Looking at the data since 1976: low risk of global spread of Ebola disease
Most effective strategy to reduce exportation of cases: local, community-based case management, infection prevention and control at the outbreak source
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Since 1976, the authors idnetified 28 confirmed Ebola disease cases outside Africa: 25 primary imported cases and three secondary cases infected by another patient in the United States (US) or Europe.
view moreCredit: Eurosurveillance
In previous Ebola disease outbreaks in Africa as well as the current outbreak of Ebola disease caused by Bundibugyo virus in the Democratic Republic of the Congo, immediate neighbouring countries are most affected when it comes to cross-border spread. As decision-makers outside Africa may be considering border and travel policies to interrupt pathways for international transmission, van Zandvoort et al. identified and analysed all known Ebola disease cases outside Africa to assess the risk of undetected Orthoebolavirus transmission outside Africa and to put it into context with possible border and travel policies. [1]
The authors searched for all laboratory-confirmed Ebola disease cases that presented outside of Africa since 1976 to date across scientific articles, public health bulletins and news reports including cases due to Bundibugyo, Ebola and Sudan virus outside Africa with exposure in Africa and subsequent travel outside the continent, as well as cases with exposure outside Africa.
Two types of exported cases: medical evacuation and latent
In total, the search yielded 28 identified confirmed Ebola disease cases outside Africa during the period 1976 to May 2026 with 25 primary imported cases and three secondary cases infected by another patient in the United States (US) or Europe.
The analysis distinguishes between two types of primary exported cases. On the one hand the analysis included people who were medically evacuated, i.e. securely transported by air ambulance for treatment outside Africa following a confirmed infection. On the other hand, latent cases were defined as people who developed symptoms during or after their return from the outbreak region on a commercial flight. While the first group represents a known risk with the possibility to mitigate transmission risk with strict measures, the second group requires diagnosis and isolation.
Most of the identified cases (27) occurred during the 2014–16 Ebola virus epidemic in Western Africa and one during the ongoing 2026 Bundibugyo virus outbreak. The authors detected four latent cases, all of which were exported during the 2014–16 Ebola disease epidemic. These four cases were among 300,000 travellers who underwent screening at the time. However, all four were asymptomatic (and hence undetectable) at the point of both exit screening and entry screening. Three were returning healthcare workers responding to the epidemic and one had helped a pregnant person obtaining medical assistance.
Low overall risk of exportation
Based on these data, according to van Zandvoort et al., the crude overall risk since the year 2000 was 0.17 Ebola disease cases outside Africa per 1,000 reported cases in Africa (excluding medically evacuated cases). The authors conclude “our results suggest overall that the risk of case exportations is low and could be substantially mitigated by infection prevention measures at the outbreak source and among outbreak response workers, in concert with enhanced travel screening and monitoring for returning response workers, as recommended in WHO border and travel guidance for the current outbreak.
The authors thus have the view that “as exit screening in an outbreak-affected country aims to reduce case importations in other countries, it is a shared international responsibility. This may be best supported by strengthening local capacity for such screening.”
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References/notes to editors:
[1] van Zandvoort Kevin, Procter Simon R, Azam James, Sherratt Katharine, Davies Nicholas G. The risk of global Ebola virus spread is low: epidemiology of Ebola disease cases outside Africa, 1976 to May 2026. Euro Surveill. 2026;31(24):pii=2600508. Available from: https://doi.org/10.2807/1560-7917.ES.2026.31.24.2600508
[2] Ebola disease is caused by viruses belonging to the genus Orthoebolavirus, Filoviridae family. There are four orthoebolaviruses that can cause disease in humans. See more: https://www.ecdc.europa.eu/en/ebola-disease
[3] Ebola disease outbreak in the Democratic Republic of the Congo and Uganda, ECDC outbreak page. Available from: https://www.ecdc.europa.eu/en/ebola-outbreak-democratic-republic-congo-and-uganda
Journal
Eurosurveillance
Method of Research
Data/statistical analysis
Article Title
The risk of global Ebola virus spread is low: epidemiology of Ebola disease cases outside Africa, 1976 to May 2026
Article Publication Date
18-Jun-2026
Hantavirus and Ebola virus disease: 10 things to know
Canadian Medical Association Journal
Two deadly infectious diseases, Ebola https://www.cmaj.ca/lookup/doi/10.1503/cmaj.260834 and hantavirus https://www.cmaj.ca/lookup/doi/10.1503/cmaj.260789, have made headlines in recent weeks as they pose serious threats to public health. They both require rigorous infection and prevention control (IPAC) practices and often present with similar early symptoms.
Two succinct articles in CMAJ (Canadian Medical Association Journal) provide information about each disease for clinicians.
Hantavirus:
- A nationally notifiable disease in Canada — In Canada, 4 to 5 cases are confirmed every year and must be reported. These are usually acquired from rodents in agricultural settings in Manitoba, Saskatchewan, Alberta, and British Columbia. The Andes strain is unique as it can be transmitted from person to person.
- Causes 2 clinical symptoms — Strains in the Americas, which include the Andes virus featured recently in the news, cause hantavirus cardiopulmonary syndrome. The European and Asian strains cause hemorrhagic fever and kidney dysfunction. Both forms take about 2 to 4 weeks to incubate, and symptoms include fever, headache, muscle aches, and abdominal pain.
- Serology and polymerase chain reaction (PCR) tests are diagnostic — The National Microbiology Laboratory in Winnipeg performs these tests.
- Supportive treatment — As there is no specific antiviral treatment or vaccine for hantavirus, treatment is supportive to help alleviate symptoms.
- IPAC protocols are essential — Patients with suspected Andes strain infection must be isolated with airborne, droplet, and contact precautions, with infectious diseases experts involved and public health notified.
Ebola virus disease:
- Sporadic outbreaks have occurred in Central and West Africa since 1976 — There are 3 main viruses that can infect humans, and evidence suggests they come from fruit bats. Ebola virus is spread via person-to-person contact through bodily fluids like vomit, sperm, diarrhea, and blood, as well as by touching infected surfaces or objects. The current outbreak in the Democratic Republic of Congo is Bundibugyo ebolavirus, with a fatality rate of 30% to 50%.
- Fewer than 50% of patients have hemorrhagic symptoms — Symptoms include fever of 38°C or higher, fatigue, muscle pain, and gastrointestinal distress. Incubation is 2 to 21 days, and diagnosis is made with PCR testing.
- People with potential symptoms and exposure risk should be tested — People who have travelled to countries with Ebola virus disease or who have been in close contact with infected people or bats, primates, or game from the affected areas should be tested.
- Stringent IPAC must be used for suspected cases — Health Canada has a detailed process for screening, assessment, and IPAC precautions, which must include a fit-tested N95 respirator, face shield, gloves, and fluid-impermeable gear for full protection.
- Important advances in prevention and management of the disease have been made — Vaccines to prevent Zaire ebolavirus are very effective, and 2 antivirals can reduce mortality from 50% to 35%. However, there are no current vaccines or medications to prevent or treat Bundibugyo ebolavirus, for which supportive care is the main approach.
Journal
Canadian Medical Association Journal
Method of Research
Literature review
Subject of Research
People
Article Title
Hantavirus”and “Ebola virus disease
Article Publication Date
22-Jun-2026
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