2026 Bundibugyo virus disease outbreak: Person under investigation case definition
Last updated: August 28, 2026
On this page
- Overview and intended use
- Person under investigation (PUI) case definition
- Appendix 1: Current Bundibugyo virus outbreak-affected areas
- Footnotes
Overview and intended use
This person under investigation (PUI) case definition has been adapted specifically for the 2026 Bundibugyo virus disease (BVD) outbreak and differs from the Ebola disease outbreak case definitions. The epidemiological risk factors and definition of outbreak-affected areas have been refined to reflect the current epidemiological situation of the BVD outbreak. Symptoms and signs have also been updated to reflect commonly reported orthoebolavirus-related symptoms and signs.
This PUI case definition is intended for surveillance and reporting purposes to support standardized national reporting to PHAC and subsequent national and international (including to PAHO/WHO) reporting of case counts. The case definition is not intended for use in clinical management.
Provinces and territories are required to notify the PHAC Health Portfolio Operations Centre (HPOC) at 1-800-545-7661 of any person meeting the PUI definition and for any person for whom orthoebolavirus testing is being ordered. For information on reporting, consult Ebola disease: For health professionals, humanitarian aid workers. For additional information on testing, consult National Microbiology Laboratory (NML) Laboratory testing for Orthoebolavirus, 2026 June, which includes information on notification and shipping requirements.
Person under investigation (PUI) case definition
A person:
- With one or more Ebola disease-compatible symptoms or signs (as defined below) AND
- With exposure to one or more of the epidemiological risk factors (as defined below) within 21 days prior to symptom onset AND
- For whom Bundibugyo virus disease is considered a plausible diagnosis
Note:
- A positive test from the National Microbiology Laboratory (NML) would move a PUI into the confirmed case definition.
- Negative tests, particularly if within the first 72 hours after symptom onset, do not in and of themselves preclude Bundibugyo virus disease as a plausible diagnosis.
Symptoms and signs
Ebola disease-compatible symptoms or signs are defined as:
- fever
- malaise, weakness, or fatigue
- myalgia or arthralgia
- headache
- loss of appetite
- conjunctival redness
- difficulty breathing
- sore throat
- chest pain
- cough
- abdominal pain
- vomiting
- diarrhoea
- confusion of recent onset
- hemorrhagic manifestations or unexplained bleeding
- hiccups
- skin rash
- jaundice
Epidemiological risk factors
Epidemiological risk factorsFootnote 1 are defined as one or more of the following in the 21 days before the onset of symptoms:
Geographic risk
- Residence in, or travel to, a Bundibugyo virus outbreak-affected area (consult Appendix 1) within 21 days prior to onset of symptoms.
Known or likely exposure to Bundibugyo virusFootnote 2
- Percutaneous (i.e., piercing the skin), mucous membrane (e.g., eye, nose or mouth), sexual or skin contact with blood or other body fluids (e.g., semenFootnote 3, breastmilk) from a person with confirmed BVD or who is considered likely to have BVD, including through objects contaminated by that person
- Cared for a person with confirmed BVD or who is considered likely to have BVD (with or without personal protective equipment)
- Close contact with a person with confirmed BVD or who is considered likely to have BVD (with or without personal protective equipment)
- Physical contact with any human remains of a person who had confirmed BVD or who was considered likely to have had BVD (with or without personal protective equipment)
- Lived in the same household as a person with confirmed BVD or who is considered likely to have BVD
- Laboratory or other worker who handled Bundibugyo virus or processed body fluids and/or tissues from a person with BVD or who is considered likely to have BVD (with or without personal protective equipment)
Appendix 1: Current Bundibugyo virus outbreak-affected areas
For the purposes of case classification, Bundibugyo virus outbreak-affected areas are geographic areas with ongoing community transmission, where travel alone is considered a sufficient epidemiological risk factor for exposure.
Bundibugyo virus outbreak-affected areas are currently defined as the following:
- 5 provinces in Democratic Republic of Congo:
- Ituri
- North Kivu
- Tshopo
- Haut-Uélé
- Bas-Uélé
This list is intended to support timely case identification and classification and may differ from broader geographic designations used for other purposes. The list will be reviewed regularly and updated as the epidemiological situation evolves, including the addition of new areas where ongoing community transmission is identified and the removal of areas where community transmission is no longer occurring. Updates will be informed by the best available epidemiological evidence, including official reports from affected countries, the World Health Organization (WHO), regional public health partners, and other verified public health intelligence on the geographic extent of community transmission.
Footnotes
- Footnote 1
-
Although not relevant for human-to-human transmission in the current outbreak, contact with bats, non-human primates or wild animal bush meat are potential risks for new introduction of orthoebolaviruses to people
- Footnote 2
-
Exposure to a person with confirmed BVD or who is likely to have BVD refers to exposure that occurred while the person is infectious (i.e., from the onset of symptoms until no longer deemed infectious by their clinical care team).
- Footnote 3
-
For sexual contact, semen from people who have recovered from Ebola disease can remain infectious for months.