Flu cases waning in Waikato

Data shows the number of people plagued by the flu is on the decline, but the winter sickness period is not over just yet.

A Te Whatu Ora Waikato report on respiratory viruses says Influenza A, the prevalent strain of flu in New Zealand, has peaked and cases will now start to decline.

But the numbers of people with the BA.5 strain of Covid-19 and RSV are building – and there is a chance other respiratory viruses could still be on their way.

High numbers of people were still reporting a fever and cough, but the flu hit its peak two or three weeks ago, Director of the World Health Organisation National Influenza centre at ESR Dr Sue Huang said.

But other strains of influenza – circulating at a lower level – could still peak, she said.

‘‘We need to monitor closely throughout the winter.’’

It had been much worse this year because there had been no flu in the country for two years, Huang said.

‘‘I’ve been 20 years working on the flu. We always have a flu, but there wasn’t.’’

The borders were shut, the few people entering the country were isolated, and people with flu-like symptoms stayed home.

‘‘That population didn’t build up enough immunity because of the last two years, she said.

This meant more people were susceptible to the flu infection this year and as a result it had come earlier, and hit people harder.

Huang said the flu was worst in June this year, compared to the usual time of July or August.

But the good news was the flu vaccine matched the strains of flu circulating this year, she said.

‘‘It’s not too late to get the flu vaccine. That is the most effective way to prevent the flu and related illness.’’

Wearing masks, social distancing and staying home if unwell were still great tools for avoiding respiratory illness.

Despite this, Huang said Covid-19 cases were rising again.

The seven-day rolling average number of cases yesterday was 9803, up from 9000 a week ago.

There are 733 people in hospital with the virus, including 16 who are in intensive care or high dependency units.

Huang said the BA.5 strain of Covid-19 was a new and mutated variant, and was good at evading people’s already developed immune response.

This meant the vaccine was less effective in protecting against it, she said.

RSV hadn’t been as bad this year, but usually peaked after the flu, Huang said.

There were high numbers of cases last year, which came from an off-season outbreak in Australia.

This meant that a group of people had built immunity.

Te Whanau Ora Waikato Laboratory clinical microbiologist Dr Chris Mansell said, in the report, it was Influenza A H3N2 that had hit its peak. But different variants may be yet to circulate later in the winter.

‘‘A diversity of other viruses is also present, with the rhinoviruses, adenoviruses, human metapneumovirus and para influenza virus 4 all circulating.’’

‘‘It’s not too late to get the flu vaccine. That is the most effective way to prevent the flu and related illness.’’

Dr Sue Huang