Zika virus infected five New Zealanders – probably people on winter breaks – who travelled to Fiji during the incubation period, a surveillance report says.
However, the number of zika cases in New Zealand for the year so far is much lower than the first half of 2016 – dropping from 95 notified cases in the first six months of 2016 to eight confirmed cases and two probable cases so far this year.
An Institute of Environmental Science and Research public health May surveillance report said five cases of zika virus infection were notified during the month.
FELICITY REID/FAIRFAX NZ
Four cases were confirmed, one was under investigation, and probably all of them involved holidaymakers.
Institute public health physician Dr Jill Sherwood said the numbers had fallen and the demography of those infected had changed slightly.
The recent cases were likely to involve Kiwi holidaymakers in the South Pacific.
“What we’re seeing really reflects what’s circulating in different countries and the type of travel that New Zealanders do.
“At the same time last year, at that stage we had 95 cases notified, 90 confirmed.
“For all of 2016 there were 100 cases notified, a big increase on 2015 when there were nine cases for the year.”
Sherwood said the increase in 2016 was associated with the prevalence of the disease in countries where zika was present, travel patterns, and an increase in the disease globally.
In 2016, 99 out of 100 cases in New Zealand involved people who had travelled overseas and one case involved transmission from sex. The majority of cases involved people who travelled to Tonga, Samoa, and Fiji, and cases largely occurred during the Kiwi summer.
Sherwood said these cases probably involved Pacific islanders travelling to and from their birth countries, or Kiwis travelling back to New Zealand.
This was also the Pacific tropical rainy season, when mosquitoes were more active.
Many of the 2016 cases involved Pacific islanders whereas the recent cases involved New Zealanders and New Zealand Europeans.
This was more like the pattern in 2014 and “probably people going as tourists for a holiday”.
Zika virus remained a significant public health concern globally, she said.
People needed to take precautions and realise zika symptoms can be mild or even asymptomatic.
In the recent cases, district health boards reported two cases in the Southern region and one each in Auckland, the Bay of Plenty and the Nelson-Marlborough region.
Of those, three were people in their 50s, one person was in their 30s and one person was in the 70-plus age group.
“All cases reported overseas travel during the incubation period to Fiji.”
SafeTravel has extensive advice on travelling to areas with a risk of zika virus.
Other advisory bodies say most of the South Pacific region carries a risk and the Centers for Disease Control and Prevention in the United States says there is a risk in Fiji.
The Ministry of Health advises travellers to any Pacific country to take precautions against mosquito bites.
Pregnant women are advised to avoid travel to countries where the virus has been detected.
ZIKA IN NEW ZEALAND
In 2014, there were 14 cases reported between January and March.
The number of cases spiked to 42 between April and June that year, most involving travellers who had visited the Cook Islands, as well as one from Tonga, and another from Vanuatu.
But the numbers dropped considerably in 2015, when just six cases were reported, all in travellers who had been to the Pacific, including two cases from Samoa.
In 2016, the number of cases jumped to 100 then, so far this year, the numbers dropped to 10 cases for the first half of the year.
The Ministry of Health said the aedes mosquito, which spread zika and other viruses, were not normally found in New Zealand.
TIPS FOR AVOIDING MOSQUITOES
* Wear long-sleeved shirts and long pants
* Use insect repellents containing DEET, picaridin, oil of lemon eucalyptus (OLE), or IR3535
* Apply sunscreen before insect repellent, if you are using both
* Use clothing and gear treated with the insecticide permethrin
* Use a bed net, and stay and sleep in screened-in or air-conditioned rooms