Could the Zika virus come here?

Q: How likely is it that Zika will spread to New Zealand?

A: Nelson-marlborough Institute of Technology neurologist Professor Gareth Parry:

The Zika virus infection has raised considerable concern in New Zealand, but the risks faced by most New Zealanders, while real, are quite small, as New Zealand does not harbour the primary mosquito vector.

For those with a competent immune system, the acute illness caused by Zika virus infection is generally mild. Serious complication associated with Zika virus infections include microcephaly (a birth defect which results in an abnormally small head) and Guillain-barre Syndrome (an auto-immune disorder).

Pacific Island countries have reported cases of Zika virus infection and these climates support the mosquito vector, so travellers to these areas are at risk of infection. New Zealand travellers returning from endemic areas have developed the illness associated with the virus, but the probability of autochthonous transmission here is very small.

The aedes mosquito is the vector for Zika virus, with the yellow fever mosquito Aedes aegypti almost exclusively responsible for human transmission cycles. It is of concern that the virus has adapted to [the Asian tiger mosquito] Aedes albopictus, a much more widely distributed mosquito which is found throughout tropical regions but also in the United States and parts of Europe.

The aedes mosquito is not endemic in New Zealand, but our major trading partners Australia, the Pacific Islands and Southeast Asia harbour the mosquito.

The New Zealand climate is capable of supporting a population of the aedes mosquito and the mosquito is occasionally identified at the borders, so continuing vigilance is essential.

The virus has been identified in human saliva and semen as well as blood, and direct human-to-human transmission is strongly suspected by sexual activity, by blood transfusion and from infected mothers to their infants.

New Zealand women should avoid pregnancy while travelling in endemic areas and, if pregnant, should avoid sexual contact with potentially infected partners

New Zealand had 57 confirmed human cases of Zika infection in 2014, six in 2015 and 11 through the end of January 2016, coinciding with the spread across the Pacific, the Americas and elsewhere.

Source: NZ Medical Association (via Science Media Centre)