What distinguishes a confirmed case from a probable or possible case?

A confirmed case is distinguished by the presence of laboratory confirmation, meaning that specific diagnostic tests have been conducted and have yielded results that meet the required criteria for that disease. This level of certainty is essential in epidemiology, as it allows health professionals to establish a definitive diagnosis. Laboratory confirmation typically involves testing for pathogens (like bacteria or viruses) or specific immune responses that validate the diagnosis.

In contrast, probable and possible cases often rely on clinical symptoms and other forms of evidence that do not have the same level of definitive support as laboratory findings. Probable cases may have strong clinical indicators or exposure history, but they lack laboratory confirmation, while possible cases may rely on anecdotal evidence or untested symptoms, making them less certain. Therefore, laboratory confirmation is the key factor that categorically differentiates a confirmed case from probable or possible cases.