Pacific health authorities are stepping up surveillance of dengue-like illnesses as a new epidemic infecting one in ten people in French Polynesia spreads rapidly throughout the territory.
Over the past six weeks up to 30,000 people may have been infected with the virus, named 'zika' after its origins in Uganda.
Jenny Meyer reports:
Zika fever is a viral illness - similar to dengue fever, chikungunya, yellow fever and Japanese encephalitis. The head of the surveillance office, Dr Henri-Pierre Mallet, says the virus is spread by the Aedes aegypti mosquito and symptoms of the week-long sickness include a rash, fever, joint pain, headaches and red eyes. He says it is not as severe as the similar dengue fever but the local population has no immunity.
"HENRI-PIERRE MALLET: So there is a very fast spreading of the infection. And one place is infected with a lot of cases, after that it is better; but another place, again, is infected. And so like that, from place to place, island to island, yes the cases are still increasing and spreading all over the country."
Dr Mallet says authorities may soon need to appeal to France for further support. In New Caledonia, the head of Health Services Dr Jean Paul Grangeon, says border control measures are now in place after two people in their thirties returning from French Polynesia were recently diagnosed.
He says not much is known about zika virus yet but it's similar to dengue fever.
JEAN PAUL GRANGEON: It's quite the same symptoms except in zika virus there is more cutaneous rash. But we in New Caledonia can make a blood test to make the difference. So each people coming with a fever or pain in joints or muscles or headache or cutaneous rash; especially if they're coming from overseas; they are being tested for the three viruses: dengue, chikungunya and zika virus.
Dr Susan Hills, who is a US-based medical epidemiologist at the centre for disease control, says it's hard to predict how the illness might spread.
SUSAN HILLS: It's certainly a concern that when any outbreak occurs, not only for the local community but also for transmission in other places both in the local area or in other remote sites. There has certainly been cases documented of travellers who have become sick and subsequently been ill on return to their country.
She says the incubation period between being bitten by a mosquito and becoming unwell is typically 2 - 3 days, but can be up to 10 days and travellers need to use insect repellants, cover up and see a doctor if they feel unwell. The World Health Organisation's Dr Eric Nilles says it's now stepping up surveillance of dengue-like illnesses in 23 Pacific countries in response to the French Polynesian epidemic, making the condition notifiable.
ERIC NILLES: We're also supporting laboratory testing; so New Caledonia, French Polynesia, have the capacity to test the zika virus but they're really the only two territories or countries in the Pacific that can do that. So we're supporting countries, if they have suspected cases, to refer samples for testing to reference laboratories for confirmation.
Dr Nilles says zika is not severe enough for the WHO to implement regional travel restrictions.