Complications of varicella infection in children in southern Taiwan.

Background and Purpose: This study was designed to compare the change in complications of varicella infection in children requiring hospitalization before and after varicella vaccine introduction at a tertiary care hospital in southern Taiwan.
Methods: Based on the results of a retrospective study conducted in the pre-vaccine era (1988-1998), a second study was carried out from 1998-2004 (post-vaccine era). In children admitted for varicella-related complications, demographic data, clinical features, microbiological findings, and outcomes were recorded and compared between the two eras.
Results: A decreased annual rate of hospitalization was observed between the two eras. Age-specific hospitalization rates significantly declined in the age group of 1-10 years after vaccine introduction. Secondary skin or soft tissue infections were the most common complications in both periods (pre-vaccine era, 44.1%; post-vaccine introduced era, 56.6%). In the post-vaccine era, 23 (52%) patients had positive bacterial isolates, including 19 Staphylococcus aureus (12 oxacillin-sensitive, 7 oxacillin-resistant) and 4 coagulase-negative staphylococci; a higher rate of pneumonitis and lower rate of central nervous system involvement were also observed. No differences were observed in other complications between the two eras. In the post-vaccine era, hematological diseases were the most common underlying conditions (17/18, 94%). The case-fatality rate in the post-vaccine era (1.3%) was similar to that in the pre-vaccine era (2.2%).
Conclusions: A universal childhood varicella vaccination program would ultimately prevent the spread and potential complications of varicella. The result of this study may serve as baseline information as the national vaccination program begins.