Regional variations of childhood immunisations in Senegal: a multilevel analysis.

OBJECTIVES: To estimate geographical variations of child immunisation at the regional level in Senegal, to identify individual and contextual factors that could explain these regional discrepancies, and to measure their effects. METHODS: Data come from the 2015, 2016 and 2017 Senegalese Demographic and Health Survey, a national survey targeting women aged 15-49, with a questionnaire focusing on health and reproductive issues including their children's immunisation status. We restricted the analysis to children aged 12-23 months (n = 4955) and conducted a multilevel logistic regression to assess individual and contextual factors associated with complete immunisation coverage. RESULTS: The complete immunisation coverage rate of children was estimated at 68% and ranged from 41% in the region of Kedougou to 83% in the region of Dakar. The inter-regional variance was significantly different from zero (P = 0.006) in the empty multilevel model. It decreased by more than half (57 %) after adjusting for individual factors but remained significantly different from zero (P = 0.010). Regional variations of complete immunisation rates drastically decreased and were no longer statistically significant (P = 0.343) after adjusting for the following regional factors: population density, density of hospitals, literacy rate and proportion of health facilities with an antenatal care service. CONCLUSIONS: Regarding health policies designed to improve childhood immunisation and to reduce related inequalities, our results highlight the need to take into account both individual and contextual factors, with a focus on rural and deprived areas where children are at higher risk of incomplete immunisation.

OBJECTIFS: Estimer les variations géographiques de la vaccination des enfants au niveau régional au Sénégal, identifier les facteurs individuels et contextuels qui pourraient expliquer ces écarts régionaux et mesurer leurs effets. MÉTHODES: Les données proviennent de l'enquête démographique et la santé du Sénégal de 2015, 2016 et 2017, une enquête nationale ciblant les femmes âgées de 15 à 49 ans, avec un questionnaire axé sur les problèmes de santé et de reproduction, y compris le statut vaccinal de leurs enfants. Nous avons limité l'analyse aux enfants âgés de 12 à 23 mois (n = 4.955) et avons effectué une régression logistique à plusieurs niveaux pour évaluer les facteurs individuels et contextuels associés à une couverture vaccinale complète. RÉSULTATS: Le taux de couverture vaccinale complète des enfants était estimé à 68% et variait de 41% dans la région de Kédougou à 83% dans la région de Dakar. La variance interrégionale était significativement différente de zéro (P = 0,006) dans le modèle vide à plusieurs niveaux. Il diminuait de plus de la moitié (57%) après ajustement pour les facteurs individuels mais est restait significativement différent de zéro (P = 0,010). Les variations régionales des taux de vaccination complète ont considérablement diminué et n'étaient plus statistiquement significatives (P = 0,343) après ajustement pour les facteurs régionaux suivants: densité de population, densité des hôpitaux, taux d'alphabétisation et proportion d'établissements de santé disposant d'un service de soins prénatals. CONCLUSIONS: En ce qui concerne les politiques de santé conçues pour améliorer la vaccination des enfants et réduire les inégalités associées, nos résultats soulignent la nécessité de prendre en compte les facteurs individuels et contextuels, en mettant l'accent sur les zones rurales et défavorisées où les enfants sont plus à risque de vaccination incomplète.

The effect of matrix stiffness on the differentiation of mesenchymal stem cells in response to TGF-ß.

Bone marrow mesenchymal stem cells (MSCs) are a valuable cell source for tissue engineering and regenerative medicine. Transforming growth factor ß (TGF-ß) can promote MSC differentiation into either smooth muscle cells (SMCs) or chondrogenic cells. Here we showed that the stiffness of cell adhesion substrates modulated these differential effects. MSCs on soft substrates had less spreading, fewer stress fibers and lower proliferation rate than MSCs on stiff substrates. MSCs on stiff substrates had higher expression of SMC markers α-actin and calponin-1; in contrast, MSCs on soft substrates had a higher expression of chondrogenic marker collagen-II and adipogenic marker lipoprotein lipase (LPL). TGF-ß increased SMC marker expression on stiff substrates. However, TGF-ß increased chondrogenic marker expression and suppressed adipogenic marker expression on soft substrates, while adipogenic medium and soft substrates induced adipogenic differentiation effectively. Rho GTPase was involved in the expression of all aforementioned lineage markers, but did not account for the differential effects of substrate stiffness. In addition, soft substrates did not significantly affect Rho activity, but inhibited Rho-induced stress fiber formation and α-actin assembly. Further analysis showed that MSCs on soft substrates had weaker cell adhesion, and that the suppression of cell adhesion strength mimicked the effects of soft substrates on the lineage marker expression. These results provide insights of how substrate stiffness differentially regulates stem cell differentiation, and have significant implications for the design of biomaterials with appropriate mechanical property for tissue regeneration.