Final answer:
A pathogen that spreads from its original location to other parts of the body is known as a systemic infection. This can lead to widespread effects in the host, and in certain circumstances, may cause secondary infections.
Step-by-step explanation:
When a pathogen spreads from the original site to other tissues or organs it is called a systemic infection. Infections can be classified as local, focal, or systemic, depending on how extensively the pathogen spreads through the body. A local infection is contained in a small area, while a focal infection involves a pathogen or its toxins spreading from a primary location to a secondary location. On the other hand, a systemic infection indicates the pathogen has disseminated throughout various systems of the body.
An example of a systemic infection is chickenpox, caused by the varicella-zoster virus, which initially enters through the mucous membranes and then spreads, resulting in widespread red skin lesions. If a secondary infection occurs due to a compromise of the immune system by a primary infection or antibiotic treatment, it can further impact the patient's health, such as oral thrush following HIV or bacterial pneumonia after influenza.