Download Ontario Ebola Virus Disease (EVD) Outbreak Case

Ministry of Health and Long-Term Care
Ontario Ebola Virus Disease (EVD) Outbreak
Case Definition – May 2016
Population and Public Health Division
Important Note: These specific EVD case definitions for Ontario have been created
based on the outbreak activity that has occurred in West Africa since 2014.
Note that these case definitions are for surveillance purposes and recording in the integrated
Public Health Information System (iPHIS). These surveillance case definitions are not intended
to replace clinician or public health practitioner judgment in individual patient management, or
intended to be used for the purpose of infection control triage.
Please see MOHLTC website www.ontario.ca/ebola for current information on affected
village/areas.
Clinically compatible symptoms for
new EVD infection are defined as one
or more of the following:
Clinically compatible symptoms of
EVD relapse are defined as one or
more of the following1:
•
Fever ≥ 38.0 degrees Celsius;
•
Fever ≥ 38.0 degrees Celsius;
•
Malaise;
•
•
Myalgia;
•
Severe headache;
Ocular symptoms such as eye pain,
redness, sensitivity to light, and/or blurry
vision
•
Conjunctival injection;
•
•
Pharyngitis;
Neurologic symptoms such as
headache, neck stiffness, photophobia,
altered mental status, and/or seizures
•
Abdominal pain;
•
Vomiting;
•
Diarrhea that can be bloody;
•
Unexplained hemorrhage;
•
Rash
1
Note that Ebola virus has been found to persist in EVD
survivors in sites that are harder for the immune system to
reach (immunologically privileged sites) (e.g., eyes, central
nervous system, male reproductive tract and mammary
glands). Therefore finding virus in an immunologically
privileged site would not constitute a relapse unless the
patient is symptomatic.
Person Under Investigation
Confirmed Cases
New Infection
New Infection
A person, previously NOT known to have
Ebola virus disease (EVD), with clinically
compatible symptoms for new infection (as
defined above) with one of the following
EVD exposures within the 21 days before
onset of symptoms AND with laboratory
results pending:
A person, previously NOT known to have
Ebola virus disease, with clinically
compatible symptoms for new EVD
infection and laboratory confirmation of
Ebola virus infection using at least one of
the methods below:
•
Direct or close contact with a person or
a recently deceased person known or
highly likely to have EVD or their blood
or body fluids with or without full,
appropriate personal protective
equipment at all times
OR
•
•
Isolation and identification of virus from
an appropriate clinical specimen (e.g.
blood, serum, tissue, urine specimens or
throat secretions)
OR
•
Sexual contact with a man previously
diagnosed with EVD since December
2013 (regardless of condom use)
Detection of virus-specific RNA by
reverse-transcriptase PCR from an
appropriate clinical specimen (e.g.
blood, serum, tissue) using two
independent targets or two independent
samples
OR
OR
•
•
In the 21 days prior to symptom onset,
lived in or visited a village/area where
EVD transmission has occurred in the
preceding three months
Person Under Investigation
Relapse
A person previously known to have EVD
and to have cleared their infection 2 who
presents with clinically compatible
symptoms of a relapse (as defined above)
AND with laboratory results pending or not
available.
2
Infection is considered to have been cleared when the
patient has been assessed as non-infectious and
discharged from EVD-specific care based on two negative
Ebola PCR tests performed by an accredited laboratory
Demonstration of virus antigen in tissue
(e.g. skin, liver or spleen) by
immunohistochemical or
immunofluorescent techniques AND
another test (e.g. PCR)
OR
•
Demonstration of specific IgM AND IgG
antibody by EIA, immunofluorescent
assay or Western Blot
OR
•
Demonstration of a fourfold rise in IgG
serum antibody by EIA,
immunofluorescent assay or Western
Blot from serial samples
2
Confirmed Cases
Relapse 3
A person, previously known to have Ebola
virus disease and to have cleared their
infection 4, who presents with symptoms
compatible with a relapse of EVD (as
defined above) and has laboratory
confirmation of Ebola virus infection using
at least one of the methods below:
•
Isolation and identification of virus from
an appropriate clinical specimen (e.g.,
site clinically involved with relapse
based on symptoms, or blood or serum)
OR
•
Detection of virus-specific RNA by
reverse-transcriptase PCR from an
appropriate clinical specimen (e.g., site
clinically involved with relapse based on
symptoms or blood or serum) using two
independent targets or two independent
samples
OR
•
Demonstration of virus antigen in tissue
clinically involved with the relapse (e.g.,
eye, brain, testes) by
immunohistochemical or
immunofluorescent techniques AND
another test (e.g. PCR)
3
This is an interim definition and may be subject to
change
4
Infection is considered to have been cleared when the
patient has been assessed as non-infectious and
discharged from EVD-specific care based on two negative
Ebola PCR tests performed by an accredited laboratory
3