Fatal Infection with Varicella in An Adult

Background:
Varicella is a potentially fatal vaccine-preventable disease. Routine vaccination, recommended for pre-school children over 12 months of age and all susceptible persons 13 years and over, is effective against severe disease. Varicella deaths became nationally reportable in 1999, and a 78% decline for all age groups in the United States was seen during 1999—2001 (n=118), compared with 1990—1994 (n=525). However, varicella deaths continue to occur despite availability of a safe and effective varicella vaccine.

Setting:
Varicella is not a notifiable condition in Washington State. Estimates based on the Behavioral Risk Factor Surveillance System (BRFSS) suggest that varicella incidence in Washington has dropped from 11.1 per 1000 in 2000 to 2.4 per 1000 in 2006. No deaths due to primary varicella disease had been reported in Washington State since 1999.

Population:
Varicella vaccination coverage estimates among Washington's children aged 19-35 months in 2006 was 79.1%. Varicella vaccination coverage for Washington adults is not known.

Project Description:
In November 2007 the death of a 24 year old person, possibly due to varicella, was reported to the Washington State Department of Health by a medical examiner in Snohomish County. The death was investigated county, state, and Centers for Disease Control and Prevention pathologists, microbiologists, and epidemiologists in order to learn whether varicella was the primary cause of death and to understand the relationship of the person's treatment with immunosuppressive medications to the unusual presentation and untoward outcome of her varicella illness.

Results/Lessons Learned:
Information from autopsy findings, medical records, and family interviews were used to describe an unusual clinical course of illness and assess the possibility of increased risk for severe outcome due to an underlying chronic condition requiring immunosuppressive medications. Serum avidity testing was used to clarify the timing of initial infection and better understand the unusual presentation. Transmission to an unimmunized school-aged child was documented.