(CNN) -- Up to three Ebola-infected travelers might board an international flight each month in West Africa, according to a new study, and potentially spread the deadly virus to other countries. Scientists used a model to predict that, on average, three people who are infected with Ebola will leave Guinea, Liberia or Sierra Leone in each of the coming months to fly to another country. They based their model on scheduled flights for September 1 to December 31, 2014, historic flight itineraries from 2013, and Ebola surveillance numbers from the current outbreak. The results were published in The Lancet this week.
@highlight
Scientists use model to predict number of Ebola-infected travelers leaving West Africa
@highlight
Up to three people with the deadly virus might travel internationally each month
@highlight
Majority of people flying out of affected countries are going to low- or middle-income nations
Overall, they concluded that exit screening is more effective than screening passengers for @placeholder when they arrive in another country.