“That's four cases linked to Ironside State School including one teacher, two cases to Indooroopilly State High School, one case linked to Brisbane Boys Grammar and nine cases that are close contacts or family members of cases already identified in the cluster,\" he said. “That brings this outbreak to 63 genomically linked cases meaning that in less than a week, this has become our biggest outbreak since the first wave last year. “That's four cases linked to Ironside State ...Queensland is in the grips of the most significant Covid-19 outbreak it has faced since the very beginning of the pandemic, after 17 new local cases were recorded on Wednesday. Authorities have resigned themselves to the fact that they “may never know” how the Brisbane outbreak started, and that it’s possible the missing link might never be discovered. Of the new cases, 16 are linked to the Brisbane schools cluster, which began last week when an Indooroopilly State High School student tested positive.