The number of COVID-19 cases linked to a wedding held in Bluff last month has now reached 53.

The figures were revealed in today’s national briefing by Director-General of Health Dr Ashley Bloomfield. The wedding is one of biggest of 10 significant clusters identified throughout the country.

Dr Bloomfield said the rising numbers associated with the wedding were not unexpected.

“What that represents is that all the close contacts have been identified, they’ve been self-isolated and been tested if they become symptomatic. So, I think it’s good that we are finding those cases because then we can take appropriate action.”

The total cases in New Zealand now stands at 868. There have been 49 new confirmed cases and 20 new probable cases since yesterday. Thirteen people are in hospital, one of whom is in intensive care. All are in a stable condition.

103 reported cases have recovered.

Laboratory testing for COVID-19 reached a high yesterday with 3446 tests processed. That brings the total number of lab tests to date to 29,485. New Zealand now has capacity to carry out more than 5400 tests each day.

“We have very good testing capacity, it’s spread around the country, it’s not reliant on a single platform and our testing criteria are now broad – in fact they’re as broad as pretty much any other country. And so we want to keep finding those cases and ensure we have capacity to do surveillance testing as well,” Dr Bloomfield said.

Confirmed cases were still showing strong links to overseas travel but the proportion of those had just dipped below 50% to 49%. Another 33% had close contact with a confirmed case. So far confirmed community transmission had occurred in just 1% of cases but 17% of cases were still under investigation and it was to be expected that many of those would end up confirmed as community transmission, Dr Bloomfield said.

He also quoted from a World Health Organisation situation report update, which spoke to current evidence around how COVID-19 was transmitted.

“The data from the published epidemiological and viralogical studies provide evidence that COVID-19 is clearly primarily transmitted from symptomatic people to others who are in close contact, by respiratory droplets, by direct contact with each other, or by contact with contaminated objects and surfaces,” he said.

“It seems that people are most infectious early on in the infection, that may be before or just as they are developing symptoms and for the first two or three days. The average time before people develop symptoms after they have come in contact with the virus is around five to six days.”

There had been a lot of speculation, and studies, around pre-symptomatic transmission. During the period when people were pre-symptomatic, some infected people could be contagious.

“So, it may be that people are infectious for one to three days before they develop symptoms.”

However, Dr Bloomfield noted that transmission occurred through the same routes as it did if people were symptomatic so the messaging was consistent. The same precautions would protect people: physical distancing, not going out if you were unwell and putting others at risk, good cough and sneeze etiquette, and meticulous hand washing, he said.

View the full briefing below.