Director of health Ashley Bloomfield, who, on most days, reads the numbers that will define how the rest of this year plays out (Illustration: Simon Chesterman)

Covid-19: New Zealand cases mapped and charted, April 29

The latest in our series of charts, graphics and data visualisations by Chris McDowall. David Garcia worked with Chris to create today’s charts.

This work is entirely funded by the generosity of The Spinoff Members, with support from the Science Media Centre

These posts collate the most recent statistics and present them as charts and maps. The Ministry of Health typically publishes data updates in the early afternoon, which describe the situation at 9am on the day of release. These data visualisations are interactive so use your mouse or thumb to hover over each graph for more detail.

This afternoon’s Ministry of Health figures report that the total number of confirmed and probable Covid-19 cases increased by two to 1,474 (1,126 confirmed and 348 probable). A total of 1,229 people have recovered, an increase of 15 since yesterday. There were no further deaths overnight.

The number of significant clusters with 10 or more cases remains at 16. There are six people in hospital, which is a decrease of three since yesterday. For the first time in many days, there are no known Covid-19 cases in intensive care units.

Yesterday, 2,637 tests were processed. The ministry reported averaging 4,844 Covid-19 lab tests per day during the week ending April 28. A total of 128,703 lab tests have been conducted since January 22. There are 64,442 test supplies in stock, down from 66,322 yesterday.

One of the statistics I keep an eye on is the number of testing supplies that New Zealand has in stock. The ministry reports this as a snapshot count each day. This afternoon, I trawled back through the Internet Archive to reconstruct the last three weeks of daily counts. Those numbers are shown the line chart above. The data shows a gradual increase in capacity between April 9 and April 17. On April 18 the ministry reported a sharp jump from 67,702 to 94,820 testing supplies in stock. From this peak there has been steady decline in the daily supply counts. I will watch this number with interest over the days to see whether stocks are replenished.

This chart compares active and recovered cases. Active cases are confirmed or probable cases of Covid-19 where the person has neither recovered nor died. Recovered cases are people who were once an active case, but are at least 10 days since onset and have not exhibited any symptoms for 48 hours.

The overall downward trend of active case counts that started around April 8 continues. Note how the blue curve is levelling off, while the purple bars continue to decline. This means there are very few new cases being reported while existing cases steadily recover.

The symbol map shows confirmed and probable Covid-19 cases arranged by district health board. In keeping with the relatively small number of new cases, there is minimal change in regional counts. Waitematā (no change at 223), Southern (no change at 216), Waikato (up one to 187) and Auckland (down one to 172) remain the four district health boards with the largest number of active cases.

The Auckland decrease is due to a case getting reclassified to another district health board.

There are 16 significant clusters under investigation by the Ministry of Health. No new cases reported in any of these clusters in the last 24 hours.

This chart shows the number of active, recovered and deaths associated with each cluster. The ministry has not released formal counts associating deceased persons with clusters. Instead, we compiled these numbers from ministry media releases about each case.

In most clusters the number of recovered cases outweighs the number of active cases. Three clusters buck this trend. Both Auckland residential care facilities and the Rosewood aged care cluster in Christchurch all have more active than recovered cases.

This chart shows cases by the date they were first entered into EpiSurv, ESR’s public health surveillance system. Note that the number of cases reported on a particular date may not match the number of cases reported in the last 24 hours. This is because the number of confirmed and probable cases reported in the last 24 hours includes cases that were entered on an earlier date as “under investigation” or “suspected” whose status has now been changed to confirmed or probable.

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