What term describes a person who carries a disease but shows no symptoms?

The term that describes a person who carries a disease but shows no symptoms is a carrier. Carriers can harbor a pathogen and potentially transmit it to others without exhibiting any signs of illness themselves. This is particularly important in understanding the spread of infectious diseases, as asymptomatic carriers can often pose a significant risk to public health by unknowingly facilitating the transmission of diseases in a community.

In contrast, a host refers to an organism that supports the growth of a parasite or pathogen, but it does not necessarily imply the host is symptom-free. A vector is typically an organism, such as an insect, that transmits a pathogen from one host to another, while a parasite is an organism that lives on or in a host and benefits at the host's expense, often causing harm. Therefore, the concept of a carrier is critical in epidemiology and disease control, as it highlights the importance of monitoring asymptomatic individuals in infectious disease management.