“The tests were negative, so cholera has been excluded now,” Professor Lucille Blumberg told Sapa.
“The source of the problem is contaminated water and that needs to be fixed.”
The institute was conducting more tests to check for other viruses, like gastroenteritis.
Gastroenteritis (infectious diarrhoea) is a condition characterised by inflammation of an intestinal tract which results in diarrhoea, vomiting, abdominal pain and cramping. Gastroenteritis is referred to as gastro, stomach bug, and stomach virus.
Earlier, the North West health department confirmed that two more babies had died from diarrhoea in Bloemhof, where water contamination left the town without water last week.
“One baby was seven-months-old and the other was 13-months-old,” said spokesman Tebogo Lekgethwane.
The circumstances surrounding their deaths were similar to the first baby that died last Wednesday, he said.
Dozens of residents went to local clinics to be examined last week following the contamination. Five babies were admitted to hospital for observation.
The Lekwa-Teemane municipality shut down its water supply system more than a week ago. The national water affairs department on Friday said the system had been cleaned and sanitised, and water was restored on Thursday evening.
But residents said the water coming out of taps was still brown on Friday, and residents were asked to boil the water first before using it.
Water samples were taken for testing. On Sunday, Water and Sanitation Minister Nomvula Mokonyane visited the area. Her spokeswoman Nomvula Khalo told Sapa she expected to receive the results on Monday afternoon.
Meanwhile, civil rights group Afriforum conducted its own water tests.
“We haven’t received the results yet. We expect it by tomorrow [Tuesday] or Wednesday,” said Afriforum North West co-ordinator Carmea Huysamen.