Tshwane Mayor Nasiphi Moya this week rejected a claim by her predecessor, Cilliers Brink, that cholera bacteria had been found in Bronkhorstspruit, in eastern Tshwane, where 408 people, most of them children under four, have fallen ill with diarrhoea and stomach cramps since early October.

Water and Sanitation Minister Pemmy Majodina said the Bronkhorstspruit Water Treatment Works, which supplies the town and surrounding areas east of Pretoria, sent out unchlorinated water from 24 September to 14 October after the City ran into problems with its chlorine supply. Tests on 14 October found very high levels of E. coli, a sign of sewage contamination, at the plant and in two reservoirs. Moya said the supplier had quadrupled its price and officials had not told the City’s leaders. “We take responsibility for the negligence,” she said. No deaths have been reported. Residents have been advised to use tap water only to flush toilets.

Brink, the Democratic Alliance (DA) mayor until September 2024 and now its candidate for the 4 November local elections, first raised the chlorine failure on 16 October, citing a whistleblower. On Monday he said a whistleblower had also reported cholera bacteria in samples from the town’s sewage works. “Residents have a right to know whether their water is safe to drink,” he said. The DA opened a criminal case against the City at Pretoria Central police station.

“Let me be absolutely clear: cholera has not been identified as the cause of the gastrointestinal illness outbreak in Bronkhorstspruit,” Moya said. She said a variant of Vibrio cholerae, the bacterium behind cholera, had been found in water samples, but not the variant that causes epidemic cholera.

The Water Research Commission is investigating how contaminated water reached homes and is due to report by Wednesday next week. No date has been set for when tap water will be safe to drink.