Stephen Everett1, Susan Goodykoontz
2, Kris Bisgard
3, Blaine Mathison
2, Pam Cassiday
4, and Gary Sanden
5. (1) Yavapai County Health Department, 930 Division Street, Prescott, AZ, USA, (2) Arizona Department of Health Services, 150 N. 18th Ave, Suite 140, Phoenix, AZ, USA, (3) National Immunization Program/ESD, Centers for Disease Control and Prevention, 1600 Clifton Road NE, MS E-61, Atlanta, GA, USA, (4) Pertussis/Diphtheria Laboratory, Centers for Disease Control and Prevention, 1600 Clifton Road NE, MS D-11, Atlanta, GA, USA, (5) Centers for Disease Control and Prevention, 1600 Clifton Road NE, MS D-11, Atlanta, GA, USA
BACKGROUND:
A pertussis outbreak occurred in Yavapai County, Arizona in the Fall of 2002. Seventy percent of the lab-confirmed cases and 42% of all cases were associated with at least one of three schools.
OBJECTIVE:
To determine the prevailing strains associated with the outbreak through pulsed-field gel electrophoresis(PFGE).
METHOD:
Nasopharyngeal swabs were collected from 1,066 suspected pertussis cases. Seventeen were identified as being lab-positive for pertussis and underwent PFGE analysis.
RESULT:
Four different strains of pertussis were identified via PFGE analysis. Ten cases were identified as having Strain 10; of these, nine were associated with two of the outbreak schools. Four cases were identified as having Strain 160; of which two were associated with the third outbreak school. Strain 13 was identified in two cases that had no contact with each other. Finally, Strain 55 was found in one case who was a student at one of the Strain 10 outbreak schools.
CONCLUSION:
The presence of strains other than the one prevailing illustrates how pertussis is an endemic disease that can often go mis- or undiagnosed.
LEARNING OBJECTIVES:
Describe how some cases in a pertussis outbreak may be unrelated to the outbreak and the importance of education and surveillance in identifying "endemic" pertussis.