Adrian Esterman, University of South Australia

Victoria has recorded 288 new COVID-19 cases since yesterday, the largest daily increase we’ve seen so far.

This big jump must have the Victorian government and health authorities very concerned, especially since nearly all of these cases are under investigation, with many likely having no known source of infection.

This rapid spike in numbers is likely to be an extension of the outbreak that began with the private security guard bungle at the quarantine hotels.

The progression of this outbreak was probably compounded when nearly 1,000 people refused testing during the recent testing blitz in hotspot areas.

What will happen next?

Once a person has been infected with SARS-CoV-2, the coronavirus that causes COVID-19, it can generally take up to 14 days for symptoms to appear (if they do at all).

So cases are likely to keep increasing for the next couple of weeks, until the reintroduced restrictions take effect.

Notably, nearly half of current cases are among people under 30. This probably has a lot to do with the spread of infection within families.

It’s a positive step that residents of Melbourne’s public housing towers who have tested positive for COVID-19 will be offered the option of hotel quarantine until they are well. As much as possible, to prevent spread in families, any infected person living in crowded conditions should be moved to hospital or hotel quarantine.

Knuckling down

The Victorian government has made the right move in reintroducing restrictions and now needs to pull out all stops to crush the current outbreak.

They have today taken the step of advising people in Melbourne to wear masks when they may not be able to practise physical distancing.

It’s also essential the government presents clear messaging around why the restrictions are needed, especially to communities from non-English-speaking backgrounds.

At the same time, they may need to get stricter in enforcing the various facets of their strategy. They should not allow people to refuse testing and should limit exemptions to restrictions as much as possible.

Any person found to be a contact of an infected person should be tested on entry into 14 days quarantine, and then tested again towards the end.

Will Victoria’s woes spread to other states and territories?

New South Wales and South Australia have now closed their borders with Victoria. Nonetheless, there are still many people living near Victorian border areas being granted exemptions.

Because there have been no community-acquired cases in these border areas (there was a recent case in Albury, but he was a contact of a known case), the risk at the moment is not high.

However, in the next couple of weeks, if we see community transmissions spreading outside the current greater Melbourne area, the provision of these exemptions should be re-evaluated.

I have suggested a possible strategy might be to incorporate these Victorian border towns into the states they are close to, just for the period of the epidemic. For example, to make Mildura part of South Australia and Wodonga part of New South Wales. This would be much more convenient for the populations affected, and much easier to police.

There are already epidemiologists who believe New South Wales should reimpose restrictions — though perhaps not as severe as those in Victoria — to eliminate the current steady drip of infections. I think it might be a little bit early for that, but as we’ve seen from the current situation in Victoria, it’s better to be early than late.

In the meantime, all other states and territories should be offering support to Victoria, particularly in lending staff for contact tracing.

Adrian Esterman, Professor of Biostatistics, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.