Cost-effectiveness analysis of medical management versus conservative surgery for early tubal pregnancy.

STUDY QUESTION: Is conservative surgery (laparoscopic salpingotomy) cost-effective, using fertility as the endpoint compared with medical management (Methotrexate) in women with an early tubal pregnancy? SUMMARY ANSWER: Conservative surgery appeared slightly, but not statistically significantly, more effective than medical management but also more costly. WHAT IS KNOWN ALREADY: Women with an early tubal pregnancy treated with medical therapy (Methotrexate) or conservative surgery (laparoscopic salpingotomy) have comparable future intrauterine pregnancy rates by natural conception. Also, cost-minimisation studies have shown that medical therapy was less expensive than conservative surgery, but there is no cost-effectiveness study comparing these two treatments with fertility as the endpoint. STUDY DESIGN, SIZE, DURATION: A multicentre randomised controlled trial-based (DEMETER study) cost-effectiveness analysis of conservative surgery compared with medical therapy in women with an early tubal pregnancy was performed. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Included women had an ultrasound that confirmed an early tubal pregnancy. They were randomly allocated to conservative surgery or to medical therapy. The study clinical outcome was the intrauterine pregnancy rate. The payer's perspective was considered. Costs of conservative surgery and medical therapy were compared. The analysis was performed according to the intention-to-treat principle. Missing variables were imputed using the fully conditional method. To characterise uncertainty and to provide a summary of it, a non-parametric bootstrap resampling was executed and cost-effectiveness accessibility curves were constructed. MAIN RESULTS AND THE ROLE OF CHANCE: At baseline, costs per woman in the conservative surgery group and in the medical therapy group were 2627€ and 2463€, respectively, with a statistically significant difference of +164€. Conservative surgery resulted in a marginally, but non-significant (P = 0.46), higher future intrauterine pregnancy rate compared to medical therapy (0.700 vs. 0.649); leading, after bootstrap, to an incremental cost-effectiveness ratio of 1299€ (95% CI = -29 252; +29 919). Acceptability curves showed that conservative surgery could be considered a cost-effective treatment at a threshold of 3201€ for one additional future intrauterine pregnancy. LIMITATIONS, REASONS FOR CAUTION: A limitation was that monetary valuation was carried out using 2016 euros while the DEMETER study took place from 2005 to 2009. Anyway, the results would not have been very different given the marginal changes in the health insurance reimbursement tariffs during this period. WIDER IMPLICATIONS OF THE FINDINGS: Conservative surgery can be considered a cost-effective treatment, if the additional cost of 3201€ per additional future intrauterine pregnancy is an acceptable financial effort for the payer. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: NCT 00137982.

Prognosis of isolated congenital diaphragmatic hernia using lung-area-to-head-circumference ratio: variability across centers in a national perinatal network.

OBJECTIVE: Congenital diaphragmatic hernia (CDH) is a severe anomaly. The observed-to-expected lung-area-to-head-circumference ratio (o/e-LHR) has been shown to provide a useful prediction of subsequent survival of fetuses with CDH in referral centers with expertise and a large caseload. However, the accuracy of o/e-LHR measurements in general fetal medicine units with less expertise is not well known. The aim of this study was to evaluate the capacity of o/e-LHR to provide a useful prediction of mortality of fetuses with CDH when the measurement is performed in fetal medicine units with different levels of expertise. METHODS: Between January 2008 and November 2013, 305 live births with expectantly managed left-sided isolated CDH were recorded in the database of the French National Center for Rare Diseases (31 centers) and followed up after birth. Centers were grouped into two categories according to their mean annual CDH caseload over the study period: large centers with an average of ≥ 14 cases and smaller centers with < 14 cases per year. The relationship between o/e-LHR and 28-day and 6-month mortality was modeled using fractional polynomials and the predictive value of o/e-LHR was quantified using the area under the receiver-operating characteristics curve. Comparisons between the two center categories were carried out. Analyses were adjusted for potential confounders such as thoracic herniation of the liver and gestational age at birth and at diagnosis. RESULTS: During the study period, two large centers managed a total of 82 CDH cases and 29 smaller centers a total of 223 CDH cases. Overall, there was a significant inverse relationship between 28-day mortality rate and o/e-LHR, which decreased from 54% when o/e-LHR was 20% to 6% when o/e-LHR was 75% (P < 0.01). When the category of center was considered, adjusted associations between o/e-LHR and 28-day mortality were significantly different (P = 0.032) between large and smaller centers. The ability to predict survival at 28 days postpartum based on o/e-LHR was better in large centers; for a specificity of 0.30, the sensitivity was 0.71 in large centers and 0.55 in smaller ones. The results were similar for 6-month mortality. CONCLUSIONS: Our results show that o/e-LHR measured on two-dimensional ultrasound is a good indicator of neonatal prognosis in cases of CDH that may be used even in fetal medicine centers with a small caseload. However, our results also suggest that LHR measurement may be difficult to perform correctly. Therefore, appropriate training should be offered to professionals. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

A two-phase sampling survey for nonresponse and its paradata to correct nonresponse bias in a health surveillance survey.

BACKGROUND: The decline in participation rates in surveys, including epidemiological surveillance surveys, has become a real concern since it may increase nonresponse bias. The aim of this study is to estimate the contribution of a complementary survey among a subsample of nonrespondents, and the additional contribution of paradata in correcting for nonresponse bias in an occupational health surveillance survey. METHODS: In 2010, 10,000 workers were randomly selected and sent a postal questionnaire. Sociodemographic data were available for the whole sample. After data collection of the questionnaires, a complementary survey among a random subsample of 500 nonrespondents was performed using a questionnaire administered by an interviewer. Paradata were collected for the complete subsample of the complementary survey. Nonresponse bias in the initial sample and in the combined samples were assessed using variables from administrative databases available for the whole sample, not subject to differential measurement errors. Corrected prevalences by reweighting technique were estimated by first using the initial survey alone and then the initial and complementary surveys combined, under several assumptions regarding the missing data process. Results were compared by computing relative errors. RESULTS: The response rates of the initial and complementary surveys were 23.6% and 62.6%, respectively. For the initial and the combined surveys, the relative errors decreased after correction for nonresponse on sociodemographic variables. For the combined surveys without paradata, relative errors decreased compared with the initial survey. The contribution of the paradata was weak. CONCLUSION: When a complex descriptive survey has a low response rate, a short complementary survey among nonrespondents with a protocol which aims to maximize the response rates, is useful. The contribution of sociodemographic variables in correcting for nonresponse bias is important whereas the additional contribution of paradata in correcting for nonresponse bias is questionable.

Variations in attack behaviours between Glossina palpalis gambiensis and G. tachinoides in a gallery forest suggest host specificity.

Tsetse flies Glossina palpalis gambiensis and G. tachinoides are among the major vectors of sleeping sickness (Human African Trypanosomiasis-HAT) and nagana (African Animal Trypanosomiasis - AAT) in West Africa. Both riparian species occur sympatrically in gallery forests of south west Burkina Faso, but little is known of their interspecies relationships although different authors think there may be some competition between them. The aim of this study was to check if sympatric species have different strategies when approaching a host. A man placed in a sticky cube (1 m × 1 m × 1 m) and a sticky black-blue-black target (1 m × 1 m) were used to capture tsetse along the Comoe river banks in a Latin Square design. The number and the height at which tsetse were caught by each capture method were recorded according to species and sex. Glossina p. gambiensis was more attracted to human bait than to the target, but both species were captured at a significantly higher height on the target compared with the human bait (P < 0.05). No significant difference in heights was found between G. tachinoides and G. p. gambiensis captured on targets (33 and 35 cm, respectively, P > 0.05). However, catches on human bait showed a significant difference in height between G. tachinoides and G. p. gambiensis (22.5 and 30.6 cm, respectively, P < 0.001). This study showed that these sympatric species had different attack behaviours to humans, which is not the case with the target. The implications of these findings are discussed.

Colonization of the Mediterranean basin by the vector biting midge species Culicoides imicola: an old story.

Understanding the demographic history and genetic make-up of colonizing species is critical for inferring population sources and colonization routes. This is of main interest for designing accurate control measures in areas newly colonized by vector species of economically important pathogens. The biting midge Culicoides imicola is a major vector of orbiviruses to livestock. Historically, the distribution of this species was limited to the Afrotropical region. Entomological surveys first revealed the presence of C. imicola in the south of the Mediterranean basin by the 1970s. Following recurrent reports of massive bluetongue outbreaks since the 1990s, the presence of the species was confirmed in northern areas. In this study, we addressed the chronology and processes of C. imicola colonization in the Mediterranean basin. We characterized the genetic structure of its populations across Mediterranean and African regions using both mitochondrial and nuclear markers, and combined phylogeographical analyses with population genetics and approximate Bayesian computation. We found a west/east genetic differentiation between populations, occurring both within Africa and within the Mediterranean basin. We demonstrated that three of these groups had experienced demographic expansions in the Pleistocene, probably because of climate changes during this period. Finally, we showed that C. imicola could have colonized the Mediterranean basin in the Late Pleistocene or Early Holocene through a single event of introduction; however, we cannot exclude the hypothesis involving two routes of colonization. Thus, the recent bluetongue outbreaks are not linked to C. imicola colonization event, but rather to biological changes in the vector or the virus.

Tsetse diversity and abundance in Southern Burkina Faso in relation with the vegetation.

The increase of human population, combined with climatic changes, contributed to the modification of spatial distribution of tsetse flies, main vector of trypanosomiasis. In order to establish and compare tsetse presence and their relationship with vegetation, entomological survey was performed using biconical traps deployed in transects, simultaneously with phyto-sociological study, on the Comoe river at its source in the village of Moussodougou, and in the semi-protected area of Folonzo, both localities in Southern Burkina Faso. In Folonzo, the survey revealed a diversity of tsetse with 4 species occurring with apparent densities as follows: Glossina tachinoides (8.9 tsetse/trap/day); G. morsitans submorsitans (1.8 tsetse/trap/day); G. palpalis gambiensis (0.6/trap/day) and G. medicorum (0.15 tsetse/trap/day). In Moussodougou, a highly anthropized area, mainly G. p. gambiensis was caught (2.06 tsetse/trap/day), and rarely G. tachinoides. The phyto-sociological study allowed discrimination of 6 types of vegetation in both localities, with 3 concordances that are riparian forest, shrubby and woody savannah. In Moussodougou, all tsetse were caught in the riparian forest. That was also the case in Folonzo where a great proportion (95 to 99 % following the season) of G. p. gambiensis and G. tachinoides were caught in the gallery, while G. m. submorsitans was occurring as well in the gallery as in the savannah, and G. medicorum in the forest gallery. This study showed that although G. tachinoides and G.p. gambiensis are both riparian, they do not have the same preference in terms of biotope.

Importance of vector-borne infections in different production systems: bovine trypanosomosis and the innovation dynamics of livestock producers in Senegal.

In Senegal, a project has been undertaken to eradicate a population of tsetse flies (Glossina palpalis gambiensis) from a prime area for intensifying livestock production--the coastal region of Niayes. The project is intended to remove the constraint of trypanosomosis and allow the ecological intensification of cattle production. A cross-sectional analysis of ten case studies was the inductive phase of an assessment to gauge the impact of removing trypanosomosis on livestock production strategies. The methodology used was comprehensive analysis, with participatory epidemiology tools to understand farmers' rationales. The authors analysed the strategies of three main types of livestock producer (agro-pastoralists, mixed crop/livestock farmers and intensive dairy farmers). The strategies were in line with the farmers' goals and their ability to mobilise the socio-technical network. The risk management of trypanosomosis has been incorporated into livestock management practices through the use of trypanotolerant breeds, medical prophylaxis or placing livestock in low-risk areas. Removing the risk of disease would therefore have a major impact on decisions about the composition and strategic direction of herds. This change in the animal health environment would steer livestock production along different routes of intensification in a highly competitive environment. The indicators of innovation capacity revealed by this study will be used to quantitatively monitor various change scenarios, taking livestock producers' reasoning into account, in order to assess the socio-economic impact of eradicating the tsetse fly population in this area. The methodology presented in the study can be used to understand the impact of controlling other vector-borne infections on the innovation dynamics of livestock producers.

Efficiency assessment of a novel automatic mosquito pupae sex separation system in support of area-wide male-based release strategies.

This study provides a comparative analysis of two state-of-the-art automatic mosquito pupae sex sorters currently available: the ORINNO and the WOLBAKI Biotech pupae sex separation systems, which both exploit the sexual size dimorphism of pupae. In Aedes aegypti, the WOLBAKI sex sorter and the ORINNO with a sieve mesh size of 1.050 mm achieved sex separation with female contamination rates below 1%, low pupae mortality rates and high male flight capacity. However, in Ae. albopictus, there was more variability, with female contamination rates above the 1% threshold and pupae mortality reaching 27% when using the ORINNO sorter. On the other hand, the WOLBAKI sorter achieved a male pupae recovery of 47.99 ± 8.81% and 50.91 ± 11.77% in Ae. aegypti and Ae. albopictus, respectively, while the ORINNO sorter with a smaller sieve size achieved male pupae recoveries of 38.08 ± 9.69% and 40.16 ± 2.73% in Ae. aegypti and Ae. albopictus, respectively. This study provides valuable information for researchers and practitioners in the field, assisting in the selection of the most suitable system for mosquito control, management and research programs depending on their specific requirements.

Mass irradiation of adult Aedes mosquitoes using a coolable 3D printed canister.

In the last decade, the use of the sterile insect technique (SIT) to suppress mosquito vectors have rapidly expanded in many countries facing the complexities of scaling up production and procedures to sustain large-scale operational programs. While many solutions have been proposed to improve mass production, sex separation and field release procedures, relatively little attention has been devoted to effective mass sterilization of mosquitoes. Since irradiation of pupae en masse has proven difficult to standardise with several variables affecting dose response uniformity, the manipulation of adult mosquitoes appears to be the most promising method to achieve effective and reliable sterilization of large quantities of mosquitoes. A 3D-printed phase change material based coolable canister was developed which can compact, immobilize and hold around 100,000 adult mosquitoes during mass radio sterilization procedures. The mass irradiation and compaction treatments affected the survival and the flight ability of Aedes albopictus and Aedes aegypti adult males but the use of the proposed irradiation canister under chilled conditions (6.7-11.3 °C) significantly improved their quality and performance. The use of this cooled canister will facilitate adult mass irradiation procedures in self-contained irradiators in operational mosquito SIT programmes.

Cumulative incidence rate of medical consultation for fecundity problems--analysis of a prevalent cohort using competing risks.

STUDY QUESTION: What is the incidence of medical consultation for fecundity problems in the French population, taking into account pregnancy occurrence and resumption of contraceptive use?. SUMMARY ANSWER: Considering the occurrence of a pregnancy and resumption of use of contraception as competing risks, the cumulative incidence rate of medical consultation for fecundity problems was 9.0% [95% confidence interval (CI): 6.5%; 11.9%] after 12 months of unprotected intercourse and 12.2% [95% CI: 9.6%; 15.3%] after 24 months. WHAT IS KNOWN ALREADY: Estimates of the prevalence of medical consultation due to involuntary infertility among couples who have sought a pregnancy for more than 12 months range from 25 to 50%. Most of the studies however are limited by retrospective data collection, without considering the duration of time since the beginning of the period of unprotected intercourse (PUI) and without considering medical consultation for fecundity problems as a competing risk. STUDY DESIGN, SIZE, DURATION: This study is based on the Observatory of Fecundity in France survey, a population-based probability survey designed to estimate the frequency of involuntary infertility on a nationwide basis and to explore the associations with environmental factors. Women answered two telephone questionnaires, the first at the time of enrolment in 2007, the second at follow-up 1 year later. The current analysis was performed among a subsample of 6577 women recruited before or during a PUI and followed-up for 1 year. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study sample comprised 940 women aged 18-44 years who had a PUI between the time of enrolment and the 1-year follow-up, and who had not consulted a physician for fecundity problems for the current PUI prior to enrolment. Women reported all the medical consultations they had because of difficulties becoming pregnant during the current PUI. The date of each consultation was carefully assessed. In France, women can consult a gynaecologist directly without referral by their general practitioner. The occurrence of a pregnancy and resumption of contraceptive use were considered as informative censoring events, using a competing risk model. MAIN RESULTS AND THE ROLE OF CHANCE: Using the competing risk survival model, the cumulative incidence rate of first consultation was 9.0% [95% CI: 6.5%; 11.9%] 12 months after the start of the PUI and 12.2% [95% CI: 9.6%; 15.3%] after 24 months. The Kaplan-Meier method, which does not take competing risks into account, yielded substantially higher estimates: 26.0% [95% CI: 18.8%; 32.5%] at 12 months and 56.8% [95% CI: 44.2%; 66.6%] at 24 months. Among the 219 women who had attempted to become pregnant for at least 12 months, cumulative incidences of first medical consultations were 28.2% [18.7-38.9%] 24 months after the start of the PUI, and 31.2% [21.3- 42.4%] after 36 months. The rates were higher among nulliparous but non-nulligravid women, followed by nulligravid women, as compared with parous women. Age was not strongly related to the occurrence of medical consultation. LIMITATIONS, REASONS FOR CAUTION: The main limitation of this study is the number of women lost to follow-up (29.7%). In addition, results regarding the absence of an age effect should be taken with caution as few women in our study were aged over 35 years. Although such an attrition rate is commonly observed in prospective studies in the general population, it could have induced a selection bias that may have led to an underestimation of the rates of medical consultation. Sensitivity analyses, using the inverse probability weighting method suggest that our results are unlikely to be biased. WIDER IMPLICATIONS OF THE FINDINGS: This study reveals frequencies of medical consultation for fertility problems, which, after considering competing events such as pregnancy in a relevant statistical model, are lower than generally reported in the literature. The results also indicate the existence of a difference between the potential need and the actual use of medical care for fecundity problems. This suggests a need for studies to look for factors other than medical recommendations that may play a role in the patterns of medical seeking behaviours for fecundity problems, such as women's reproductive history, socio-economic characteristics or accessibility to infertility services. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by grants from ANR (French Agency for Research, SEST call on Environmental and Occupational Health), ANSES (French Agency for Food, environmental and Occupational Health Safety, EST call on Environmental and Occupational Health), InVS (French Institute for Public Health Surveillance). The team of Environmental Epidemiology applied to Fecundity and Reproduction has been funded by an AVENIR grant from Inserm (2007). Authors declare no conflict of interest.

Factors affecting feasibility and quality of second-trimester ultrasound scans in obese pregnant women.

OBJECTIVES: To evaluate the feasibility of completing in one session a second-trimester ultrasound scan in obese pregnant women, to compare the quality of images obtained with those of non-obese women and to analyze factors that can improve the completion rate. METHODS: This prospective study, from 2009 to 2011, included all obese pregnant women (prepregnancy body mass index (BMI) > 30 kg/m2) who had an ultrasound examination at 20-24 weeks in our department, and a control group of pregnant women with normal BMI (20-24.9 kg/m2) who had the same examination. A single operator reviewed the standardized ultrasound images (three biometric and six to assess key anatomical features) required under French guidelines, to assess their presence, evaluate the quality of all images and score the quality of the six anatomical images. Each image was assessed according to between four and six criteria, each worth one point. We sought excellent quality, defined as the frequency of maximum points for a given image type. The factors associated with completing the scan in one session were evaluated with multivariate logistic regression. RESULTS: The obese group included 223 women and the control group 60; a complete scan in one session was achieved in 70.4% and 81.7% of these, respectively (P = 0.08). The completion rate for each image type was at least 95% in the control group and 90% in the obese group, except for diaphragm and right outflow tract images. Significant factors associated with completing the scan in the multivariate model were: having 10 additional minutes for the scan (P = 0.03), moving the fetus so that the back was in posterior or lateral position (P = 0.01), more experienced sonographer (P = 0.03) and thinner maternal abdominal wall thickness (P = 0.01). Overall, the excellence rate varied from 35% to 92% in the normal BMI group and from 18% to 58% in the obese group, and was significantly lower in the latter for all images except abdominal circumference (P = 0.26) and spine (P = 0.06). Anatomical quality scores were also significantly lower in the obese group (22.3 vs. 27.2; P = 0.001). CONCLUSION: Although ultrasound scans of obese pregnant women are feasible, image quality and global anatomical scores are significantly lower among obese than normal-weight women. However, certain simple improvements may increase fetal visualization.

Are children born after infertility treatment at increased risk of retinoblastoma?

BACKGROUND: Retinoblastoma (RB) is the most frequent eye tumour in children, with an incidence of 1 in 15-20,000 births. It accounts for 11% of all cancers in the first year of life. Except for the hereditary forms, its causes are not well-known. Studies have recently suggested an increased risk of RB among children born after IVF, but the relevant literature is sparse. We assessed the association between infertility treatment, subfertility and RB. METHODS: We included all children living in France diagnosed with RB between 1 January 2000 and 31 December 2006 at the Institut Curie, the national reference centre for RB diagnosis and treatment. We used multiple logistic regression to compare them with a national sample of births in France in 1998 and 2003 (n = 28 170). RESULTS: The study included 244 non-familial RB cases. The risk of RB increased with maternal age [adjusted odds ratio (adj OR) = 2.07, 95% confidence interval (CI) 1.33-3.22 at 35-39 years compared with younger than 25 years and adj OR = 2.42, 95% CI 1.22-4.81 at 40 years or older], but the associations with IVF (adj OR = 1.37, 95% CI 0.64-2.95) and ovarian stimulation or intrauterine insemination (adj OR = 1.35, 95% CI 0.77-2.38) were not statistically significant after adjustment for maternal age and tobacco use. Among women who had no infertility treatment, the risk of RB was significantly increased when time to pregnancy exceeded 24 months (adj OR = 2.02, 95% CI 1.17-3.48) compared with time to pregnancy ≤ 24 months. CONCLUSIONS: Our study did not observe a significantly increased risk of RB associated with infertility treatment, in particular with IVF. But we did find an increased risk for women for whom time to pregnancy exceeded 24 months.

Estimation of the frequency of involuntary infertility on a nation-wide basis.

BACKGROUND: Assessing couple fecundity on a nation-wide basis without excluding couples who eventually remain infertile is challenging. Our aim was to describe couple fecundity (in terms of frequency of involuntary infertility) among the general population living in France. METHODS: We used a current-duration design. A random sample of 64 262 households was selected in 2007-2008, allowing us to identify 15 810 women aged 18-44 years. Eligible women (n= 1089) were those having regular sexual intercourse with a male partner, not using any method of contraception and not having delivered in the previous 3 months. These women reported information on the current duration of unprotected intercourse (CDUI, the time elapsed between the start of the period of unprotected intercourse and the time of inclusion in the study). The CDUI distribution was used to estimate the frequency of involuntary infertility, using a newly developed statistical technique that does not require couples to be followed up until the end of the period of unprotected intercourse. RESULTS: CDUI was defined for 867 women. An estimated 46% of couples had no detected pregnancy conceived during the first 6 months of unprotected intercourse [95% confidence interval (CI), 36-56%]. The proportions of couples with no detected pregnancy within 12 and 24 months were 24% (19-30%) and 11% (8-14%), respectively. CONCLUSIONS: These results constitute one of the few descriptions of the fecundity of a nation-wide representative sample of couples from the general population, not limited to couples who eventually conceived or to those resorting to medical help.

The mosquito Aedes (Aedimorphus) vexans arabiensis as a probable vector bridging the West Nile virus between birds and horses in Barkedji (Ferlo, Senegal).

Active catches of adult females of Aedes vexans arabiensis Patton, (Diptera: Culicidae) Patton by nets or aspirator, were conducted in 2003 and 2004 in the vegetation at the edge of temporary ponds in Barkedji, Senegalese Ferlo area. Two hundred and forty-one engorged females were captured, dissected and the gut content adsorbed on a Whatman filter paper and analysed using the enzyme-linked immunosorbent assay (ELISA) technique to determinate the bloodmeal origin. Results indicated that Ae v. arabiensis fed primarily on mammals, including horses (35.7% of the bloodmeals), but also on birds (10%). Moreover, associations between horses and birds accounted for 42% of the mixed bloodmeals. These results show an opportunistic feeding behaviour and suggest that Ae v. arabiensis is a probable vector bridging the West Nile virus between horses and birds hosts in the Ferlo area.

Effects of Chilling and Anoxia on the Irradiation Dose-Response in Adult Aedes Mosquitoes.

The success of the sterile insect technique (SIT) relies on the achievement of high levels of sterility and mating success of the factory-reared sterile males and thus their biological quality, which can be enhanced by the reduction of stress factors encountered during rearing, handling, and irradiation procedures. The achievement of consistent sterility levels requires reliable and standard irradiation protocols. Additionally, mosquito adults require immobilization prior to, and during irradiation to increase processing efficiency and to avoid physical damage caused by movement in restricted space. Common methods for immobilization include chilling and anesthetics such as nitrogen. Here we assessed the effects of chilling and exposure to nitrogen on the irradiation dose-response of Aedes mosquitoes, and their downstream effects on some male quality parameters including longevity and flight ability. We found that chilling does not incur damage in the insects in terms of longevity and flight ability when chilling duration and temperature are carefully controlled, and a recovery phase is provided. Irradiation in nitrogen shows high radioprotective effects during irradiation, resulting in reduced induction of sterility. Overall, longevity of males can be improved by irradiating in anoxia, however the exposure to nitrogen itself comes with negative impacts on flight ability. The results reported here will assist in the standardization and optimization of irradiation protocols for the SIT to control mosquito populations of medical relevance.

Do social inequalities in cervical cancer screening persist among patients who use primary care? The Paris Prevention in General Practice survey.

OBJECTIVE: Social inequalities in cervical cancer screening may be related to either lack of access to care or inadequate delivery of preventive care by providers. We sought to characterize social inequalities among women consulting general practitioners with a wide range of social position indicators. METHODS: In 2005-06, 59 randomly recruited general practitioners from the Paris metropolitan area enrolled every woman aged 50-69 years seen during a two-week period. Cervical cancer screening status (overdue if the last cervical cancer screening had been more than 3 years earlier) was analyzed for 858 women in a logistic mixed model that considered: occupational class (in 5 levels, based on last occupation), education, income, characteristics related to family, housing, neighborhood, household wealth (social allocations, perceived financial difficulties in 4 levels, income tax), employment status, supplementary health insurance, and social network (4 levels). RESULTS: The rate of overdue patients did not vary between general practitioners (21%). social position indicators associated with overdue status (odds ratio between 2 adjacent decreasing social levels) were occupational class (1.20, 95% CI: 1.03-1.41), social network (1.52, 95% CI: 1.18-1.94), financial difficulties (1.42, 95% CI: 1.07-1.88), neighborhood safety (2.15, 95% CI: 1.10-4.20), and allocations (3.34, 95% CI: 1.12-9.96). CONCLUSIONS: Even among women visiting general practitioners we observed marked social inequalities that persist above and beyond occupational class.

Spatio-temporal distribution of tsetse and other biting flies in the Mouhoun River basin, Burkina Faso.

In the Mouhoun River basin, Burkina Faso, the main vectors of African animal trypanosomoses are Glossina palpalis gambiensis Vanderplank and Glossina tachinoides Westwood (Diptera: Glossinidae), both of which are riverine tsetse species. The aim of our study was to understand the impact of landscape anthropogenic changes on the seasonal dynamics of vectors and associated trypanosomosis risk. Three sites were selected on the basis of the level of disturbance of tsetse habitats and predominant tsetse species: disturbed (Boromo, for G. tachinoides) and half-disturbed (Douroula for G. tachinoides and Kadomba for G. p. gambiensis). At each of these sites, seasonal variations in the apparent densities of tsetse and mechanical vectors and tsetse infection rates were monitored over 17 months. Tsetse densities differed significantly between sites and seasons. Of 5613 captured tsetse, 1897 were dissected; 34 of these were found to be infected with trypanosomes. The most frequent infection was Trypanosoma vivax (1.4%), followed by Trypanosoma congolense (0.3%) and Trypanosoma brucei (0.05%). The mean physiological age of 703 tsetse females was investigated to better characterize the transmission risk. Despite the environmental changes, it appeared that tsetse lived long enough to transmit trypanosomes, especially in half-disturbed landscapes. A total of 3021 other biting flies from 15 species (mainly Tabanidae and Stomoxyinae) were also caught: their densities also differed significantly among sites and seasons. Their relative importance regarding trypanosome transmission is discussed; the trypanosomosis risk in cattle was similar at all sites despite very low tsetse densities (but high mechanical vector densities) in one of them.

Physicochemical factors affecting the diversity and abundance of Afrotropical Culicoides species in larval habitats in Senegal.

Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are the biological vectors of arboviruses of global importance in animal health. We characterized the physicochemical parameters that determine the density and composition of the main Culicoides species of veterinary interest in larval habitats of the Niayes region of Senegal. For this purpose, we combined larval and substrate sampling in the field in different habitat types with adult emergence and physicochemical analyses in the laboratory. Three major habitat types were identified, conditioning the predominant species of Culicoides and pH and the amount of organic matter were positively correlated with the abundance of larvae and emerging Culicoides, as opposed to salinity. The diversity of emerging Culicoides was positively correlated with pH while it was negatively correlated with salinity. Culicoides distinctipennis was the predominant species in the larval habitat group of freshwater lake edges. In the larval habitat group of pond and puddle edges, C. oxystoma and C. nivosus were predominant; both species were again most abundant in the larval habitat group of saltwater lake edges. These variabilities in physicochemical parameters support the distribution of different Culicoides species in different habitat groups. These results make it possible to implement effective, selective and environmental-friendly control measures but also to improve current models for estimating the abundance of adult vector populations at a local scale.

Fertility is not altered in young adults born small for gestational age.

BACKGROUND: The intrauterine environment may have a lifelong impact on individuals' health. However, results on the relationship between birth size and gonadal function are conflicting, and it remains unknown whether reproductive function is altered in adults born small for gestational age (SGA). The aim of the present study was to compare the fertility of young adults from the general population, born either SGA or appropriate for gestational age (AGA). METHODS: There were 579 adults born SGA (birthweight under the 10th percentile) who were compared with 703 subjects of the same age (age 29.4 +/- 4.1 years) born AGA (birthweight between 25th and 75th percentiles). They fulfilled a questionnaire focusing on the first attempt to give birth, to have a measure of the time to pregnancy and an estimation of the fecundability (the monthly pregnancy probability), two relevant indicators of fertility at the couple level. Ratios of fecundability between AGA and SGA subjects were adjusted for known fertility factors (age, smoking, reproductive history) and for socioeconomic status. RESULTS: Time to pregnancy was comparable in the two groups: 5.7 +/- 8.0 versus 6.6 +/- 10.5 months in AGA and SGA, respectively (P = 0.31), in women and 5.1 +/- 7 versus 6.0 +/- 9 months in AGA and SGA, respectively, in men (P = 0.53). The adjusted ratios of fecundability comparing SGA to AGA subjects were not significant: HR = 0.91 [0.68;1.21] (P = 0.5) in women and HR = 0.95 [0.67;1.74] (P = 0.82) in men. CONCLUSION: When studied in young adults from the general population, fertility is not reduced in those born SGA.

Population structuring of the tsetse Glossina tachinoides resulting from landscape fragmentation in the Mouhoun River basin, Burkina Faso.

The impact of landscape fragmentation resulting from human- and climate-mediated factors on the structure of a population of Glossina tachinoides Westwood (Diptera: Glossinidae) in the Mouhoun River basin, Burkina Faso, was investigated. Allele frequencies at five microsatellite loci were compared in four populations. The average distance between samples was 72 km. The sampling points traversed an ecological cline in terms of rainfall and riverine forest ecotype, along a river loop that enlarged from upstream to downstream. Microsatellite DNA demonstrated no structuring among the groups studied (F(ST) = 0.015, P = 0.07), which is contrary to findings pertaining to Glossina palpalis gambiensis Vanderplank in the same geographical area. The populations of G. tachinoides showed complete panmixia (F(IS) = 0, P = 0.5 for the whole sample) and no genetic differentiation among populations or global positioning system trap locations. This is in line with the results of dispersal studies which indicated higher diffusion coefficients for G. tachinoides than for G. p. gambiensis. The impact of these findings is discussed within the framework of control campaigns currently promoted by the Pan African Tsetse and Trypanosomosis Eradication Campaign.