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Leptospirosis has been so far poorly described in Cambodia and is probably underdiagnosed in the current local medical practices, although conditions to its active circulation exist in this country. Between June 2006 and July 2007, 612 patients admitted to Takeo hospital and Calmette hospital in Phnom Penh presenting clinical symptoms compatible with leptospirosis, were recruited for biological investigation of leptospirosis markers: PCR detection of bacterial DNA and serology using an Elisa-IgM test and the micro-agglutination reference test (MAT). One hundred eighty-three patients (29.9%) were found to be carrying at least one biological marker of leptospirosis, 88 (14.4%) showed an acute infection profile, evidenced by a positive PCR. The proportion of patients with an immune phase profile (15.5%) suggests former contacts with Leptospira and possible infections with little or no symptoms. Thirteen serogroups of Leptospira have been identified, with predominance of Panama, Pyrogenes and Australia, illustrating a probable wide range of animal reservoir hosts. Serogroup Icterohaemorrhagiae was found in only 4% of cases, contrasting with usual features of human leptospirosis. No significant link between infection and sex, age or occupation could be established, suggesting a permanent exposure of the population in its daily life rather than the existence of risk groups. This study, the largest conducted to date on leptospirosis in Cambodia, confirms the importance of this zoonotic disease, that must be considered a real public health issue in this country.

International audience; Exceptionally high incidence rates of thyroid cancer have been reported in New Caledonia, particularly in Melanesian women. To clarify the reasons of this elevated incidence, we conducted a countrywide population-based case-control study in the multiethnic population of Caledonian women. The study included 293 cases of thyroid cancer and 354 population controls. Based on a food frequency questionnaire, we investigated the role in thyroid cancer of food items rich in iodine-such as seafood-and of vegetables containing goitrogens-such as cruciferous vegetables. A measure of total daily iodine intake based on a food composition table was also used. Our findings provided little support for an association between thyroid cancer and consumption of fish and seafood. We found that high consumption of cruciferous vegetables was associated with thyroid cancer among women with low iodine intake (OR = 1.86; 95% CI: 1.01-3.43 for iodine intake

International audience

Background Parameters predicting the evolution of leptospirosis would be useful for clinicians, as well as to better understand severe leptospirosis, but are scarce and rarely validated. Because severe leptospirosis includes septic shock, similarities with predictors evidenced for sepsis and septic shock were studied in a hamster model. Methodology/Principal Findings Using an LD50 model of leptospirosis in hamsters, we first determined that 3 days post-infection was a time-point that allowed studying the regulation of immune gene expression and represented the onset of the clinical signs of the disease. In the absence of tools to assess serum concentrations of immune effectors in hamsters, we determined mRNA levels of various immune genes, especially cytokines, together with leptospiraemia at this particular time-point. We found differential expression of both pro- and anti-inflammatory mediators, with significantly higher expression levels of tumor necrosis factor α, interleukin 1α, cyclo-oxygenase 2 and interleukin 10 genes in nonsurvivors compared to survivors. Higher leptospiraemia was also observed in nonsurvivors. Lastly, we demonstrated the relevance of these results by comparing their respective expression levels using a LD100 model or an isogenic high-passage nonvirulent variant. Conclusions/Significance Up-regulated gene expression of both pro- and anti-inflammatory immune effectors in hamsters with fatal outcome in an LD50 model of leptospirosis, together with a higher Leptospira burden, suggest that these gene expression levels could be predictors of adverse outcome in leptospirosis., Author Summary Leptospirosis is a widespread bacterial infection that is transmitted by soil or water contaminated by the urine of infected animals, or directly from these animals. It has highly diverse clinical presentations, making its differential diagnosis difficult. Though most cases are minor and self-resolving, there are also severe forms that include a sepsis pattern and multiple organ failure, and have possible fatal outcomes. Predictors of disease evolution and outcome are scarce, yet they would be very valuable to clinicians as well as to better decipher disease pathogenesis. In this study, we used a hamster model of leptospirosis to evaluate if immune genes were differentially expressed between individuals and if their expression levels could help forecast the outcome of the disease. We found that hamsters that later died from leptospirosis had significantly higher expression levels of both pro- and anti-inflammatory mediators compared to survivors. These results suggest that expression levels of these immune effectors might be helpful predictors of outcome in leptospirosis and that septic shock contributes to fatal leptospirosis.

Ciguatera is a food poisoning well known to island populations living in the tropics and many scientific works have been undertaken to understand and treat this pathology. Initially, activities focused on the inventory of fish species at risk, the clinical study of the disease and possible treatments. The analysis of ciguatoxins (CTXs) and the determination of their structures were then decisive in order to better understand their mode of action and the mechanisms involved in the pathophysiology of ciguatera. While certain neurological signs of the disease, fairly well described in the literature, are explained by the direct action of CTXs on the potential-dependent sodium channel (CSSP), little explanation is provided concerning the appearance of recurrent sequelae such as chronic fatigue syndrome, the persistence of neurological disorders or the resurgence of clinical signs following the consumption of non-ciguaterogenic foods, thus suggesting an allergic phenomenon.Modern medicine only offers essentially symptomatic treatments with the prescription of antihistamines, antispasmodics or vitamins that have no real effect in treating the persistent symptoms of ciguatera. The populations of the South Pacific then resorted to traditional medicine, using certain tropical plants such as Heliotropium foertherianum commonly known as false tobacco (former Argusia argentea) which seems to be the reference remedy according to a large number of anonymous accounts. However, while some of these plants have shown a notable ability to reduce the effects of CTXs in vitro and in vivo, their precise mode of action as well as the active molecules that constitute them still remain a mystery in the eyes of the scientific world. It is in this context that two scientific teams from New Caledonia have invested in research programs aimed at understanding the pathophysiology of ciguatera and studying the therapies available to treat this food poisoning.The study of a new aspect of the pathology was thus undertaken during these years of thesis concerning the implication of inflammatory mechanisms in the phenomenon according to several indices which led to develop this project: the possible evolution of the symptoms to pathologies such as polymyositis or neuropathies known to be associated with cytokines; the action of CTXs on secondary messengers of cell signaling pathways; and the recent discovery of the induction of nitric oxide NO by P-CTX-1B in an in vitro study model. This is how the role of cytokines, mediators of inflammation, in the pathophysiology of ciguatera is explored in this manuscript. This study also opens the way to new therapeutic perspectives and has led to the evaluation of the anti-inflammatory potential of remedies traditionally used in the South Pacific to treat ciguatera., La ciguatéra est une intoxication alimentaire bien connue des populations insulaires vivant sous les tropiques et de nombreux travaux scientifiques ont été entrepris afin de comprendre et soigner cette pathologie. Dans un premier temps, les activités se sont portées sur l’inventaire des espèces pisciaires à risque, l’étude clinique de la maladie et les thérapeutiques possibles. L’analyse des ciguatoxines (CTXs) et la détermination de leurs structures ont ensuite été déterminantes afin de mieux comprendre leur mode d’action et les mécanismes impliqués dans la physiopathologie de la ciguatéra. Si certains signes neurologiques de la maladie, assez bien décrits dans la littérature, sont expliqués par l’action directe des CTXs sur le canal sodique dépendant du potentiel (CSSP), peu d’explications sont fournies concernant l’apparition des séquelles récurrentes tels que le syndrome de fatigue chronique, la persistance des troubles neurologiques ou la résurgence de signes cliniques suite à la consommation d’aliments non ciguatérigènes, faisant alors penser à un phénomène allergique.La médecine moderne ne propose que des traitements essentiellement symptomatiques avec la prescription d’antihistaminiques, d’antispasmodiques ou de vitamines n’ayant pas d’effet réel à soigner les symptômes persistants de la ciguatéra. Les populations du Pacifique Sud ont alors recours à la médecine traditionnelle, utilisant certaines plantes tropicales telles que Heliotropium foertherianum communément appelé faux tabac (ancien Argusia argentea) qui semble être le remède de référence d’après un grand nombre de témoignages d’anonymes. Toutefois, si certaines de ces plantes ont montré une faculté notable à réduire les effets des CTXs in vitro et in vivo, leur mode d’action précis ainsi que les molécules actives qui les constituent restent encore un mystère aux yeux du monde scientifique. C’est dans ce contexte que deux équipes scientifiques de Nouvelle-Calédonie ont investi des programmes de recherche orientés vers la compréhension de la physiopathologie de la ciguatéra et l’étude des thérapeutiques disponibles pour soigner cette intoxication alimentaire.L’étude d’un nouvel aspect de la pathologie fut ainsi entrepris au cours de ces années de thèse concernant l’implication de mécanismes inflammatoires dans le phénomène d’après plusieurs indices qui ont amené à élaborer ce projet : l’évolution éventuelle des symptômes vers des pathologies comme les polymyosites ou les neuropathies connues pour être associées aux cytokines ; l’action des CTXs sur les messagers secondaires des voies de signalisation cellulaire ; et la récente découverte de l’induction de l’oxyde nitrique NO par la P-CTX-1B dans un modèle d’étude in vitro. C’est ainsi que le rôle des cytokines, médiateurs de l’inflammation, dans la physiopathologie de la ciguatéra est exploré dans ce manuscrit. Cette étude ouvre également la voie à de nouvelles perspectives thérapeutiques et a conduit à évaluer le potentiel anti-inflammatoire de remèdes traditionnellement utilisés dans le Pacifique Sud pour soigner la ciguatéra.

International audience; OBJECTIVE: To determine in Neisseria gonorrhoeae (NG) isolates from different geographical areas whether monitoring of major determinants involved in chromosomal antimicrobial resistance correlated with phenotypes and could constitute complementary tools for surveillance. METHODS: Real-time multiplex PCR assays targeting penA, mtrR, penB, ponA, gyrA and parC determinants were applied to 169 NG extracts. Minimum inhibitory concentrations for penicillin and ciprofloxacin were determined by E tests, and beta-lactamase production was analysed using nitrocefin discs. RESULTS: A total of 169 NGs were examined, 110 from New Caledonia, 44 from Madagascar and 15 from Cambodia. Despite the heterogeneity in the number of isolates tested, the susceptibility trends observed in the different geographic areas studied showed a good fit with the multigene genotypes. In addition, features related to a specific geographical diversity were found: (1) a high prevalence of strains harbouring the porB1a allele and showing reduced penicillin susceptibility in Madagascar and Cambodia (39% and 40% respectively); (2) almost all strains from Cambodia were resistant to the drugs tested (11/15 and 14/15 resistant to penicillin and ciprofloxacin respectively); and (3) identification of novel penB and mtrR genotypes associated with a moderately decreased penicillin susceptibility in New Caledonia (mtrR novel genotype in 47% of intermediate vs 14% of susceptible isolates). CONCLUSIONS: Showing a good correlation with phenotypic trends of susceptibility, multiplex real-time PCR assays could be used successfully for prospective epidemiological studies notably by characterising mtrR and penB determinants for their fundamental and complementary roles in increasing the antibiotic resistance. These molecular tools could also provide useful alternative surveillance tools for non-viable strains.

Aims: A description of bacterial pathogens in shrimp ponds is necessary to understand their pathogenesis. Vibrio nigripulchritudo was shown to contain saprophytic and pathogenic strains among New Caledonian isolates. We established a method to map the development of V. nigripulchritudo in pond sediments at three different genetic levels: the species level, then at the pathogenic cluster level and finally at the plasmid level, present only in all highly pathogenic isolates. Methods and Results: PCR methods were applied to shrimp pond sediments both before and after a mortality outbreak. Using crude samples, the species V. nigripulchritudo is not detected at first (0/42 samples at day 56 post stocking) but appears frequently in the sediments after the mortality event (30/42 at day 107). The distribution of strains from the pathogenic cluster of V. nigripulchritudo also follows this pattern. In contrast, the pSFn1 virulence-associated plasmid was detected in one sample at day 56 and none at day 107. An enrichment method was developed to lower the detection limits of our assays. After enrichment, the species V. nigripulchritudo was detected in all samples at both dates. The number of samples positive for pSFn1 was 42/42 samples at day 56 and 29/42 at day 107. Conclusions: These results show that the sediments contain V. nigripulchritudo, notably pathogenic strains. Surprisingly, the virulence-associated plasmid pSFn1 found in all V. nigripulchritudo isolated from moribund shrimp appears less frequently in sediments, possibly being useless or even detrimental to its recipient bacteria in this environment. Significance and Impact of the Study: This study confirms the presence of pathogenic V. nigripulchritudo strains in shrimp pond sediment before a mortality outbreak complying with a previous hypothesis that sediments could be the infecting reservoir. After the outbreak, both total V. nigripulchritudo and pathogenic strains populations have largely increased, possibly contributing to the recurrent mortality observed in this shrimp vibriosis.

International audience; Leptospirosis is a zoonotic disease that has emerged as an important cause of morbidity and mortality among impoverished populations. One hundred years after the discovery of the causative spirochaetal agent, little is understood about Leptospira spp. pathogenesis, which in turn has hampered the development of new intervention strategies to address this neglected disease. However, the recent availability of complete genome sequences for Leptospira spp. and the discovery of genetic tools for their transformation have led to important insights into the biology of these pathogens and their pathogenesis. We discuss the life cycle of the bacterium, the recent advances in our understanding and the implications for the future prevention of leptospirosis.

Summary A leptospirosis epidemic affected New Caledonia during the first semester of 2008. A total of 135 cases were diagnosed with a relatively low fatality rate of 3.7%. Heavy rainfalls, related to La Nina, favoured this epidemic. The PCR, routinely used, confirmed 54% of the cases, and the microagglutination test 56%. Epidemiological and economical data on this epidemic are presented and discussed. Epidemie de la leptospirose en Nouvelle-Caledonie: enjeux du diagnostic et charge de morbidite Une epidemie de leptospirose a affecte la Nouvelle-Caledonie au cours du premier semestre de 2008. Un total de 135 cas ont ete diagnostiques avec un taux de letalite relativement faible de 3,7%. Des pluies abondantes liees a‘La Nina’ ont favorise cette epidemie. La PCR utilisee en routine a confirme 54% des cas et le test de microagglutination 56% des cas. Les donnees epidemiologiques et economiques sur cette epidemie sont presentees et discutees ici. Brote de leptospirosis en Nueva Caledonia: cuestiones diagnosticas y carga de enfermedad Una epidemia de leptospirosis afecto a Nueva Caledonia durante el primer semestre del 2008. Se diagnosticaron 135 casos con una tasa de fatalidad relativamente baja del 3.7%. Las lluvias torrenciales, relacionadas con La Nina, favorecieron esta epidemia. La PCR, utilizada rutinariamente, confirmo un 54% de los casos, y la prueba de microaglutinacion un 56%. Se presentan y discuten los datos epidemiologicos y economicos sobre esta epidemia.

International audience; We report a duplex real-time PCR assay for the simultaneous screening of mutations involved in fluoroquinolone resistance within gyrA and parC quninolone resistance-determining regions (QRDRs) in Neisseria gonorrhoeae. Our assay clearly detects all mutated QRDRs and allows the identification of common genotypes, whether the QRDRs contain single or double mutations, providing valuable epidemiological tools. When this method is used in conjunction with similar assays and in vitro analyses, essential antibiotic resistance surveillance can be performed for public health purposes.

Summary Objective To evaluate dipstick rapid diagnostic tests (RDTs) for meningococcal meningitis in basic health facilities. Methods Health facility staff received a one-day training. During the meningitis season, they performed RDTs on cerebrospinal fluid (CSF) specimens from suspected cases of meningitis. A frozen aliquot of CSF was later tested using polymerase chain reaction (PCR) to establish the reference diagnosis. RDTs used in health facilities were archived to allow checking the concordance between reported diagnosis and observed results. Reported diagnosis was also compared to PCR diagnosis. A second RDT was performed on each CSF specimen at the reference laboratory. Results Using RDTs, health facilities reported 382 negative results (73.9%), 114 NmA (22.1%), 12 NmW135 (2.3%) and nine uninterpretable results (1.7%), the latter corresponding to the misuse of a reagent by three agents. The agreement between reported diagnosis and archived dipsticks was excellent (kappa = 0.98). The agreement between PCR diagnosis and reported RDTs results was strong (kappa = 0.82). In health facilities, the sensitivity of RDTs for N. meningitidis A was Se = 0.91. The kappa coefficient measuring the agreement between RDTs operated in the reference laboratory and RDTs operated in health facilities was κ = 0.78. Conclusion We confirmed that dipstick RDTs to identify N. meningitidis serogroups A, C, W135 and Y can be reliably operated by non-specialized staff in basic health facilities. RDTs proved very useful to recommend vaccination in NmA epidemics, and also to avoid vaccination in epidemics due to serogroups not included in vaccines (NmX).

Fluoroquinolone resistance in Streptococcus pneumoniae mainly involves stepwise mutations predominantly in the parC and gyrA genes. We have developed a single-run real-time PCR assay for detection of the four most common mutations in the quinolone resistance-determining regions of these genes. This assay provides a useful tool for both clinical and epidemiological use.

International audience; Carbapenem-resistant Acinetobacter baumannii (CR-Ab) ranked third, with a frequency of 24.8%, among 202 strains of multidrug-resistant bacteria isolated from clinical samples in the main hospital of New Caledonia in 2004. All CR-Ab isolates were analysed by isoelectric focusing, conjugation, pulsed-field gel electrophoresis and PCR for the presence of carbapenemase genes. Fifty CR-Ab isolates produced carbapenemase OXA-23. The isolates belonged to a single clone presenting several subtypes, suggesting an endemic situation. This study further illustrates the widespread prevalence of carbapenemase OXA-23-producing CR-Ab isolates in the South Pacific.

Antibiotic resistance in Neisseria gonorrhoeae continues to be a major concern in public health. Resistance of N. gonorrhoeae bacteria to penicillin G is widespread in most developed countries, which has necessitated a change to newer drugs for treatment of gonococcal infections. Recent reports indicate that resistance to these newer drugs is increasing, highlighting the need for accurate therapeutic recommendations. In some countries or communities, however, N. gonorrhoeae isolates are still susceptible to penicillin, so the use of this antibiotic for single-dose treatments of medically under-resourced patients is beneficial. In order to evaluate the adequacy and sustainability of this treatment approach, we explored the presence and prevalence of chromosomally mediated resistance determinants in N. gonorrhoeae isolates collected from 2005 to 2007 in New Caledonia. We developed two new real-time PCR assays targeting the penB and mtrR determinants, to be used together with a previously described duplex assay targeting the penA and ponA determinants. The results of this study provided evidence that neither the most-common mtrR determinants nor the most-resistance-associated penB alleles are currently circulating in New Caledonia, suggesting that penicillin should still be considered a valuable treatment strategy. Additionally, using our genotyping assay, we observed an unexpected penB genotype at a relatively high frequency that was associated with a decreased susceptibility to penicillin (average MIC, 0.15 μg/ml). Sequencing revealed that this genotype corresponded to an A102S mutation in the penB gene. The molecular tools developed in this study can be used successfully for prospective epidemiological monitoring and surveillance of penicillin susceptibility.

International audience

International audience; Tinea imbricata, also known as ‘Tokelau’, is an uncommon superficial mycosis caused by the anthropophilic dermatophyte Trichophyton concentricum. Cutaneous lesions appear characteristically as scaly and concentric rings that may cover all parts of the body. Often acquired in childhood, tinea imbricata is a chronic disease and lichenification is extremely common due to pruritus. The dermatophytosis mainly occurs in the South Pacific, but also in some regions of Southeast Asia and Central or South America. Tinea imbricata usually affects people living in primitive and isolated conditions. Mycological analysis is required for the diagnosis. The epidemiological and mycological study reported here took place in the Solomon Islands from June–September 2006. Skin scrapings were collected from 29 Melanesian patients (aged 8 months to 58 years) with chronic cutaneous lesions and were analysed mycologically in the Laboratory of Parasitology and Mycology of Angers University Hospital (France). Ten patients showed very evocative lesions with a positive direct examination, but T. concentricum was only isolated from three patients. Identification of the strains was confirmed by sequencing of the internal transcribed spacer (ITS) regions. With the increase in international travel, one cannot disregard that this very rare species may be isolated by mycologists in temperate areas from patients coming from endemic foci.

International audience; We show human herpesvirus 8 with diverse molecular subtype D variants to be highly endemic among the Ni-Vanuatu population. Most K1 genes were nearly identical to Polynesian strains, although a few clustered with Australian or Taiwanese strains. These results suggest diverse origins of the Ni-Vanuatu population and raise questions about the ancient human population movements in Melanesia.

Background In the framework of the monitoring and evaluation of the Nigerien schistosomiasis and soil-transmitted helminth control programme, a follow-up of children took place in eight sentinel sites. The objective of the study was to assess the evolution of Schistosoma haematobium infection and anaemia in schoolchildren after a single administration of praziquantel (PZQ) and albendazole. Methods/Principal Findings Pre-treatment examination and follow-up at one year post-treatment of schoolchildren aged 7, 8, and 11 years, including interview, urine examination, ultrasound examination of the urinary tract, and measurement of haemoglobin. Before treatment, the overall prevalence of S. heamatobium infection was 75.4% of the 1,642 enrolled children, and 21.8% of children excreted more than 50 eggs/10 ml urine. Prevalence increased with age. The overall prevalence of anaemia (haemoglobin, Author Summary The World Health Organization's recommendation for the control of urinary schistosomiasis is to reduce morbidity by reducing the prevalence of heavy infections. In Niger, where urinary schistosomiasis is endemic along the Niger River valley and in proximity to ponds, a national control programme for schistosomiasis and soil-transmitted helminth was launched in 2004 with the financial support of the Gates Foundation through the Schistosomiasis Control Initiative. In the framework of the monitoring and evaluation of the control programme, a follow-up of school children took place in eight sentinel sites. The aim of this study was to assess the evolution of Schistosoma haematobium infection and associated morbidity after a single-dose administration of praziquantel and albendazole. Before treatment, the overall prevalence of S. heamatobium infection was 75.4% and anaemia (haemoglobin

International audience; Exceptionally high incidence rates of thyroid cancer are observed in New Caledonia, particularly in Melanesian women. To investigate further the etiology of thyroid cancer and to clarify the reasons of this elevated incidence, the authors conducted a countrywide population-based case-control study in this multiethnic population. The study included 332 cases with histologically verified papillary or follicular carcinoma (293 women and 39 men) diagnosed in 1993-1999 and 412 population controls (354 women and 58 men) frequency matched by gender and 5-year age group. Thyroid cancer was negatively associated with tobacco smoking and alcohol drinking, but no inverse dose-response relation was observed. Height was positively associated with thyroid cancer, particularly in men. Strong positive associations with weight and body mass index were observed in Melanesian women aged 50 years or more, with an odds ratio of 5.5 (95% confidence interval: 1.5, 20.3) for a body mass index of 35 kg/m(2) or greater compared with normal-weight women, and there was a clear dose-response trend. This study clarifies the role of overweight for thyroid cancer in postmenopausal women. Because of the high prevalence of obesity among Melanesian women of New Caledonia, this finding may explain in part the exceptionally elevated incidence of thyroid cancer in this group.

International audience; Exceptionally high incidence rates of thyroid cancer are observed in New Caledonia, particularly in Melanesian women. To investigate further the etiology of thyroid cancer and to clarify the reasons of this elevated incidence, the authors conducted a countrywide population-based case-control study in this multiethnic population. The study included 332 cases with histologically verified papillary or follicular carcinoma (293 women and 39 men) diagnosed in 1993-1999 and 412 population controls (354 women and 58 men) frequency matched by gender and 5-year age group. Thyroid cancer was negatively associated with tobacco smoking and alcohol drinking, but no inverse dose-response relation was observed. Height was positively associated with thyroid cancer, particularly in men. Strong positive associations with weight and body mass index were observed in Melanesian women aged 50 years or more, with an odds ratio of 5.5 (95% confidence interval: 1.5, 20.3) for a body mass index of 35 kg/m(2) or greater compared with normal-weight women, and there was a clear dose-response trend. This study clarifies the role of overweight for thyroid cancer in postmenopausal women. Because of the high prevalence of obesity among Melanesian women of New Caledonia, this finding may explain in part the exceptionally elevated incidence of thyroid cancer in this group.

In a previous study, we demonstrated the existence of an emerging cluster of Vibrio nigripulchritudo that proved to be associated with shrimp mortality events in New Caledonia. Using sequence polymorphisms evidenced in this previous MultiLocus Sequence Typing study, we developed two new quantitative PCR assays permitting the detection and quantification of V. nigripulchritudo at the genospecies level using SYBR Green I chemistry and at the emerging cluster level using Fluorescence Resonance Energy Transfer technology with hybridization probes. The use of this molecular diagnostic tool evidenced the colonization of the shrimp pond ecosystem by the pathogenic cluster at least at the onset of the disease. This new tool will allow better investigation of the dynamics of this bacterial pathogen in the shrimp farm ecosystem. (C) 2007 Elsevier B.V. All rights reserved.

International audience; BACKGROUND: Melanesia is endemic for human T lymphotropic virus type 1 (HTLV-1) subtype C. In 2005, we identified 4 infected women from Ambae Island, Vanuatu. Subsequently, 4247 Ni-Vanuatu originating from 18 islands were enrolled to define HTLV-1 epidemiological determinants and to characterize the viral strains molecularly. METHODS: Plasma from 1074 males and 3173 females were screened for HTLV-1/2 antibodies by particle agglutination (PA) and an immunofluorescence assay (IFA). Positive and/or borderline samples were then tested by a Western blot (WB) confirmatory assay. DNAs were amplified to obtain a 522-bp env gene fragment. Phylogenetic and molecular-clock analyses were performed. RESULTS: Of 4247 samples, 762 were positive and/or borderline by IFA/PA, and 26 of them were confirmed to be HTLV-1 positive by WB. The overall HTLV-1 seroprevalence was 0.62%. Viral transmission was found within families of infected index case patients. A geographic heterogeneity of HTLV-1 seroprevalence was observed among the islands. All 41 of the new env sequences belonged to HTLV-1 subtype C. Phylogenetic and molecular-clock analyses suggested that Ni-Vanuatu and Solomon Islander strains emerged from a common ancestor ~10,000 years ago. CONCLUSION: The Vanuatu archipelago is endemic for HTLV-1 with a diversity of subtype C variants. These strains were probably introduced into Vanuatu during ancient migration of the original settlers a few thousand years ago.

Shrimp farming is a small but growing industry in New Caledonia. Since 1993, "Syndrome 93" has been affecting New Caledonian shrimp farming industry every cold season, causing severe epizootic mortalities in grow-out ponds and significant losses. Highly pathogenic strains of Vibrio penaeicida are considered the etiological agent of the disease in Litopenaeus stylirostris. On one hand, studies demonstrated that healthy shrimp may carry V penaeicida for weeks with a high overall prevalence, regardless of any seasonal pattern or temperature conditions. On the other hand, larvae are free of V penaeicida and are also resistant to experimental infection. V penaeicida is frequently detected in incoming water pumped from the bays, which was shown, by a molecular typing study, to be the infectious source. This particular epidemiological pattern highlights the major role of the factors that trigger and aggravate the disease in grow-out ponds, where shrimp populations carry the pathogen all year round. In order to gain a better understanding of "Syndrome 93" epidemiology, quantification of V penaeicida both in shrimp and the shrimp farm ecosystem is necessary. This article describes the steps in the successful development of a real-time PCR quantification assay of V penaeicida in shrimp haemolymph, seawater (from ponds or bays) and sediment pore water, including the choice of an accurate extraction technique. The entire detection method; including sample processing, DNA extraction and real-time PCR amplification, can be completed within 4 h. (c) 2006 Elsevier B.V All rights reserved.

International audience; Exceptionally high incidence rates of thyroid cancer have been reported for Melanesian women in New Caledonia (South Pacific). To investigate the occurrence of thyroid cancer in that country and to clarify the role of goiter and hormonal factors in that disease in women, a countrywide population-based case-control study was conducted in 1993-1999. The study included 293 cases, identified through pathology registers and whose thyroid cancer was verified histologically, and 354 population controls. Thyroid cancer was associated with goiter, age at menarche, irregular menstruation, and hysterectomy. There was a dose-response trend with number of full-term pregnancies (p = 0.01), with an odds ratio of 2.2 (95% confidence interval: 1.1, 4.3) for women with eight or more pregnancies. Miscarriage, particularly as an outcome of the first pregnancy, was also indicated as a risk factor. The association between voluntary abortion and thyroid microcarcinoma could be explained by enhanced medical surveillance and improved cancer detection in women undergoing abortion. Oral contraceptives and hormone replacement therapy were unrelated to thyroid cancer. The very high birth rate among Melanesian women in New Caledonia, as well as late age at menarche, may explain, in part, their elevated incidence of thyroid cancer.

uman T-cell leukemia virus type 1 (HTLV-1), ahuman oncoretrovirus, is the etiologic agent of adultT-cell leukemia and of tropical spastic paraparesis/HTLV-1–associated myelopathy. Molecular epidemiologic stud-ies have shown HTLV-1 proviruses to be remarkably stablegenetically. The low levels of genetic drift in this virushave been used as a means for monitoring viral transmis-sion and the movement of ancient human populations(1,2). The few nucleotide substitutions observed in HTLV-1 strains are specific to the geographic origin of the patientand are unrelated to viral pathology (1,2). Four major geo-graphic HTLV-1 subtypes have been described: subtype A,cosmopolitan (1,2); subtype B, central African; subtype C,Melanesian (3–6); and subtype D, present in central Africa,mainly in pygmies. Previous reports have indicated that HTLV-1 is endem-ic in some remote or ancient populations in Melanesia(3–14). These populations include a small number of tribesfrom Papua New Guinea (especially the Hagahai people)(5) and some inhabitants of the Solomon Islands (7).Evidence of HTLV-1 infection has also been found in someaboriginal groups from Australia (8). Rare cases of adult T-cell leukemia and tropical spastic paraparesis/HTLV-1–associated myelopathy have also been described in thesepopulations (9).Genetic characterization of the few availableMelanesian HTLV-1 strains has indicated that these HTLV-1 strains are the most divergent, constituting molecularsubtype C (also called Melanesian subtype [3,4,6,10]) inphylogenetic analyses. The discovery of such divergentvariants has increased our understanding of the migrationof HTLV-1–infected populations throughout the Pacificregion. Furthermore, 1 of the calibration methods fre-quently used, in phylogenetic analyses, to estimate a timescale for the evolution of HTLV and simian T-cellleukemia virus (STLV) appears to coincide with thefirst human migrations to Melanesia and Australia40,000–60,000 years ago (2).We carried out a large serologic and molecular study todetermine the prevalence of HTLV-1 and associated dis-eases in the Vanuatu Archipelago. Vanuatu, formerlyknown as the New Hebrides, is a Y-shaped archipelagomade up of ≈80 islands. It is located in Melanesia, in theSouth Pacific region, northeast of Australia and south ofthe Solomon Islands. Vanuatu has a population of≈200,000 inhabitants, most of whom (95%) are ofMelanesian origin and are known as the Ni-Vanuatu. Very few seroepidemiologic studies on HTLV-1 inVanuatu have been carried out, and these studies examinedmostly small populations more than a decade ago and werenot based on stringent serologic criteria (11–14). Nomolecular characterization data are available for HTLV-1from this area. The main goals of this study were to evalu-ate the situation concerning HTLV-1 infection in a remoteNi-Vanuatu population by using stringent serologic criteriafor Western blotting and molecular characterization of theviruses.

Archives de Journal of Food Protection (https://jfoodprotection.org/toc/food/65/1); International audience; An international multicenter study of ready-to-eat foods, sandwiches, and ice creams or sorbets sold in the streets and their vendors was carried out to assess the microbiological quality of these foods and to identify characteristics of the vendors possibly associated with pathogens. Thirteen towns in Africa, America, Asia, and Oceania were involved in the study. A single protocol was used in all 13 centers: representative sampling was by random selection of vendors and a sample of foods bought from each of these vendors at a time and date selected at random. Microbiological analyses were carried out using standardized Association Française de Normalisation methods, and the use of a standardized questionnaire to collect data concerning the characteristics of the vendors. Fifteen surveys were carried out, with 3,003 food samples from 1,268 vendors. The proportion of unsatisfactory food samples was between 12.7 and 82.9% for ice creams and sorbets and between 11.3 and 92% for sandwiches. For ice creams and sorbets, the sale of a large number of units (>80 per day) increased the risk of unsatisfactory food by a factor of 2.8 (95% confidence interval [CI]: 1.5 to 5.1), lack of training in food hygiene by 6.6 (95% CI: 1.1 to 50). and by a factor of 2.8 (95% CI: 1.4 to 5.4) for mobile vendors. These risk factors were not identified for sandwiches, this difference may be due to the presence of a cooking step in their preparation. These results show that the poor microbiological quality of these street foods constitutes a potential hazard to public health, that the extent of this hazard varies between the cities studied, and that vendors' health education in food safety is a crucial factor in the prevention of foodborne infections.

A molecular typing study on Vibrio strains implicated in shrimp disease outbreaks in New Caledonia and Japan was conducted by using AP-PCR (arbitrarily primed PCR). It allowed rapid identification of isolates at the genospecies level and studies of infraspecific population structures of epidemiological interest. Clusters identified within the species Vibrio penaeicida were related to their area of origin, allowing discrimination between Japanese and New Caledonian isolates, as well as between those from two different bays in New Caledonia separated by only 50 km. Other subclusters of New Caledonian V. penaeicida isolates could be identified, but it was not possible to link those differences to accurate epidemiological features. This contribution of AP-PCR to the study of vibriosis in penaeid shrimps demonstrates its high discriminating power and the relevance of the epidemiological information provided. This approach would contribute to better knowledge of the ecology of Vibrio spp. and their implication in shrimp disease in aquaculture.

Background Leptospirosis is a major public health concern in New Caledonia (NC) and in other tropical countries. Severe manifestations of the disease are estimated to occur in 5–15% of all human infections worldwide and factors associated with these forms are poorly understood. Our objectives were to identify risk factors and predictors of severe forms of leptospirosis in adults. Methods and Findings We conducted a retrospective case-control study of inpatients with laboratory-confirmed leptospirosis who were admitted to two public hospitals in NC in 2008–2011. Cases were patients with fatal or severe leptospirosis, as determined by clinical criteria. This approach was meant to be pragmatic and to reflect the routine medical management of patients. Controls were defined as patients hospitalized for milder leptospirosis. Risk and prognostic factors were identified by multivariate logistic regression. Among the 176 patients enrolled in the study, 71 had criteria of severity including 10 deaths (Case Fatality Rate = 14.1%). Three risk factors were independently associated with severe leptospirosis: current cigarette smoking (OR = 2.94 [CI 1.45–5.96]); delays >2 days between the onset of symptoms and the initiation of antibiotherapy (OR = 2.78 [CI 1.31–5.91]); and Leptospira interrogans serogroup Icterohaemorrhagiae as the infecting strain (OR = 2.79 [CI 1.26–6.18]). The following post-admission laboratory results correlated with poor prognoses: platelet count ≤50,000/µL (OR = 6.36 [CI 1.79–22.62]), serum creatinine >200 mM (OR = 5.86 [CI 1.61–21.27]), serum lactate >2.5 mM (OR = 5.14 [CI 1.57–16.87]), serum amylase >250 UI/L (OR = 4.66 [CI 1.39–15.69]) and leptospiremia >1000 leptospires/mL (OR = 4.31 [CI 1.17–15.92]). Conclusions To assess the risk of developing severe leptospirosis, our study illustrates the benefit for clinicians to have: i) the identification of the infective strain, ii) a critical threshold of qPCR-determined leptospiremia and iii) early laboratory results. In New Caledonia, preventative measures should focus on early presumptive antibacterial therapy and on rodent (reservoir of Icterohaemorrhagiae serogroup) control., Author Summary Leptospirosis is a neglected tropical disease and a public health concern worldwide. Factors responsible for the progression towards severe forms have not been clearly established. However, pathogen- as well as host-related factors are both believed to play a role in the development of severe leptospirosis. This study aimed to determine risk and prognostic factors independently associated with severe leptospirosis in laboratory-confirmed cases in adults in New Caledonia. Our study provides important results on these factors. One major finding was the independent association between the serogroup Icterohaemorrhagiae and severe leptospirosis in the multivariate analysis. Though empirically recognized, we think that this association between this highly prevalent serogroup and most severe forms of the disease was seldom (if ever) clearly demonstrated. Our data also illustrate the benefit of using a critical threshold of qPCR-determined leptospiremia to assess the risk of developing severe leptospirosis in patients after their admission to hospital.

Background Most of the current knowledge of leptospirosis epidemiology originates from serological results obtained with the reference Microscopic Agglutination Test (MAT). However, inconsistencies and weaknesses of this diagnostic technique are evident. A growing use of PCR has improved the early diagnosis of leptospirosis but a drawback is that it cannot provide information on the infecting Leptospira strain which provides important epidemiologic data. Our work is aimed at evaluating if the sequence polymorphism of diagnostic PCR products could be used to identify the infecting Leptospira strains in the New Caledonian environment. Results Both the lfb1 and secY diagnostic PCR products displayed a sequence polymorphism that could prove useful in presumptively identifying the infecting leptospire. Using both this polymorphism and MLST results with New Caledonian isolates and clinical samples, we confirmed the epidemiological relevance of the sequence-based identification of Leptospira strains. Additionally, we identified one cluster of L. interrogans that contained no reference strain and one cluster of L. borgpetersenii found only in the introduced Rusa deer Cervus timorensis russa that is its probable reservoir. Conclusions The sequence polymorphism of diagnostic PCR products proved useful in presumptively identifying the infecting Leptospira strains. This could contribute to a better understanding of leptospirosis epidemiology by providing epidemiological information that cannot be directly attained from the use of PCR as an early diagnostic test for leptospirosis.

International audience; The mosquito-borne arbovirus Zika virus (ZIKV, Flavivirus, Flaviviridae), has caused an outbreak impressive by its magnitude and rapid spread. First detected in Uganda in Africa in 1947, from where it spread to Asia in the 1960s, it emerged in 2007 on the Yap Island in Micronesia and hit most islands in the Pacific region in 2013. Subsequently, ZIKV was detected in the Caribbean, and Central and South America in 2015, and reached North America in 2016. Although ZIKV infections are in general asymp-tomatic or causing mild self-limiting illness, severe symptoms have been described including neuro-logical disorders and microcephaly in newborns. To face such an alarming health situation, WHO has declared Zika as an emerging global health threat. This review summarizes the literature on the main vectors of ZIKV (sylvatic and urban) across all the five continents with special focus on vector competence studies.

SUMMARYMelioidosis is an infectious disease caused byBurkholderia pseudomallei, a bacterium endemic in Southeast Asia and northern Australia. In New Caledonia, sporadic cases were first described in 2005; since then, more cases have been identified. To improve our understanding of melioidosis epidemiology in New Caledonia, we compared the local cases andB. pseudomalleiisolates with those from endemic areas. Nineteen melioidosis cases have been diagnosed in New Caledonia since 1999, mostly severe and with frequent bacteraemia, leading to three (16%) fatalities. All but one occurred in the North Province. Besides sporadic cases caused by non-clonal strains, we also identified a hotspot of transmission related to a clonal group ofB. pseudomalleithat is phylogenetically related to Australian strains.

[This corrects the article DOI: 10.3389/fimmu.2020.02007.]., (Copyright © 2022 Holzapfel, Bonhomme, Cagliero, Vernel-Pauillac, d’Andon, Bortolussi, Fiette, Goarant, Wunder, Picardeau, Ko, Werling, Matsui, Boneca and Werts.)