Trends in varicella mortality in the United States: Data from vital statistics and the national surveillance system

Abstract

This manuscript describes trends in US varicella mortality using national vital statistics system data for 2008–2011, the first years of the routine 2-dose varicella vaccination program, and characteristics of varicella deaths reported to CDC during 1996–2013. We obtained data on deaths with varicella as underlying or contributing cause from the 2008–2011 Mortality Multiple Cause-of Death records and calculated rates to compare with the prevaccine and mature 1-dose varicella vaccination program eras. We also reviewed available records of varicella deaths reported to CDC through the national varicella death surveillance. The annual average age-adjusted mortality rate for varicella as the underlying cause was 0.05 per million population during 2008–2011, an 87% reduction from the prevaccine years. Varicella deaths among persons aged <20 y declined by 99% in 2008–2011 compared with prevaccine years. There was a 70% decline in varicella mortality rates among those <20 y in 2008–2011 compared to 2005–2007. Among the 83 deaths reported to CDC during 1996–2013 classified as likely due to varicella, 24 (29%) were among immunocompromised individuals. Five were among persons previously vaccinated with 1 dose of varicella vaccine. In conclusion, although the US varicella vaccination program has significantly reduced varicella disease burden, there are still opportunities to prevent varicella and its associated morbidity and mortality through routine varicella vaccination, catch-up vaccination, and ensuring that household contacts of immunocompromised persons have evidence of immunity.

Keywords:

• CDC
• NCHS
• surveillance
• varicella deaths
• varicella mortality
• vaccine-preventable disease
• varicella vaccine
• VZV

Abbreviations:

• CDC, Centers for Disease Control and Prevention
• CSTE, Council of State and Territorial Epidemiologists
• NCHS, National Center for Health Statistics
• VZV, Varicella-zoster virus

Disclosure of Potential Conflicts of Interest

No potential conflicts of interest were disclosed.

Acknowledgments

We would like to thank state and local health departments for their valuable work in conducting varicella death surveillance. We would like to thank Barry Sirotkin for his assistance in providing and compiling the varicella-related mortality files from the National Center for Health Statistics (NCHS). We would also like to thank Dr. Jane F. Seward and Sandra Roush for additional information on the history of national varicella death surveillance. We would finally like to acknowledge Susan Galea's input regarding the data included in her publication describing Merck's safety data on varicella vaccine.

Disclaimer

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention, US Department of Health and Human Services.