[Arboviral diseases in South-West Pacific islands (author's transl)].

Islands of the south-west Pacific area belong to the melanesian group, excepted Niue, Tonga, Wallis and Futuna which are polynesian. Through New Guinea, there is a geographic relation to the eastern part of Australia, rich of 42 arbovirus types. Dengue and Ross River fever are the most important arboviral diseases in the region; both affect islanders after introduction of virus by travellers to localities where efficient vectors are present. Dengue types 1, 2 and 4 were isolated from man and from mosquitoes in this area. Successive outbreaks, transmitted by Aedes aegypti or by Ae. polynesiensis, resulted in thousands of cases with a few fatal hemorrhagic forms. Ross River virus, responsible of epidemic polyarthritis, evaded in 1979, from Australia to Fidji, Wallis, Futuna and New Caledonia. Suspected vectors are Aedes vigilax and Culex annulirostris. Aedes aegypti and Ae. polynesiensis are also possible carriers. Murray Valley encephalitis virus caused severe outbreaks in Australia and fatal cases in New Guinea; it is a possible invader when Culex annulirostris is abundant. Expansion of arboviral diseases is a major epidemiological problem in south-west Pacific islands. Research work on pathogeny and vectors control must be intensified in this area.