Close contacts to the Brooklyn abattoir staff are among four new cases recorded in Victoria on Thursday.

The state's coronavirus tally is now 1581, with 88 active cases, 10 people in hospital, including five people in intensive care.

Fortunately Police Minister Lisa Neville said there were no new cases in aged care.

But a woman at HammondCare's Caulfield Village dementia facility is due to receive the results of a COVID-19 test today after she was tested a third time.

The facility went into lockdown after the woman tested positive on Monday before a second swab came back negative the following day.

She has now been tested for a third time.

HammondCare chief executive Stephen Judd said yesterday the woman was "doing really well" despite a cough that prompted the testing.

More than 150 staff and residents have tested negative.

Three aged care homes were put in lockdown after residents tested positive.

A resident from Villa Maria Aged Care Home in Bundoora went to hospital at the weekend with a fever, but more tests were negative.

A resident at Lynden Aged Care at Camberwell was diagnosed with COVID-19 while being treated at a metropolitan hospital, prompting the facility to also shut its doors to visitors on Tuesday.

A Doherty Institute for Infection and Immunity study released this week showed Victoria had 76 distinct clusters by April 14.

Researchers made the finding through genetic analysis of samples from 903 coronavirus patients, which was about 75 per cent of the state's cases at that time.

Of the cases sampled, the majority (737) of people were linked with social venues, healthcare facilities and cruise ships.

- With AAP

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