More than 50,000 people are now infected with cholera in Zimbabwe's epidemic, which has so far killed 2,773 people, the latest figures from the World Health Organisation said on Friday.
Most alarming is a mortality rate of 5.7 percent, said a statement from the International Federation of Red Cross and Red Crescent Societies (IFRC), a fact which indicates the outbreak is still far from under control.
"Overall, this signifies a 20 percent increase in cholera deaths over the past week and rings alarm bells about the need to push back this epidemic and better fund the humanitarian effort on the ground," said the statement.
Tony Maryon, head of the IFRC team in Zimbabwe, said: "Because of the severity of this outbreak, we fear that it will take many more weeks to get it under control."
Aid agencies have for several weeks been preparing for a worst-case scenario in which the rainy season spreads the infection to 60,000 people.
But although the IFCR launched a Zimbabwe Cholera Emergency Appeal on December 23 for 9.2 million dollars (6.6 million euros), it is currently 60 percent underfunded.
"We are active in all of the affected areas," said Emma Kundishora, the secretary general of the Zimbabwe Red Cross.
"Our volunteers and staff are on the ground, producing clean water, establishing and supporting sanitation and treatment facilities and passing on life-saving health awareness messages."
But the battle against the epidemic has been hampered by the strike over pay by Zimbabwe's doctors.