Covid 19 Omicron: Reinfection within 90 days rare but possible, health advice says

Covid reinfection within 90 days is rare but can happen, new health advice says, and the Ministry of Health is urging vigilance over the colder months. Photo / Dean Purcell

Older New Zealanders and people with high-risk health conditions are urged to stay cautious about Covid even if they've just had the virus because reinfection can occur, new health advice says.

The Ministry of Health put out the advice to urge doctors and healthcare workers to remain vigilant when patients show up with respiratory infections as we head into winter.

"We are continuing to monitor international evidence on reinfection rates," the ministry's deputy director of public health Dr Harriette Carr said.

"Current evidence shows the chance of having Covid-19 again within 90 days of a first infection, especially if it is the same variant, is low but it can occasionally happen.

"Ensuring you minimise your chances of catching Covid-19 again is especially important for older people, those with higher-risk health conditions, or people who have frequent close contact with vulnerable people."

People who become unwell with respiratory symptoms within 90 days after a Covid-19 infection but are low-risk should stay at home and recover until 24 hours after most symptoms cleared up, the ministry said.

"We don't advise routinely retesting at home within this period, but if someone becomes increasingly unwell they should seek advice from their GP or Healthline," Carr said.

More at-risk people who became unwell again within 90 days of their initial illness should seek further advice from a health practitioner, she said.

People who became infected more than 90 days after catching Covid-19 should treat their new case as if it was a first infection, Carr said.

"Our advice to health practitioners when testing for reinfection is that it's exceptionally unlikely if symptomatic less than 28 days after the original infection," she said.

"People who are symptomatic within 29 to 90 days after original infection could be tested with a supervised rapid antigen test.

"It's really important to take any respiratory illness seriously and take time to recover."

Carr said there was traditionally more sickness in the population during the colder months and that meant it was important people still followed public health guidance, she said.

"Please continue to stay at home if you're unwell, practice good hand hygiene, wear a face mask when out in public and continue to maintain physical distance from others when possible."

"Again, vaccination remains a key defence against winter ills and chills – both the Covid-19 vaccine and the influenza vaccine.

"Please book your appointment today."