PATIENT PLACEMENT, STAFF
ALLOCATION AND VISITORS:
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32. Suspected or confirmed cases in single isolation rooms (IRs).
If IRs are unavailable, cohort patients in specific confined
area keeping suspected and confirmed cases separate. At least
1 meter distance between patient beds.
Clinical and non-clinical personnel are assigned exclusively
to patient care areas.
 Restrict all non-essential staff from patient care areas.
 Stopping visitor access to the patient, or limit their number.
 Do not allow other visitors to enter the isolation
rooms/areas and ensure adequate distance for observation
(≈3 meters).
 Before allowing visitors, screen for of EVD
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33. •HAND HYGIENE, PERSONAL
PROTECTIVE EQUIPMENT AND
OTHER PRECAUTIONS2,9.
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35. Visitors use PPE and perform hand hygiene (HH) prior entry.
HCPs, PPE before entering isolation areas.
Scrub or medical suits NOT personal clothing.
HH:
1. before gloving and wearing PPE on entry.
2. before any clean/aseptic procedures performed
3. after any exposure with the patient’s blood and body fluids,
4. after touching contaminated surfaces/items/equipment in the
patient’s surroundings,
5. after removal of PPE, upon leaving the care area.
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36. HH within the isolation rooms/areas.
Before entering the isolation areas, PPE in dedicated
changing zone.
Correctly sized gloves.
Changing gloves if heavily soiled while providing care to
the same patient (HH immediately after removal).
Change gloves, HH, moving from one patient to another in
same room.
Disposable, impermeable gown to cover clothing and
exposed skin.
Medical mask and eye protection to prevent splashes.
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37. Rubber boots.
If NOT, overshoes, removed while wearing gloves.
 Strenuous activity (respirator) or tasks in which contact
with blood and body fluids is anticipated (waterproof
apron over the gown).
Avoid aerosol-generating procedures, use a respirator.
Before exiting isolation room/area, carefully remove and
dispose PPE into waste containers and perform HH.
Avoid any contact between the soiled items (e.g. gloves,
gowns) and any area of the face or non-intact skin.
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39. Do not recycle any single-use disposable PPE.
Dedicated equipment (e.g. stethoscopes) for each
patient.
If NOT decontaminate between each patient contact.
 Waste generated should be treated as infectious waste.
Items and equipment should not be moved between
isolation rooms/areas and other areas of HCF.
Patient charts and records should be kept outside the
isolation rooms/areas to avoid their contamination.
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40. INJECTION SAFETY AND
MANAGEMENT OF SHARPS 3,10
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41. Injection and medication equipment disposed of at point of care.
 Limit the use of needles and other sharp objects.
 Limit the use of phlebotomy and laboratory testing to minimum.
a) Never recapping .
b) Never direct the point of a used needle towards any part of the body.
c) Do not remove used needles from syringes by hand, bend, break or
manipulate.
d) Dispose sharps in puncture-resistant containers.
e) Containers are placed upright to the immediate (‘point of use’).
• Kidney dish or similar to carry to the sharps container.
• Containers placed in an area not easily accessible by visitors,
particularly children .
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42. ENVIRONMENTAL CLEANING 1,2,11,12
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43. 1- PPE
Heavy duty/rubber gloves, impermeable gown and closed
shoes (e.g. boots) when cleaning the environment and
handling infectious waste.
 Facial protection (mask and goggle or face shield) and
overshoes if boots are unavailable.
Respirator:
- Blood and body fluids is anticipated (cleaning surfaces heavily
soiled with vomit or blood) or
- Cleaning areas closer < 1 meter from a patient with
symptoms like diarrhoea, bleeding or vomiting, etc.).
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44. 2- CLEANING PROCESS
 Environmental surfaces or objects contaminated cleaned
and disinfected using (e.g. a 0.5% chlorine solution).
Change cleaning solutions and refresh equipment
frequently.
Clean floors and horizontal work surfaces at least once a
day with clean water and detergent.
Dry sweeping never be done.
Rags not be shaken out and surfaces should not be cleaned
with dry rags.
From “clean” areas to “dirty” areas.
Do not spray (fog) occupied or unoccupied clinical areas
with disinfectant.
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45. 3- LINEN
Handling soiled linen from patients, use PPE and facial
protection.
 Clearly-labeled, leak-proof bags or buckets at the site of
use.
Never be carried against the body.
 Transported directly to the laundry area in its
container.
Washing contaminated linen by hand discouraged.
 Burn the linen to avoid any unnecessary risks.
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46. •Waste Management
1- PPE
 PPE and facial protection.
Goggles provide greater protection than visors from
splashes.
Avoid splashing when disposing of liquid infectious waste.
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47. 2- WASTE MANAGEMENT PROCEDURES
Segregated at point of generation.
 Puncture resistant waste containers.
 Solid, non-sharp, infectious waste in leak-proof waste bags covered
bins.
Bins should never be carried against the body (e.g. on the shoulder).
Designated pit of appropriate depth (2 m) and filled to a depth of 1–
1.5 m, covered with 10 to 15 cm soil layer.
 Controlled access.
Feces, urine and vomit, and liquid waste, disposed sewer or latrine.
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48. NON-PATIENT CARE ACTIVITIES 1,12
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49. A. DIAGNOSTIC LABORATORY ACTIVITIES:
Laboratory sample processing under a safety cabinet
or at least a fume cabinet with exhaust ventilation.
No procedures on the open bench.
Micro-pipetting and centrifugation are prohibited.
PPE, particulate respirator when aliquotting,
centrifugation.
Discard apron or gown immediately.
Specimens in clearly-labeled, non-glass, leak-proof
containers .
Disinfect all surfaces of specimen containers.
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51. B. MOVEMENT AND BURIAL OF HUMAN REMAINS .
PPE , rubber boots to handle.
Plug the natural orifices.
Double bag, wipe surface with disinfectant (e.g., 0.5%
chlorine solution) and seal and label.
Immediately move the body to the mortuary.
Remains should not be sprayed, washed or embalmed.
Washing for “clean burials” should be discouraged.
Buried promptly.
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52. POST-MORTEM EXAMINATIONS
Limited to essential evaluations by trained personnel.
Eye protection, PPE.
 Performing autopsies, particulate respirator .
 Specimens in clearly-labeled, non-glass, leak-proof
containers.
External surfaces of specimen containers disinfected prior
transport.
 Tissue or body fluids for disposal carefully placed in clearly
marked, sealed containers for incineration.
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53. MANAGING EXPOSURE TO VIRUS THROUGH BODY FLUIDS
INCLUDING BLOOD
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54. a) Immediately and safely stop any current tasks,
b) Leave the patient care area,
c) Safely remove PPE
d) Wash the affected skin or percutaneous injury site with soap and
water.
e) Irrigate mucous membranes with copious amounts of water.
f) Immediately report the incident.
g) Medically evaluated (e.g., HIV), receive follow-up care, including
fever monitoring, twice daily for 21 days after the incident.
h) Consultation for exposed person develops fever within 21 days of
exposure.
i) Suspected of being infected , isolated, with same management
recommendations until a negative diagnosis is confirmed.
j) Contact tracing is essential.
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55. References
1) 1 Interim manual - Ebola and Marburg virus disease epidemics: preparedness, alert, control, and evaluation World Health Organization,
Geneva, 2014; Available from: http://www.who.int/csr/disease/ebola/manual_EVD/en/
2) 2 Clinical Management of Patients with Viral Haemorrhagic Fever: A pocket Guide for the Front-line Health Worker. World Health
Organization, Geneva, 2014.
3) 3 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings. Centers for Disease Control
and Prevention, Atlanta, GA, 2007; Available from: http://www.cdc.gov/HAI/prevent/prevent_pubs.html
4) 4 Standard precautions in health care AIDE-MEMOIRE. World Health Organization, Geneva, 2007; Available from:
http://www.who.int/csr/resources/publications/standardprecautions/en/.
5) 5 Hand Hygiene Posters. World Health Organization, Geneva, 2009. ; Available from:
http://www.who.int/gpsc/5may/tools/workplace_reminders/en/
6) 6 Glove Use Information Leaflet. World Health Organization, Geneva, 2009.; Available from:
http://www.who.int/gpsc/5may/tools/training_education/en/
7) 7 Infection Prevention and Control Recommendations for Hospitalized Patients with Known or Suspected Ebola Hemorrhagic Fever in
U.S. Hospitals. Centers for Disease Control and Prevention, Atlanta, GA; Available from:
http://www.cdc.gov/vhf/ebola/hcp/infection-prevention-and-control- recommendations.html
8) 8 Guide to Local Production: WHO-recommended Handrub Formulations. World Health Organization, Geneva, 2010; Available from:
http://www.who.int/gpsc/5may/tools/system_change/en/.
9) 9 Hoffman PN, Bradley C, Ayliffe GAJ, Health Protection Agency (Great Britain). Disinfection in healthcare. 3rd ed. Malden, Mass:
Blackwell Pub.; 2004.
10) 10 How to safely collect blood samples from persons suspected to be infected with highly infectious blood-borne pathogens (e.g. Ebola)
World Health Organization.
11) 11 WHO best practices for injections and related procedures toolkit. World Health Organization, Geneva, 2010; Available from:
http://www.who.int/injection_safety/toolbox/9789241599252/en/
12) 12 Management of Hazard Group 4 viral haemorrhagic fevers and similar human infectious diseases of high consequence. Department of
Health, United Kingdom, 2012; Available from: http://www.dh.gov.uk/publications.
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56. Thank you
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