Résultats préliminaires sur l'immobilisation chimique de rongeurs africains : l'athérure (Atherurus africanus, Gray 1842) et le cricétome (Cricetomys emini, Waterhouse 1840). Etude portant sur quatre protocoles

Le projet Développement au Gabon de l'élevage de gibier travaille sur la mise au point de référentiels techniques sur l'élevage de plusieurs espèces sauvages parmi lesquelles se trouvent l'athérure africain (Atherurus africanus) et le cricétome (Cricetomys emini). Dans le cadre de leur pratique courante, les auteurs ont été amenés à effectuer sur ces animaux des soins qui ont parfois nécessité une anesthésie. Les effets de quatre protocoles ont été testés à différentes posologies : l'acépromazine, la xylazine, une combinaison de xylazine et de kétamine et une combinaison de zolazépam et de tilétamine. Chez l'athérure, la xylazine seule a entraîné des durées d'induction, d'état et de réveil très variables. L'association de la xylazine à 1 mg/kg et de la kétamine à 5 mg/kg s'est avérée très efficace pour l'obtention d'une anesthésie chirurgicale. Chez le cricétome, l'acépromazine à 5 mg/kg a fourni un état de tranquillisation satisfaisant. Pour obtenir une anesthésie chirurgicale, l'association xylazine à 10 mg/kg et kétamine à 50 mg/kg s'est avérée efficace. L'utilisation de xylazine seule ne semble pas indiquée chez cette espèce. (Résumé d'auteur

Assessment of hepatic glucose metabolism by indirect calorimetry in combination with a non-invasive technique using naturally enriched 13C glucose in healthy children and adolescents

The metabolic fate of hepatic glucose can be best studied using invasive techniques such as tracer infusions and frequent blood sampling which have been revealed to be impractical in the pediatric age group. The aim of this study was to develop a non-invasive method based on indirect calorimetry and expired 13CO2 monitoring in order to gain insight into the mechanisms leading to impaired glucose tolerance in children and teenagers. As a first step, net glucose oxidation (NGO) and energy expenditure (EE) were measured in 47 subjects (range 7.5-17.3 years) of whom 18 were prepubertal (P1), 11 in early puberty (P2-P3) and 18 in late puberty (P4-P5) after 3-hourly loads of 180 mg/kg of oral maize glucose containing naturally enriched 13C. Isotope analysis allowed to calculate exogenous and endogenous glucose oxidation (EXGO, ENGO) and, hence, to derive TGS and NGS, that is glycogen turnover. NGO and EE decreased significantly with pubertal progression, reflecting higher metabolism at younger ages, whereas EXGO remained constant. TGS did not change significantly whereas NGS showed a significant negative correlation with pubertal progression: this can be explained by the fact that glycogenolysis exceeded glycogen synthesis in this experimental setting. This non-invasive method appears to be a promising tool to study the fate of hepatic glucose and therefore glycogen turnover in children at risk of developing glucose intolerance and/or type 2 diabetes

High-spatial resolution epidemic surveillance of bacterial meningitis in the African meningitis belt in Burkina Faso

International audienceDespite improved surveillance capacities and WHO recommendations for subdistrict analysis, routine epidemic surveillance of acute bacterial meningitis in the African meningitis belt remains largely limited to the district level. We evaluated the appropriateness and performance of analyses at higher spatial resolution. We used suspected meningitis surveillance data at health centre (HC) resolution from Burkina Faso from 14 health districts spanning years 2004–2014 and analysed them using spatio-temporal statistics and generative models. An operational analysis compared epidemic signals at district and HC-level using weekly incidence thresholds. Eighty-four percent (N = 98/116) of epidemic clusters spanned only one HC-week. Spatial propagation of epidemic clusters was mostly limited to 10–30 km. During the 2004–2009 (with serogroup A meningitis) and 2010–2014 (after serogroup A elimination) period, using weekly HC-level incidence thresholds of 100 and 50 per 100,000 respectively, we found a gain in epidemic detection and timeliness in 9 (41% of total) and 10 (67%), respectively, district years with at least one HC signal. Individual meningitis epidemics expanded little in space, suggesting that a health centre level analysis is most appropriate for epidemic surveillance. Epidemic surveillance could gain in precision and timeliness by higher spatial resolution. The optimal threshold should be defined depending on the current background incidence of bacterial meningitis

Atmospheric dust, early cases, and localized meningitis epidemics in the African meningitis belt: an analysis using high spatial resolution data.

8 pagesInternational audienceBackground : Bacterial meningitis causes a high burden of disease in the African meningitis belt, with regular seasonal hyperendemicity and sporadic short, but intense, localized epidemics during the late dry season occurring at a small spatial scale [i.e., below the district level, in individual health centers (HCs)]. In addition, epidemic waves with larger geographic extent occur every 7–10 y. Although atmospheric dust load is thought to be an essential factor for hyperendemicity, its role for localized epidemics remains hypothetic.Objectives : Our goal was to evaluate the association of localized meningitis epidemics in HC catchment areas with the dust load and the occurrence of cases in the same population early in the dry season.Methods : We compiled weekly reported cases of suspected bacterial meningitis at the HC resolution for 14 districts of Burkina Faso for the period 2004–2014. Using logistic regression, we evaluated the association of epidemic HC-weeks with atmospheric dust [approximated by the aerosol optical thickness (AOT) satellite product] and with the observation of early meningitis cases during October–December.Results : Although AOT was strongly associated with epidemic HC-weeks in crude analyses across all HC-weeks during the meningitis season [odds ratio (OR) = 6.82; 95% CI: 4.90, 9.50], the association was no longer apparent when controlling for calendar week (OR = 0.92; 95% CI: 0.60, 1.50). The number of early meningitis cases reported during October–December was associated with epidemic HC-weeks in the same HC catchment area during January–May of the following year (OR for each additional early case =1.14 ; 95% CI: 1.06, 1.21).Conclusions : Spatial variations of atmospheric dust load do not seem to be a factor in the occurrence of localized meningitis epidemics, and the factor triggering them remains to be identified. The pathophysiological mechanism linking early cases to localized epidemics is not understood, but their occurrence and number of early cases could be an indicator for epidemic risk

Apport iode et prevalence du goitre chez les adolescents dans le canton de Vaud. [Iodine nutrition and prevalence of goiter in adolescents in the Canton of Vaud]

Iodine deficiency disorders virtually disappeared in Switzerland after iodized salt was introduced in 1922 and the iodine content increased from 3.75 to 7.5 mg/kg in 1962 and to 15 mg/kg in 1980. However, a decreasing iodine intake has recently been reported again. The status of iodine nutrition in the Canton of Vaud was therefore assessed in 348 representative adolescents aged 11 to 17 years from the urban area of Lausanne in 1995. Thyroid size was estimated by inspection and palpation and thyroid volume measured by ultrasonography. Iodine concentration was determined in urine. Thyroid enlargement, as assessed by clinical examination, was found in 15% of the adolescents (stage 1a: 12.9%, 1b: 1.8%, 2: 0.3%), but its positive predictive value was low. The goitre prevalence determined by ultrasonography was only 1.4%. In addition, 4% of the adolescents had nodular or diffuse echo-structure abnormalities. Percentiles of thyroid volume as a function of sex, chronological age and body surface area were lower than WHO reference values. Median iodine concentration in urine was 92 micrograms/l (56.6% < 100 micrograms/l), slightly below WHO recommendations. Iodized cooking salt was consumed by 82% of the adolescents. In conclusion, the adolescents living in the Canton of Vaud had a low normal iodine intake with subclinical thyroid abnormalities. These findings support the recent decision to increase the salt iodine content to 20-30 mg/kg in order to prevent iodine deficiency during puberty and pregnancy. Percentiles of thyroid volume determined in the present study can be used as local reference