Estimating the effectiveness of syndromic screening at airports for Bundibugyo ebolavirus disease

We used a stochastic simulation model to estimate the effectiveness of exit and/or entry syndromic screening at airports for Bundibugyo ebolavirus disease (BVD). For a 12-hour international flight from DRC or Uganda at 86% screening sensitivity, approximately 73% of infected people presenting for travel would evade combined exit and entry screening (95% CrI: 68–77%). Among those who successfully boarded, approximately 92% would arrive without detection (95% CrI: 90–94%). This high undetected fraction reflects the relative durations of the incubation period (approximately 7.7 days; Wamala et al. 2010 ¹ ) and the onset-to-severe-disease interval (approximately 4 days; Funk & Abbott 2026 ² ): most infected travellers board before symptom onset and are undetectable by any syndromic screen, whilst those who are symptomatic progress rapidly to illness severe enough to preclude travel. Because the proportion of confirmed cases presenting without fever is itself uncertain, we also report a conservative scenario in which all confirmed cases are febrile (0% asymptomatic-equivalent), under which the undetected fraction remains substantial at approximately 64% (95% CrI: 57–70%). This is compounded during active epidemic growth, when recently exposed (and therefore pre-symptomatic) cases are overrepresented among travellers. Syndromic airport screening offers limited protection against BVD spread via air travel, and should be complemented by outbreak control at source, strengthened clinical surveillance in receiving countries with high travel connectivity to affected areas, and post-departure self-monitoring guidance for travellers from affected regions.