Government has since declared the cholera outbreak a state of emergency while police have banned public gatherings in the capital to contain the disease.
"The Zimbabwe Republic Police is appealing to members of the public to take heed of this warning and cooperate as this will assist in alleviating the continuous spread of cholera".
Most towns and cities are facing massive water shortages, often caused by breakdown in pumps, power cuts and sometimes water purification chemical shortages, according to local media.
The Health Minister, Obadiah Moyo, on Tuesday acknowledged that poor water supply, blocked sewers, and a failure to collect waste were making a cholera outbreak in the capital worse.
"When cholera strikes a major metropolis such as Harare, we need to work fast to stop the spread of the disease before it gets out of control", Matshidiso Moeti, WHO regional director for Africa, said in a statement.
Authorities say there are more than 3,000 suspected cases of cholera with some 45 confirmed.
"The current cholera epidemic is a awful outcome of Zimbabwe's failure to invest in and manage both its basic water and sanitation infrastructure and its health care system".
Residents in some Harare suburbs have gone for months without tap water, forcing them to dig shallow wells and boreholes that have been contaminated by raw sewage flowing from burst pipes.
The EU has just passed a controversial overhaul of copyright law
To be clear, the United Kingdom leaving the European Union will not protect United Kingdom businesses from these new requirements. A final deal will be discussed with member states, before being put to a final vote in January 2019.
"As the government itself has now admitted, this is a national disaster which requires an immediate and effective response".
A total of 4,000 people died and at least 100,000 people fell ill.
The outbreak represents the first serious public health emergency for President Emmerson Mnangagwa following his disputed election at the end of July.
The Government of Zimbabwe has declared a state of emergency and is working with global partners to rapidly expand recommended cholera response actions, including increasing access to clean and safe water in the most affected communities and decommissioning contaminated water supplies.
Amnesty International castigated the authorities for failing to invest in and manage basic water, sanitation and health care systems even after the 2008 outbreak.
She urged the Mnangagwa administration to "learn from its predecessor's mistakes" and act urgently before more lives are lost.
UNICEF advised Zimbabweans to prevent cholera spreading by regular hand-washing, drinking only safe water, washing food, cooking it throughly and avoiding shaking hands.