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PubMedDate not supplied

Effect of two successive annual treatments with single doses of ivermectin on microfilaraemia due to Wuchereria bancrofti var. pacifica.

Between 1986 and 1988 a single-blind, dose-ranging study was carried out in French Polynesia to determine the efficacy and tolerability of single 50, 100, 150 and 200 micrograms/kg doses of ivermectin in Wuchereria bancrofti carriers. Forty male microfilariae (mf) carriers between 18 and 50 years of age, in whom mf density was greater than or equal to 20 mf/ml, were treated twice at a one-year interval. Twelve months after the second treatment, in carriers who were given a dose greater than or equal to 100 micrograms/kg, mean mf density was 4-7% of the initial pretreatment mf density. Therefore, several successive annual treatments with single doses greater than or equal to 100 micrograms/kg of ivermectin should result in reducing mf densities to a very low level. Nevertheless, at 9 months after the second treatment, residual parasitaemia ranged from 1 to 2182 mf/ml (median 85) in 30 patients. Finally, in patients with pretreatment mf counts less than or equal to 150 mf/ml, mean mf density was 2.8 and 8.9 mf/ml, respectively, during the 2 six-month periods following treatment, while in patients with pretreatment mf densities greater than 150 mf/ml (median 1500) it was 92.3 and 334.1 mf/ml during the same periods. These results suggest that, when implementing filariasis control programmes, the best strategy might be administration of several treatments with a single dose of ivermectin every 6 months to the entire population, at least in French Polynesia. Afterwards, when mf densities had been reduced to a relatively low level (100-150 mf/ml), annual treatments could be considered.

Adolescent↗
PubMed1999

Transport of radionuclides from the Mururoa and Fangataufa atolls through the marine environment.

A dispersion of radionuclides (3H, 90Sr, 137Cs, 239Pu) potentially released from the Mururoa and Fangataufa atolls through the South Pacific Ocean has been studied by means of computer models. The models used consisted of three differently structured compartmental models for the regional field and a hydrodynamic world ocean model for the far-field simulations. The outcome of regional modelling is predicted activity concentrations with time in different regions of French Polynesia (over up to 10,000 years for plutonium). The far-field model simulates large-scale dispersion in the South Pacific Ocean over periods of up to 50 years. The overall result suggests that there will not be radioactive contamination of any radiological interest at inhabited sites in French Polynesia or anywhere else in the ocean at present or in the future.

Models, Chemical↗
PubMed1999

Identification and phylogenetic characterization of a human T-cell leukaemia virus type I isolate from a native inhabitant (Rapa Nui) of Easter Island.

Human T-cell leukaemia virus type I (HTLV-I) is endemic in Melanesia, one of the three ethnogeographic regions of the Pacific; in the other two regions, Polynesia and Micronesia, the incidence of the virus is relatively low. In an effort to gain new insights into the prevalence of HTLV-I in the Pacific region, we did a seroepidemiological survey on Easter Island, which is located on the eastern edge of Polynesia. Of 138 subjects surveyed, including 108 Rapa Nui (the native inhabitants of this island), we identified one HTLV-I-seropositive Rapa Nui. The new HTLV-I isolate derived from this carrier (E-12) was phylogenetically analysed to ascertain the origin and past dissemination of HTLV-I in the island. The analysis demonstrated that isolate E-12 belongs to subgroup A of the Cosmopolitan group, and that it differs from HTLV-Is found in Melanesia, which are highly divergent variants. In subgroup A, E-12 grouped with South American HTLV-Is including those from Amerindians. This result suggests that this isolate originated in South America rather than in Melanesia.

Adult↗
PubMed2002

Affinities among Melanesians, Micronesians, and Polynesians: a neutral biparental genetic perspective.

The human colonization of Remote Oceania, the vast Pacific region including Micronesia, Polynesia, and Melanesia beyond the northern Solomon Islands, ranks as one of the greatest achievements of prehistory. Many aspects of human diversity have been examined in an effort to reconstruct this late Holocene expansion. Archaeolinguistic analyses describe a rapid expansion of Austronesian-speaking "Lapita people" from Taiwan out into the Pacific. Analyses of biological markers, however, indicate genetic contributions from Pleistocene-settled Near Oceania into Micronesia and Polynesia, and genetic continuity across Melanesia. Thus, conflicts between archaeolinguistic and biological patterns suggest either linguistic diffusion or gene flow across linguistic barriers throughout Melanesia. To evaluate these hypotheses and the general utility of linguistic patterns for conceptualizing Pacific prehistory, we analyzed 14 neutral, biparental genetic (short tandem repeat) loci from 965 individuals representing 27 island Southeast Asian, Melanesian, Micronesian, and Polynesian populations. Population bottlenecks during the colonization of Remote Oceania are indicated by a statistically significant regression of loss of heterozygosity on migration distance from island Southeast Asia (r = 0.78, p < 0.001). Genetic and geographic distances were consistently correlated (r > 0.35, p < 0.006), indicating extensive gene flow primarily focused among neighboring populations. Significant correlations between linguistic and geographic patterns and between genetic and linguistic patterns depended upon the inclusion of Papuan speakers in the analyses. These results are consistent with an expansion of Austronesian-speaking populations out of island Southeast Asia and into Remote Oceania, followed by substantial gene flow from Near Oceanic populations. Although linguistic and genetic distinctions correspond at times, particularly between Western and Central-Eastern Micronesia, gene flow has reduced the utility of linguistic data within Melanesia. Overall, geographic proximity is a better predictor of biparental genetic relationships than linguistic affinities.

Alleles↗
PubMed2004

[Nursing practice in the context of geographic isolation: implications for training].

A survey on the characteristics of the unique working context of nursing practice in remote areas of French Polynesia and semi-remote areas of northern Quebec demonstrates the importance of a specific training to best prepare the professionals who find themselves in this type of setting. Twenty professionals were interviewed: six nurses practicing in isolated stations in French Polynesia (Tuamotu Archipelago, Marquesas Islands and Austral Islands), six nurses practicing in semi-remote areas within northern Quebec (namely among the Algonquins, the Crees and the Attikameks), four officials of the French Polynesian Health Directorate and four training programme designers from Quebec who were encountered during an expedition to Montreal, Mistissini and Trois-Rivieres. The authors identified ten characteristics which were then regrouped into two categories for both of the practice contexts: first, those inherently linked to professional practice in an isolated context (including the characteristics of nursing practice, the working conditions, the community's health problems, their forms of socio-professional relations, their way of life, and their perception and responses to isolation); and second, those pertaining to the social and natural environment, the economic conditions and the community's cultural specificities. All of the results strongly demonstrate that the specificities of the skills utilised by these nurses are indeed very different than those which they received in their initial preparatory training. If a training programme specific to nursing practice in isolated settings seems essential for these nurses, their individual predisposition to practice in such a complex environment and the acknowledgement of their professional competencies are equally to be considered within the perspective of human resources management.

Adult↗
PubMed1991

Longitudinal study on relapses of leprosy in Polynesian multibacillary patients on dapsone monotherapy between 1946 and 1970.

Between 1946 and 1970, 295 new leprosy patients were detected in French Polynesia, of whom 145 were multibacillary. Of these 145, put on dapsone monotherapy, 131 reached bacteriological negativity in a period of time ranging from 2 to 12 years (average 4.72 years) and were followed-up for a period of time ranging from 19 to 43 years (median follow-up period after bacteriological negativity; 18 years). Among the 131 patients, 36 relapses were detected, the first one 4 years after bacteriological negativity and the last one 26 years after. The crude relapse rate was 27.5%, the risk of relapse was 1.39 per 100 patient years and the cumulative relapse probability, calculated using the lifetable method, reached 0.38 +/- 11 by year 31 of the study. From these findings one may assume that, at least in French Polynesia, one-third to one-half of multibacillary patients put on dapsone monotherapy would relapse if still present 36 years after bacteriological negativity. Such results re-emphasize the need for leprosy patients to be treated with multidrug therapy as recommended by WHO.

Dapsone↗
PubMed1989

Implementation of chemoprophylaxis of leprosy in the Southern Marquesas with a single dose of 25 mg per kg rifampin.

Between 1967 and 1987 in the Southern Marquesas, a remote archipelago in French Polynesia, the detection rate of leprosy was 48.9 per 100,000 when it was 8.6 per 100,000 for French Polynesia as a whole. In 1988, a program of chemoprophylaxis of leprosy with a single dose of 25 mg/kg rifampin was implemented, and 2751 persons (98.7% of the population) were treated in the Southern Marquesas. In addition, 678 South Marquesans and 2466 members of their families living in the Northern Marquesas and in the Society Archipelago, received the same chemoprophylaxis. Among 2676 persons studied in the Southern Marquesas (97.4% of the treated population), 130 had elevated IgM anti-phenolic glycolipid-I antibodies by ELISA without any evidence of leprosy. The onset of a skin lesion of borderline leprosy in a boy 3 months after chemoprophylaxis raises the question of the nature of such a skin lesion and, indirectly, of the effectiveness of the chemoprophylaxis.

Antibodies, Bacterial↗
PubMed1994

Polynesian mitochondrial DNAs reveal three deep maternal lineage clusters.

The 4000-year-old human population expansion into Remote Oceania has been studied from a variety of genetic perspectives. Here, we report the discovery that Polynesians, traditionally considered to be a single cohesive linguistic and cultural unit, exhibit at least three distinct mitochondrial DNA (mtDNA) groups that probably shared a common maternal ancestor more than 85,000 years ago. The major lineage groups were first identified by PCR amplification of the mitochondrial region V deletion marker, known to be present at high frequency in Polynesian populations. Sequence analysis of mtDNA hypervariable control regions reveals a surprising number of lineages in Polynesia. We also note high sequence divergence between lineage groups deleted and not deleted in region V. Major group I lineages are common in Remote Oceania and include about 95% of the Native Hawaiian, 90% of the Samoan, and 100% of the Tongan donors in our sample. They contain the region V deletion and generally share three control region transition substitutions. This group also contains non-Polynesian individuals, such as Indonesians, Native Americans, Micronesians, Malaysians, Japanese, and Chinese. The group I Polynesians differ by 4.4% in sequence identity from major lineage group II Polynesians, who do not have the region V deletion and who share among themselves four distinct single-base substitutions. Group II individuals are seen at low frequency (< 10%) in Hawaii, Samoa, and the Cook Islands and may represent the predominant maternal lineage group of Papuan Melanesia. Major lineage group III, not found in Hawaii, tentatively links Samoa to Indonesia. Our observation of deep maternal genetic branches in Polynesia today confirms the notion that during the colonization of the Pacific, mainland Asian immigrants mixed with Melanesian peoples already inhabiting Near Oceania and carried a complex assortment of maternal genotypes derived from two distinct geographic sources to isolated island archipelagoes.

Base Sequence↗
PubMed2001

Maori origins, Y-chromosome haplotypes and implications for human history in the Pacific.

An assessment of 28 pertinent binary genetic markers on the non-recombining portion of the Y chromosome (NRY) in New Zealand Maori and other relevant populations has revealed a diverse genetic paternal heritage of extant Maori. A maximum parsimony phylogeny was constructed in which nine of the 25 possible binary haplotypes were observed. Although approximately 40% of the samples have haplotypes of unequivocal European origin, an equivalent number of samples have a single binary haplotype that is also observed in Indonesia and New Guinea, indicative of common indigenous Melanesian ancestry. The balance of the lineages has either typical East Asian signatures or alternative compositions consistent with their affinity to Melanesia or New Guinea. Molecular analysis of mtDNA variation confirms the presence of a single predominant characteristic Southeast Asian (9-bp deletion in the Region V) lineage. The Y-chromosome results support a pattern of complex interrelationships between Southeast Asia, Melanesia, and Polynesia, in contrast to mtDNA and linguistic data, which uphold a rapid and homogeneous Austronesian expansion. The Y-chromosome data highlight a distinctive gender-modulated pattern of differential gene flow in the history of Polynesia.

Chromatography, High Pressure Liquid↗
PubMed1999

Epidemiology of biliary atresia in France: a national study 1986-96.

BACKGROUND/AIMS: The reported incidence of biliary atresia varies from 5 to 32/100000 live births. The existence of seasonality and/or clustering is controversial. Based on a large population analysis, we examined the incidence of biliary atresia in France, and the space-time distribution of cases. METHODS: All patients with biliary atresia living in France and born in the years 1986-96 were recorded. Geographic distribution, seasonality, time clustering and space-time clustering were analysed. Statistical analysis used the Chi square test, the Spearman nonparametric correlation test, the Walter and Elwood test for seasonality of events and Knox analysis for time and space-time clustering. RESULTS: We identified 461 patients: 421 born in metropolitan France (incidence 5.12 [4.63-5.61]/100000 live births), and 40 born in overseas territories. No significant regional variation in incidence was found in metropolitan France, while the incidence was higher in French Polynesia (incidence 29.4 [15.4-43.3]/100000 live births) (p<0.001). Seasonality, time-clustering and time-space clustering could not be demonstrated. CONCLUSIONS: 1) The incidence of BA was 5.7-fold higher in Polynesia than in metropolitan France. 2) Neither seasonal variation in incidence nor clustering was identified.

Biliary Atresia↗
PubMed2003

Pyrethroid and DDT cross-resistance in Aedes aegypti is correlated with novel mutations in the voltage-gated sodium channel gene.

Samples of the dengue vector mosquito Aedes aegypti (L.) (Diptera: Culicidae) were collected from 13 localities between 1995 and 1998. Two laboratory strains, Bora (French Polynesia) and AEAE, were both susceptible to DDT and permethrin; all other strains, except Larentuka (Indonesia) and Bouaké (Ivory Coast), contained individual fourth-instar larvae resistant to permethrin. Ten strains were subjected to a range of biochemical assays. Many strains had elevated carboxylesterase activity compared to the Bora strain; this was particularly high in the Indonesian strains Salatiga and Semarang, and in the Guyane strain (Cayenne). Monooxygenase levels were increased in the Salatiga and Paea (Polynesia) strains, and reduced in the two Thai strains (Mae Kaza, Mae Kud) and the Larentuka strain. Glutathione S-transferase activity was elevated in the Guyane strain. All other enzyme profiles were similar to the susceptible strain. The presence of both DDT and pyrethroid resistance in the Semarang, Belem (Brazil) and Long Hoa (Vietnam) strains suggested the presence of a knock-down resistant (kdr)-type resistance mechanism. Part of the S6 hydrophobic segment of domain II of the voltage-gated sodium channel gene was obtained by RT-PCR and sequenced from several insects from all 13 field strains. Four novel mutations were identified. Three strains contained identical amino acid substitutions at two positions, two strains shared a different substitution, and one strain was homozygous for a fourth alteration. The leucine to phenylalanine substitution that confers nerve insensitivity to pyrethroids in a range of other resistant insects was absent. Direct neurophysiological assays on individual larvae from three strains with these mutations demonstrated reduced nerve sensitivity to permethrin or lambda cyhalothrin inhibition compared to the susceptible strains.

Aedes↗
PubMed1993

Biogeography of Tongan birds before and after human impact.

Bones deposited in caves show that, before the arrival of humans, at least 27 species of land birds lived on the Tongan island of 'Eua, where 13 indigenous species live today. Six of these 13 species were recorded from pre-human strata; three others probably occurred on 'Eua in pre-human times but were not in the fossil sample; and four others probably colonized 'Eua since the arrival of humans approximately 3000 years ago. Of the 23 species of extinct or extirpated land birds recorded from 'Eua, the nearest geographic occurrences of conspecifics or most closely related congeners are from the Solomon Islands (1 species), New Caledonia (2 species), Fiji and/or Samoa (9 species), elsewhere in Tonga (8 species), or unknown (3 species). The avifauna of West Polynesia (Fiji-Tonga-Samoa) is more closely related to that of Melanesia than that of East Polynesia. There was little pre-human turnover in Tongan land birds. The arrival of humans has influenced the Tongan avifauna more than any climatic, tectonic, or biological event of the past approximately 100,000 years.

Journal Article↗
PubMed2002

Reduced Y-chromosome, but not mitochondrial DNA, diversity in human populations from West New Guinea.

To investigate the paternal population history of New Guinea, 183 individuals from 11 regional populations of West New Guinea (WNG) and 131 individuals from Papua New Guinea (PNG) were analyzed at 26 binary markers and seven short-tandem-repeat loci from the nonrecombining part of the human Y chromosome and were compared with 14 populations of eastern and southeastern Asia, Polynesia, and Australia. Y-chromosomal diversity was low in WNG compared with PNG and with most other populations from Asia/Oceania; a single haplogroup (M-M4) accounts for 75% of WNG Y chromosomes, and many WNG populations have just one Y haplogroup. Four Y-chromosomal lineages (haplogroups M-M4, C-M208, C-M38, and K-M230) account for 94% of WNG Y chromosomes and 78% of all Melanesian Y chromosomes and were identified to have most likely arisen in Melanesia. Haplogroup C-M208, which in WNG is restricted to the Dani and Lani, two linguistically closely related populations from the central and western highlands of WNG, was identified as the major Polynesian Y-chromosome lineage. A network analysis of associated Y-chromosomal short-tandem-repeat haplotypes suggests two distinct population expansions involving C-M208--one in New Guinea and one in Polynesia. The observed low levels of Y-chromosome diversity in WNG contrast with high levels of mtDNA diversity reported for the same populations. This most likely reflects extreme patrilocality and/or biased male reproductive success (polygyny). Our data further provide evidence for primarily female-mediated gene flow within the highlands of New Guinea but primarily male-mediated gene flow between highland and lowland/coastal regions.

Chromosomes, Human, Y↗
PubMed2005

Prevalence and penetrance variation of male-killing Wolbachia across Indo-Pacific populations of the butterfly Hypolimnas bolina.

Male-killing bacteria are generally thought to attain low to intermediate prevalence in natural populations, with only mild effects on the host population sex ratio. This view was recently challenged by reports of extremely high infection frequencies in three butterfly species, raising the prospect that male killers, by making males rare, might drive many features of host ecology and evolution. To assess this hypothesis, it is necessary to evaluate how often male killers actually produce a highly female-biased population sex ratio in nature, which requires both high prevalence of infection and high penetrance of action. To this end, we surveyed South Pacific and Southeast Asian populations of Hypolimnas bolina, a butterfly in which extreme prevalence of male-killing Wolbachia bacteria has recently been recorded. Our results indicate that highly female-biased populations are common in Polynesia, with 6 out of 12 populations studied having in excess of 70% of females infected with a fully efficient male killer. However, heterogeneity is extreme in Polynesia, with the male-killing Wolbachia absent from three populations. In contrast to the Polynesian situation, Wolbachia does not kill males in any of the three Southeast Asian populations studied, despite its very high prevalence there. We conclude that male killers are likely to have significant ongoing ecological and evolutionary impact in 6 of the 15 populations surveyed. The causes and consequences of the observed spatial variation are discussed with respect to host resistance evolution, host ecology and interference with additional symbionts.

Animals↗
PubMed1978

New hepatitis B surface antigen subtypes inside the ad category.

In addition to the 10 HBs Ag subtypes already described, 2 new subtypes were defined by using the q determinant. Exceptions to the rule generally accepted were found in that the q determinant was only lacking in HBs Ag/adw4. These exceptions occurred in adw and adr categories. These 2 new subtypes are adw q positive and adr q negative. Out of 98 HBs Ag/adw4 from silent carries and patients from different parts of the world, mainly from France (79), 6 were found q positive. 3 out of these 6 cases came from Montpellier (South of France) and another 3 from Germany. The 92 other cases were found q negative. Further studies will be necessary to better know the location of this new subtype adw4 q positive, but it seems to be present only in certain parts of Europe. Out of 86 HBs Ag/adr from silent carriers from Asia (58), Oceania (17), France (10, most of them contaminated in Asia) and Réunion (1), 10 were found q negative. All these 10 cases were detected in Oceania, 2 out of 2 in carriers from New Caledonia and 8 out of 13 from French Polynesia. The new subtype adr q negative seems localized in Melanesia and Polynesia and absent from Asia. These 2 new markers of hepatitis B virus will allow better epidemiological and geographical studies.

Epitopes↗
PubMed1983

Distribution of HBsAg subtypes in the world.

HBsAg subtyping was performed in 5,337 sera from chronic carriers who originated from 54 different countries of the 5 continents. Nine subtypes were defined: ayw1, ayw2, ayw3, ayw4, ayr, adw2, adw4, adr q- and adr q+. The repartition of these subtypes, according to the country of origin of the carriers, enhances the previous results and supplies new data: ayw1 is prevalent only in Vietnam (51%); ayw2 in Mediterranean countries (73%); ayw3 in Greece and Yugoslavia (54%) along with ayw2 (41%); ayw4 in West Africa (82%) and Central Africa (42%) along with ayw2; ayr was only found in Vietnam (3.4%); adw2 is prevalent in North and Central Europe (70%), East and South Africa (95%), India (55%), along with ayw3 (35%) in northern South American (74%), and in the Antilles (82%); adw4 is widespread in French Polynesia (45%)--with a 100% frequency in the Marquesas archipelago--as well as in Argentina (42%); adr q--was found only in Ocean: French Polynesia (34%) with a 69% frequency in the Australes, New Caledonia (3 out of 3 HBsAg carriers); adr q+ is the prevalent subtype in South-East Asia if we exclude Vietnam (61%). These results show that a precise geographical distribution of HBsAg subtypes needs more than 'four main subtypes' generally used. Enlarging from 4 subtypes to 9 is a requirement for valuable epidemiologic studies, as well as for the specification of anti-HBs antibodies produced by hybrids or induced by synthetic peptide. The geographical distribution of these 9 HBsAg subtypes and the serological relationship between some determinants suggest a genetic recombination of viral DNA.

Africa↗
PubMed1976

The prevalence of toxoplasmosis on Pacific Islands, and the influence of ethnic group.

The prevalence of Toxoplasma dye-test antibody was determined in inhabitants of a number of Pacific islands, in Melanesia, Micronesia and Polynesia, and on Taiwan. With the exception of one island in French Polynesia, two Hawaiian islands, and Taiwan, Toxoplasma antibody prevalences were high, ranging between 84% and 100% in the adult populations tested. On the Hawaiian islands of Oahu and Hawaii, populated by several ethnic groups, and where about 50% of the total adult populations were estimated to have been infected with Toxoplasma gondii, a marked variation in prevalence of infection by ethnic group was observed. The lowest prevalence in the Hawaiian islands estimated at about 15% to 20% in adults, was observed in Japanese. On Taiwan, only 6% of adult ethnic Chinese and 1% of aborigines tested had Toxoplasma antibody.

Adolescent↗
PubMed2005

Detection and characterization of Wolbachia infections in Wuchereria bancrofti (Spirurida: Onchocercidae) var. pacifica and Aedes (Stegomyia) polynesiensis (Diptera: Culicidae).

Despite control programs based on mass drug administration (MDA) of microfilaricidal compounds, Bancroftian lymphatic filariasis remains a problem in French Polynesia. For an alternative strategy to MDA, we investigated the potential role of Wolbachia to control filarial transmission. Wolbachia are intracellular alpha-proteobacteria endosymbionts that infect a broad range of insects and nematodes. These bacteria have a suspected role in the pathogenesis of filariasis. They also may be useful in mosquito control through cytoplasmic incompatibility. To detect and characterize these bacteria in the filarial and mosquito-vectors in French Polynesia, a survey was conducted on field-collected mosquitoes and microfilariae from infected people. Samples were analyzed by a polymerase chain reaction and gene sequencing. The results indicate that these bacteria are widespread. Sequence analysis of the wsp and ftsZ genes positioned the Aedes polynesiensis Wolbachia in cluster A and Wuchereria bancrofti var. pacifica Wolbachia in cluster D. The implications for possible improved treatment and vector control are discussed.

Aedes↗