Data from Investigation
Community Health Department
Case Number 0439-b
Disease Outbreak at Lincoln Elementary School
Results from initial investigation:
I. Infection rates of vaccinated compared to unvaccinated students
Parents were interviewed to see if the children had been vaccinated. They also were asked if the children had already had and recovered from chicken pox. Children cannot get the disease a second time. Over 90 percent of the parents reported that they had chicken pox as a child.
|Number of students||470||50|
|Number who got chicken pox||51||15|
|Number who had chicken pox in the past||25||30|
II. Severity of the disease
Two doctors examined the sick children and classified each case as mild, moderate, or severe.
|Number of students with mild disease||43||3|
|Number of students with moderate disease||7||9|
|Number of students with severe disease||1||3|
III. Time of vaccination
Parents of children who were vaccinated were asked if the child was vaccinated within the past four years. Those children who were vaccinated over four years ago were five times as likely to get chicken pox as compared to those children vaccinated within the past four years.