The highly infectious cases emerged almost a year to the day City of Ballarat residents were declared COVID-free.

Previously, the last new COVID case for a Ballarat resident had been recorded on August 24, 2020. The last active case was on September 9, 2020.

A construction worker, who lives in Ballarat and works in Melbourne, and a child have been reported COVID-positive on Tuesday. It has not been confirmed whether the pair are related.

The Lake View Hotel and Ballarat Clarendon College were quick to name themselves as exposure sites by Tuesday afternoon ahead of the Victorian health department's official listings.

The Forge Pizzeria on Armstrong Street and Big W were added as exposure sites by late afternoon.

Forge director Tim Matthews was also quick to respond and take a proactive stance in spreading the word.

"We've informed all staff that were working at the time and the Department of Health will be in touch with any customers who signed in during the times listed," Mr Matthews said.

"The deep clean will be finished [Wednesday] and we'll continue to work with the Grampians Public Health Team to follow the right steps."

IN COVID NEWS

City of Ballarat mayor Daniel Moloney and City chief executive Evan King called for calm as Delta hit.

They said how we managed our response as a community, still taking all COVID precautions, was going to be vital.

"We have gone just over a year without a positive case in Ballarat and that's a combination of good management but also good luck and the luck won't hold forever," Cr Moloney said.

The Courier understands The Lake View Hotel was exposed to an active COVID case three times on Thursday and Friday, early on both mornings and again late Friday morning.

College principal David Shepherd issued a letter to parents on Tuesday stating a child in the early learning centre, on the Mair Street campus, had tested positive to the virus.

The child was in class on Friday, the school's last day before holidays and first day with grades prep to two back on site.

The Forge in Armstrong Street had a case visit mid-afternoon on Saturday while Big W had a case attend its store late Friday afternoon

Until now, the region's only exposure to the deadly Delta strain had been three cases in the past fortnight, all arriving from Melbourne unknowingly infected: a nursing student at Australian Catholic University, a Daylesford hospitality staffer and a disability carer working overnight in a residential facility.

Grampians Public Health Unit medical director Rosemary Aldrich this week said the Daylesford case had been a good example of how individual precautions, workplace precautions and medical response had stopped the virus' spread.

Ballarat Health Services has confirmed on Tuesday it was now was working to support a Ballarat resident who had contracted COVID-19 and was isolating at home.

BHS and Grampians Public Health Unit were conducting contact tracing.

"It remains extremely important that anyone - no matter where they live - with even the mildest of symptoms be tested for COVID-19, and stay home until they can be tested, and until they receive their results," a BHS statement read.

The case was identified as a construction worker in Tuesday morning's state government press conference.

Construction workers have come under fire from the Victorian government this week as major sources of transmission, particularly due to the workforce's mobile nature across sites and with widespread home bases.

Community and state health leaders also appealled to authorised workers to take greater care in moving between metropolitan areas and regional Victoria.

City of Ballarat chief executive Evan King, in a lengthy public statement, said this was not a time for panic.

Mr King said the City continued to work closely with Ballarat Health Services and community partners through pandemic challenges and it was important everyone look after each other and follow the latest health advice.

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