Covid mystery defies our need to know
It is human nature, especially in these times of frequently acclaimed scientific advancement, to expect to uncover all we wish to know. With Covid-19, the list of what we don’t know remains infuriatingly long. Why do some people get sick, and some don’t? What’s the long-term health impact of infection? How long will vaccine immunity last? And when will the pandemic end?
A South Auckland family who tested positive in August last year still do not know for certain, nor do we, how the virus emerged. Three potential sources have been suggested: a border incursion from the UK or Ecuador; undetected community transmission; or the virus arriving via foreign goods.
There was speculation a September cluster originating from the Christchurch Crowne Plaza Hotel, which infected six people, started from a rubbish bin touched by a returnee at the facility. Then there was the mystery November transmission from a member of the Defence Force working at an Auckland quarantine facility to a shop assistant who lived, worked and studied in the CBD.
In January, a Northland woman tested positive for the virus after leaving managed isolation. She visited 30 Northland locations. However, all 16 close contacts she encountered tested negative. Phenomenally, perhaps, everyone she came into contact with tested negative.
Later in the month, two people from the same MIQ facility tested positive after leaving. Officials closed the facility for a complete review. It reopened with improved ventilation, although links between the cases could only be theorised on.
The Valentine’s Day cluster in February also left questions. Fifteen positive cases were eventually tracked back to a person who worked at a catering and laundry service in Auckland International Airport. How this person was infected is still unknown. The case of an airport worker who apparently picked up the virus while cleaning a plane that landed on April 10 has never been solved.
In many of these cases, we do know the virus somehow passed from case to case because genome sequencing confirms it is the same variant. In some cases, the chain of events and clearly trackable movements of people makes it clear missing links must exist. The only reasonable conclusion is people carried the virus but escaped detection and therefore, most likely, symptoms. This is as confounding as it is alarming.
Despite our science and desire to understand, it is humbling to realise there are some things we may never know. It’s also a good reminder to avoid complacency — this pandemic is still throwing up surprises.