Canterbury health officials say the case of four children who fell ill after drinking raw milk on a school trip to a farm shows the danger of consuming untreated dairy products.
Two of the children from a Timaru school had to be hospitalised and tests have since confirmed their illness was caused by the bug E. coli, which causes bloody diarrhoea, nausea and vomiting.
South Canterbury medical officer of health Daniel Williams says it's unfortunate people are told to buy unpasteurised milk for health reasons.
"It's one of the least safe foods that you can buy. You wouldn't suggest that people eat raw chicken - I wouldn't recommend that people drink raw milk."
Dr Williams told Radio New Zealand's Checkpoint programme on Friday this case is a wake-up call for everyone.
Listen to Daniel Williams