Epidemiology of hospital admissions for chickenpox in children: an Italian multicentre study in the pre-vaccine era.

AIM

To describe the chickenpox complications in children in Italy.

METHODS

Hospital discharge data from 1 January 2002 to 15 June 2006 were queried for patients less than 18 years of age in three Italian paediatric university hospitals.

RESULTS

During the study period, 349 children (189 males, 160 females) were admitted. Thirteen out of 349 (3.7%) of them had serious underlying diseases. Two hundred and sixty-one (74.8%) children (median age: 41 months, range: 6 days -to 200 months) had complicated chickenpox. Among complications, neurological disorders were the most common (100/261 = 38.3%), followed by skin and soft tissue infections (63/261 = 24.1%), lower respiratory tract infections (57/261 = 21.8%) and haematological disorders (24/261 = 9.2%). Children with neurological complications were significantly older and had a longer hospital stay than those with other complications. Three children with encephalitis and cerebellitis had developed long-term sequelae by the 6-month follow-up. The mortality rate was 0.4% (1/261 children with complicated chickenpox).

CONCLUSION

Chickenpox is a disease that can provoke serious complications and long hospital stays, even in healthy children. Our findings may be useful as background to evaluate the impact of a tetravalent measles-mumps-rubella-varicella vaccine (MMRV) which is going to be introduced in Italy.