NSW Food Authority: How did this outbreak happen? The investigation found that the contamination is likely to have occurred due to adverse weather (localised storm over the farm and subsequent dust storms during the season) increasing the levels of Listeria on the fruit prior to harvest. On this occasion and despite following industry best practice, the washing and sanitising at Rombola Family Farms was not able to remove all the trapped bacteria from the rockmelon surfaces, resulting in a low level of Listeria being present.

Read the full summary at the NSW Food Authority website