Incidence and hospitalisation rates of Lyme borreliosis, France, 2004 to 2012.

Lyme borreliosis (LB) has become a major concern recently, as trends in several epidemiological studies indicate that there has been an increase in this disease in Europe and America over the last decade. This work provides estimates of LB incidence and hospitalisation rates in France. LB data was obtained from the Sentinelles general practitioner surveillance network (2009­2012) and from the Programme de Médicalisation des Systèmes d'Information (PMSI) data processing centre for hospital discharges (2004­09). The yearly LB incidence rate averaged 42 per 100,000 inhabitants (95% confidence interval (CI): 37­48), ranging from 0 to 184 per 100,000 depending on the region. The annual hospitalisation rate due to LB averaged 1.55 per 100,000 inhabitants (95% CI: 1.42­1.70). Both rates peaked during the summer and fall and had a bimodal age distribution (5­10 years and 50­70 years). Healthcare providers should continue to invest attention to prompt recognition and early therapy for LB, whereas public health strategies should keep promoting use of repellent, daily checks for ticks and their prompt removal.

[Will climate and demography have a major impact on malaria in sub-Saharan Africa in the next 20 years?]. / Le climat et la démographie peuvent-ils avoir un impact important sur le paludisme en afrique subsaharienne dans les 20 prochaines années?

The purpose of this review of the literature is to present factors possibly affecting the spread of malaria in sub-Saharan Africa over the next 20 years. Malaria is a vector-borne disease that depends on environmental and human constraints. The main environmental limitations involve susceptibility of the vector (mosquitoes of the Anopheles genus) and parasite (Plasmodium falciparum) to climate. Malaria is a stable, endemic disease over most of the African continent. Climatic change can only affect a few regions on the fringes of stable zones (e.g. altitude areas or Sahel) where malaria is an unstable, epidemic disease. Higher temperatures could induce a decrease of malaria transmission in regions of the Sahel or an increase in the highlands. The extent of these overall trends will depend on the unpredictable occurrence of major meteorological phenomenon as well as on human activities affecting the environment that could lead to dramatic but limited outbreaks in some locations. The most influential human factors could be runaway demographic growth and urban development. Estimations based on modeling studies indicate that urbanization will lead to a 53.5% drop in exposure to malaria by 2030. However this reduction could be less than expected because of adaptation of Anopheles gambiae and An. arabiensis, the main vectors of malaria in sub-Saharan Africa, to the urban environment as well as increasing vector resistance to insecticides. Another unforeseeable factor that could induce unexpected malaria epidemics is mass migration due to war or famine. Finally immunosuppressive illnesses (e.g. HIV and malnutrition) could alter individual susceptibility to malaria. Social constraints also include human activities that modify land use. In this regard land use (e.g. forest clearance and irrigation) is known to influence the burden of malaria that is itself dependent on local determinants of transmission. Overall the most important social constraint for the population will be access to malarial prevention and implementation action to control this scourge.

Le climat et la demographie peuvent-ils avoir un impact important sur le paludisme en Afrique subsaharienne dans les 20 prochaines annees?

Cette revue de la litterature presente les conditions d'evolution du paludisme en Afrique subsaharienne dans les 20 prochaines annees. Le paludisme est une maladie vectorielle limitee par des contraintes environnementales et humaines. Les limites environnementales sont essentiellement dictees par la sensibilite du vecteur (moustiques du genreAnopheles) et du parasite Plasmodium falciparum au climat. Le paludisme est stable; dit endemique; sur une grande superficie de l'Afrique. Seules les zones ou le paludisme est instable; dit epidemique; principalement les franges de la zone stable (Sahel; altitude) pourront etre influencees par les changements climatiques. L'accroissement de la temperature; notamment; pourrait induire une reduction du paludisme en zone sahelienne ou une augmentation en altitude. Ces tendances globales devraient etre modulees par des evenements meteorologiques exceptionnels conjugues aux activites humaines s'exercant sur l'environnement qui pourront entrainer localement des epidemies dramatiques de paludisme. Les contraintes humaines impliquent en particulier une demographie galopante et un developpement des villes. Des modelisateurs projettent que l'urbanisation va entrainer une reduction de l'exposition palustre de 53;5en 2030. Toutefois; l'adaptation au milieu urbain d'Anopheles gambiae et d'An. arabiensis; principaux vecteurs du paludisme en Afrique subsaharienne; ainsi que leur resistance croissante aux insecticides; pourraient influencer cette diminution. De maniere imprevisible; les mouvements massifs de population resultant de guerres ou de famines pourront aussi entrainer des epidemies palustres inattendues. Enfin les maladies immunosuppressives (HIV; malnutrition) pourraient alterer la susceptibilite des individus au paludisme. Les contraintes sociales impliquent l'activite anthropique qui modifie l'utilisation des sols. On sait que l'utilisation des terres (deforestation; irrigation)peut influencer le poids du paludisme qui lui-meme depend des determinants locaux de la transmission. In fine; la contrainte sociale la plus importante demeure l'acces des populations aux interventions pour prevenir et lutter contre le paludisme