A Ministry of Health variant update report released last week showed all 79 cases sequenced between July 19 and August 9 reported by ESR were the highly infectious variant.
The Delta variant is the most transmissible variant to date, spreading a lot more easily than the original version of the Covid-19 virus, prompting Covid-19 Response Minister Chris Hipkins to warn a community outbreak would result in a “short, sharp” level 4 lockdown.
Meanwhile, the ministry is advising people to maintain precautionary public health measures, including wearing face coverings on public transport and indoors in “busy places” such as supermarkets.
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During this three-week period, New Zealand saw an average of 303,000 active daily users of the Covid Tracer App – just one in 10 of the 2.9 million registered users.
Delta can cause people to develop more serious Covid-19 illness than other variants of the virus, and people with Delta infection are at a higher risk of needing hospitalisation, the ministry says.
The chance of infecting others, such as within your household or other contacts, is very high.
It is estimated that on average, one person with the Delta variant may infect five or six other people.
The incubation period – the time from exposure to the virus, until very infectious – tends to be shorter with the Delta variant, only about four days.
And people sick with the variant seem to carry “much more” virus for longer than those with the original virus or other variants.
A Ministry of Health spokesman said it has “always encouraged” people to use face coverings in busy indoor places if it makes them feel safer – “we have now given supermarkets as an example” of such a place.
“We encourage people to consider wearing face coverings when you cannot maintain physical distance in crowded indoor places,” the spokesman said.
This currently also includes retail settings, he said.
Face coverings remain mandatory on all public transport and on flights.
They should be used alongside other precautions: scanning, staying at home if sick, hand hygiene, covering coughs and getting tested if sick.
The spokesman said the ministry also want to urge people to scan in wherever they go, using the Covid Tracer App.
This remains “as important” at level one as at other levels, because it means contact tracers can rapidly trace contacts should there be a community case.
Early detection of cases and “swift” contact tracing will be “critical” due to Delta’s shorter incubation period, the ministry says.
Other recommended public health measures include social distancing of two metres where possible, and keeping indoor rooms well ventilated by opening windows and doors, the ministry website states.