Each year, there are approximately 700,000 varicella cases (more than 90% are under 10 years old), approximately 3,000 hospitalizations (25% are over 10 years old) and 20 deaths (70% are over 10 years old), according to Santé publique France (computer translated).

A number of varicella, or chickenpox lesions on the face of a young child/CDC
A number of varicella, or chickenpox lesions on the face of a young child/CDC

This data reflects the frequent and unusually severe nature of the disease in childhood but also the increased risk of complications with age.

Chickenpox is a “seasonal” disease in France. There is an annual spring surge in the number of cases, this is an expected increase in the disease. A second peak can also be observed in June / July.

During the week ending Mar. 26, the incidence rate of chickenpox in Metropolitan France was an estimated 28 cases per 100,000 population. This is considered moderate chickenpox activity.

The current situation of chickenpox with incidence rates in some areas well above the national average reported since mid-March: There are six regional clusters of the disease reported in Hauts-de-France, Grand Est, Pays de la Loire, Ile-de-France, Centre-Val de Loire and Auvergne-Rhone-Alps.

Chickenpox is a very contagious viral disease, most often benign, which occurs preferentially during childhood. It is caused by a herpes virus (Varicella-Zoster Virus or VZV). Chickenpox is the primary infection with VZV. The risk of developing chickenpox during a lifetime is very high (about 95%) and that of at least one reactivation of the virus (shingles) is of the order of 15 to 20%. More than 90% of the population is immunized after the age of 10 years.