Ovation of the Seas sailed into Napier on Monday from Tahiti. Photo: DPA Picture-Alliance via AFP
A Covid-19 modeller says small towns like Picton face an increased risk of the virus spreading when cruise ships dock, but transmission can be avoided by taking basic precautions.
Picton's population of 4790 effectively doubled yesterday as cruise ship Ovation of the Seas docked in the Marlborough Sounds town, carrying 4500 crew and passengers.
Of that number, 129 passengers and two crew members have so far tested positive for Covid-19.
Covid-19 Modelling Aotearoa co-lead Dr Emily Harvey told Morning Report the risk of Covid-19 spread in a small town like Picton was significant during the days the ship was docked, but that transmission rates would depend on the town's mitigation factors.
"We've definitely seen a lot of spread from cruise ships in the past," she said.
"So in 2020, we definitely knew it was an issue and that's really going to depend on what the local communities risk is in terms of have they got good ventilation ... that sort of thing.
"If you're not masking and you don't have good ventilation, you're likely to get spread into the community from those people coming ashore."
She said international arrivals increased the risk of introduction of new variants and can lead to an increase in infection risk in the community if the prevalence is higher in the country of origin than in Aotearoa.
"If you're not masking and you don't have good ventilation, you're likely to get spread into the community from those people coming ashore" - Covid-19 Modelling Aotearoa co-lead Dr Emily Harvey
Earlier Picton pharmacist Graham Smith told media people from the ship had come into his store coughing without masks and presenting with cold symptoms.
Harvey said the likelihood of outbreaks in a small town like Picton was much higher than the risk posed to a larger city like Wellington.
"In those small cities, if you don't normally have a lot of international tourists coming in, this is going to massively increase your risk for the day or two while that ship is there.
"Whereas in Pōneke or Tāmaki Makaurau, we've got a lot of people who come in from overseas and and a lot of people we interact with locals who have Covid-19 as well, so the risk profile increases much less than the big cities."
Harvey said the basic means of avoiding Covid-19 from tourists remained the same as it would for any other situation.
"It's the same sort of thing that we should be thinking about with locals coming into town we do have Covid-19 in the community," she said.
"Now it is around we need to be thinking about do we have good ventilation. Do we have good air cleaning.
"Is the air that someone breathed out going to be me breathing it in or not? So, it's those simple measures, those layers of protection that we really want in place now that Covid is out and about."