Unknown extent of spread a ‘nightmare’

New Zealand could face a ‘‘messy’’ future in detecting and managing long Covid in people, given the full extent of infections is unknown.

Last week, Aotearoa recorded a million confirmed Covid-19 cases. However, modelling suggests the true number of infections could be 2-4 times higher. The World Health Organisation estimates 10-20% of people with Covid-19 experience mid-and long-term effects. If that’s the case, up to 200,000 Kiwis could be affected by long Covid. But if we’re counting infections we don’t know about, more than three-quarters of a million people may be impacted.

Aotearoa’s long Covid mass is going to come from Omicron, University of Auckland cellular immunologist and leading long Covid researcher, Dr Anna

Brooks, says. But how we navigate this, taking into account that the number of infections is likely a magnitude higher than reported, is going to be a ‘‘nightmare’’ given medical management of post-viral illnesses has been largely ‘‘neglected’’ historically.

Data from the UK’s Office for National Statistics shows that among triple-vaccinated adults, self-reported long Covid from Omicron BA.2 (making up most of Aotearoa’s Omicron wave) hovers at about one in 10 people (9.3%). Among double-vaccinated adults with Delta, this rose to 15.9%.

Even if just 1% of people infected develop long Covid, ‘‘that’s a lot of people,’’ Brooks says.

Brooks said if a person is experiencing symptoms they believe could be long Covid, but don’t know they were infected, they can ask their doctor to be tested for an historical infection. However, this comes with a price

tag, which won’t be accessible for everyone.

Brooks says we need a pathway when a doctor suspects a person has long Covid if you think or know you had Covid-19 (even if a RAT was negative): ‘‘we should be pushing for that’’.

You don’t want long Covid concerns to be dismissed, but you also don’t want a situation where every niggling condition is lumped into being long Covidrelated, and other conditions are missed.

‘‘We’ve got a giant mess ahead of us.’’

There is hope if we invest in the ‘‘huge demand’’ for research, which could see, for example, cellular biomarker tests for all post-infection illnesses, including long Covid developed, she says.

But until research advances, all doctors can do is check for severe symptoms – such as heart and lung issues – and manage them. ‘‘There’s nothing else we can do in terms of treatments’’.

‘‘There’s no magic bullet to cure long Covid, which is why the message, fiercely, is: don’t get it.’’

New Zealand Institute of Medical Laboratory Scientists president Terry Taylor says there is evidence some serology tests could detect prior Covid-19 infection for up to 12 months, but we don’t yet have 12 months worth of data to draw on for Delta or Omicron to know for sure.

Serology testing also isn’t foolproof and Taylor said scientists are pushing for a change in approach to serology testing.

‘‘There’s no magic bullet to cure long Covid, which is why the message, fiercely, is: don’t get it.’’

Dr Anna Brooks

University of Auckland cellular immunologist