Lantagne says comparison of the Haitian cholera strain with one circulating in Nepal, around the same time, shows the two differed in only one out 4 million genetic elements.
"That's considered an exact match – that they're the same strain of cholera," she tells Shots.
Most scientists now think Nepalese soldiers unwittingly brought cholera to Haiti when they joined a U.N. peacekeeping force there in 2010. The outbreak started just downstream from their camp. Sewage from the camp spilled into a nearby river.
Lantagne was one of four scientists appointed by the U.N. to look into the matter. Their report, issued in May 2011, implicated the U.N. camp as a likely origin, but it concluded that the outbreak was caused by "a confluence of circumstances."
She tells Shots that the report would come out different today.
"If we had had the additional scientific evidence that's available now, we definitely would have written the report in 2011 differently, to state the most likely source of introduction was someone associated with the peacekeeping camp," Lantagne says.
That's important because the U.N. insists that whatever way cholera got to Haiti, terrible sanitary conditions and lack of clean water were responsible for its remarkably fast spread.
But lawyer Brian Concannon doesn't buy that.
"It's like lighting a fire in a dry field on a windy day, and then blaming the wind or the drought for the fire," says Concannon, who directs a Boston-based group called the Institute for Justice and Democracy in Haiti.
More than a year ago, the group filed a legal claim against the U.N. demanding that it accept responsibility.
“ Haiti has done some great things with vaccination. They've eliminated measles, rubella and polio, and you can't say that in many countries in Europe.