OPINION: This column was going to be about the Auckland woman who returned to New Zealand from northern Italy, where there was a serious Covid-19 outbreak, and who became our country's second confirmed case.

The Italian Government has, by the way, this week closed all schools and universities in a desperate effort to slow the rate of infection.

It seemed to me the woman, in her 30s, did everything wrong, even if she was unaware she was sick from the new virus, now loose in more than 80 countries. My point was going to be that, given the information she had, she neglected to take a host of precautions you would have expected from a sensible person.

She took two domestic flights despite feeling ill with Covid-19 symptoms and then visited a couple of medical centres to seek advice. She also sent her children to school. They were not sick but had obviously been exposed to an infected person.

READ MORE:

* 'Outbreak' or 'pandemic'? Translating coronavirus jargon

* Coronavirus: Kiwi family in isolation in Auckland 'battered' online

* Coronavirus: GPs warn of mass closure of medical centres if people continue to turn up unannounced

* Coronavirus vs influenza: The differences between the two according to WHO

It appeared on the face of it to be an appallingly negligent reaction to a dangerous threat to other people's health and well-being, not to mention their lives.

What appeared even worse was Auckland Regional Public Health Service director Dr William Rainger​ saying the family had done everything right and had minimised the risk to others. I thought in this case some healthy condemnation and advice about what the woman should have done would have been very useful. While authoritarianism is never attractive, it can work wonders, as can the fear of peer condemnation. I was even prepared to forgive the social media buffoons who attacked the woman.

Then one of our reporters interviewed her. Talk about the facts spoiling a good column.

It turned out she had a sinus infection before she set off overseas. She felt unwell on return but put it down to the long trip. She then visited several private healthcare providers, explained where she had been and was told she did not have Covid-19. She took a flight to Palmerston North and returned immediately when she became unwell. More tests showed she was infected.

I had to review my outrage.

However my point that good decisions from well-informed, trusting individuals, properly directed by trustworthy authorities, are the key to minimising the spread of the virus still holds.

Luca Bruno A man wears a mask in Codogno in northern Italy on Saturday, Feb. 22. Many places in northern Italy are on effective lockdown after the Covid-19 virus stuck the country.

Dealing with Covid-19 is not like trying to limit climate change, where individual measures can feel like whistling into the wind.

With Covid-19, individual actions matter enormously and government measures will depend on people remaining calm, well-informed and co-operative. It's already become abundantly clear just how difficult it is to stop the new disease spreading.

For instance, it's virtually impossible to check every person the Auckland woman had been in contact with and isolate them. The latest positive test for the virus was a man who attended the Tool concert at Spark Arena in Auckland last Friday when he may have been infectious. Again it's not practicable for authorities to chase down all the people who stood near the man at the concert.

Experts are still hotly debating whether infected people who have no symptoms can transmit the disease. They do, however, agree that the virus spreads in droplets from coughs, sneezes and breathing, so while it's still unlikely anyone at the concert was infected, I wouldn't be placing any bets on it.

Nothing appears surer than that the virus will spread in New Zealand but it's worth remembering the rate of spread is the crucial factor. If you can avoid a big surge in infections, fewer people will immediately need intensive medical treatment or other special measures. Fewer medical staff will get sick.

The time bought by slowing the spread gives health authorities more time to prepare, gather supplies and set up procedures.

Although a vaccine is still believed to be at least a year away, scientists learn more about the virus and how to treat patients every day.

Slowing the spread to a certain rate will also avoid more draconian methods.

The next step in New Zealand is called social distancing. An extreme version of this would be to isolate the South Island, which some think is quite a good idea.

Unfortunately the disease is probably already in the south and it's a good bet it will emerge in Queenstown or Christchurch.

Social distancing means closures, cancellations, stoppages and isolation. Such eventualities will obviously threaten incomes.

These measures have worked well in China and South Korea but New Zealanders may not take as kindly to a mass order to stay at home and wait for instructions.

Fortunately New Zealand does have a high level of social cohesion, trust in authorities and willingness to co-operate. We can always fault our health authorities but they are generally competent and well organised.

If this country can't keep the spread of Covid-19 to a minimum, there's not much hope for the rest of the world.