Genetic diversity and phylogeny of Aedes aegypti, the main arbovirus vector in the Pacific

Background The Pacific region is an area unique in the world, composed of thousands of islands with differing climates and environments. The spreading and establishment of the mosquito Aedes aegypti in these islands might be linked to human migration. Ae. aegypti is the major vector of arboviruses (dengue, chikungunya and Zika viruses) in the region. The intense circulation of these viruses in the Pacific during the last decade led to an increase of vector control measures by local health authorities. The aim of this study is to analyze the genetic relationships among Ae. aegypti populations in this region. Methodology/Principal Finding We studied the genetic variability and population genetics of 270 Ae. aegypti, sampled from 9 locations in New Caledonia, Fiji, Tonga and French Polynesia by analyzing nine microsatellites and two mitochondrial DNA regions (CO1 and ND4). Microsatellite markers revealed heterogeneity in the genetic structure between the western, central and eastern Pacific island countries. The microsatellite markers indicate a statistically moderate differentiation (FST = 0.136; P < = 0.001) in relation to island isolation. A high degree of mixed ancestry can be observed in the most important towns (e.g. Noumea, Suva and Papeete) compared with the most isolated islands (e.g. Ouvea and Vaitahu). Phylogenetic analysis indicated that most of samples are related to Asian and American specimens. Conclusions/Significance Our results suggest a link between human migrations in the Pacific region and the origin of Ae. aegypti populations. The genetic pattern observed might be linked to the island isolation and to the different environmental conditions or ecosystems

[Incidence and mortality of central nervous system tumors in France: trends over the period 1978-2000 and influence of registration practices on results]

International audienceBACKGROUND: In France, cancer incidence figures are produced by cancer registries covering only 13.5% to 16% of the whole population of the country. Thus, to produce national figures, estimates have to be computed. Registration disparities between registries concerning tumors of the Central Nervous System (CNS) could have biased these estimates. METHODS: National estimates are based on modelling of the incidence/mortality ratio. The most recent estimations for year 2000 were calculated by the French Cancer Registry Network (FRANCIM) and the department of biostatistics of Lyon University Hospital. Since benign tumors are not recorded in some cancer registries, a new estimate of the incidence of CNS tumors was produced by estimating the number of benign tumors in these registries. RESULTS: In 2000 in France, the number of estimated cases of CNS tumors was 2697 in men and 2602 in women, with incidence rates (World standard) of 7.4 and 6.4 per 100,000 respectively. The incidence increased between 1978 and 2000, on an average by 2.25% per year in men and 3.01% per year in women. However, these estimates do not provide a correct picture of CNS incidence. First of all, pathological diagnoses are not performed in 3.5%-27.5% of the patients with CNS tumors registered in French registries. Second, figures for benign tumors (mainly meningiomas) were provided by only two of nine cancer registries. If benign tumors had been registered by all cancer registries, computed incidence would have increased by 12% for men and 26% for women. CONCLUSION: Incidence of CNS tumors is increasing in France, as in many other countries. To improve comparability with other countries, French cancer registries should also collect data on benign tumors. The discrepancies observed between registries in the proportion of patients without information on histology show differences in diagnostic practices and should be the starting point for a survey on this topic

[Incidence and mortality of central nervous system tumors in France: trends over the period 1978-2000 and influence of registration practices on results]

International audienceBACKGROUND: In France, cancer incidence figures are produced by cancer registries covering only 13.5% to 16% of the whole population of the country. Thus, to produce national figures, estimates have to be computed. Registration disparities between registries concerning tumors of the Central Nervous System (CNS) could have biased these estimates. METHODS: National estimates are based on modelling of the incidence/mortality ratio. The most recent estimations for year 2000 were calculated by the French Cancer Registry Network (FRANCIM) and the department of biostatistics of Lyon University Hospital. Since benign tumors are not recorded in some cancer registries, a new estimate of the incidence of CNS tumors was produced by estimating the number of benign tumors in these registries. RESULTS: In 2000 in France, the number of estimated cases of CNS tumors was 2697 in men and 2602 in women, with incidence rates (World standard) of 7.4 and 6.4 per 100,000 respectively. The incidence increased between 1978 and 2000, on an average by 2.25% per year in men and 3.01% per year in women. However, these estimates do not provide a correct picture of CNS incidence. First of all, pathological diagnoses are not performed in 3.5%-27.5% of the patients with CNS tumors registered in French registries. Second, figures for benign tumors (mainly meningiomas) were provided by only two of nine cancer registries. If benign tumors had been registered by all cancer registries, computed incidence would have increased by 12% for men and 26% for women. CONCLUSION: Incidence of CNS tumors is increasing in France, as in many other countries. To improve comparability with other countries, French cancer registries should also collect data on benign tumors. The discrepancies observed between registries in the proportion of patients without information on histology show differences in diagnostic practices and should be the starting point for a survey on this topic

First evaluation of antibody responses to Culex quinquefasciatus salivary antigens as a serological biomarker of human exposure to Culex bites: A pilot study in Côte d’Ivoire

International audienceBackground Culex mosquitoes are vectors for a variety of pathogens of public health concern. New indicators of exposure to Culex bites are needed to evaluate the risk of transmission of associated pathogens and to assess the efficacy of vector control strategies. An alternative to entomological indices is the serological measure of antibodies specific to mosquito salivary antigens. This study investigated whether the human IgG response to both the salivary gland extract and the 30 kDa salivary protein of Culex quinquefasciatus may represent a proxy of human exposure to Culex bites. Methodology/Principal findings A multidisciplinary survey was conducted with children aged 1 to 14 years living in neighborhoods with varying exposure to Culex quinquefasciatus in the city of Bouaké, Côte d’Ivoire. Children living in sites with high exposure to Cx quinquefasciatus had a significantly higher IgG response to both salivary antigens compared with children living in the control site where only very few Culex were recorded. Moreover, children from any Culex -high exposed sites had significantly higher IgG responses only to the salivary gland extract compared with children from the control village, whereas no difference was noted in the anti-30 kDa IgG response. No significant differences were noted in the specific IgG responses between age and gender. Sites and the use of a bed net were associated with the level of IgG response to the salivary gland extract and to the 30 kDa antigen, respectively. Conclusions/Significance These findings suggest that the IgG response to Culex salivary gland extracts is suitable as proxy of exposure; however, the specificity to the Culex genus needs further investigation. The lower antigenicity of the 30 kDa recombinant protein represents a limitation to its use. The high specificity of this protein to the Culex genus makes it an attractive candidate and other specific antibody responses might be more relevant as a biomarker of exposure. These epidemiological observations may form a starting point for additional work on developing serological biomarkers of Culex exposure

Recensement national histologique des tumeurs primitives du système nerveux central : résultats généraux sur 40 000 cas, principales applications actuelles et perspectives. [French brain tumor database: general results on 40,000 cases, main current applications and future prospects].

International audienceBACKGROUND AND PURPOSE: This work aimed at prospectively record all primary central nervous system tumor (PCNST) cases in France, for which histological diagnosis was available. The objectives were to (i) create a national database and network to perform epidemiological studies, (ii) implement clinical and basic research protocols, and (iii) harmonize the health care of patients affected by PCNST. METHODS: The methodology is based on a multidisciplinary national network already established by the French Brain Tumor DataBase (FBTDB) (Recensement national histologique des tumeurs primitives du système nerveux central [RnhTPSNC]), and the active participation of the Scientific Societies involved in neuro-oncology in France. RESULTS: From 2004 to 2009, 43,929 cases of newly diagnosed and histologically confirmed PCNST have been recorded. Histological diagnoses included gliomas (42,4%), all other neuroepithelial tumors (4,4%), tumors of the meninges (32,3%), nerve sheath tumors (9,2%), lymphomas (3,4%) and others (8,3%). Cryopreservation was reported for 9603 PCNST specimens. Tumor resections were performed in 78% cases, while biopsies accounted for 22%. Median age at diagnosis, sex, percentage of resections and number of cryopreserved tumors were detailed for each histology, according to the WHO classification. DISCUSSION/CONCLUSION: Many current applications and perspectives for the FBTDB are illustrated in the discussion. To our knowledge, this work is the first database in Europe, dedicated to PCNST, including clinical, surgical and histological data (with also cryopreservation of the specimens), and which may have major epidemiological, clinical and research implications

Descriptive epidemiology of 13,038 newly diagnosed and histologically confirmed meningiomas in France: 2006–2010

International audiencePURPOSE:This work describes the clinical epidemiology and pathology for patients undergoing surgery for newly diagnosed meningiomas in France between 2006 and 2010.METHODS:The methodology is based on a multidisciplinary national network previously established by the French Brain Tumor DataBase (FBTDB) (in French: Recensement national histologique des tumeurs primitives du système nerveux central [RnhTPSNC]), and the active participation of the scientific societies involved in neuro-oncology in France.RESULTS:From 2006 to 2010, 13,038 incident cases of meningioma with histological validation were identified and analyzed (9769 women, 3269 men, resection 98.2%, cryopreservation 20.5%). For each histological subtype of meningioma (meningothelial, fibrous, transitional, psammomatous, angiomatous, rare variety, microcystic, secretory, lymphoplasmacyte-rich, clear-cell, chordoid, rhabdoid, metaplastic, atypical, papillary, anaplastic and not otherwise specified), number of cases, sex, median age, cryopreservation and surgery were reported. Among the various histological subtypes, atypical meningioma (grade II) slightly, but significantly, increased after 2007. Headache, sensory-motor impairments and seizures were the most frequent clinical symptoms. Time between the first clinical symptom and surgery ranged from 0 to 314 months, and was <3 months in 37% of cases. At the time of surgery, 9% of patients were asymptomatic.DISCUSSION/CONCLUSION:Given the number of meningiomas not histologically-validated, we can estimate that the gross incidence rate for meningiomas operated in France is about 4.2 per 100,000 person/year. To our knowledge, this work is the most important study evaluating the different subtypes of meningiomas and it validates the relevance of histological databases for central nervous system tumors