Mr Sharp said already more positive cases have been recorded and are expected to be added to tomorrow's numbers.
"Already today we're seeing there's more positive cases...that means the virus is still spreading in the community. That's a concern," he said.
"Anyone who has symptoms, no matter how mild, needs to get tested straight away.
"There is a delay between when people have their first have the onset of their symptoms (and get tested)...on average it can be two or three days until they get tested."
Mr Sharp said this was leading to "greater opportunity for them to be spreading coronavirus".
There are three exposure sites in particular GV Health are concerned about: SkySalon Hairdressing between August 15 and 19, the community centre at Central Park Rec reserve between August 13 and 19, and the Ian McLennan Centre from August 13 to 19.
"If you've been to an exposure site, get tested," Mr Sharp said.
"We're not getting the numbers we would like coming forward from those exposure sites."
From tomorrow people who have been to a Tier 1 exposure site and sent into 14-day quarantine will begin to present for day 13 testing.
Mr Sharp said he is confident the system can cope with the testing surge.
"At this stage the numbers we are planning for the peak day 13, which is Thursday, is about 1500 primary close contacts. On our busiest days towards the middle of last week we were able to cope with 3500 tests...We're confident we can deal with that demand, but there may be some queues," he said.
He said further information would be forth coming about how day 13 testing will be carried out via schools, community leaders and the GV Health Facebook pages.
Yesterday, Victorian COVID-19 commander Jeroen Weimar "in the space of six or seven days (the Shepparton outbreak) has come under control - at a huge cost to the Shepparton community in doing so."
While Mr Sharp agreed the situation was "controlled", he said it's not yet "under control", setting a target of zero new cases for several days in a row before being able to say the outbreak has been squashed.
"We are still having relatively higher numbers of people testing positive," he said.
"While we're still having positive results that is concerning."
Mr Sharp said he believed all the people who tested positive yesterday were in isolation, but that contact tracing was continuing to link two cases to the current outbreak.
Mr Sharp implored those in quarantine to stay the course, with many nearing the end of their 14-day quarantine.
"If you break your quarantine during the current 14 day period, you will have a reset," he said.
"While it might be tempting, and I know it is difficult for people to stay at home...I can only encourage people to hang in there."
The relief effort for those in isolation is continuing, with agencies working to ensure that households have access to food and essential goods throughout their quarantine periods.
Ms Abbott said 700 households received relief yesterday, including 270 Halal relief packs.
"This is only a snapshot of what those multitudes of agencies are doing," Ms Abbott said.
A total of 530 GV Health staff remain furloughed, with 17 returning to work from today. Mr Sharp thanked the remaining staff for working to maintain services during the outbreak.
He said the hospital is continuing to vaccinate hundreds of people a day, with further discussion about whether the opening hours of the GV Health vaccination hub at the Shepparton Showgrounds can be extended.
Our sister-site The Shepparton News is maintaining daily rolling coverage. Today's coverage available here.
