Port-au-Prince, Nov 19 (DPA) Protesters clashed with police and UN peacekeepers in Haitian capital Port-au-Prince over the spreading cholera epidemic, as US health experts warned of a substantial increase in cases.

More than 1,100 people have died from cholera and an additional 18,000 have been sickened by the disease, which is contracted through contaminated water and causes severe diarrhoea and vomiting.

The first cases were reported in the lower Artibonite region, north of Port-au-Prince Oct 19. The UN anticipates that up to 200,000 people will show symptoms of cholera, ranging from cases of mild diarrhoea to severe dehydration.

While the Haitian government immediately declared a public health emergency and non-governmental organisations have been working to increase access to prevention and treatment measures, the course of the epidemic takes is difficult to predict, US health experts have said.

The Haitian population has no pre-existing immunity to cholera, and current conditions in the quake-shattered country are favourable for its continued spread, according to the US Centre for Disease Control and Prevention (CDC), with millions of displaced people living in overcrowded camps with poor drinking water and sanitation facilities.

But conditions were ripe for an epidemic even before the earthquake because of the country’s unsafe water supply system, which was further weakened over the years by a series of hurricanes, followed by floods and mudslides.

The CDC cautioned that recurrent cholera outbreaks are possible and said it was critical to protect the Haitian population from other water-borne diseases. It said that as surveillance systems improve, the number of cases identified is likely to increase substantially.

On Thursday, demonstrators threw stones at UN soldiers guarding the presidential palace, and the US embassy asked its citizens to avoid the area.

Haitian police used tear gas to disperse the agitated crowd in front of the palace, which is surrounded by hundreds of makeshift camps housing the homeless from the Jan 12 earthquake that levelled much of the capital, killing an estimated 230,000 people.

Some Haitians have blamed UN troops from Nepal for the cholera epidemic. The UN Stabilization Mission in Haiti (MINUSTAH) has denied these allegations amid calls from some quarters for the peacekeepers to leave the country.

Three people were killed in clashes through the week in northern Cap Haitien, Haiti’s second-largest city.

The UN and Haitian government have blamed much of the unrest on political machinations leading up to the presidential elections Nov 28.

Meanwhile, a Haitian man died of cholera in the Dominican Republic, which shares with Haiti the Caribbean island of Hispaniola.

A woman who recently returned to the US state of Florida from Haiti was also diagnosed with cholera symptoms, but she had been discharged from hospital and was recovering.

Outbreaks of cholera, a gastrointestinal infection also referred to as a disease of poverty, are frequent in Asia and Africa. During the 1990s, several Latin America countries had cholera outbreaks, but none have been reported from Haiti in several decades.

As cholera has not been reported in Haiti in this generation, ‘likely in past generations as well, so the education and training on how to diagnose and manage a patient with cholera is not present,’ said CDC’s Manoj Menon.

According to the CDC, the Haiti outbreak underscores the continuing vulnerability of much of the world’s population to sudden severe illness and death from cholera.

A total of 221,226 cases of cholera and 4,946 cholera deaths were reported in 2009 to the World Health Organization from 45 countries. The actual number of annual cases, however, is believed to be substantially higher.