Surge in coronavirus infections in Victoria means that hospital system will be severely stressed tested over the next 2 weeks

 A Bitter Pill to swallow.

Today’s announcement by the Victorian health Department of a massive surge in coronavirus infections which are almost certainly mostly the Omicron variant raises many urgent questions.

The massive vaccination campaign in Victoria and particularly recent introduction of 3rd dose vaccination – the so-called boosters – offer some protection but the question is will it be enough?

One of the challenges is prediction of how much severe disease is occurring that will cause people to need hospital support.

Fortunately it’s possible to predict the future quite well because the most recently infected people will not need hospital until about 5 days after infection.

The following graph shows what’s happened so far in Victoria.

The daily cases of new infections reported are shown in blue and the hospital occupation number– how many people are present in the Victorian hospital system for treatment of severe Covid-19 illness – are shown in orange.

It covers the events of the last 2 years up to the most recent available official reports.

The main point is during most of the epidemic daily case numbers are an excellent predictor of  hospital numbers 13 days later. This is the time that most patients infected on the date mentioned would be about to leave hospital after a typical 8 day stay.

There are 2 extremely interesting features of the curve – the rapid rise in cases at the end of the period which is due to the Omicron variant and the more subtle departure of the orange curve from overlap with the blue curve in the last few months. This latter feature has been the subject of a discussion in several recent GMO pundit posts, and is the benefit of vaccination in reducing the chances of severe disease.

But clearly the number effect on new cases is dramatically larger than the protection effect of vaccination reflected in lower than expected hospital occupancy.

To understand better what these trends mean the the Pundit made some careful calculation of risk measures they can be used to anticipate how serious this upsurge might be for the hospital system. Here is a summary of those calculations:

The key take-home from this chart is that hospitalisation needs of new cases are dropping over time and the most recent value is much less serious of those in the early stages of the epidemic.

The numbers in columns IV and V can be used to estimate how much a load the most recent infections are going to cause the hospital system.

The latest daily figures are 20,000 to 50,000 new infections a day.

Using the numbers in the table, this indicates predicted hospital occupancy of 10,000 or more patients within 2 weeks. (eg. 40,000 cases/day time 0.34= 13,600)

As current numbers of hospital patients with severe Covid are “only” 644, this will necessarily be a severe stress to hospital workers, nurses, doctors, and support staff and the resources needed by these workers. 

There is no easy way to see this as anything other than a medical crisis, even if Pundit’s estimates are out by factors of 5 or so. And they may even be under estimates.