By Paul Purcell
One of New Zealand's handful of Zika cases has been traced to American Samoa as the World Health Organisation declares the mosquito-borne virus to be an international public health emergency.
The eight travellers confirmed with the virus in 2016 had all recently arrived in New Zealand from Tonga and Samoa with the Ministry of Health linking one of the cases to American Samoa today.
Two other cases are unconfirmed.
Health Minister Jonathan Coleman says the decision by WHO to classify Zika as a international public health emergency is appropriate, although the risk of the virus spreading within New Zealand is "virtually non-existent".
"By elevating this to a public health emergency, much needed research can now be fast-tracked," he said.
"I am advised that the threat within New Zealand is virtually non-existent as we don't have the mosquito species, Aedes aegypti, which is spreading the disease.
"New Zealanders are only at risk if travelling to areas where Zika is prevalent."
He advised pregnant women or women planning to become pregnant to consider delaying travel to areas with the Zika virus.
Four of New Zealand's cases are women and while the potential for pregnancy has been ruled out for two of them, further tests are under way for the remaining two.
One of the cases, a 47-year-old Waikato man, ended up being admitted to hospital also with symptoms indicative of Guillain-Barre, a condition which can cause paralysis, but from which most patients make a full recovery.
The man is in a stable condition, while the other eight have recovered.
WHO called for an international coordinated response to the crisis after declaring the international public health emergency on Tuesday.
Thousands of children in Brazil have been born with suspected cases of microcephaly, in which infants are born with smaller-than-usual brains, which is linked to the virus.
WHO said last week the Zika virus was "spreading explosively" and could infect as many as 4 million people in the Americas alone.
It is the fourth time the WHO has declared a global health emergency since the International Health Regulations were enacted in 2007 after declarations for Swine Flu in 2009 along with Polio and Ebola in 2014.
In 2014 there were 57 Zika virus notifications in New Zealand. Last year there were six.