The World Health Organization said on Wednesday it will temporarily suspend the standard two-dose vaccination regimen for cholera, replacing it with a single dose due to vaccine shortages and rising outbreaks worldwide.

The U.N. agency said "the exceptional decision reflects the grave state of the cholera vaccine stockpile" at a time when countries like Haiti, Syria, Malawi are fighting large outbreaks of the deadly disease, which spreads through contact with contaminated water and food.

As of Oct. 9, Haiti had confirmed 32 cases and 18 deaths from the disease, while many cases were still awaiting confirmation.

"The pivot in strategy will allow for the doses to be used in more countries, at a time of unprecedented rise in cholera outbreaks worldwide," WHO said in a statement on Wednesday.

The one-dose strategy had proved to be effective as a response to cholera outbreaks, the agency said, although the duration of protection is limited and appears to be much lower in children.

The disease often causes no symptoms, but serious cases cause acute diarrhoea and can kill within hours if untreated.

Cholera cases have surged this year, especially in places of poverty and conflict, with outbreaks reported in 29 countries and fatality rates rising sharply.

A cholera outbreak in Syria has already killed at least 33 people, posing a danger across the frontlines of the country's 11-year war and stirring fears in crowded camps for the displaced.

(Reporting by Akriti Sharma in Bengaluru; Editing by Nick Macfie)