Ebola Virus Disease Prevention, Monitoring and Surveillance Recommendations
An Advisory Committee Statement (ACS)
Committee to Advise on Tropical Medicine and Travel (CATMAT)
July 11, 2018
On this page
- Key points / Messages
- Risk of exposure of travellers
- Preventive Measures for Travellers
- Recommendations for monitoring and surveillance of travellers arriving from EVD affected areas
- Treatment of EVD
- Conflict of interest
The Committee to Advise on Tropical Medicine and Travel (CATMAT) provides the Public Health Agency of Canada (PHAC) with ongoing and timely medical, scientific, and public health advice relating to tropical infectious disease and health risks associated with international travel. PHAC acknowledges that the advice and recommendations set out in this statement are based upon the best current available scientific knowledge and medical practices, and is disseminating this document for information purposes to both travellers and the medical community caring for travellers.
Persons administering or using drugs, vaccines, or other products should also be aware of the contents of the product monograph(s) or other similarly approved standards or instructions for use. Recommendations for use and other information set out herein may differ from that set out in the product monograph(s) or other similarly approved standards or instructions for use by the licensed manufacturer(s). Manufacturers have sought approval and provided evidence as to the safety and efficacy of their products only when used in accordance with the product monographs or other similarly approved standards or instructions for use.
This statement outlines interim recommendations intended for use during active outbreaks of Ebola Virus Disease occurring outside of Canada.
- Transmission of Ebola Virus Disease (EVD) occurs via direct contact with infected blood, body fluids, or tissues of a symptomatic person, deceased case, or infected animal.
- There is no risk of transmission from casual interaction with asymptomatic returning travellers from outbreak areas.
This statement developed by the Committee to Advise on Tropical Medicine and Travel (CATMAT) is intended to provide recommendations for preventive measures, monitoring and surveillance of travellers, including healthcare and other humanitarian workers, returning from areas experiencing an outbreak of EVD, based on likelihood of exposure.
EVD is a severe, potentially fatal illness caused by an RNA virus that is spread to humans via the infected blood, body fluids, or tissues of a person with symptomatic disease or deceased case or via contact with infected animal reservoirs (including bushmeat)Footnote 1Footnote 2Footnote 3Footnote 4Footnote 5Footnote 6.
The previous experiences of early sustained transmission of EVD in urban settings in West Africa in 2014-2016, highlighted the importance of rapid response for outbreak management including timely mobilization of resources for the prevention of spread of EVD through active management of clinical cases (isolation and treatment)Footnote 7 and contacts (tracing, quarantine, vaccination and monitoring)Footnote 8. Timely response also includes enhanced monitoring and case detection at land and riverine transport hubs; entrance and exit screening at international airports; enhancement of local laboratory capacity; strategic vaccination of contacts and healthcare workers; treatment of clinical cases in dedicated Ebola treatment units (ETUs); and community engagement, public awareness and education, including promotion of safe and dignified burial practicesFootnote 7Footnote 8Footnote 9Footnote 10Footnote 11Footnote 12Footnote 13.
This statement was developed by a CATMAT working group of volunteers, none of whom declared a relevant conflict of interest. Criteria outlined in the CATMAT statement on Evidence based process for developing travel and tropical medicine related guidelines and recommendationsFootnote 14 were used to decide whether a Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodological approach would be appropriate for this chapter. The GRADE approach was not used as this statement is in response to an existing outbreak for which urgent travel-related guidance is required. Advice is based on a narrative review of the relevant literature and on expert opinion, and consideration of applicable World Health Organization (WHO) guidance. The final statement and recommendations were approved by CATMAT.
EVD occurrence is typically restricted geographically to outbreak-prone areas of sub-Saharan Africa, such as communities along the Ebola RiverFootnote 2; however, exportation of cases elsewhere in Africa and to Europe and North America occurred with limited secondary transmissions during the large scale EVD outbreak from 2014 to 2016 affecting Sierra Leone, Liberia, and GuineaFootnote 15Footnote 16. Thus, given the prolonged incubation period of EVD (i.e., up to 21-days) and relative ease of international travel, travel-acquired EVD manifesting once the traveller has returned home is a more recently recognized possibilityFootnote 17. Nevertheless, experience indicates that the risk of EVD transmission outside of an outbreak area, by an individual traveller who returns home without symptoms, is very lowFootnote 16. In the 2014-2016 West African outbreak, no cases of EVD were imported to Canada. A number of EVD outbreaks have occurred in the Democratic Republic of the Congo (DRC) over the last decades. Most recently, an outbreak of EVD was identified on May 8, 2018, occurring in the northwestern region of the countryFootnote 18.
Transmission of EVD occurs via handling, preparing or ingesting infected animal reservoirs (e.g., bats, bushmeat), or contact with the blood, body fluids (e.g., stool, vomitus, saliva, semen), or tissue of infected human cases, during their symptomatic illness or soon after death, directly, or via objects, contaminated with such fluidsFootnote 1Footnote 2Footnote 3Footnote 5Footnote 6Footnote 19). Those at particular risk for acquisition of EVD include healthcare workersFootnote 20 and family members tending to ill relatives, and those involved with the burial process including preparing the deceased for burialFootnote 4.
EVD has an incubation period of up to 21-days, with most cases manifesting clinical disease within 6 or 7 days following exposure. Risk of transmission is highest when viral load is greatest in EVD-infected individuals, such as patients who are acutely unwell with fever, vomiting, and diarrhea, or soon after their deathFootnote 3. As well, following recovery and release from isolation, when an EVD survivor may feel relatively asymptomatic, the risk of sexual transmission remains a concern, due to persistence of Ebola virus in semenFootnote 21Footnote 22Footnote 23. Likewise, Ebola virus can persist for several months in body organs that are protected from the survivor’s immune system, such as the eyes and central nervous system (CNS)Footnote 23. Transmission of EVD from mother-to-child has been well documented, and nearly all cases of congenital EVD transmission during the 2014-2016 EVD outbreak in Sierra Leone, Liberia and Guinea were fatalFootnote 24. Pregnant women with EVD may also have severe clinical outcomes, including death, more frequently than non-pregnant adultsFootnote 25.
EVD is characterized by an abrupt onset viral syndrome of: fever, malaise, myalgia, vomiting, pharyngitis, severe headache, conjunctival injection, and large-volume (potentially cholera-like) diarrhea that can be bloodyFootnote 19Footnote 26Footnote 27. It is often accompanied by a maculopapular or petechial rash that may progress to purpura. In up to half of patients, bleeding may occur from mucosa such as the gums, nose, gastrointestinal tract, and venipuncture sitesFootnote 19Footnote 27. As the disease progresses, dehydration with consequent electrolyte abnormalities may become severe, after which, wasting and listlessness ensueFootnote 26.
Severe EVD cases that manifest hemorrhagic diatheses are also usually accompanied by severe end-organ damage such as acute kidney injury, CNS dysfunction, bone marrow suppression leading to leukopenia and thrombocytopenia, and liver failureFootnote 19Footnote 26. In addition, survivors can experience a range of complications after recovering from EVD, such as non-specific fatigue, joint pain, muscle aches, etc.Footnote 23.
Risk to travellers is incurred through participation in activities that place them in contact with infected blood or body fluids of an EVD patient (e.g., provision of healthcare, attending a burial, sexual contact) or infected animal reservoirs (e.g., consumption of bushmeat) in EVD affected areas. Canadian travellers following typical tourist or business itineraries are unlikely to encounter these exposures.
Travellers to EVD-affected areas are advised to monitor the local news media and adhere to all airport procedures, including entry and exit screening, as directed by local authorities.
Definition of EVD-affected areas
During an EVD outbreak, areas considered to be affected are those where there has been a confirmed locally acquired case of EVD or where an individual with an infectious case of EVD has resided.
Guidance on preventive measures for healthcare workers who are providing care to patients with suspected or confirmed EVD is available elsewhereFootnote 28Footnote 29, and not otherwise addressed in this section. Humanitarian aid workers should follow guidance provided by their organization in addition to the guidance provided in this document. Preventing EVD rests on limiting exposure to potentially infected blood and body fluids and animal reservoirs. Travellers are advised to practise frequent hand hygiene with soap and water, or alcohol-based hand rub, while abroad for prevention of common viral infections, such as influenza and norovirus, as well as potentially severe infections like EVD. Travellers are advised to avoid close contact with live or dead animals, avoid handling raw or undercooked meat and avoid consuming any bushmeat. Condoms should be used during sexual activity while abroad for the prevention of common sexually transmitted diseases as well as EVD.
Travellers to an EVD-affected area, for the purpose of visiting friends and relatives, should exercise a degree of caution beyond that of typical tourist or business travellers, given that they will be staying in local homes often for a more prolonged period of time, and may be consuming local foods that may present a risk for EVD transmission. In addition to preventive measures suggested to tourists and business travellers, such travellers are advised to be cautious of exposure to ill friends and relatives in a household setting and be aware of and adhere to safe burial practices. Extensive recommendations for provision of care to a family member in EVD-affected areas are available from the WHOFootnote 30; however, in an EVD-affected area, fever and/or severe clinical illness in a local household where the traveller may be exposed should be brought to the attention of local health authorities whose recommendations should be followed, and transfer of care to a healthcare facility should occur promptly in such a scenario. If a traveller was residing in the household or in close contact with the ill individual, or attended or participated in a burial process, the traveller would likely be considered a contact of a suspect case, and should follow the instructions provided locally for appropriate contact management.
An investigational vaccine (rVSV-ZEBOV-GP, Merck) has completed early stage investigational trialsFootnote 31 and has been used for humanitarian workers and contacts in an outbreak of EVD in DRCFootnote 32. As an outbreak management measure, the vaccine may be offered to some humanitarian workers deploying to an EVD-affected area (i.e., to those that may provide care to confirmed EVD cases or their contacts, including contacts of a deceased case), or to those that may be engaged in safe burials, and to other healthcare or frontline workers in affected areas and areas at high risk of spreadFootnote 13. However, rVSV-ZEBOV-GP is neither licensed nor marketed in Canada, and is thus unavailable to the vast majority of travellers at this point in time. Vaccinated individuals must undergo the same monitoring and surveillance measures as those who have not been vaccinated.
The risk of exportation and further transmission of EVD outside affected areas can be mitigated through the implementation of effective exit screening measures. Such measures are usually put into place to identify symptomatic persons and/or those who may have had a high risk of exposure to an EVD case. They can be implemented within an affected country (for example, between areas of active transmission and areas where no transmission has been documented) as well as at international points of entry/exit (e.g., air and water ports, land border crossings etc.)Footnote 9.
As part of usual practice, Canada Border Services Agency personnel screen for ill passengers as per the Quarantine ActFootnote 34 with subsequent referral of symptomatic travellers to a Quarantine Officer for health assessment. As per the Quarantine Act, when arriving in Canada, all travellers who are feeling unwell, must disclose to a Canadian Border Services Agent if they have been or suspect to have been in close proximity with someone who has a communicable disease.
Assessment of the exposure risk of travellers
A traveller is considered to have no known exposure to Ebola virus:
- if they have no known contact with a symptomatic EVD case or their body fluids or contaminated materials; or
- even if they have interacted with an asymptomatic person who has been providing care or living in the same household as an EVD case (this is a subpopulation of the above).
Any of the following are considered low-risk of exposure to Ebola virus:
- direct contact with a symptomatic EVD case, their body fluids, their corpse, or any other known source of Ebola virus, while adhering to recommended Infection Prevention and Control (IPC) precautions and no known breach in IPC precautions; or
- living in the same household, but did not have direct contact with a symptomatic EVD case or their body fluids (e.g., through contaminated surfaces); or
- had only casual interactions, and no direct contact, with an EVD case or their body fluids. Examples of casual interactions include sharing a seating area on public transportation or sitting in the same waiting room.
- direct contact with a symptomatic EVD case, their body fluids, their corpse, or any other known source of Ebola virus, without adhering to recommended IPC precautions; or due to a breach in IPC precautionsFootnote 28; or
- unprotected sexual contact with an infected person or a person recovering from EVD since the virus can persist for months in the semen of infected males and possibly the vaginal secretions of infected femalesFootnote 23.
Healthcare and humanitarian aid workers are considered differently in terms of assessment of their exposure risk from other travellers. Due to the nature of their potential risk of exposure, upon arrival in Canada, healthcare and humanitarian aid workers should:
- self-identify to the appropriate public health authority the first business day following their arrival, even if they have no exposures or a low risk of exposure
- self-identify to Canadian Border Services Agent/Quarantine officer at the airport, if they have a high risk of exposure or have EVD compatible symptoms
It should be noted that travellers who are symptomatic or with high risk of exposure are unlikely to present at a point of entry into Canada as EVD-affected areas usually implement exit screening. However, in the early stages of an outbreak, there is a possibility that travellers could exit an EVD-affected area via public conveyance either due to inadequate exit screening or due to the unknown nature of the exposure.
1. Travellers from an EVD-affected area with no known exposure
- Returning travellers with no symptoms should be encouraged to check the Public Health Agency of Canada’s website for information on EVDFootnote 35 and what to do if they develop symptoms in the 21 days following their return to Canada.
- It is recommended that these travellers follow the Category 1 recommendations regarding monitoring and surveillance provided in Table 1.
Physicians seeing travellers with symptoms and with no known exposure should contact their appropriate public health authority for further guidance.
2. Travellers from an EVD-affected area with low risk of exposure and without symptoms
Upon arrival in Canada, it is recommended that these travellers:
- Self-identify to the appropriate public health authority during the first business day following arrival in Canada for counselling regarding processes and procedures in the event that EVD compatible symptoms develop over the potential incubation period.
- Follow the Category 2 recommendations regarding monitoring and surveillance provided in Table 1 for the remaining balance of the 21-day period following the last potential exposure to EVD.
3. Travellers from an EVD-affected area with high risk of exposure and without symptoms
In the event that a traveller learns of their high risk of exposure while in transit to Canada, it is recommended that these travellers:
- Self-identify to a Canadian Border Services Agent who will contact a Quarantine Officer who will perform an individual risk assessment and determine what actions will be required to support the traveller and protect those around them.
- Follow the Category 3 recommendations regarding monitoring and surveillance provided in Table 1 for the remaining balance of the 21-day period following the last potential exposure to EVD.
In the event that a traveller learns of their high risk of exposure, after entering Canada, it is recommended that these travellers:
- Self-identify to the appropriate public health authority who will perform an individual risk assessment and determine what actions will be required to support the traveller and protect those around them.
- Public health monitoring by the public health authority will include monitoring for symptoms of EVD, including having the traveller check and document their oral temperature twice daily.
- Follow the Category 3 recommendations regarding monitoring and surveillance provided in Table 1 for the remaining balance of the 21-day period following the last potential exposure to EVD.
Humanitarian aid workers should follow the guidance provided by their organization in addition to the guidance provided in this document.
4. Travellers from an EVD-affected area who have developed EVD compatible symptoms
If a traveller from an EVD-affected area is found to have EVD compatible symptoms upon arrival at a point of entry in Canada, the traveller should:
- Self-identify to a Canadian Border Services Agent who will contact a Quarantine Officer. As per the Quarantine ActFootnote 34 the Quarantine Officer will immediately conduct a health assessment and make any necessary arrangements (including issuing any necessary orders) for medical and/or appropriate public health authority follow-up.
- Follow the Category 4 recommendations regarding monitoring and surveillance provided in Table 1 for the remaining balance of the 21-day period following the last potential exposure to EVD.
If a traveller from an EVD-affected area develops EVD compatible symptoms after entering Canada, during the 21-day period following the last potential exposure to EVD, the traveller should:
- Immediately self-isolate (maintain a 2-metre distance and no physical contact).
- Wash hands, especially after vomiting or toileting.
- Ensure that others do not come into contact with their blood or body fluids (including urine, feces, emesis, saliva, sweat, and semen) or anything that may have come in contact with their blood or body fluid (e.g. linens, clothing, toilet, toiletries). Refer to Measures for the Management of Ebola Virus Disease-associated Waste in Home or Alternate SettingsFootnote 36 for management of EVD associated waste.
- Follow instructions provided by the appropriate public health authority.
- Travellers who have not been in contact with the appropriate public health authority should call immediately to receive instructions.
If the traveller's symptoms require immediate medical intervention, the appropriate public health authority should follow the recommendations below to ensure that all Paramedic / Emergency Medical Services and health care providers the patient may interact with are prepared to take appropriate IPC precautions. The public health authority will:
- Arrange for the individual to have a medical assessment at an acute care facility (where appropriate IPC measures can be implemented, if located in close proximity to the individual), to confirm or rule out EVD.
- Recommend that the individual not take public conveyances (bus, train, taxi) to that facility. The individual should be transported to hospital via ambulance unless the public health authority permits travel to the medical facility by private vehicle.
- Ensure the Paramedic / Emergency Medical Services (if involved) and the receiving acute care facility are informed of status of the traveller with the EVD-compatible symptoms in advance to help ensure that appropriate IPC measures are in place during transport and before their arrival at the acute care facility.
|Risk Categories||Category 1: Travellers with no known exposureFootnote 1 without symptoms||Category 2: Travellers with low risk of exposureFootnote 2 without symptoms||Category 3: Travellers with high risk of exposureFootnote 3 without symptoms||Category 4: Travellers with EVD compatible symptomsFootnote 4|
|Action upon arrival in Canada||
|Operational Guidance (for balance of the 21 day period since last possible exposure)|
|Onward Domestic Travel Permitted?||Yes||Yes||To be determined by Quarantine Officer or Medical Officer assessment||No|
|Monitoring||No||Travellers should immediately start self-monitoring for symptoms of EVDFootnote 6||Public health authority immediately starts monitoring for symptoms of EVDFootnote 6||Yes (in hospital and then according to exposure risk if EVD ruled out at time of assessment)|
|Contingency planning||Not applicable||Travellers should:
|Attendance at WorkFootnote 5||Yes||Yes (following assessment by public health authority)||No||No (until EVD ruled out)|
|Going out in public placesFootnote 5||Yes||Yes (following assessment by public health authority)||No||No (until EVD ruled out)|
|Use of public conveyancesFootnote 5||Yes||Yes (following assessment by public health authority)||No||No (until EVD ruled out)|
|Other precautions||Not applicable||Travellers should:
Humanitarian aid workers should:
The Association of Medical Microbiology and Infectious Diseases of Canada (AMMI Canada) along with the Canadian Critical Care Society and Canadian Association of Emergency Physicians have published guidelines pertaining to the care of patients with suspected and confirmed EVDFootnote 37Footnote 38. Treatment of patients with confirmed EVD in Canada will occur at a designated EVD treatment centre, as directed by federal and provincial protocols.
This statement was developed by the Ebola Working Group: Andrea K. Boggild, Michael D. Libman, Anne E. McCarthy, Jeffrey Pernica, Maryanne Crockett, Jennifer Geduld and Elspeth Payne (CATMAT Secretariat) and approved by CATMAT.
CATMAT acknowledges and appreciates the contribution of Jill Sciberras, Thomas Piggott and Nicole Pachal to the statement.
CATMAT members: McCarthy A (Chair), Acharya A, Boggild A, Bui Y, Crockett M, Greenaway C, Libman M, and Vaughan S.
Liaison members: Angelo K (United States Centers for Disease Control and Prevention), Audcent T (Canadian Paediatric Society) and Pernica J (Association of Medical Microbiology and Infectious Disease Canada).
Ex officio members: Marion D (Canadian Forces Health Services Centre, Department of National Defence), McDonald P (Bureau of Medical Sciences, Health Canada), Rossi C (Medical Intelligence, Department of National Defence) and Schofield S (Pest Management Entomology, Department of National Defence).
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