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Director general of health Ashley Bloomfield (Illustration: Simon Chesterman)
Director general of health Ashley Bloomfield (Illustration: Simon Chesterman)

ScienceApril 7, 2020

Covid-19: New Zealand cases mapped and charted, April 7

Director general of health Ashley Bloomfield (Illustration: Simon Chesterman)
Director general of health Ashley Bloomfield (Illustration: Simon Chesterman)

The latest in our new series of charts, graphics and data visualisations by Chris McDowall.

This work is entirely funded by the generosity of The Spinoff Members

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 – use your mouse or thumb to hover over each graph for more detail.

Note for users of The Spinoff App: if the charts below are not appearing, please click here to launch in a separate browser window. An update is imminent!

This afternoon’s Ministry of Health figures report that the total number of confirmed and probable Covid-19 cases stands at 1,160 (943 confirmed and 217 probable). A total of 241 people have recovered, an increase of 65 since yesterday. For the first time the number of people who have recovered in the last 24 hours was greater than the number of new confirmed/probable cases.

Yesterday 2,098 tests were processed. The ministry reported averaging 3,063 Covid-19 lab tests per day during the week ending April 6. A total of 42,826 lab tests have been conducted since March 9. There are 43,885 lab testing supplies in stock.

This chart compares active and recovered cases. Active cases are people who currently have the Covid-19 virus. Recovered cases are people who had the virus, but are at least 10 days since onset and have not exhibited any symptoms for 48 hours. Although the ministry does not supply the number of active cases, we can calculate it with the following formula:


Today is the first time we have seen a slight drop in the number of active cases — from 929 active cases yesterday to 918 this morning. As there have been no further deaths relating to Covid-19, all of these people are now in the recovered category.

Ashley Bloomfield, director general of health, noted that these “signs are promising”. He cautioned that we are not in the clear yet and people need to continue adhering to level four precautions.

The symbol map shows confirmed and probable Covid-19 cases arranged by district health board. Southern (187), Waitematā (160), Waikato (156) and Auckland (153) remain the four district health boards with the largest number of active cases.

Most of the attention goes to health boards with relatively large numbers of cases. This table shows the counts for all localities. Twelve health boards recorded increases in the number of confirmed/probable cases in the last 24 hours, seven reported no change and one district reported a decrease. The decrease in Whanganui was presumably due to a probable diagnosis proving negative after testing.

Please do not interpret these statistics to imply that any district is “in the clear”. A single contagion could grow quickly into a cluster, especially if people relax physical distancing precautions.

There are still 12 significant clusters under investigation. The largest increase was in the Bluff wedding cluster, which grew from 62 to 73 cases overnight.

The time series chart showing confirmed and probable cases based on the “date of report” also looks promising. Remember, though, that the bars near the righthand side of the chart may get backfilled in the coming days as potential cases get upgraded to probable or confirmed.

The shape of the age profile breakdown looks similar to the last week of results with the 20-29 group accounting for roughly a quarter of all confirmed/probable cases. People aged 50-59 continue to be the second-largest age cohort, making up just over 16% of cases.

Keep going!