What do we call the disease-evoking power of a pathogen?

The term that describes the disease-evoking power of a pathogen is virulence. Virulence refers specifically to the degree of pathogenicity of a microorganism, which encompasses not only its ability to cause disease, but also the severity of the disease it can provoke. This can include factors such as the organism's capacity to multiply, the toxins it may produce, and its ability to evade or overcome the host's immune defenses.

Understanding virulence is critical in biomedical contexts as it can influence both treatment strategies and preventive measures against infectious diseases. For instance, highly virulent pathogens may require more aggressive treatment and control measures due to their potential to cause serious illness or outbreaks.

In contrast, infectivity refers to the ability of a pathogen to establish infection in a host, while pathogenicity is a broader term that encompasses both infectivity and virulence. Contagiousness describes how easily a disease can be spread from one host to another, which is related but distinct from the inherent power of the pathogen itself to cause disease.