UNITED NATIONS (Reuters) – Haiti’s deadly cholera epidemic is spreading faster than originally estimated and is likely to result in hundreds of thousands of cases and last up to a year, a senior U.N. official said on Tuesday.

Since the disease first appeared in mid-October it has killed 1,344 people as of Friday in the poverty-stricken and earthquake-ravaged Caribbean nation.

But U.N. humanitarian coordinator in Haiti Nigel Fisher said the real death toll might be “closer to two thousand than one” because of lack of data from remote areas, and the number of cases 60,000-70,000 instead of the official figure of around 50,000.

Addressing a U.N. news conference by video link from Haiti, Fisher said experts from the World Health Organization were now revising their estimate that the diarrheal disease, spread by poor sanitation, would cause 200,000 cases within six months.

“They are now revising that to 200,000 in closer to a three-month period. So this epidemic is moving faster,” he said, adding that it was now present in all 10 of Haiti’s provinces. “It’s going to spread.”

“The medical specialists all say that this cholera epidemic will continue through months and maybe a year at least, that we will see literally hundreds of thousands of cases,” Fisher said.

It was “almost impossible to stop the spread of these cases because it is so contagious, and those who carry the cholera bacterium often take days to show it, and in that (time) they may move anywhere,” he added.

Fisher said U.N. and other aid workers needed to “significantly ratchet up” their response, including going through faith groups to distribute chlorine tablets to purify water, and increasing the number of treatment centers.

But he said opening new treatment centers was running into resistance from local authorities because of people’s fears of having them in their neighborhoods.

The anti-cholera campaign has been complicated by unconfirmed reports that U.N. peacekeepers from Nepal brought the disease to Haiti, where it had been absent for 100 years.

At least two people were killed and dozens were injured in clashes last week between U.N. troops and protesters. The United Nations has blamed the trouble on political agitators looking to inflame tensions ahead of elections next Sunday.

Edmond Mulet, head of the U.N. MINUSTAH peacekeeping mission in Haiti, told the news conference there was still “no scientific evidence” the epidemic had come from the Nepalese and that all tests carried out had proved negative. But experts continued to investigate, he said.

(Editing by Cynthia Osterman)