Case-control study of vaccination history in relation to pertussis risk during an outbreak among school students.

Background: Between September and December 2003, an outbreak of pertussis occurred in Cass County, MO, mostly among adolescent school children.

Methods: We conducted a 1:2 matched case-control study among school children and used conditional logistic regression to evaluate risk factors for pertussis, including the total number of vaccine doses received, age at administration of each dose of vaccine and the type of vaccine (whole cell or acellular).

Results: Of all 127 pertussis cases reported in this outbreak, the majority were adolescents (10-19 years of age, 50%) and adults (20 years or older, 22%); only 10% were infants and children less than 5 years of age.

Impact on health departments after a seventh grade hepatitis B immunization requirement.

Objectives: This research was designed to evaluate the impact on health departments of the implementation of a 1999 policy requiring hepatitis B (HBV) vaccination for seventh grade school entry in the state of Missouri.

Methods: The authors employed a retrospective descriptive design using data from the Missouri Health Strategic Architectures and Information Cooperative (MOHSAIC) system. They based their assessment of the impact of the new policy on six outcome variables: total immunizations administered, HBV immunizations administered, HBV immunizations given to children ages 10 to 14, percentage of total immunizations that were HBV, percentage of total HBV immunizations that were given to children ages 10 to 14, and percentage of total immunizations that were HBV given to children ages 10 to 14.