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.

Brain involvement in Dengue fever.

During the 1994-1995 outbreak of dengue fever in New Caledonia (1079 cases), two cases of encephalopathy were seen. Both patients suffered transient clinical (drowsiness, confusion) and electroencephalographic disturbances from which they fully recovered. Although this condition has been described in dengue infection a number of different pathological mechanisms are probably implicated.

Pulmonary haemorrhage as a predominant cause of death in leptospirosis in Seychelles.

We examined the cause of death during a 12-month period (1995/96) in all consecutive patients admitted to hospital with leptospiral infection in Seychelles (Indian Ocean), where the disease is endemic. Leptospirosis was diagnosed by use of the microscopic agglutination test and a specific polymerase chain reaction assay on serum samples. Seventy-five cases were diagnosed and 6 patients died, a case fatality of 8%.

[Probable Miller Fisher syndrome during Dengue fever type 2].

A 57 year-old-man developed a left ophthalmoplegia associated with ataxia and areflexia while he had fever (39 degrees C) for two days. Dengue fever (DF) was diagnosed by definite criteria, i.e.

In vitro antiviral activity on dengue virus of marine natural products.

Metabolites isolated from marine invertebrates, callipeltin A, crambescidin, ptilomycalin A, celeromycalin, gymnochrome B, gymnochrome D and isogymnochrome D previously shown bioactive on either herpes simplex virus 1 or human immunodeficiency virus, were tested on a new in vitro bioassay using the dengue virus 1. Only gymnochrome D and isogymnochrome D isolated from the living fossil crinoid Gymnocrinus richeri are highly potent dengue antiviral agents.

Molecular epidemiology of dengue-1 and dengue-4 viruses.

Genetic variation between geographically and temporally distinct isolates of dengue-1 (DEN-1) and dengue-4 (DEN-4) viruses was investigated. The nucleotide sequences of a fragment of the envelope protein gene encoding amino acids 28 to 87 of 35 DEN-1 isolates and 28 DEN-4 isolates were determined. Maximum nucleotide sequence variation was 6.

Molecular epidemiology of dengue 3 viruses and genetic relatedness among dengue 3 strains isolated from patients with mild or severe form of dengue fever in French Polynesia.

The nucleotide sequences of a short fragment of the envelope protein gene encoding amino acids 25 to 89 of 27 dengue 3 viruses were determined by direct sequencing of PCR-amplified products, and the viruses were compared regarding their time of isolation and geographic distribution. Four distinct genotypic groups were discerned at 6% divergence between nucleotide sequences. The first group contained isolates from the South Pacific (1988 to 1992), Singapore (1973) and Indonesia (1973 to 1991).

[Dengue epidemic in New Caledonia (1989). Environmental factors and prevention].

An extensive dengue epidemic was reported in New Caledonia en 1989. Environmental factors (temperature and rainfalls) directly controlled the mosquitos population at the end of 1988. The introduction of a new dengue virus, transmitted by Aedes aegypti, was responsible for an epidemic that occurred in January-April 1989 and lasted until July 1989.

Demonstration of concurrent dengue 1 and dengue 3 infection in six patients by the polymerase chain reaction.

A dual viremia resulting from naturally acquired dengue 1 and dengue 3 infections in six patients experiencing a dengue-like syndrome during the epidemic in New Caledonia in 1989 is reported. Serotype identification was first based on virus isolation in mosquito cells and immunofluorescence using type-specific monoclonal antibodies. The double infection was confirmed directly in blood samples by the polymerase chain reaction (PCR) on genomic RNA and hybridization of the amplified cDNA fragments with type-specific DNA probes.

Identification of dengue sequences by genomic amplification: rapid diagnosis of dengue virus serotypes in peripheral blood.

Polymerase chain reaction (PCR) was developed for the in vitro amplification of dengue virus RNA via cDNA. A fraction of the N-terminus gene of the envelope protein in the four dengue serotypes was amplified using synthetic oligonucleotide primer pairs. Amplified products were cloned and used as dengue type-specific probes in gel electrophoresis and dot-blot hybridization.

[40 cases of dengue (serotype 3) occurring in a military camp during an epidemic in New Caledonia (1989). The value of vector control].

An epidemic of dengue occurred at the beginning of 1989 in New Caledonia. About 18 p.c.

[The presence of Aedes (Stegomyia) albopictus in the Fiji Islands].

An entomological survey conducted at the international airports of the Fiji Islands showed Aedes albopictus breeding in the protective area of Nadi airport. No Aedes aegypti nor Anopheles accidentally imported have been seen during the visit. Aedes vexans, A.

[Study on the vertical transmission of the dengue virus in the South Pacific].

In the course of a dengue outbreak, 765 larvae and 20 pupae were collected in Noumea and in Wallis island around patients premises, to investigate a possible natural infection. On 15 pools made of 335 Aedes aegypti larvae and pupae, 3 appeared to be infected. Dengue virus type 1 was the only serotype identified.

[Reappearance of dengue in New Caledonia from 1985 to 1988].

From 1971 to 1980, dengue outbreaks occurred in New-Caledonia due to dengue viruses type 2, 1 and 4 successively. After an eclipse of four years, dengue reappeared in 1985 through 1988. Out of 109 cases confirmed by virus isolation, dengue serotypes 1, 2, 3 and 4 caused 15, 23, 17 and 54 cases respectively; in 28 other cases, the Flavivirus type could not be identified and in 26 cases an Alphavirus (Ross River) was pointed out.

Hepatitis B infection in Vanuatu: age of acquisition of infection and possible routes of transmission.

Seroepidemiological studies of hepatitis B were carried out on diverse groups of children (477) and adults (629) from the Pacific Island country of Vanuatu. In children under 14 years, prevalences of HBsAg and of all markers were 6% and 53.3% respectively; in adults greater than or equal to 20 years the prevalences were 15% and 70%.

[Trial of hepatitis B prophylaxis in children born to mothers carrying HBs antigen in New Caledonia].

A prophylaxis trial of hepatitis B at birth was carried out in New Caledonia. Ninety-nine newborns from women carrying hepatitis B antigen during pregnancy were immunized. The prophylaxis protocol was as follows: anti-HBs immunoglobulin and the first dose of vaccine at birth if the mother was HBe Ag+ or HBe Ag- without anti-HBe, only vaccination if the mother showed anti-HBe antibodies.

[Chlamydia trachomatis infections in New Caledonia. Study of 1,023 patients over a 12-month period].

A study of chlamydial infections was realized in New Caledonia during a period of one year. It concerned 1,023 patients: 775 adults and 248 children. It showed the high frequency of chlamydial urethritis in the male population, chlamydial cervicitis in gynecologic patients, chlamydial pneumonia and conjunctivitis in neonates and infants.