There has been an increase in cases of diarrhoea among children under the age of five in Cape Town, a city health official said amid fears that good hygiene might be taking a back seat to water saving efforts to avoid Day Zero.
"On 28 January 2018, these were the statistics for the diarrhoea surge season in children under five: 9 019 cases recorded compared to 8 287 last year and 10 614 the year before," said Doctor Virginia De Azevedo, a manager in the city's department of public health on Tuesday in response to a request for information.
The city regards the period between November and May as "surge season" for diarrhoea and pneumonia due to the prevalence of certain contagious diseases when temperatures rise.
At the #DayZero media briefing on Monday JP Smith, member of the mayoral committee for safety and security, said the city did not want to lose the gains it had made in protecting children under five from diarrhoea.
On Monday the city's health officials urged residents and visitors to treat water as precious but to keep washing their hands regularly and bathing themselves with clean drinking water, even though there is a restriction of 50l per person per day in force.
People are currently being encouraged to save as much drinking water as possible, and to reuse the "grey" water collected from washing and bathing where possible to bring the city's overall water consumption down to 450 million litres a day, from 547 million litres.
Use of clean water encouraged
The city is also reducing water pressure in some areas. There may be disruptions to water supply during the installation of the equipment needed to do this.
Taps at many public and private facilities such as schools and shopping centres have been switched off, with only hand sanitiser available, or one tap with a thin stream of water.
However, the health department stressed that in spite of the water shortage, it is important to use clean drinking water supplied by the city to wash hands, bathe, cook, clean surfaces and for food preparation.
Grey water that has been saved from other household activities such as laundry, cleaning and washing dishes should never be reused for hand washing, bathing, food preparation, cooking and surface cleaning.
Grey water for flushing toilets should not be kept for longer than 24 hours because of the risk of bacteria and contaminants.
Food should not be kept in the open for long periods, and if there is no fridge available for storage, only cook what you need for one meal.
The city said on Tuesday that the number of cases per month of listeriosis had also increased from 11 in December 2017 to 12 in January 2018. The total for 2017 for the city was 38 cases.
For February only one case of listeriosis has been reported so far. Listeria bacteria can be found in soil, water and vegetation in nature, and the disease is treatable. The national Department of Health raised the alarm last year when it said the "usual" average of between 60 to 80 cases nationally had increased to 557 for 2017 (until 9 November).
Most of those cases, 345, were in Gauteng and 71 in the Western Cape.
In 2016 there were 32 cases of typhoid in the city, which dropped to 26 in 2017. In January there were three cases compared with one in January 2017, and six in January 2016. Figures for cholera and pneumonia were not yet available.
Officials warned that water from boreholes and springs and rainwater is also not suitable for drinking, cooking or bathing.
The city's health department works with the Western Cape health department and has to notify the National Institute of Communicable Diseases of water- and food-borne diseases such as listeria, cholera and food poisoning involving more than four people at once.