Epidemiology of idiopathic nephrotic syndrome in children: endemic or epidemic?
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The etiology of idiopathic nephrotic syndrome (INS) remains partially unknown. Viral infections have been reported to be associated with INS onset and relapse. The aim of this study was to describe the epidemiology of a population-based cohort of children with INS and propose a spatiotemporal analysis.
All children aged 6 months to 15 years with INS onset between December 2007 and May 2010 and living in the Paris area were included in a prospective multicenter study. Demographic and clinical features at diagnosis and 2 years were collected.
INS was diagnosed in 188 children, 93 % of whom were steroid sensitive. Annual incidence was 3.35/100,000 children. Standardized incidence ratio (SIR) was higher in one of the eight counties: Seine-Saint-Denis, with SIR 1.43 [95 % confidence interval (CI) 1.02–1.95]. A spatial cluster was further identified with higher SIR 1.36 (95 % CI 1.09–1.67). Temporal analysis within this overincidence area showed seasonal variation, with a peak during the winter period (p <0.01). In addition, partition of the Paris area into quintiles of the population showed that the average delay of occurrence, with regard to the first study case, followed a longitudinal progression (p <0.0001).
The clustering of cases, the seasonal variation within this particular area, and the progression over the Paris area altogether suggest that INS may occur on an epidemic mode.
KeywordsNephrotic syndrome Childhood Epidemiology Cluster Seasonal periodicity
Compliance with ethical standards
Conflict of interest
All authors declare no conflict of interest.
The study was reviewed and accepted by the local ethic committee. A written informed consent was systematically signed by the parents and, when possible, by the patient (age >10 years).
- 4.Hodson E, Craig J, Willis N (2002) Congenital and idiopathic nephrotic syndrome. In: Ninth Annual Report Australian Paediatric Surveillance Unit. Eliott E, Australia, pp 6–8Google Scholar
- 12.French National Authority for Health (2008) Idiopathic nephrotic syndrome in children. French National Authority for Health: 1–22Google Scholar
- 16.Breslow N, Day N (1993) Statistical methods in cancer research: the design and analysis of cohort studies. Int Agency Res Cancer: 406Google Scholar
- 18.Levine N (2013) CrimeStat IV: A spatial statistics program for the analysis of crime incident locations (version 4.0). Houston, TX, and the National Institute of Justice, Washington DCGoogle Scholar
- 19.Mitchell A (2005) The ESRI guide to GIS analysis. VOlume 2 : spatial measurements and statisticsGoogle Scholar
- 21.De Smith M, Goodchild M, Longley P (2007) Geospatial analysis : a comprehensive guide to principles, techniques and software tools. Troubadour Publishing LtdGoogle Scholar
- 22.Larmarange J, Vallo R, Yaro S, Msellati P, Méda N (2011) Methods for mapping regional trends of HIV prevalence from demographic and health surveys (DHS). Cybergeo : Europ J Geography 2011:558Google Scholar