A nurse is completing a disease investigation. Based on the clinical symptoms presented, the individual is assumed to have measles. However, there has been no laboratory evidence documenting that this individual has the disease. Which of the following types of cases is the nurse investigating?

A. A suspected case: A suspected case is based on clinical symptoms without lab confirmation. This aligns with the case described. B. A prolonged case: This term is not a standard classification in case investigation and surveillance. C. An identified case: Too vague - this does not specify whether the diagnosis is clinical or laboratory-confirmed. D. A confirmed case: Confirmed cases require laboratory evidence, which is explicitly lacking in this scenario.