New Zealand is in the midst of its first wave of the omicron variant of covid-19.

Case numbers, hospitalisations, ICU admissions and deaths are currently at their highest point since the pandemic started two years ago, but total ICU admissions are low versus a total national number of ICU beds available, estimated to be about 185 beds.

Official case numbers are widely considered to be well below the actual numbers of infections with some experts, including covid response minister Chris Hipkins, believing the number to be as high as 100,000 cases per day.  

Likewise, not all hospital admissions are for the treatment of covid but many people tested positive during their stay, unaware they had the virus. Data from Waikato Hospital in March suggested just 19% of people in the hospital were there specifically for the treatment of covid.

The remainder were admitted for other reasons, such as surgery, a co-morbidity or childbirth.

Regional outbreaks

The outbreak is at different stages in different parts of the country, with the Auckland region being more advanced than other parts.

While many covid hospitalisations may be incidental, the numbers can give us a sense of the course of an outbreak in a specific region.

On a per-capita basis, the Northern region's (Auckland and Northland) outbreak is far advanced to other parts of the country.

DHB breakdown

Hospitalisations in the three Auckland DHBs (district health boards) are following a similar course.

Based on reported case numbers, a significant proportion of those in the Auckland DHBs are current active cases.

Vaccinations

About 73% of the population has received a booster, although only those 18 or older are eligible.

Booster rates vary from more than 80% in Wellington to 68% in Counties-Manukau DHB.

Those currently hospitalised in the Northern region are almost six times more likely to be unvaccinated, relative to their share of the total population.

However, according to the director general of Health, Dr Ashley Bloomfield, 84% of those in hospital purely for covid in the Auckland region are not boosted. 

This indicates that many of those who are boosted and in hospital are there for other reasons.