An epidemiologist from the Pacific Community (SPC) says dengue fever outbreaks are currently active in American Samoa as well as Wallis and Futuna.
An eight-year-old girl with dengue from Wallis and Futuna recently died after her condition deteriorated and she was flown to New Caledonia for treatment.
SPC epidemiologist Salanieta Saketa said all Pacific countries were vulnerable to dengue, especially as the wet season approached and mosquitoes carrying the virus bred in places where rain water collected.
There had been 1933 suspected cases so far this year in American Samoa and 461 suspected cases in Wallis and Futuna, Dr Saketa said.
"So we have two countries that are still having circulation of dengue fever. One of them is Wallis and Futuna which has a circulation of dengue serotype one. And American Samoa with dengue serotype two."
All Pacific nations need to take dengue protection measures, Dr Saketa said.
Kiribati had recently controlled a cluster of dengue cases while the disease had also been reported this year in Solomon Islands, Papua New Guinea, Vanuatu, New Caledonia, French Polynesia, Tonga, and Niue, she said.
"All countries in the Pacific actually should be alerted and to make sure that as they approach the rainy season to prepare themselves and make sure that any control measure is put in place to prevent dengue transmission within the country, and particularly when we still have dengue circulating."
Dr Sekata said people must be vigilant about cleaning up potential mosquito breeding sites around their homes
While dengue was usually self limiting, it can kill, with children and the elderly being more at risk, she said.
Families should seek medical help for any relative with a high fever.