The cholera epidemic affecting Haiti may get much, much worse than officials originally thought.
Before last year's devastating earthquake, the BBC reports, no cases of cholera had been seen in Haiti for more than a century.
But in the three months between October and December 2010, about 150,000 people in Haiti contracted cholera and about 3500 died.
Around this time, the United Nations projected that the total number infected would likely rise to 400,000.
But researchers at the University of California, San Francisco, say that's a gross underestimate. They believe the toll could reach 779,000, with 11,100 deaths by the end of November 2011.
Using data from Haiti's ministry of health, Dr Sanjay Basu and his colleagues concluded that the UN estimates were "crude" and based on a simple assumption that the disease would infect a set portion (2-4%) of the population.
World Health Organisation sceptical
The researchers' calculations take into account factors like which water supplies have been contaminated and how much immunity the population has to the disease.
They say, however, that thousands of lives could be saved by the provision of clean water, vaccination and expanded access to antibiotics.
The World Health Organisation, which says everything possible is being done to contain the disease, warns that modelling estimates do not necessarily reflect what's seen on the ground.
It says latest figures show there have been 252,640 cases and 4672 deaths as of 10 March 2011.