Harare/Johannesburg  - Zimbabwe's cholera epidemic, the worst in Africa in 15 years, has slowed from the meteoric infection rates recorded earlier this year, but the risk of another escalation is still high, the International Federation of the Red Cross and Red Crescent Societies warned Tuesday.

The warning came as the epidemic was predicted to notch up its 100,000th case this week since it began nine months ago in a township outside the capital Harare.

Since then, the water-borne diarrhoeal disease has killed nearly 4,300 people, in what the Red Cross describes as an "unacceptably high" fatality rate of 4.4 per cent, for a disease that is easily preventable and treated.

The infection rate in recent weeks has slowed to 1.7 per cent, after aid agencies set up emergency camps to deal with new infections, provided millions of litres of clean water, sank new boreholes and distributed water purification tablets, among other measures.

The dramatic aggression of the epidemic has also burnt itself out, health officials say.

"But the steady decline in the spread of the illness should not be seen as a complete victory," the Red Cross said in a statement, noting that the fundamental drivers of Zimbabwe's public health crisis remained largely unchecked.

Unless significant efforts were made to rehabilitate at least some components of the country's degraded water and sanitation infrastructure, communities remain vulnerable to further and severe outbreaks, the Red Cross said.

Until the mid 1990s, Zimbabwe's well-run health system kept the cholera pathogen largely at bay.

But accelerating economic decay under President Robert Mugabe's former government saw urban infrastructure collapse. Water supplies to millions of people dried up, sewerage systems jammed and rubbish heaps grew, creating the conditions for a cholera outbreak.

Cholera is now endemic in Zimbabwe, health experts say.

The Red Cross says its emergency treatment centres "were only ever interim measures."

The organisation now needs 3.4 million dollars for medium- to long-term measures, including the rehabilitation of 1,150 boreholes, the drilling of 263 new water points and construction of 3,755 pit latrines for 655,000 families in high-risk areas.

"Today our appeal is less than half-funded," said Emma Kundishora, secretary-general of the Zimbabwe Red Cross Society, in a statement. "We will be revising our operation, scaling back just at the time when humanitarian assistance needs to be dramatically scaled up. This is simply untenable." (dpa)