Objective: Evaluation of the varicella severity through a prevalence study of hospital admissions justified by a complication directly related to the onset of an acute episode of varicella.
Methods: Retrospective study in one paediatric center in France with a follow-up of a paediatric cohort from April 1987 to December 2002. This general paediatric hospital recruits children from a 400,000 inhabitants area. Inclusion criterion: diagnosis main or associated of varicella.
Exclusion criteria: congenital or acquired immunodepression, including long-term oral high dosage steroid therapy.
Results: Three hundred and forty-three (343) complications of varicella were reported in 309 children hospitalised for a symptom in relationship with varicella. Most of children (75%) were <2 years of age. The annual number of hospitalisations varied with a maximum of 44. An increase of the number of hospitalisations was reported since 1997 but particularly since 2000. Main complications were gastro-intestinal (75), neurological (68), bronchopulmonary (52), and skin and soft tissue infections (52). Superinfections of soft tissues such as Streptococcus pyogenes cellulitis and life-threatening complications, which occurred in children treated by a short-course of corticosteroïds for an acute episode such as an asthma crisis, were mostly noticed since 1995. Two deaths occurred.
Conclusion: These data collected over 16 years as part of a retrospective survey of a paediatric cohort show that varicella, often considered as a mild disease, can be responsible for severe complications in young immunocompetent children. The digestive complications (30%) are the main complication in our study with existence of gingivitis-stomatitis but also lower digestive manifestations (erosive gastritis aspect through endoscopy). These data have all the more to be taken into account because a vaccine, developed for healthy children, is now available in France. A national survey of hospitalised varicella has been set up since March 2003.