Immunization Science

Chickenpox and life-threatening infections

The article

Reduction in pediatric hospitalizations for varicella-related invasive group a streptococcal infections in the varicella vaccine era. Patel RA, Binns HJ, and Shulman ST. The Journal of Pediatrics 2004;144(1): 68-74.

The question

Children with varicella (chickenpox) are more likely to have invasive group A streptococcal (IGAS) infections, life threatening conditions. Has the use of the varicella vaccine reduced the number of IGAS in persons age 1 year to 21 years of age?

The study

The researchers reviewed the medical records of all patients with group A streptococcal infections admitted to Children’s Memorial Hospital in Chicago between 1993 and 2001, and identified the patients who had had recent varicella. They then compared the proportion of IGAS hospitalizations during the prevaccine era (1993 to 1995) with that of varicella vaccine implementation (1996 to 1998) and its widespread use (1999 to 2001) in Illinois.

The findings

The proportion of IGAS hospitalizations that were varicella-associated declined from 27% in the prevaccine era to 16% during vaccine implementation and to only 2% with widespread vaccine use in Illinois. “Since the introduction of varicella vaccine in 1995 and its widespread use in Illinois by 1999, we have documented a significant decline in varicella-associated IGAS hospitalizations at our pediatric institution, perhaps the most important justification for universal varicella immunization. The continued use of universal varicella vaccination in the United States is certainly supported by this finding.”

The relevance/bottom line

A decline in pediatric varicella-related IGAS hospitalizations was temporally associated with increasing utilization of varicella vaccine.

NNii’s comment

IGAS infections are a serious, sometimes fatal, complication of chickenpox. The data from this study reinforce the importance of universal varicella vaccination.