The World Health Organisation on Friday said the number of cholera cases in Haiti was expected to reach 500,000 by the end of the year.
"If current trends continue, we can expect around 75,000 more cases by the end of the year bringing the total to approximately 500,000 cases since the beginning of the epidemic," WHO spokesman Tarik Jasarevic said.
In October, the WHO had already recorded 470,000 cases.
The cholera epidemic broke out in 2010 when the disease has killed 6,600 people.
The number of new cholera cases in Haiti halved in August, but the rainy season is once again worsening the situation, the WHO warned.
"We are going towards an endemic situation," noted Claire-Lise Chaignat, who heads the WHO's anti-cholera group.
"We should consider cholera vaccine introduction to Haiti for the most vulnerable. This discussion is ongoing," added Chaignat.
"But you can imagine that it is not easy to identify where to start, with the limited amount of vaccines available, because the vaccines are still produced in a very limited amount and quantity," she said, adding that she hoped this would change with the production of new vaccines in India.