A school nurse notes that 60 children have missed days of high school because of pertussis this past year and this rate has been relatively constant for the past 5 years. The nurse plans to work with the community to increase awareness of the seriousness of this disease for children younger than 6 months of age and to raise and maintain the immunization rates, because in this community the pertussis is:

• A. Endemic.
• B. Epidemic.
• C. Pandemic.
• D. Sporadic.

Answer: (A)

The key idea is that a disease that remains present at a steady level in a community over time is described as endemic. Because pertussis in this population has caused a similar number of missed school days for five consecutive years, it indicates a baseline, ongoing transmission that’s expected in this area. The nurse’s plan to raise awareness and boost immunization rates targets reducing that ongoing transmission, especially to protect the most vulnerable—infants younger than 6 months who are at high risk for severe illness. If the pattern were an epidemic, you’d see a sudden spike above the usual level; sporadic would be irregular and unpredictable occurrences; and a pandemic would involve widespread spread across large geographic areas.