A recent study published on June 18 found that the risk of international transmission of Ebola virus disease remains low, even during major outbreaks in Africa. The research by van Zandvoort et al. analyzed all known laboratory-confirmed Ebola cases that occurred outside Africa from 1976 through May 2026 to inform policy decisions regarding border and travel measures.
The authors searched scientific articles, public health bulletins, and news reports for cases involving Bundibugyo, Ebola, and Sudan viruses with exposure in Africa followed by travel abroad or exposure outside Africa. They identified a total of 28 confirmed cases outside Africa during this period: 25 were primary imported cases and three were secondary infections occurring in the United States or Europe.
The analysis distinguished between medically evacuated patients—who are transported under strict infection control—and latent cases who developed symptoms after traveling commercially from outbreak regions. Most exported cases (27) occurred during the 2014–16 West African epidemic; one case was linked to the ongoing Bundibugyo outbreak in 2026. Four latent exported cases were detected during the West African epidemic among approximately 300,000 screened travelers; all four were asymptomatic at both exit and entry screenings. Three involved returning healthcare workers and one involved an individual assisting a pregnant patient.
According to van Zandvoort et al., "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 further said, "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."
