Dengue and Dengue Haemorrhagic Fever in French Polynesia-Current Situation

All four dengue virus serotypes have occurred in French Polynesia. The first epidemic of dengue on Tahiti island of known serotype (dengue 1) occurred in 1944 as part of the Pacific-wide spread of the disease during World War II. The next outbreak of dengue took place in 1964 and was the result of the introduction of dengue 3 virus. With the increase in air travel by humans, dengue has occurred as successive epidemics, especially between 1969 and 1979 with each epidemic involving a different serotype. Each time, the epidemic serotype replaced the unique endemic serotype that had been transmitted during the preceeding interepidemic period: dengue type 3 in 1969, dengue 2 in 1971, dengue 1 in 1975-1976 and dengue 4 in 1979. With the exception of the dengue 2 epidemic, during which severe haemorrhagic cases and several deaths were observed on Tahiti on 1971, cases of dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS) were not common. Following a long inter-epidemic period involving a low transmission of dengue 4, two back-to-back epidemics of dengue 1 and dengue 3 took place during 1988-1989. Of great interest was the occurrence of DHF/DSS in the latter epidemic (11 fatalities) while mildness characterized the former. Surveillance of both epidemics involved clinically and laboratory-based systems. Public health control measures were instituted. These viruses were throughoutly spread in the Pacific region with varying degrees of disease severity. Molecular epidemiology studies provided new information on geographic distribution, origin, evolution and strain variation among dengue viruses