The French Polynesian health authorities warn the latest dengue type 2 outbreak may spread to all archipelagos after the latest two discoveries.
A man on Taiohae in the Marquesas, who has not recently been to Tahiti, has been diagnosed with type 2 dengue as has a person on Bora Bora.
Until now the epidemic was confined to island of Tahiti where the mosquito-borne illness spread since the arrival in February of an infected traveller from New Caledonia.
Despite efforts to eliminate mosquito breeding sites, the new strain has so far infected 23 people.
Dengue type 1 is affecting more than a dozen people across several French Polynesian archipelagos, including the Marquesas.
French Polynesia had been spared a dengue type 2 epidemic for about two decades which means that the public has low immunity to the disease.
Those considered most at risk are people below the age of 20 and those who arrived in Tahiti after 2000.
New Caledonia declared a dengue type 2 epidemic in December.