Too young to be vaccinated: hospitalizations caused by varicella among children in the first year of life.

Aim: The aim of this study was to analyse the causes of hospitalization in the course of varicella in children during the first year of life.

Methods: An analysis was performed of the medical documentation of 359 children hospitalized for varicella on the infectious diseases ward at the Children's Hospital in Poznan (Poland) between January 2007 and August 2015.

Results: Of the 359 children in the study group, 96 were younger than 1 year old. The most common cause of hospitalization was respiratory infections, found in 31 (32%) children. A severe course of varicella was observed in 38 (14%) children, and 21 (22%) developed skin infections, while 11 (11%) exhibited more than one complication. Treatment with acyclovir was implemented in 90 cases and parenteral antibiotic therapy was applied in 49 children. Contact with siblings suffering from varicella was confirmed in 46 children; for 16, the source of the infection was the mother.

Conclusions: The main source of varicella virus among hospitalized children in the first year of life is home contact. An infant may become infected from its mother suffering from zoster. Children who are exclusively breastfed and are born of mothers who have previously had varicella may develop varicella with a severe course during the first year of life.