The cholera outbreak in Zimbabwe has so far killed more than 1,500 people, and the fatality rates are rising, a United Nations agency says.

The World Health Organization (WHO) says some 1,518 people have died of the disease and 26,497 cases have been recorded since August when the outbreak occurred.

The WHO says on its website that the outbreak is still not under control, and Zimbabwe's neighboring countries are encouraged to reinforce their active surveillance and preparedness systems.

The agency says the epidemiological week ending December 20 saw more than 5,000 new cases, an increase in the number of weekly cases relative to previous weeks and a rise in deaths outside treatment and health centers.

The percentage of cholera patients dying from the disease has risen to 5.7 percent from 4 percent at the beginning of the month, the WHO says.

Normally, only 1 percent of patients die in large cholera outbreaks, it says.

The Zimbabwean Ministry of Health said on December 25 that new infections were still occurring in all parts of the country.

(Xinhua News Agency December 29, 2008)