A state public health region reported 39 cases of meningitis in children 15 years of age and younger to date this year. Seven of those children died. The total population of the region is 780,000, of whom 84,000 are children age 15 years old and younger. Only four cases of meningitis were reported in the public health region during the previous year. No other public health region in the state has an incidence of meningitis that is higher than expected for that region. Based on the information given, the relative frequency of meningitis in the region at this time can best be described as:

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

Answer: (B)

The question tests recognizing when a disease occurrence in a defined area is substantially higher than what is normally expected. An epidemic is a sudden and marked increase in cases in a specific region or population above the baseline level within a given time frame. Here, 39 cases in children aged 15 and younger in a region with 84,000 children to date this year, compared with only four cases in the previous year, shows a sharp rise above the usual baseline. This localized surge, rather than a widespread spread to many regions, supports labeling the situation an epidemic. The lack of higher-than-expected incidence in other regions argues against a pandemic, and the sustained, clustered increase argues against a sporadic or endemic pattern, which would reflect normal background levels.