Local authorities have been urged to be on high alert for a possible national cholera outbreak after the disease was reported in Chiredzi and Manicaland.
Harare City Council has started treating all diarrhoea cases free of charge and as potential cholera cases.
The city was hardest hit by the 2008 cholera outbreak that claimed 4 211 lives countrywide.
So far, 23 cases of suspected cholera have been reported - 22 in Chiredzi and one in Manicaland.
Health and Child Welfare Ministry head of epidemiology and disease control Dr Portia Manangazira confirmed the cases.
Out of 22 cases recorded in Chiredzi, 10 were positive for cholera, while the Manicaland case was also positive.
"We are monitoring the situation very closely to make sure the cholera does not spread. The health sector is on high alert," she said.
Dr Manangazira said the Ministry was appealing for Government intervention and funding to address water and sanitation issues.
This comes after the realisation that without ensuring access to safe drinking water and proper sanitation, the cholera threat will always be there.
She said there was need to address water and sanitation woes if the country was to eradicate cholera and typhoid.
"We are appealing to Government to assist local authorities to improve their water and sanitation facilities," she said.
Harare health services director Dr Prosper Chonzi confirmed council had activated its surveillance system "because Chiredzi is just one bus trip away from Harare".
He said the city was treating acute watery diarrhoea cases as suspected cholera cases.
"We are treating all diarrhoea cases for free. At the moment we have not had any cholera case," he said.
The cholera threat has coincided with the city's calls for residents to use water sparingly in the face of acute shortages.
This week, some parts of the city have been without water, especially in the eastern suburbs.
Harare Water director Engineer Christopher Zvobgo said the situation in parts of the eastern suburbs, especially Mandara and Greendale, is expected to improve today following the installation of a new transformer at Letombo water reservoirs.
"We have portions of eastern suburbs without water. Mabvuku and Tafara have water," he said.
Water and sanitation experts have confirmed that the city's sanitation coverage has plummeted from 95 percent to around 60 percent, a development that can fuel the outbreak of cholera and typhoid.
To compound the situation, mounds of garbage have been piling in some residential areas because council is not collecting refuse.
Harare produces on average 620 million litres of water everyday against a demand of 1 200 million litres.
This means half the city population is without water if no strict water demand management scheme is in place.
Executive director of the Institute for Water and Sanitation Development Mrs Noma Neseni said sanitation coverage for Harare had drastically fallen to 60 percent from about 95 percent prior 2000.
She said some households in Harare were using "flying toilets" which explains why at dumpsites one can find human waste wrapped in papers.
Mrs Neseni said pampers were polluting water as they and other solid waste always find their way into water bodies.
Pampers might have human waste which causes cholera.
She said water bodies were full of used condoms, pampers and sanitary pads, suggesting that such waste should be sorted at the household level.