Which type of case usually presents clinical features of disease but lacks laboratory confirmation?

A probable case is characterized by the presence of clinical features or signs of disease that align with the disease's expected manifestations but lacks definitive laboratory confirmation. This classification is often used when there is supportive evidence or clinical judgment suggests a high likelihood of disease, yet the diagnostic criteria for confirmation have not been fully met.

For example, in an outbreak situation, a patient exhibiting symptoms consistent with an infectious disease may be classified as a probable case if they have been in contact with confirmed cases or if they display significant clinical symptoms but do not yet have laboratory results.

This classification helps public health officials and epidemiologists track the progression and transmission of diseases, even when not all data points are fulfilled. It acknowledges the likelihood of disease based on clinical evidence, facilitating timely public health responses.