The Secretariat of the Pacific Community says the mosquito-borne illness chikungunya is building in the region, with two cases confirmed in New Caledonia which appear to have come from Tahiti.
The head of surveillance in Public Health says French Polynesia has been carrying a heavy burden of arboviruses with concurrent outbreaks of chikungunya, dengue and zika earlier this year.
Adam Roth says dengue fever types 1 and 3 are still circulating but appear to be declining and there have been no new reports of zika virus in the second half of this year so far.
However he says the main concern is an increase of chikungunya with over 500 cases.
"What is currently very worrying is the chikungunya outbreak in French Polynesia. So far they have reported 541 confirmed cases. And also there have been two cases imported from Tahiti to New Caledonia. So that's the main outbreak that's currently building I think."
Dr Roth says chikungunya is also ongoing in Tonga and Samoa and people need to destroy mosquito breeding sites as the rainy season approaches and anyone with a fever and joint pain should see a doctor.