Homology of complete genome sequences for dengue virus type-1, from dengue-fever- and dengue-haemorrhagic-fever-associated epidemics in Hawaii and French Polynesia.

Dengue epidemic virulence is thought to be conferred by various factors, including the genotype of the virus involved. Increased or decreased epidemic virulence has been associated not only with the introduction of type-2 (DENV-2) strains into the South Pacific, the Caribbean and South America, but also with newly emergent DENV-3 genotypes in Sri Lanka, and the year-to-year variation in the DENV-4 strains circulating in Puerto Rico. These observations indicate that there are inherent differences among viral genotypes in their capacity to induce severe disease, that is, their virulence potential.

Dengue-3 virus genomic differences that correlate with in vitro phenotype on a human cell line but not with disease severity.

We compared the full genome sequence of nine clinical isolates of dengue virus obtained during an epidemic of dengue-3 in French Polynesia in 1989, from patients with various presentations of disease. The isolates, all belonging to Genotype I, had 25 amino acid substitutions. There was no association with disease severity.

Molecular epidemiology of dengue in the Pacific: introduction of two distinct strains of dengue virus type-1 [corrected] into Hawaii.

In 2000, a major dengue epidemic, caused by the type-1 virus (DENV-1), began in the Pacific and Asia, with cases still being reported in 2006. The phylogenetic analysis of full-length sequences of the envelope-protein gene of DENV-1 isolates recovered during outbreaks in Hawaii and Tahiti in 2001-2002 indicated that most Hawaiian isolates were Tahitian in origin. All the Hawaiian and Tahitian isolates were identified as the Pacific subtype (i.

Structure-activity relationships of dengue antiviral polycyclic quinones.

The virucidal and antiviral photoactivities of three compounds, hypericin, tetrabromohypericin and gymnochrome B, were evaluated against dengue viruses. All the three products were active, and both the virucidal and antiviral activities were enhanced by light. Gymnochrome B was more potent than hypericin and tetrabromohypericin.

Comparison of dengue-1 virus envelope glycoprotein gene sequences from French Polynesia.

Dengue (DEN) is the leading arboviral infection of humans, with 100 million cases annually in the tropical areas of the world. The recent severe DEN-1 epidemic in French Polynesia in 2001, with an incidence rate of 16% and more than 45% of the cases with dengue hemorrhagic fever/dengue shock syndrome among 1,400 hospitalized children and eight fatalities, led us to study this new circulating strain. The entire envelope (E) gene of two French Polynesian DEN-1 virus isolates from the two epidemics of 1988-1989 (FP89) and 2001 (FP01) were sequenced and compared with 29 published DEN-1 virus E gene sequences.