Long Covid and symptoms that linger well after a person has "recovered" from the virus will soon become a "significant health burden" in Aotearoa, a researcher warns.

Emeritus Professor Warren Tate said the overall symptomology of Chronic Fatigue Syndrome (CFS), also known as Myalgic Encephalomyelitis (ME), and long Covid suggests they're very similar.

And Tate said those with long Covid were coming up against the same issues people with ME/CFS do.

"We're still hearing that people with long Covid now in New Zealand, and their concerns, are being dismissed just like ME/CFS patients have experienced in the past.

"I am concerned particularly as day by day, we're notching up 100 cases a day, so on the basis of what the world experiences [which is] that up to 30 per cent of people getting long Covid will have an ongoing illness of some sort."

He said this means about 20 to 30 of those people will have some ongoing illness.

Up until now, Tate said New Zealand has been lucky because we haven't been having that many long Covid cases, however, there is a small but growing group.

"Very rapidly this number will grow and it can become a significant ongoing health burden, not only for the health system, but also for families and their communities."

A 22-year-old Auckland man, who got the virus in mid-August, told the Herald he is now one of those people suffering long Covid.

The man, who spoke on the condition of anonymity, said after the initial infection it kind of "went away" and he was living relatively normally.

But about two months from the initial infection the man said he started experiencing long Covid symptoms.

The man isn't working at the moment and said each day he spends about 13 to 14 hours in bed.

"You're exhausted, you can't really do anything, it's very incapacitating. Whenever I tell my friends I've got long Covid, they're like 'what's that?' No one really knows what it is."

He felt fortunate that his illness wasn't as bad as others, and that he had support by living with his mum.

"This exists... I don't think anyone knows it exists, when it comes to concerns of catching Covid no one is really thinking about this, I didn't think about this.

Tate told the Herald his personal feeling was that long Covid and ME/CFS were the same illness, however the critical difference will be that those with long Covid originally had a Covid infection.

"Whereas ME/CFS comes from a number of different viruses and other stressor events."

He said they now have to find out whether there are major differences in the molecular pathways.

"The World Health Organisation has actually come out now with a clinical case definition for long covid and it's virtually identical for what is accepted for ME/CFS."

At the moment he's looking at ME/CFS DNA and proteins to see if the same signatures are there in long covid.

Although Tate said the increase of long Covid is sad, he said there will be much more attention on ME/CFS due to long covid.

"ME/CFS people have found it really difficult to access social services and the support systems they needed. That's the experience, and we hope long Covid will jump-start to make sure they get really good services."

In a statement, a Ministry of Health spokesperson told the Herald the agency had recently updated its long Covid guidance.

"At this time, there's limited well-evidenced and tested information about long Covid, and we appreciate that this can be difficult for some people who experience symptoms."

The ministry said it was continuing to monitor and evaluate new evidence about the effects of Covid-19 including the health impacts of long Covid.

"This includes reviewing the currently available literature about long Covid, with the intent of bringing together clinical experts to further update our guidance material for rehabilitation of both acute and long Covid once the review is complete."